Semiconductor Electronics Materials Devices and Simple Circuits - Result Question 26

26. In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is

(a) an insulator

[2007]

(b) a metal

(c) an $n$-type semiconductor

(d) a $p$-type semiconductor

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Answer:

Correct Answer: 26. (d)

Solution:

  1. (d) For a $p$-type semiconductor, the acceptor energy level, as shown in the diagram, is slightly above the top $E_v$ of the valence band. With very small supply of energy an electron from the valence band can jump to the level $E_A$ and ionise acceptor negatively.

In p-type semiconductor-acceptor energy level lies just above the valence band. And in N-type semiconductor-donor energy level lies just below the conduction band.