H Exp – Radiation and Matter 13 – Forward and reverse-biased photodiode

Aim – To investigate the relationship between the current and applied p.d. for 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.