Radiative recombination from non‐equilibrium states in cathodo‐excited semiconductors

Application of the theory of non‐equilibrium processes is made to the relaxation and recombination of high‐excited electrons in semiconductors. Following the scheme of a hot‐electron theory based on the method of nonequilibrium statistical operator, developed by Zubarev and, independently, by McLennan, expressions for relaxation and recombination times of hot carriers has been established, resulting directly from a microscopial description of the system. As an example a free‐to‐bound transition is discussed (transitions between donor levels and the valence band or between acceptor levels and the conduction band) in (Ga, Al)As. With this en the one hand the concept of hot electrons is shown to be related to the general theoretical description and on the other hand, intensity curves of time‐resolved spectra, i.e., the time‐variation of spectra after an excitation pulse, are given.