论文部分内容阅读
采用半经验紧束缚近似方法对生长在ＧａＳｂｘＰ１－ｘ（００１）衬底上ＧａＰ的电子能带结构进行计算。ＧａＰ为间接能隙型的半导体，计算表明，当衬底中Ｓｂ组分ｘ≥０．５７时，应变的ＧａＰ薄层由间接能隙变成直接能隙的半导体。因应变，ＧａＰ原来简并的最低Ｘ点导带能级及价带顶（Γ点）能级发生分裂。随着Ｘ增大，分裂值变大。文中最后计算了价带能级到导带底跃迁的振子强度，对发光效率作了讨论。
The electron band structure of GaP grown on GaSbxP1-x (001) substrate was calculated by semi-empirical tight-binding approximation. GaP is an indirect energy gap type semiconductor. Calculations show that when the Sb content in the substrate is x ≧ 0.57, the strained GaP thin layer changes from an indirect energy gap to a direct energy gap semiconductor. Due to strain, the original degenerate GaP lowest X conduction band level and valence band top (Γ point) level split. As X increases, the split value becomes larger. In the paper, the oscillator strength of the transition from the valence band level to the conduction band bottom is calculated, and the luminescence efficiency is discussed.