In the field of semiconductors, understanding the behavior of charge carriers is fundamental. The question specifically asks about the majority carriers found in n-type material.

N-type Material Overview

N-type material is an extrinsic semiconductor that is created by introducing impurities into a pure, intrinsic semiconductor like silicon or germanium. These impurities are called dopants. For n-type material, the dopants used are pentavalent elements, meaning they have five valence electrons. Common examples include phosphorus (P), arsenic (As), and antimony (Sb). These pentavalent impurities are also known as donor impurities because they "donate" an extra electron to the semiconductor lattice.

• When a donor impurity atom replaces an atom in the intrinsic semiconductor crystal lattice, four of its five valence electrons form stable covalent bonds with the surrounding semiconductor atoms.
• The fifth valence electron from the donor atom is very loosely bound to its parent atom.
• At normal operating temperatures (even room temperature), this fifth electron gains enough thermal energy to break free from the donor atom and become a free electron, available for electrical conduction. This process requires very little energy, typically around 0.05 eV.

Electrons as Majority Carriers in N-type Material

The introduction of donor impurities significantly increases the concentration of free electrons in the semiconductor. Each donor atom contributes one free electron without creating a corresponding "hole" in the valence band. This creates a large excess of electrons compared to holes. Therefore:

• Electrons are the majority carriers in n-type material. They are the primary charge carriers responsible for electrical current flow.
• Holes are the minority carriers in n-type material. Although some holes are still generated due to the thermal breaking of covalent bonds in the semiconductor lattice (creating electron-hole pairs), their concentration is orders of magnitude lower than that of the free electrons donated by the impurities.

This distinct characteristic makes n-type material highly conductive due to the abundance of free electrons.

Therefore, in n-type material, the majority carriers are electrons.