Question

How is the resistance of a semiconductor affected with the rise in temperature?

Answer 1

The resistance of a semiconductor decreases with a rise in temperature. When temperature increases, more electrons gain sufficient thermal energy to break free from their atoms and jump from the valence band to the conduction band. This increases the number of free charge carriers (electrons and holes) in the semiconductor. Since more charge carriers are available to conduct electricity, the current increases for the same applied voltage, so the resistance decreases. Thus, unlike metals, semiconductors show a decrease in resistance with an increase in temperature.