Current flowing in a certain PN junction at room temperature is 2 X 10^-7A, when a large reverse bias voltage is applied. Calculate current when a forward voltage of 0.1 V is applied across junction.

Ans:

The diode current is given as I = I₀ (e^V/V_T - 1)

From given data:

Large reverse bias current I≈I_O= 0.2 µA

Applied Voltage V = 0.1 V

Volt-equivalent of temperature, V_T= 26 mV or 0.026 V at room temperature

So, the current flowing through the diode, I = 0.2 X 10^-6(e^0.1/0/026 -1) = 29.38 µA