Question

In a n-type semiconductor which of the following statements is true.

A. Electrons are minority carrier and trivalent atoms are dopants

B. Electrons are majority carrier and pentavalent atoms are dopants

C. Holes are minority carrier and pentavalent atoms are dopants

D. Holes are majority carrier and trivalent atoms are dopants

Answer 1

Hint:  In this question we have been given some statements about the n-type semiconductor and we have been asked to find the correct statement regarding n-type semiconductor. We know that n-type semiconductor receives the free electrons from the impurities. Therefore, to solve this question we shall discuss the n-type semiconductor and select the correct statement.

Complete step-by-step answer:

In a semiconductor production, the doping did the intentional addition of impurities to the intrinsic semiconductor. The doped semiconductor is referred to as extrinsic semiconductor. We know that to produce n-type semiconductor pentavalent impurities such as arsenic is added. 

In n-type semiconductor the electrons are the majority carrier because the four electrons of pentavalent element bond with the surrounding atom leaving one free electron. The pentavalent impurity that is added is known as dopant and the process is known as doping. Therefore, from the above discussion, we can say that in n-type semiconductors the electrons are the majority carrier and pentavalent atoms are the dopants. 

So, the correct answer is “Option B”.

Note: N-type semiconductors are usually made by doping pentavalent atoms with silicon. The n-type semiconductors are extrinsic semiconductors where the dopant atoms conduct electrons to the host material. Similarly the p-type semiconductors are produced by doping trivalent impurities with host material. Holes are the majority carrier in p-type semiconductor.