Electrical Engineering XYZ MCQs
The majority carrier in P-type extrinsic semiconductor material is:
- Electrons
- Holes
- Both of the above
- None of the above
Correct answer: 2. Holes
Explanation: The majority carrier in a semiconductor refers to the type of charge carrier (either electrons or holes) that predominates in the material.
In a P-type extrinsic semiconductor, the majority carrier is holes.
Here’s why:
- P-type semiconductor: In P-type semiconductors, impurity atoms (like boron, aluminum, or gallium) are intentionally added to the semiconductor crystal lattice. These impurity atoms have fewer valence electrons compared to the atoms they replace. For instance, boron has three valence electrons, so when it replaces a silicon atom (which has four valence electrons), it creates a “hole” where an electron could be.
- Holes as majority carriers: When an electron moves from one atom to fill the hole left by the missing electron in a neighboring atom, it creates another hole. This process continues, creating a chain of holes. Hence, in P-type semiconductors, the majority carriers are these “holes,” which are essentially vacancies in the valence band where an electron could exist.
So, the correct answer to the MCQ is: