Question

The diffusion capacitance of a PN junction _______

(a) decreases with increasing current and increasing temperature

(b) decreases with decreasing current and increasing temperature

(c) increasing with increasing current and increasing temperature

(d) doesnot depend on  current and temperature

This question was posed to me in examination.

This key question is from Diode Capacitances topic in chapter Semiconductor-Diode Characteristics of Electronic Devices & Circuits

Answer 1

Right choice is (b) decreases with decreasing current and increasing temperature

To elaborate: CD =τ I /n0 VT

Where, I is the current and VT is temperature factor. The diffusion capacitance is directly proportional to current and indirectly proportional to the temperature.