The conduction band is the band of higher-energy states into which electrons can move freely and so carry an electric current. In a metal it overlaps with or is continuous with the filled band, but in a semiconductor or insulator it lies above the valence band, separated by a band gap. Electrons reaching the conduction band leave behind holes in the valence band.

导带是电子可自由移入、从而传导电流的较高能量态所组成的能带。在金属中,它与已填满的能带重叠或相连,但在半导体或绝缘体中,它位于价带之上,二者由能隙分隔。到达导带的电子会在价带中留下空穴。