基于第一性原理的Mn纳米线掺杂二维SnSe热电性能研究

本文提出了一种在二维SnSe中掺杂一维Mn纳米线的2D-1D复合结构,并系统地研究了其热电性能。结果表明,一维Mn纳米线将电子态汇聚在纳米线附近,提高了材料的各向异性,降低了电子在某一方向上的散射效应,导致了较高的迁移率和电导率。自旋向上和向下的电子态发生简并,导致了较高的塞贝克系数和电导率。此外,Mn纳米线将晶格热导率降低了约0.17 W·m^?1·K^?1。在200至650 K的温度范围内,3Mn-SnSe具有0.73至3.78的极高ZT值,比本征二维SnSe平均提高了约39.2%。

First Principle Study on Thermoelectric Properties of Two-Dimensional SnSe Doped with One-Dimensional Mn Nanowires

We proposed a 2D-1D composite structure by doping one-dimensional Mn nanowires into two-dimensional SnSe.The thermoelectric properties were investigated systematically using the first principle theory.1D Mn nanowires cause the electronic states to gather near nanowires,which can reduce the electron-phonon scattering effect in the armchair direction.Therefore,the carrier mobility and electrical conductivity have a significant increase.Furthermore,the spin-up and spindown states have a high degeneracy,indicating a high Seebeck coefficient and electrical conductivity.In addition,Mn nanowires reduce the lattice thermal conductivity by about 0.17 W·m^?1·K^?1.In the temperature range of 200 to 650 K,3Mn-SnSe has ultrahigh ZT values of 0.73 to 3.78,which is 39.2%larger than the ZT values of intrinsic 2D SnSe.