Effect of Li doping on photoluminescence from Er, O-codoped GaAs

Abstract

We investigated the effect of Li doping into Er-doped GaAs and Er, O-codoped GaAs on the enhancement of photoluminescence (PL) intensity. The Li doping into Er-doped GaAs increases the integrated intensity by 50 times higher than that from the Er-doped layer without Li doping. Main peak position of the Er, Li-codoped layer was slightly smaller than that of the Er-doped layer. This difference of peak position means that Li doping induced Er-related active centers different from those in Er-doped layer are formed. In the previous study, we have revealed that oxygen doping into Er-doped GaAs produced sharp and strong PL peak intensity due to Er-2O center. The Li doping into Er, O-codoped GaAs increases the integrated intensity twice higher than that from the Er, O-codoped layer without Li doping. However, the peak intensity decreased and the PL spectrum shape becomes broader. These results indicated that Li doping partly modified the Er-2O center and introduced many kinds of luminescent Er centers.