Question

What is a semiconductor? What are the two main types of semiconductors?

Answer 1

Answer:

Semiconductors are non ohmic substances which are conducting at higher temperatures and act as insulators at lower temperatures.

They contain FEW electrons in the conduction band at room temperature making them poor conductors.

The main types are elemental and compound semiconductors.

Answer 2

Explanation:

Semiconductors are the materials whose conductivity lies between metals and insulators.

They are characterised by narrow energy gaps (-1ev) between the valence band and conduction band.

• In a semiconductor, conduction band is partially filled and valence band is partially empty.

• Coefficient of thermal resistance (alpha) for semiconductor is negative, this means that when temperature increases, resistance of semiconductor materials decreases.

• At 0°K, pure semiconductor behaves as insulator.

• Ge [32] and Si [14] are typical semiconductors that belongs to IVth group.

There are two of semiconductors :-

1. Intrinsic Semiconductors

2. Extrinsic Semiconductors