Excitonic effects in band-edge luminescence of semiconductors at room temperatures

Abstract

A theoretical analysis is developed for ascertaining the influence of exciton states on edge luminescence in different semiconductors at high temperatures and high levels of excitation. Screening effects and the Mott transition for excitons have been taken into account using simple relations obtained with a variational method. Dependencies of luminescence quantum efficiency on excitation level are discussed. A mechanism of exciton non-radiative annihilation due to Auger recombination via deep impurity levels is analysed as well. It is shown that the probability of this process decreases with an energy of exciton binding.