Majority carriers in n-type: In an n-type semiconductor, which particles constitute the majority carriers responsible for conduction?

Introduction / Context:
Classifying carriers as majority or minority is central to understanding PN junctions, diode action, and transistor operation. In n-type material, the Fermi level shifts upward, and electron concentration greatly exceeds hole concentration, defining electrons as the majority carriers.

Given Data / Assumptions:

• Material is n-type due to donor (pentavalent) doping.
• Thermal equilibrium conditions unless otherwise stated.
• Conduction primarily occurs via majority carriers in uniform fields.

Concept / Approach:
Donor dopants contribute free electrons to the conduction band. Thus, electrons dominate carrier statistics and current transport in n-type regions, while holes are the minority carriers. This asymmetry underlies injection and diffusion in PN devices.

Step-by-Step Solution:

Verification / Alternative check:
Hall-effect measurements on n-type samples yield negative Hall coefficients, indicating electrons dominate conduction, corroborating the majority-carrier identification.

Why Other Options Are Wrong:

• Holes: Majority carriers in p-type, not n-type.
• Dopants: Impurity atoms, not mobile charge carriers.
• ”Slower”: Not a carrier type; mobility is a parameter, not a category.

Common Pitfalls:
Assuming both carriers contribute equally; in doped material one type vastly dominates, which is why diode junctions behave as they do under bias.

Final Answer:
electrons