高性能GeTe基热电材料的研究进展

Research Progress on High-performance GeTe-based Thermoelectric Materials

随着环境相容性的提出,热电材料除具有优异的性能外,还需要由环境友好型元素构成。GeTe具有无毒无害的特点,因而被作为理想的PbTe替代物广泛研究。近年来,研究者主要以掺杂方式对其进行改善,由于单掺存在局限性,双掺便成了主导,且Pb元素逐渐被Sb、Bi等代替。本文从GeTe的晶体结构及能带结构特点出发,总结了载流子调控、能带调控和结构调控3种优化手段。目前的GeTe热电器件主要以p型单臂为主,n型GeTe热电材料还需要深入研究,同时,解决相变引起的界面断裂问题也是该材料的发展方向之一。

With the development of environmental compatibility,thermoelectric materials are required high performance coupled with environmental friendly elements.Therefore,GeTe materials have been widely studied as an ideal alternative to PbTe alloys owing to their non-toxic characteristics.In recent years,the doping method is considered to be the main way.Due to the limitations of single element doping,double elements doping have become the leading ways.Meanwhile,the Pb elements have gradually replaced by Sb,Bi and etc.This paper has introduced the crystal structures as well as band structures.Moreover,the optimization methods have been summarized as well,including carrier concentration optimization,energy band engineering and structure control.Nowadays,the GeTe thermoelectric devices are mainly p-type legs,while the n-type of GeTe-based alloys are required for further research.Furthermore,the fracture of the interface in thermoelectric devices caused by phase transition should be solved in the near future.