Nonthreshold Auger recombination in quantum wells

We calculate the Auger recombination rate of carriers in a quantum well taking into account that due to the presence of the heteroboundaries the momentum-conservation law is violated. As a result, nonthreshold Auger recombination becomes possible, i.e., low-energy carriers may recombine, the excess momentum being transferred to the well boundaries. This greatly enhances the Auger rate at low temperatures. We develop a method for calculating the overlap integrals in the limiting case which is of practical interest and obtain an explicit analytical formula for the nonthreshold Auger rate. The calculated recombination rate weakly depends on temperature but increases drastically with decreasing well width and may become more important for narrow wells.