Thermal quenching of the self-activated band of ZnSe:Cl thin films grown by molecular beam epitaxy

We studied the thermal quenching of the self-activated (SA) band of molecular beam epitaxy (MBE) grown ZnSe:Cl thin films by means of temperature dependent photoluminescence (PL) experiments. We analyzed the spectra of the self-activated (SA) band as a function of temperature and Cl concentration. All studied samples presented the emission of this band, however, the excitonic emission was observed only for those samples with lower Cl concentration. A different activation energy (Ea) associated to quenching of the SA band was obtained for each sample. These values suggest that different electron and hole levels, which depend on Cl concentration, are associated to the mechanism of quenching of the SA band.