Photo diode in engineering physics.ppttt

Photo diode

1. PHOTO DIODE Ayush Chauhan 231420109004 Electrical Engineerin g

2. Content *What is photo diode ? *Construction of photo diode *Working of photo diode *V-I Characteristics of photo diode *Dark current *Advantages and disadvantages of photo diode *Applications of photo diode

3. What is photo diode *Photo diode is device or diode that convert light energy to electrical energy(current). *It is operated under reverse bias below break down voltage.

4. Construction of photo diode *A photo diode fabricated with a transparent cover to light to fall on the diode & operated under reverse bias.

5. Working of photo diode * When  the photo  diode  is illuminated with light, with energy greater than energy  gap of the semiconductor than electron hole pair are  generated due  to the absorption of photons  these change carries contribute of the reverse current.

6. V-I characteristics of photo diode On increasing the intensity, reverse current also increase.

7. Dark current When the photo  diode is reverse biased with a voltage  less then its braked voltage and no light is incident on  it’s the reverse current is extremely small  current is called dark current.

8. Advantages and disadvantages of photo diode Advantages Photodiode detector are high NIR sensitivity and high speed. Low noise Low dark current Disadvantages Normal PN junction photo diodes have very high response times. It has very low sensitivity

9. Applications of photo diode In photodetection for optical signals. In demodulation for optical signals. In optical communications equipment. In counting machines.  

10.     Thank   you