Carriers in Semiconductors

Abstract

As we saw in section 5.2, semiconductors and insulators differ from metals in having an energy gap between the filled valence bands below the Fermi energy ε_F and the empty conduction bands above ε_F (Fig. 5.9). Because of this gap, the number of carriers (electrons and holes) varies rapidly with temperature in a semiconductor, whereas it is essentially temperature-independent in a metal, and our first task is to look at this temperature variation.