论文部分内容阅读
PbTe-based Quantum wells,which showed greatly enhanced thermoelectric figure-of-merit at room temperature (RT),have been widely studied both in theory and experiment as quantum dots and thin films [1-3].Bulk thermoelectrics in the related system have been reported which the high-performance were attributed to all-scale hierarchical architectures in the bulk samples[4].We report here the preparation,structure and property characterizations of bulk thermoelectric materials in rare earth and alkali metal doped PbTe-based systems.Alloying of extra elements in the system optimized carier concentration and augmented the Seebeck coefficient while maintaining a high conductivity.Low lattice thermal conductivity were achieved especially at high temperature range.This optimization lead to obvious increase of thermoelectric performance in bulk materials and ZT value as high as ca.1.8 obtained at 750K.The microstructures at different temperature show stable bulk effect contribution.