稳定的GaAs (2 5 1 1)高密勒指数表面的电子结构

采用格林函数方法对具有稳定结构的GaAs(2 5 11)(1×1)表面的电子结构特性进行了计算. 结果表明：对于理想的GaAs(2 5 11)表面，基本带隙内的表面态主要处在三个能量区域，即 -0.1—0.1eV，085—10eV和1.4—1.6eV之间；吸附两个As原子形成(1×1)再构后，表面态的变化主要表现在0.85—1.0eV之间的表面态完全消失.结合电子数目规则，可以确定处在 - 0.1—0.1eV之间的表面态为全部填满的阴离子悬挂键态或再构引起的As As二聚体键的表 面态，而处在1.4— 关键词： 高密勒指数表面 电子结构 电子数目规则

Electronic structure of the stable GaAs(2 5 1 1) surface

We have studied the optical properties of the interface of Al and GaAs surface q uant um well by in situ photoreflectance (PR) spectroscopy in a molecular beam e pitax y (MBE) system. The intermixing of Al and GaAs surface quantum wells forms an Al_xGa_1-xAs barrier layer on GaAs, which would shift the inte r_band transition peaks of the GaAs quantum well. Based on the calculation using effective mass approximate method, we fi nd that the intermixing length is 0.5nm, which is an important parameter in sem iconductor technology.