Influence of In volatilization on photoluminescence in InGaN/GaN multiple quantum wells
Influence of In volatilization on photoluminescence in InGaN/GaN multiple quantum wells
复制标题
In挥发对InGaN/GaN多量子阱光致发光的影响
作者：
Kaiju Shi;Chengxin Wang;Rui Li;Shangda Qu;Zonghao Wu;Jianyang Deng;Mingsheng Xu;Xiangang Xu;Ziwu Ji
制造了两个发出绿光的多量子阱 (MQW) InGaN/GaN 结构，在有源区生长期间没有使用 (A) 和使用 (B) 铟 (In) 挥发抑制技术 (IVST)。研究了不同激发功率水平下光致发光（PL）光谱对温度的依赖性。结果表明，IVST可以增加In含量，同时抑制由于掺入阱层中的In挥发而引起的相分离。另外，与包含一相结构的具有IVST的结构B相比，不具有IVST的结构A包含两个单独的相（即富In相和贫In相），在低激发功率下表现出较高的内量子效率（IQE），在高激发功率下表现出较低的IQE。前者主要归因于结构A较强的富In相相关局域效应，因为结构A在低激发功率下富In相相关发射在PL光谱中占主导地位；后者主要是由于结构A的In-poor相位相关较弱的局域效应，因为In-poor相位相关发射在高激发功率下结构A的PL光谱中占主导地位，因为该富In相中的局域态已饱和。
Two multiple quantum well (MQW) InGaN/GaN structures emitting green light, without (A) and with (B) an.indium (In) volatilization suppression technique (IVST) during growth of the active region, were fabricated. The.dependencies of the photoluminescence (PL) spectra upon temperature at different levels of excitation power.were investigated. The results indicate that an IVST can increase the In content while suppressing the phase.separation caused by volatilization of that In incorporated in the well layers. Also, compared with Structure B.with IVST, which contains one phase structure, Structure A without IVST, which contains two separate phases.(i.e., an In-rich phase and an In-poor phase), exhibits higher internal quantum efficiency (IQE) at low excitation.power and lower IQE at high excitation power. The former is mainly attributed to the stronger In-rich phaserelated localization effect of Structure A, because the In-rich phase-related emission dominates the PL spectra.of Structure A at a low excitation power; the latter is mainly due to the In-poor phase-related weaker localization.effect of Structure A, because the In-poor phase-related emission dominates the PL spectra of Structure A at.high excitation power because localized states in this In-rich phase are saturated.