@article{34183, author = {Yixuan Wu and Wen Li and Alireza Faghaninia and Zhiwei Chen and Juan Li and Xinyue Zhang and Bo Gao and Siqi Lin and Binqiang Zhou and Anubhav Jain and Yanzhong Pei}, title = {Promising thermoelectric performance in van der Waals layered SnSe2}, abstract = {

SnSe as a lead-free\ IV{\textendash}VI semiconductor, has attracted intensive attention for its potential\ thermoelectric\ applications, since it is less toxic and much cheaper than conventional PbTe and PbSe thermoelectrics. Here we focus on its sister layered compound SnSe2\ in n-type showing a thermoelectric performance to be similarly promising as SnSe in the\ polycrystalline\ form. This is enabled by its favorable electronic structure according to\ first principle\ calculations, its capability to be effectively doped by bromine on selenium site to optimize the carrier concentration, as well as its intrinsic lattice\ thermal conductivity\ as low as 0.4\ W/m-K due to the weak van der Waals force between layers. The broad carrier concentration ranging from 0.5 to 6\ {\texttimes}\ 1019\ cm-3\ realized in this work, further leads to a fundamental understanding on the material parameters determining the thermoelectric transport properties, based on a single parabolic band (SPB) model with\ acoustic scattering. The layered crystal structure leads to a texture in hot-pressed polycrystalline materials and therefore\ anisotropic\ transport properties, which can be well understood by the SPB model. This work not only demonstrates SnSe2\ as a promising\ thermoelectric material\ but also guides the further improvements particularly by band engineering and texturing approaches.

}, year = {2017}, booktitle = {Materials Today Physics}, journal = {Materials Today Physics}, series = {Materials Today Physics}, volume = {3}, pages = {127 - 136}, month = {12/2017}, issn = {25425293}, doi = {10.1016/j.mtphys.2017.10.001}, language = {eng}, }