The majority current carriers in an N-type semiconductor are electrons.

Explanation:

N-type semiconductor:

An N-type semiconductor is formed by doping a pure semiconductor material (such as silicon or germanium) with a pentavalent impurity, which introduces extra electrons into the crystal lattice. The most commonly used impurity for N-type doping is phosphorus (P), which has five valence electrons.

Electron behavior in an N-type semiconductor:

1. Extra electrons: When the pentavalent impurity is added to the pure semiconductor material, the impurity atoms replace some of the original semiconductor atoms in the crystal lattice. Each impurity atom contributes an extra electron to the crystal structure, as there is one more valence electron than required for covalent bonding.

2. Majority carriers: These extra electrons become the majority current carriers in the N-type semiconductor. They are free to move within the crystal lattice, contributing to the flow of electric current.

3. Energy levels: The extra electrons occupy energy levels closer to the conduction band, which is the energy band where electrons can move freely. This is because the energy levels of impurity atoms are closer to the conduction band than the valence band.

4. Minority carriers: The majority carriers (extra electrons) are accompanied by a small number of holes, which are the minority carriers. Holes are created when electrons from the valence band move to occupy the vacancies left by the extra electrons in the impurity atoms.

5. Electron mobility: Electrons in the N-type semiconductor have higher mobility compared to holes. This is because electrons are lighter and have a negative charge, allowing them to move more easily in response to an electric field.

Conclusion:

In an N-type semiconductor, the majority current carriers are electrons. They are introduced into the crystal lattice by doping the semiconductor material with a pentavalent impurity. These extra electrons become free to move and contribute to the flow of electric current.