First Principle Investigation on Thermoelectric Properties of Transition Metal Dichalcogenides: Beyond the Rigid Band Model
First Principle Investigation on Thermoelectric Properties of Transition Metal Dichalcogenides: Beyond the Rigid Band Model
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DOI：
10.1021/acs.jpcc.7b02570
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发表时间：
2017-06
影响因子：
3.7
通讯作者：
C. Adessi;S. Thébaud;R. Bouzerar;G. Bouzerar
中科院分区：
文献类型：
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作者：
C. Adessi;S. Thébaud;R. Bouzerar;G. Bouzerar
利用Landauer - Buttiker形式，在从头算量子输运的基础上，从理论上研究了单层过渡金属二硫族化合物（MoS2、MoSe2、WS2和WSe2）的热电性质（电导率、塞贝克系数和功率因数）。将常用的刚性带模型与实际掺杂（即取代和吸附）进行比较，发现在这种近似中缺少一些重要的控制输运的物理见解。刚性带模型显然高估了热电效率，阻碍了其与热电研究的相关性。氯化物或磷的取代掺杂会导致原始能带结构的剧烈变化，导致功率因数较差。相比之下，碱（Li, Na， K和Rb）的吸附掺杂有利于更大的功率因数。对掺杂引起的紊乱进行了实际处理，发现Cl掺杂导致定位长度很短，为3.5 nm，而kc…
The thermoelectric properties (electrical conductivity, Seebeck coefficient, and power factor) of single layer transition metal dichalcogenides (MoS2, MoSe2, WS2, and WSe2) are investigated theoretically on the basis of ab initio quantum transport using the Landauer Buttiker formalism. The often used rigid band model is compared to realistic doping, namely substitution and adsorption, it is found that several important physical insights governing the transport are missing in this approximation. The rigid band model appears to clearly overestimate the thermoelectic efficiency, hampering its relevance for thermoelectric studies. Substitution doping by chloride or phosphorus leads to poor power factor due to drastic changes of the pristine band structure. In contrast, adsorption doping by alkalies (Li, Na, K, and Rb) favors larger power factor. Realistic treatment of the disorder induced by the dopants is also investigated and reveals that Cl doping leads to very short localization length of 3.5 nm while K c...