Question

Silicon can be doped using one of the following elements as dopant:
(A) Arsenic
(B) Indium
(C) Phosphorus
(D) Boron.
To get an n-type semiconductor, the dopants that can be used are______.
Fill in the blank with the correct answer from the options given below.

• A. (A) and (C) only
• B. (B) and (C) only
• C. (A), (B), (C), and (D)
• D. (C) and (D) only

Answer 1

The Correct Option is A

To create an n-type semiconductor from silicon, dopant atoms must introduce excess electrons. Elements from Group 15 of the periodic table, possessing five valence electrons, are suitable for this purpose. Silicon has four valence electrons, so introducing a Group 15 element results in an extra electron available for electrical conduction. Analyzing the provided dopants:

• Arsenic (A): Group 15, five valence electrons.
• Indium (B): Group 13, three valence electrons (used for p-type doping).
• Phosphorus (C): Group 15, five valence electrons.
• Boron (D): Group 13, three valence electrons (used for p-type doping).

Based on these properties, only Arsenic (A) and Phosphorus (C) can act as donor atoms to create an n-type semiconductor in silicon. Therefore, the correct answer is (A) and (C) only.