Carrier confinement effect enhanced by AlGaN/GaN multi-quantum barrier in AlInGaN based high power blue-violet laser diodes

AlGaN/GaN multi-quantum barriers (MQBs) were firstly introduced into violet AlInGaN laser diodes with InGaN multi-quantum wells structure, resulting in drastic improvements in lasing performance. Comparing with conventional AlGaN single electron blocking layer (EBL), lower threshold current and higher slope efficiency at room temperature could be achieved by AlGaN/GaN multiquantum barrier. It can be explained that p-type AlGaN/GaN MQBs is more effective to suppress the overflow of electron than single p-type AlGaN EBL by the increase of effective barrier heights due to the quantum effect of MQB and the enhancement of p-type doping efficiency. Additionally, the strain effect in InGaN multiquantum wells (MQWs) from single p-type AlGaN EBL can be reduced by forming the AlGaN/GaN super lattice structure.