Question

When the conductivity of a semiconductor is only due to the breaking of covalent bonds, the semiconductor is called

• A. $\mathrm{n}-\mathrm{type}$
• B. $\mathrm{p}-\mathrm{type}$
• C. intrinsic
• D. extrinsic

Answer 1

The correct option is C

intrinsic

Semiconductor material has an electrical conductivity value falling between that of a conductor, such as metallic copper, and an insulator, such as glass.

The semiconductor is divided into two types:

• Intrinsic Semiconductor and Extrinsic semiconductor.

The pure form of the semiconductor is known as the intrinsic semiconductor and the semiconductor in which intentionally impurities is added for making it conductive is known as the extrinsic semiconductor.

(c) Intrinsic semiconductor is the correct answer.

• At room temperature, in impure semiconductors, some free charge carriers are available for conduction due to presence of impurity atoms. But in pure semiconductors , i.e., intrinsic semiconductors,, the number of excited electrons is equal to the number of holes, i.e., n = p.
• Hence, at room temperature no free electrons are available for conduction. On increasing the temperature, the covalent bonds will break and electrons will be freed, each electron will leave behind a hole and capture a new hole the whole process will continued and charge flows through intrinsic semiconductor.
• Thus, its conductivity is only due to breaking of covalent bonds.

Hence, the conductivity of a intrinsic semiconductor is only due to breaking of covalent bonds.