粗糙界面对Bi2Te3/PbTe超晶格热电优值影响的理论分析

以Bi₂Te₃/PbTe超晶格薄膜为例，分析电子在Bi₂Te₃量子阱中的输运过程，综合了薄膜的经典散射效应和理想量子效应，并以此混合效应为基础，在PbTe障碍层厚度一定时，模拟计算了两种混合效应中量子效应占不同比例时，Bi₂Te₃/PbTe超晶格热电优值的变化.在镜面反射占混合效应的0.3时，得到的热电优值与当前报道的量子阱超晶格的实验值接近. 关键词： 超晶格 粗糙界面 热电优值

Effect of rough interface on the thermoelectric figure of merit of the Bi2Te3/PbTe superlattice

Electron transport is analysed in Bi₂Te₃ quantum well of Bi₂Te₃/PbTe superlattice. The hybrid quantum-classical size effect model, considering the Boltsmann transport equation and classical size effect, is introduced to analyse the effect of rough interface on the electron transport and scattering and the thermoelectric figure of merit of Bi₂Te₃/PbTe superlattice. The PbTe barrier thickness is kept constant to avoid the influence of the variation in tunnel effect on attenuation of the carrier concentration in Bi₂Te₃ quantum well of Bi₂Te₃/PbTe superlattice. The result shows that roughness has strong influence on the thermoelectric figure of merit of Bi₂Te₃/PbTe superlattice. The Bi₂Te₃/PbTe thermoelectric figure of merit decreases with the decreasing of the portion (p) of mirror reflection in the hybrid effects. And when p is 0.3, the figure of merit is close to the experiment value.