Mechanisms of radiative and nonradiative recombination in ZnSe:Cr and ZnSe:Fe

Possible applications of ZnSe:Cr in optoelectronics are discussed. It is shown that 2+ to 1+ photo-ionization of chromium results in efficient pumping of Cr²⁺ intrashell emission and in energy up-conversion from green to blue. A distinct difference in efficiency of the energy up-conversion is observed between chromium and iron doped ZnSe samples. This difference we relate to a very efficient Auger mechanism of photoluminescence quenching in Fe-doped samples. We further demonstrate an anticorrelation of intensity of mid-infrared Cr emission and up-converted blue emission of ZnSe