acceptor atom
Acceptor atom
An impurity atom in a semiconductor which can accept or take up one or more electrons from the crystal and become negatively charged. An atom which substitutes for a regular atom of the material but has one less valence electron may be expected to be an acceptor atom. For example, atoms of boron, aluminum, gallium, or indium are acceptors in germanium and silicon (illus. a), and atoms of antimony and bismuth are acceptors in tellurium crystals. Acceptor atoms tend to increase the number of holes (positive charge carriers) in the semiconductor (illus. b). The energy gained when an electron is taken up by an acceptor atom from the valence band of the crystal is the ionization energy of the atom. See Donor atom, Semiconductor
