ASVAB (Armed Services Vocational Aptitude Battery)Electronics Information (EI)Medium
Which of the following describes the key characteristic of a P-type semiconductor material?
- AIt is doped with pentavalent impurities.
- BIt has an excess of 'holes' (electron vacancies).
- CIt has an excess of free electrons.
- DIt is an intrinsic semiconductor.
Show answer & explanationAnswer & explanation
Correct answer: B. It has an excess of 'holes' (electron vacancies).
A P-type semiconductor is created by doping an intrinsic semiconductor with trivalent impurities (like Boron or Gallium). These impurities have one less valence electron than the semiconductor, creating an abundance of 'holes' which act as positive charge carriers.
Why the other options are wrong
- A. Pentavalent impurities (e.g., Phosphorus) are used to create N-type semiconductors.
- C. This describes an N-type semiconductor.
- D. An intrinsic semiconductor is a pure, undoped semiconductor material.
P-type Semiconductor
A semiconductor material that has been doped with trivalent impurities, resulting in a majority of charge carriers being 'holes' (electron vacancies), which are treated as positive charges.
- Doped with trivalent impurities (e.g., Boron, Gallium).
- Majority carriers are 'holes'.
- Conducts electricity by the movement of these positive holes.
Memory trick: P for Positive Holes, N for Negative eLectrons.