FigsharePub Date : 2019-12-26DOI: 10.1021/acs.jpcc.9b09787.s001
Xue-Liang Zhu (8269647), Cai-Hong Hou (8269650), Ping Zhang (86495), Peng-Fei Liu (1415866), Guofeng Xie (123425), Bao-Tian Wang (8269653)
{"title":"High Thermoelectric Performance ofnNew Two-Dimensional IV–VI Compounds: A First-Principles Study","authors":"Xue-Liang Zhu (8269647), Cai-Hong Hou (8269650), Ping Zhang (86495), Peng-Fei Liu (1415866), Guofeng Xie (123425), Bao-Tian Wang (8269653)","doi":"10.1021/acs.jpcc.9b09787.s001","DOIUrl":"https://doi.org/10.1021/acs.jpcc.9b09787.s001","url":null,"abstract":"Based on first-principles calculations,nwe explore the electronic and phonon transport properties of a new-typentwo-dimensional (2D) hexagonal material XSe (X = Ge, Sn, and Pb),nwhich can be prepared by atomic isovalent substitutions of the recentlynsynthesized crystal Ge<sub>4</sub>Se<sub>3</sub>Te. Among them, 2DnPbSe possesses a large Seebeck coefficient of ∼1150 μV/Knand an ultralow lattice thermal conductivity of ∼0.50 W/mKnat room temperature. Theoretical calculations prove that the antiparallelnmovements of the atoms could lead to the strong optical-acoustic phononncoupling with low values of acoustic group velocities of 0.81–2.03nkm/s and large Grüneisen parameters of ∼4, which accordinglyngreatly suppresses the heat transport ability. Using our calculatedntransport parameters, large values of the thermoelectric (TE) figurenof merit (ZT) of 1.76, 2.32, and 3.95 can be obtained at an effectiventemperature range (GeSe and SnSe at 700 K and PbSe at 500 K) undernp-type doping for 2D GeSe, SnSe, and PbSe, respectively. Interestingly,nafter checking several series of 2D materials, we find that theirnlattice thermal conductivities are almost proportional to their valuesnof the lowest optical phonon frequencies. Our work clearly shows thenadvantages of these novel 2D group-IV selenides as TE materials andnmay stimulate further experimental and theoretical studies in thisnfield.","PeriodicalId":522192,"journal":{"name":"Figshare","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147893209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}