摘要
用分子束外延方法在GaAs（100）衬底上外延生长了不同组分的ZnTe1-xSx（0＜x＜1）合金．用X射线衍射和喇曼散射对该合金的晶体结构和光学声子散射性能进行了研究．通过对其光学声子频率随x的变化研究发现，ZnTe1-xSx合金呈现典型的双模特性．其中，ZnTe1-xSx合金中类ZnTe模和类ZnS模的长波光学声子频率随组分x呈线性变化．用改进了的随机元等位移（MREI）模型计算了该合金的长波光学声子频率和x的关系，并与测量结果作了比较，理论和实验符合很好．
ZnTe1-xSx(0<x<1) alloys are grown on GaAs (100) substrates by molecular beam epitaxy and investigated by using the method of X-ray diffraction and Raman scattering. Through Raman study of the frequency of the zone-center optical phonons as a function of composition x, it is found that the ZnTe1-xSx mixed crystal shows a typical twomode behavior. The long wavelength frequencies of ZnTe-and ZnS-like LO phonons show a linear variation with the composition x. The frequencies of the zone-center optical phonons as a function of x have also been calculated by using a modified random-element isodisplacement model. The calculated results are in good agreement with the experimental results.
