Question

In p-type semiconductors

• A. holes are minority carriers
• B. the vacancy of electron is a hole with negative charge
• C. the impurity element added is donor type
• D. for every pentavalent impurity atom added an extra hole is created
• E. the electron will move from one hole to another hole constituting a flow of current

Answer 1

The Correct Option is A

In a p-type semiconductor, the majority carriers are holes (which are the absence of electrons), while the minority carriers are electrons.

The p-type semiconductor is created by doping a pure semiconductor (like silicon) with a trivalent impurity (such as boron). The trivalent impurity atom has only three valence electrons, leaving a "hole" in the crystal structure where an electron could be. These holes behave as positive charge carriers, and they are the majority carriers in p-type semiconductors.

The other options are explained as follows:

• Holes are minority carriers: This is incorrect because, in p-type semiconductors, holes are the majority carriers, not the minority carriers.
• The vacancy of an electron is a hole with a negative charge: This is incorrect because a hole is not negatively charged. It is a positive charge carrier.
• The impurity element added is donor type: This is incorrect. Donor-type impurities create n-type semiconductors, where electrons are the majority carriers.
• For every pentavalent impurity atom added, an extra hole is created: This is incorrect because pentavalent impurities (such as phosphorus) are used to create n-type semiconductors, not p-type semiconductors.
• The electron will move from one hole to another hole constituting a flow of current: This is incorrect because the movement of holes represents the flow of current, not the movement of electrons.

Correct Answer:

Correct Answer: (A) Holes are minority carriers

Answer 2

In a p-type semiconductor, the majority charge carriers are holes. A hole refers to the absence of an electron in the atomic structure, and it behaves as a positive charge carrier. The minority charge carriers in this type of semiconductor are electrons. 

A p-type semiconductor is formed when a pure or intrinsic semiconductor (such as silicon) is doped with a trivalent impurity like boron. Trivalent elements possess only three valence electrons, which is one less than the four electrons required to form covalent bonds in the silicon crystal lattice. As a result, an electron vacancy, or a hole, is created. These holes can move through the lattice and facilitate electrical conduction, hence they are considered majority carriers in p-type materials.

Explanation of Incorrect Options:

• Holes are minority carriers: This statement is incorrect. In a p-type semiconductor, holes are the majority carriers, not minority carriers.
• The vacancy of an electron is a hole with a negative charge: This is also incorrect. A hole represents the absence of an electron and is considered to have a positive charge, not a negative one.
• The impurity element added is donor type: This statement is false. Donor-type impurities (which have five valence electrons) are used in n-type semiconductors, not p-type ones. In p-type semiconductors, the impurities are acceptor-type (trivalent).
• For every pentavalent impurity atom added, an extra hole is created: This is incorrect. Pentavalent impurities (like phosphorus) donate extra electrons and are used to create n-type semiconductors. In contrast, trivalent impurities create holes in p-type semiconductors.
• The electron will move from one hole to another hole constituting a flow of current: This is misleading. In a p-type material, the movement of holes is what constitutes the flow of current. Although this movement can be visualized as electrons jumping to fill holes, it is the holes that are treated as the moving charge carriers in theory.

Correct Answer:

Correct Answer: (A) Holes are minority carriers — Incorrect