应变超晶格(In_xGa_(1-x)As)_n/(GaAs)_n(001)的电子结构和光学性质
The Electronic and Optical Properties of the Strained Superlattices (In x Ga 1-x As) n /(GaAs) n (001)
Abstract
【中文摘要】 用半经验的紧束缚方法sp3s*计算了薄层应变超晶格(InxGa1-xAs)n/(GaAs)n(001)的电子结构.给出了组份X为0.53的超晶格(InxGa1-xAs)n/(GaAs)n的带隙值随层厚n的变化关系,以及超晶格(InxGa1-xAs)12/(GaAs)12的带隙值随组份X的变化关系.在得到超晶格能量本征值和本征函数的基础上,计算了该超晶格系统的光学介电函数虚部,并与体材料GaAs和体合金InxGa1-xAs的光学性质作了比较.计算结果表明,应变超晶格在较宽的能量范围有较好的光谱响应.
【英文摘要】 The semi empirical tight binding model sp 3s * was used to calculate the band structure of the thin strained superlattices (In x Ga 1-x As) n /(GaAs) n (001). The band gap of strained (In 0.53 Ga 0.47 As) n /(GaAs) n as a function of layer number n is given out, and the dependence of the band gap of strained (In x Ga 1-x As) 12 /(GaAs) 12 on composition x is also presented.The imaginary parts of dielectric functions for the super...