In an n-type semiconductor, which of the following is true regarding the majority charge carriers?

The correct option is 1

Concept:

• N-type semiconductors are created by doping a pure semiconductor with a material that has more valence electrons than the semiconductor. This creates an excess of free electrons (majority carriers) and the dopant atoms, after releasing their extra valence electrons, become positive ions. These positive ions are not free to move around; they are fixed in the crystal lattice, and therefore they are referred to as "immobile positive ions". 
• It's worth noting that while electrons are the majority carriers in N-type semiconductors, there are still holes (minority carriers) present due to inherent thermal generation in the semiconductor.

Additional Information:

• N-type semiconductors: An extrinsic semiconductor where the dopant atoms provide extra conduction electrons to the host material like Phosphorus P in Silicon Si.
  • This creates an excess of negative (n-type) electron charge carriers that are able to move freely.