Quasiparticle band structures and thermoelectric transport properties of p-type SnSe
Quasiparticle band structures and thermoelectric transport properties of p-type SnSe
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DOI：
10.1063/1.4907805
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发表时间：
2015-02-14
影响因子：
3.2
通讯作者：
Kioupakis, Emmanouil
中科院分区：
文献类型：
--
作者：
Shi, Guangsha;Kioupakis, Emmanouil
我们采用密度泛函和多体微扰理论计算了低温Pnma相和高温Cmcm相p型SnSe的准粒子能带结构和电子输运参数。Pnma相具有0.829 eV的间接带隙，而Cmcm具有0.464 eV的直接带隙。这两个阶段表现出多个本地带极值的能量范围内可比的载流子的热能从全球极值。我们计算了单晶和多晶材料的电子输运系数作为掺杂浓度和温度的函数，以了解以前的实验测量。电子输运系数是高度各向异性的，并且在高温下受到双极输运效应的强烈影响。结果表明，当SnSe掺杂浓度在10（19）~ 10（20）cm（-3）范围内时，SnSe具有最佳的高温热电性能。(C)2015年AIP Publishing LLC。
We used density functional and many-body perturbation theory to calculate the quasiparticle band structures and electronic transport parameters of p-type SnSe both for the low-temperature Pnma and high-temperature Cmcm phases. The Pnma phase has an indirect band gap of 0.829 eV, while the Cmcm has a direct band gap of 0.464 eV. Both phases exhibit multiple local band extrema within an energy range comparable to the thermal energy of carriers from the global extrema. We calculated the electronic transport coefficients as a function of doping concentration and temperature for single-crystal and polycrystalline materials to understand the previous experimental measurements. The electronic transport coefficients are highly anisotropic and are strongly affected by bipolar transport effects at high temperature. Our results indicate that SnSe exhibits optimal thermoelectric performance at high temperature when doped in the 10(19)-10(20) cm(-3) range. (C) 2015 AIP Publishing LLC.