β型锑烯热电输运性质的第一性原理研究

利用第一性原理与半经典玻尔兹曼方程，计算并分析β型锑烯的声子色散、声子群速度、声子弛豫时间、晶格热导率及不同温度下的塞贝克系数、电导率和电子热导率随化学势的变化；结果表明：β型锑烯由于非平面六角结构，三支声学声子在Γ点附近均呈线性变化；声学声子对整个晶格热导率的贡献高达96.68%，而光学声子仅仅占到3.32%；由于较大的声光带隙（a-o gap）导致LA支在声子群速度和弛豫时间中占据主导地位，从而增大了LA支声子对整个热导的贡献；热电优值随温度的升高而增大，在费米面附近其绝对值最大可达0.275.

First-Principles Study of Thermoelectric Transport Properties of β-Antimonene

First-principles and semiclassical Boltzmann transport formalism are employed to investigate thermoelectric properties of β-antimonene. We obtain phonon dispersion, phonon group velocity, phonon relaxation time, lattice thermal conductivity and Seebeck coefficient, electrical conductivity and electron thermal conductivity as functions of chemical potential of β-antimonene. It indicates that longitudinal acoustic (LA), transverse acoustic (TA), and z-direction acoustic (ZA) branches of β-antimonene are linear near Γ point due to its buckling structure. Acoustic phonon contribution to whole lattice thermal conductivity is as high as 96.68%, and optical phonon accounts for 3.32% only. A large a-o gap leads to LA be dominant in group velocity and relaxation time, and thus increasing LA phonon contribution to whole thermal conductivity. In addition, merit ZT increases with temperature, and reaching a maximum of 0.275 at 700 K near Fermi level.