INTENSITY-DEPENDENT ABSORPTION AND LUMINESCENCE IN SEMICONDUCTOR-DOPED GLASSES

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, freecarrier absorption, and carrier trapping are studied, and the relative merits of Boltzmann and Fermi-Dirac statistics in the analysis are discussed. © 1990 Optical Society of America.