本文利用分子束外延技术在GaAs（211）B衬底上外延CdTe（211）薄膜，系统研究不同工艺条件对CdTe 外延薄膜的表面形貌和光学性质的影响。研究表明，在一定的生长温度下，在Te气氛下生长CdTe薄膜，增加CdTe：Te的束流比，可显著降低CdTe表面金字塔缺陷的尺寸和密度，当CdTe 和Te束流比为6.5时，金字塔缺陷几乎消失，材料的表面平整度显著改善，X射线衍射（XRD）也表明CdTe晶体质量显著提高。进一步的拉曼光谱表明，随着CdTe和Te束流比的增加，Te的A₁峰减弱，CdTe LO和TO声子峰强度比增强。低温光致发光光谱（PL）研究也表明随着CdTe和Te束流比的增加，Cd空位的减少可以使与杂质能级相关的深能级区域的峰强降低，与此同时和晶体质量相关的自由激子峰半峰宽减少，材料的光学质量明显改善。该研究为探索CdTe/GaAs外延材料的理想的工艺窗口以及相关机理，并为进一步以此为缓冲层外延高质量HgCdTe材料提供基础。

CdTe(211)thin films are grown on GaAs(211)B substrates by molecular beam epitaxy(MBE), the influence of different process conditions on the surface morphology and optical properties of the CdTe epitaxial films are stematically studied. The study shows that under certain growth temperatures, growing CdTe thin films in a Te atmosphere and increasing the CdTe and Te beam ratio can significantly reduce the size and density of pyramid defects on the CdTe surface. When the CdTe and Te beam ratio is 6.5, the pyramid defects almost disappear, and the surface smoothness of the material is significantly improved. X-ray diffraction(XRD)also shows that the crystal quality of CdTe has significantly improved. Further Raman spectroscopy shows that with the increase of the CdTe and Te beam ratio, the A₁ peak of Te weakens, and the intensity ratio of the CdTe LO and TO phonon peaks increases. Low-temperature photoluminescence(PL)studies also show that with the increase of the CdTe and Te beam ratio, the reduction of Cd vacancies can reduce the peak intensity of the deep energy level region related to impurity energy levels, while the half-width of the free exciton peak related to crystal quality reduces, and the optical quality of the material is significantly improved. This study explores the ideal process window and related mechanisms of CdTe/GaAs epitaxial materials, and provides a foundation for further epitaxial high-quality HgCdTe materials using this as a buffer layer.