Question

The random motion of holes and free electrons due to thermal agitation is called

• A. Diffusion
• B. Pressure
• C. Ionisation
• D. None of the above

Answer 1

The correct option is A Diffusion

Whenever the temperature of the semiconductor increases, the charge carriers within the material i.e. holes and electrons increases due to thermal agitation. As a result, the electrons diffuse from valence to conduction band. This process is called diffusion. The electrons and holes start vibrating about the mean position. They randomly start moving. This is called diffusion. For example, in a p-n junction diode, because of thermal agitation, electron and hole pairs are produced. As a result, electrons diffuse from n to p side whereas holes diffuse from p to n side.