Minority carriers in semiconductors In which type of semiconductor are holes the minority carriers under normal doping and thermal equilibrium?

Introduction / Context:
Carrier types and their majority/minority roles underpin diode and transistor action. Recognizing which carriers dominate in each semiconductor type is essential for predicting current flow and junction behavior.

Given Data / Assumptions:

• Thermal equilibrium, moderate doping (nondegenerate).
• n-type: donors provide extra electrons.
• p-type: acceptors create holes.

Concept / Approach:
In n-type material, electrons are the majority carriers because donor impurities elevate the electron concentration well above the intrinsic level; holes arise from thermal generation and are comparatively few. Conversely, holes are majority carriers in p-type material and electrons are the minority.

Step-by-Step Solution:
Recall definitions: majority carrier has higher concentration; minority has lower.n-type: n ≫ p ⇒ holes are minority carriers.Therefore, choose “n-type”.

Verification / Alternative check:
Mass-action law n p = n_i^2 implies if n increases via doping, p must decrease, confirming holes are minority in n-type.

Why Other Options Are Wrong:
“p-type” reverses roles; “intrinsic” has n ≈ p (no minority); “extrinsic (any type)” is too vague; “degenerate” concerns Fermi level position, not necessarily hole minority.

Common Pitfalls:
Confusing majority/minority with mobility; majority depends on concentration, not speed.

Final Answer:
n-type