Question

 Explain the operation of p-n junction diode in forward bias. 
 

Hint:

In forward bias, the current flows through the diode only after the applied voltage exceeds the threshold potential barrier.

Answer 1

When a p-n junction diode is connected in forward bias, the positive terminal of the external voltage source is connected to the p-type semiconductor, and the negative terminal is connected to the n-type semiconductor. This causes the following: - The applied voltage reduces the width of the depletion region as the holes from the p-side and the electrons from the n-side are pushed towards the junction. - If the forward voltage exceeds the threshold voltage (typically 0.7V for silicon diodes), the barrier potential is overcome, and current begins to flow through the diode. This allows current to pass easily through the diode in the direction of the applied voltage.