晶格热振动对极性半导体膜中电子-表面声子强耦合极化子自陷能的影响

Effects of Lattice Vibration on Self-Trapping Energy of Polaron of Electron-Surface Phonons Strong-Coupling in Polar Semiconductor Slab

采用 Huybrechts线性组合算符和变分法 ,讨论了晶格热振动对极性半导体膜中电子 -表面光学 (SO)声子强耦合和电子 -体纵光学 (L O)声子弱耦合体系的影响 ,得到了极化子自陷能随膜厚和温度变化的规律 ,对 Cd F2半导体膜进行了数值计算 ,结果表明 ,Cd F2 极性半导体膜中表面光学声子和体纵光学声子对极化子自陷能的贡献分别在薄膜和宽膜情况下起主导作用 .并且发现 Cd F2 半导体膜中的不同支声子与电子相互作用对极化子自陷能的贡献 ,以及极化子的总自陷能都将随温度的升高而减小 ,这表明晶格热振动将削弱电子

The effects of lattice vibration on the properties of the polaron in the polar semiconductor slab has been discussed by using the Huybrechts’ linear-combination operater and variational methods,which is the electron interation with both the weak-coupling bulk longitudinal optical phonons and the strong-coupling surface optical phonons.The relationship of the self-trapping energy of the polaron versus the thickness of the slab and temperature has been obtained.The numerical results of CdF 2 semiconductor slab show that the contribution of the surface and bulk phonons on the self-trapping energy of the polarons is dominant at thinner and thicker slabs,respectively.It is also shown that the contribution of the interaction between the electron and various phonon branches on polaron's self-trapping energy and the polaron's total self-trapping energy in polar semiconductor slab will decrease with the temperature increasing.It also shows that the electron-phonons coupling is weaken by the lattice vibration.