Amplification of light in semiconductors associated with the recombination of excitons present in high concentrations

A calculation is reported of the gain curve for a luminescence band associated with the process of inelastic collisions between two excitons, one of which is transferred to a higher excited state, and the other transformed into a light quantum. It is shown that in the case of II–VI compounds the luminescence band differs considerably in width and location from the usual P and M bands associated with the ionizing collisions between two excitons.