Improvement of photoluminescence by Si delta-doping in GaN barrier layer of GaN/In _xGa _1-xN multi-quantum wells

We report on the effect of Si delta doping in the barriers of multi-quantum wells (MQWs) grown by metal-organic chemical vapor deposition (MOCVD). The room temperature photoluminescence (PL) intensity of the MQW sample with Si delta doped barriers was improved by 33 times compared to that of a MQW sample without Si delta doped barriers. The temperature dependent PL measurement showed slow quenching of the integrated PL intensity of the MQW sample grown by using Si delta doping process as temperature increased compared to that of normal MQW sample. This was attributed to the effective injection of electron from the Si delta doped layer into quantum well (QW) layer as temperature increased and also the higher hole confinement resulted from the higher band offset.