A dual-blue light-emitting diode based on strain-compensated InGaN-AlGaN/GaN quantum wells

A strain-compensated InGaN quantum well(QW) active region employing a tensile AlGaN barrier is analyzed.Its spectral stability and efficiency droop for a dual-blue light-emitting diode(LED) are improved compared with those of the conventional InGaN/GaN QW dual-blue LEDs based on a stacking structure of two In0.18Ga0.82N/GaN QWs and two In0.12Ga0.88N/GaN QWs on the same sapphire substrate.It is found that the optimal performance is achieved when the Al composition of the strain-compensated AlGaN layer is 0.12 in blue QW and 0.21 in blue-violet QW.The improvement performance can be attributed to the strain-compensated InGaN-AlGaN/GaN QW,which can provide a better carrier confinement and effectively reduce leakage current.     

反对称n-AlGaN层对GaN基双蓝光波长发光二极管性能的影响

采用数值分析方法对在InGaN/GaN混合多量子阱活性层和n-GaN之间引入n-AlGaN层的GaN基双蓝光波长发光二极管进行模拟分析.结果发现,与传统的具有p-AlGaN电子阻挡层的双蓝光波长发光二极管相比,这种反对称n-AlGaN层能有效改善电子和空穴在混合多量子阱活性层中的分布均匀性及减少电子溢出,实现电子空穴在各个量子阱中的平衡辐射,从而减弱了双蓝光波长发光二极管的效率衰减.此外,通过改变Al组分可以提高双蓝光波长发光二极管发射光谱的稳定性:当Al组分为0.16时,双蓝光波长发光二极管的光谱在小电流下比较稳定,而Al组分为0.12时,光谱在大电流下比较稳定.