Intensity-dependent absorption and luminescence in semiconductor-doped glasses
Abstract
Absorption saturation and luminescence measurements on semiconductor-doped glasses are reported, and the results are analyzed in terms of a band-filling model that is found to explain adequately the absorption data obtained with fresh as well as with photodarkened samples. With this model the free-carrier densities are calculated and the intensity dependence of both band-to-band and trap luminescence is estimated. The results show that at low intensities the luminescence stems from geminate recombination, while nongeminate recombination prevails at higher intensities. In addition, the respective influences of Auger recombination, free-carrier absorption, and carrier trapping are studied, and the relative merits of Boltzmann and Fermi–Dirac statistics in the analysis are discussed.