Question

In a semiconductor, the number of holes and number of free electrons are represented as \( n_h \) and \( n_e \), respectively. Which one of the following statements is TRUE for the semiconductor?

• A. In an intrinsic semiconductor, \( n_e = n_h \).
• B. In an extrinsic semiconductor, \( n_h = n_e \).
• C. In an intrinsic semiconductor, \( n_e>n_h \).
• D. In an intrinsic semiconductor, \( n_h>n_e \).

Hint:

In intrinsic semiconductors, the number of electrons and holes are always equal. In extrinsic semiconductors, doping creates an imbalance.

Answer 1

The Correct Option is A

Step 1: Understanding intrinsic and extrinsic semiconductors.
In an intrinsic semiconductor, the number of free electrons \( n_e \) is equal to the number of holes \( n_h \) because every electron that is excited to the conduction band leaves behind a hole. This means \( n_e = n_h \).
Step 2: Conclusion.
Thus, the correct answer is \( n_e = n_h \) for an intrinsic semiconductor, corresponding to option (A).