Higher Physics

Particles and Waves - Activity 25

Forward and reverse-biased photodiode

Aim - To investigate the relationship between the applied p.d. and the current through a forward and reverse biased photodiode.     Instructions 
The photodiode is placed near a light source which provides a fixed level of illumination.
Click on the right side of the potentiometer to increase the applied p.d. Click on the left side to reduce it.

 

  • For a range of values of p.d. across the photodiode, measure the corresponding value of the current through it.
  • Repeat for the reverse biased photodiode by reversing the 1.5 V cell.
  • Draw a graph to show the relationship between current and applied p.d. for the forward and reverse biased photodiode.

 

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