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本文先比较了几种常用方法(修正的无规元素等位移模型、虚晶近似和简化相干势近似等)对纤锌矿三元混晶体声子频率的拟合结果,再选用与实验数据接近的拟合方法,结合介电连续和单轴晶体模型导出含纤锌矿三元混晶InxGa1-xN和AlxGa1-xN单量子阱各类光学声子模的色散关系,进一步分析了声子模随组分的变化.结果表明,修正的无规元素等位移模型对单模性纤锌矿三元混晶体声子频率的拟合更接近实验数据.由于声子色散的各向异性,量子阱各类光学声子模随组分而发生变化,声子的局域模、界面模、半空间模以及传播模存在于特定组分和频率范围内,且同种声子模色散关系的形态也随组分而改变.
In this paper, we firstly compare the fitting results of phonon frequency of wurtzite ternary mixed crystals by several commonly used methods (such as modified random element displacement model, virtual crystal approximation and simplified coherence potential approximation) , The dispersion relations of various optical phonon modes of InxGa1-xN and AlxGa1-xN single quantum wells containing wurtzite ternary mixed crystals were derived by combining dielectric continuous and uniaxial crystal models. The phonon modes The results show that the fitting of the modified random element displacement model to the phonon frequency of the unimodal wurtzite ternary mixed crystal is closer to the experimental data.Due to the anisotropy of phonon dispersion, The optical phonon modes change with the components. The modes of phonons such as local mode, interface mode, half-space mode and propagation mode exist in specific component and frequency range, Components change.