CBSE Class 12 · 1998 · All India · SemiconductorsVery Short Answer

How does one understand the temperature dependence of resistivity of a semiconductor?

Solution

In a semiconductor the number density of free charge carriers is very small at low temperature.
As the temperature rises, thermal energy breaks more covalent bonds and generates additional electron-hole pairs.
The resulting large increase in carrier concentration outweighs the fall in mobility, so conductivity rises and resistivity falls.

Resistivity of a semiconductor decreases as temperature increases.

CBSE Class 12 Board · 1998 · All India · Subjective

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