PC5271 wiki - User contributions [en]

LEDs as Photodiodes

2024-04-27T13:25:09Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

[[Image:LED1.png]]

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.

[[image: B3.png|500px]] [[image: G5.png|500px]]
[[image: O3.png|500px]] [[image: O5.png|500px]]
[[image: R5.png|500px]] [[image: R5t.png|500px]]
[[image: Two led.png|500px]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:23:49Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

[[Image:LED1.png]]

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.

[[image: B3.png|500px]] [[image: G5.png|500px]]
[[image: O3.png|300px|right]]
[[image: O5.png|300px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:23:34Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

[[Image:LED1.png]]

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|500px]] [[image: G5.png|500px]]
[[image: O3.png|300px|right]]
[[image: O5.png|300px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:23:18Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

[[Image:LED1.png]]

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|550px]] [[image: G5.png|550px]]
[[image: O3.png|300px|right]]
[[image: O5.png|300px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:22:14Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

[[Image:LED1.png]]

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|550px|left]] [[image: G5.png|550px|right]]
[[image: O3.png|300px|right]]
[[image: O5.png|300px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:22:03Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

[[Image:LED1.png]]

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|510px|left]] [[image: G5.png|510px|right]]
[[image: O3.png|300px|right]]
[[image: O5.png|300px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:21:37Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|300px|left]] [[image: G5.png|300px|right]]
[[image: O3.png|300px|right]]
[[image: O5.png|300px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:20:18Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|300px|left]] [[image: G5.png|300px|centre]] [[image: O3.png|300px|right]]
[[image: O5.png|300px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:19:54Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|300px|left]] [[image: G5.png|300px|center]] [[image: O3.png|300px|right]]
[[image: O5.png|300px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:19:22Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|400px|left]] [[image: G5.png|400px|center]] [[image: O3.png|400px|right]]
[[image: O5.png|400px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:17:28Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them. [[image: B3.png|500px|left]] [[image: G5.png|500px|right]]
[[image: O3.png|500px|left]] [[image: O5.png|500px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:16:59Z

SorakadoAo: /* References */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.

[[image: B3.png|500px|left]] [[image: G5.png|500px|right]]
[[image: O3.png|500px|left]] [[image: O5.png|500px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:16:36Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.

[[image: B3.png|500px|left]] [[image: G5.png|500px|right]]
[[image: O3.png|500px|left]] [[image: O5.png|500px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:15:23Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.

[[image: B3.png|500px|left]] [[image: G5.png|500px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:13:42Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|500px|left]] [[image: G5.png|500px|right]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:12:49Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
In the LED, there is a region called the depletion region. Photons outside the LED can fall to this region. Photons with greater energy than the energy gap of the semiconductor that composes the LED will be absorbed and produce electron-hole pairs. Then, a current is produced caused by the electric field across the region that pulls those pairs. This resulting current, called photocurrent, is proportional to the number of photons that fall to the depletion region.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|300px|left]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:12:31Z

SorakadoAo: /* Results and Discussion */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
Explanation of howe photodiodes work and how LEDs as Photodiodes work.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.
[[image: B3.png|700px|centre]]

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

LEDs as Photodiodes

2024-04-27T13:05:53Z

SorakadoAo: /* Group Members */

== Group Members ==
Abas Syahbana, Lu Xinghao

== Introduction ==
Explanation of howe photodiodes work and how LEDs as Photodiodes work.

== Setup ==

=== Equipment ===
:Power Source
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Variety of LEDs
:Oscilloscope
:Probe

=== Experimental Setup ===
In this project, ....
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

== Results and Discussion ==
In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. We thought that situation was very interesting and tried to identify the inner relation between them.

== References ==
PhysicsOpenLab. (2020) “Using LED as a single photon detector”. PhysicsOpenLab. https://physicsopenlab.org/2020/02/27/using-led-as-a-single-photon-detector/

== Logbook ==
5 March 2024: we took variety of LEDs in the workshop. We detected avalanche.

7 March 2024: We tried all of the LEDs. almost all of them can not detect avalanche.

12 March 2024: We tried other variety of LEDs from the workshop. we can not see any detection of avalanche. Then, we knew that we use LEDs in unconventional way.

14 March 2024: We didn't see any detection. We plan to use function generator to see any detection.

19 March 2024: We used function generator to see the signal. We didn't see anything.

21 March 2024: We saw something that can be a signal with frequency of the function generator f=1858 Hz. We planned to use battery to lessen the noise.

26 March 2024: We were somehow doing the experiment wrongly. It was using battery for the transmitter and trying detecting avalanche

28 March 2024: We changed the power source of the receiver to battery. We still didn't get rid of the noise.

2 April 2024: We can see the difference in signal. However we need bigger sensing resistor to measure it better.

4 April 2024: We can detect the signal. Then, we changed the function generator with a power source for the transmitter. We started measuring all of the combination of LEDs as the emitter and the receiver.

9 April 2024: We continued measuring all of the combination with 10x probe. We didn't use some LEDs that cannot detect light as receiver.

11 April 2024: We completed the measurement of the combination of 5 different LEDs as emitter and receiver.

16 April 2024: We measured the same type of LEDs as the emitter and receiver. We also measured the current at the emitter

18 April 2024: We finished measuring the same type of LEDs as the emitter and receiver and the current at the emitter.

File:Two led.png

2024-04-27T13:04:16Z

SorakadoAo:

File:R5t.png

2024-04-27T13:04:00Z

SorakadoAo:

File:R5.png

2024-04-27T13:03:52Z

SorakadoAo:

File:O5.png

2024-04-27T13:03:29Z

SorakadoAo:

File:O3.png

2024-04-27T13:03:09Z

SorakadoAo:

File:G5.png

2024-04-27T13:02:57Z

SorakadoAo:

File:B3.png

2024-04-27T12:45:16Z

SorakadoAo:

Photodiodes as Single Photon Detectors

2024-04-26T14:08:42Z

SorakadoAo: /* Setup (Tentative) */

In this project, we use several photodiodes as Single Photon Avalanche Detectors (SPADs). We use a light bulb as the light source and grating to vary the wavelength of the light source. We will build a passive quenching configuration to get photons detected. Thus, by knowing which light source is working for the LEDs to detect photons, we can determine band gaps of each LEDs.

==Setup==
===Equipment===
:Photodiodes
:Arduino Uno
:Resistors
:Breadboard
:Jump wires
:Light Bulb
:Grating

===Circuit Overview===
===Software===
==Procedure==
===Basic theory===
The principle behind using LEDs as single photon detectors lies in their ability to exhibit a phenomenon known as avalanche multiplication. This phenomenon occurs when a single photon interacts with the semiconductor material within the LED, triggering a cascade of electron-hole pairs via the process of impact ionization.
1.Photon Absorption: When a single photon of sufficient energy strikes the semiconductor material of the LED, it can excite an electron from the valence band to the conduction band, creating an electron-hole pair. 2.Impact Ionization: The newly generated electron can gain enough energy to cause further excitations within the semiconductor material through impact ionization. This process leads to the creation of additional electron-hole pairs. 3.Avalanche Effect: If the conditions are right, meaning the electric field within the LED is sufficiently strong, these newly generated electron-hole pairs can also undergo impact ionization, leading to a cascade effect where the number of charge carriers rapidly increases. 4.Detecting the Avalanche: The avalanche of charge carriers results in a measurable current pulse that can be detected by external circuitry connected to the LED. By measuring this current pulse, it's possible to infer the presence of a single photon that initiated the avalanche. 4.Sensitivity and Efficiency: The sensitivity and efficiency of LED-based single photon detectors depend on various factors, including the semiconductor material used, the design of the LED structure, the applied bias voltage, and the temperature. Optimizing these parameters is crucial for maximizing the detector's performance.
===Doing experiment===
According to the specific experiment, we have designed two circuits. One of them was emitting circuit and the other one was receiving circuit. For the emitting circuit, we also used LED as the light source. By changing the voltage applied to that LED, we can control the intensity of emission. As the same time, we also measured the current through LED. For the receiving part, we also used LED to receive the light. However, by reversing the direction of LED, which would response to different wavelengths of light and produced the current. Then, by measuring the voltage of the resister, which was series connected in the circuit through oscillograph, we could detect the signals.

In the experiment, we have used 4 different colors red, blue, green and orange served as emitter color and receiver color separately. Then recorded the intensity showed in the oscillograph. Controlled the other parameters and concentrated just on the color. Mostly the voltage of signal we found are only around 0.5mV. However, we also discovered that some special LED pairs can reach the voltage about 20mV, which is far large than the others. I thought that situation was very interesting and tried to identify the inner relation between them.

===Results===

==Analyse==
===Data taking===

===Data analysis===

==Reference==