IV族碲化物MTe(M = Pb, Ge 和Sn)是性能良好的中温热电材料，在余热发电领域有广阔的应用前景，基于我们研究发现Se替代GeTe-PbTe和PbTe-BaTe等体系中的Te能增加掺杂元素Pb或Ba在GeTe或PbTe基体相固溶度的特性，本申请项目拟对可能存在类似特性的其它IV族碲化物复合材料体系，如具有优异性能II族元素掺杂IV族碲化物等体系MTe-ATe（M = Pb、Ge和Sn；A = Mg、Ca、Sr和Ba等）富MTe角的相平衡关系、固溶度范围、微量相的成相规律进行系统研究，设计和制备IV族碲化物MTe为基的纳米复合材料并研究它们的热电性能，有望通过Se的替代提高II族等元素在IV族碲化物的固溶度、调整和改善其载流子浓度及能带结构，从而提高材料的功率因子，同时固溶原子、第二相及晶界形成多尺度声子散射中心，降低热导率；通过Se及II族等元素协同调控进一步提高合金的热电性能。

Group IV tellurides MTe (M = Pb, Ge and Sn) are promising thermoelectric materials, which have potential application in electric generation from waste heat. Based on the fact that substitution of Se for Te in the alloys in GeTe-PbTe or PbTe-BaTe systems can promote the solid solubility of doping element Pb in GeTe-based or Ba in PbTe-based phase found in our previous investigations, this proposal will carry out the experimental studies systematically on the phase relationships, phase formation and homogeneity ranges in the other MTe-rich MTe-ATe systems, such as high ZT Group IV telluride - group II tellurides (MTe- ATe, A = Mg, Ca, Sr or Ba) systems with the substituion of Se for Te partly, in which may have similar behavior to Se-substituted GeTe-PbTe or PbTe-BaTe systems; to design and synthesize the MeTe-based composits and investigate their microstructures and thermoelectric properties. It is expected that the substitution of Se can increase the solubilities of group II (A) elements in the MTe compound and modify their carrier concentrations and band structures, and thus enhance their power factors. Simultaneously, the solute atoms, the second phase with nanostructures and the grain boundaries in the composites form broad band phonon scattering centers, leading to reduce their thermal conductivities. The thermoelectric properties of the group IV tellurides can be further improved by Se and group II elements co-optimization.