The band line-up and band offset calculations of GaAs_0.978Bi_0.022/GaAs single quantum well with spatial changes of Bi composition were reported. The spatial Bi profile and a certain amount of the Bi composition in the barrier layer were determined by HR-XRD measurements. Virtual Crystal Approximation and Valence Band Anti-Crossing models were used including strain effects to obtain conduction and valence band edge shifts with Bi incorporation. Photoluminescence (PL) measurements were performed at a low temperature of 8 K as a function of excitation intensity. The PL spectra have shown asymmetric line shapes, which were fitted with different Gaussian functions. Comparing experimental PL results with calculated band edge energies, it was found that optical transition is a type I under low intensity excitation while the optical transition is switched from type I to type II due to the spatial changes in Bi concentrations. The band offsets$\text{Δ}{E}_c/\text{Δ}{E}_v$ were also determined.

GaAs _0.978 Bi _0.022的能带排列和能带偏移计算报道了具有Bi组成的空间变化的/ GaAs单量子阱。通过HR-XRD测量确定阻挡层中的空间Bi分布和一定量的Bi组成。使用虚拟晶体近似和价带反穿越模型，包括应变效应，通过掺入Bi获得导带和价带边缘位移。根据激发强度，在8 K的低温下进行光致发光（PL）测量。PL光谱显示出不对称的线形，并配有不同的高斯函数。将实验PL结果与计算出的带边能量进行比较，发现在低强度激发下光跃迁是I型，而由于Bi浓度的空间变化，光跃迁从I型转变为II型。带偏移$\text{Δ}{Ë}_C/\text{Δ}{Ë}_v$ 也被确定。