Question

Which from following dopants is used in germanium to produce p-type semiconductor?

• A. B
• B. P
• C. As
• D. Sb

Hint:

For p-type semiconductors, use trivalent dopants like B, Al, Ga, and In. For n-type semiconductors, use pentavalent dopants like P, As, and Sb.

Answer 1

The Correct Option is A

Concept:
A p-type semiconductor is formed by doping silicon or germanium with a trivalent impurity. Trivalent dopants create holes, which act as majority charge carriers.

Step 1: Recall the type of dopant needed.
For p-type semiconductor, the dopant should belong to Group 13 and have valency \(3\).

Step 2: Check the given options.

• B is trivalent.
• P is pentavalent.
• As is pentavalent
• Sb is pentavalent.

Step 3: Identify the correct dopant.
Only boron is a trivalent impurity and therefore produces p-type germanium. Hence, the correct answer is:
\[ \boxed{(A)\ \text{B}} \]