The optical and structural study of a blue emitting structure with dual InGaN/GaN multiple quantum wells

The authors succeed in fabricating a blue-emitting structure with two series of InGaN/GaN quantum wells, which are different in layer thickness and indium content. The structural and optical properties of the sample were investigated. The upper MQWs works as the main light emitting source area, while the lower MQWs with higher indium content serves as strain releaser. According to the high resolution X-ray diffraction and photoluminescence result, the lower MQWs having the strain released, the upper MQWs succeed in blue emitting with low level indium incorporation, which leads to less piezo-polarization electric field and good crystal quality and high light emitting efficiency.