Question

Which of the following equations represent the correct expression for the shift in the energy levels for the p-n junction?

(a) Eo = Ecn – Ecp

(b) Eo = Ecp – Ecn

(c) Eo = Ecp + Ecn

(d) Eo = -Ecp – Ecn

This question was posed to me during an online exam.

The query is from Band Structure of an Open-Circuited p-n junction topic in chapter Semiconductor-Diode Characteristics of Electronic Devices & Circuits

Answer 1

The correct option is (b) Eo = Ecp – Ecn

To elaborate: The shift in the energy of the energy level will be the difference of the conduction band edge of the p material and conduction band edge of n material. In the energy level diagram, the conduction band edge of p material is higher than that of the n material.