Question

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

• A. metal
• B. insulator
• C. n-type semiconductor
• D. p-type semiconductor

Hint:

p-type semiconductor → holes are majority carriers; n-type → electrons are majority carriers.

Answer 1

The Correct Option is D

Step 1: Understand band diagram.
The diagram shows two energy bands separated by a forbidden energy gap \(E_g\). The lower band is the valence band and the upper band is the conduction band.

Step 2: Identify charge carriers.
Open circles represent holes and filled circles represent electrons.

Step 3: Analyze distribution of carriers.
In the valence band, there are more holes compared to electrons, while the conduction band has fewer electrons.

Step 4: Nature of semiconductor.
In p-type semiconductors, holes are the majority charge carriers and electrons are minority carriers.

Step 5: Compare with diagram.
Since the diagram shows more holes than electrons, it corresponds to a p-type semiconductor.

Step 6: Eliminate other options.
Metal: No band gap.
Insulator: Large band gap and almost no free carriers.
n-type semiconductor: More electrons than holes.

Step 7: Final conclusion.
\[ \boxed{\text{p-type semiconductor}} \] Hence, correct answer is option (D).