Theoretical Studies on the Thermo- electric Properties of Tin-based Clathrates:Cs_8M_4Sn_(42)(M=Zn,Cd,Hg) and Cs_8Sn_(44)□_2  

作　　者：WANG Peng WU Li-Ming 

机构地区：[1]State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《Chinese Journal of Structural Chemistry》2013年第12期1793-1804,共12页结构化学（英文）

基　　金：Supported by the 973 program(No.2010CB933501);NNSFC(Nos.20973175,21233009,and 21103190)

摘　　要：The site occupancies and thermoelectric properties of tin-based clathrates Cs8M4Sn44□2 （M = Zn, Cd, Hg） and CssSn44□2 were studied by the first principle calculations. We had provided an efficient way to probe the relationship between the crystalline structure and power factor. Detailed analyses indicated the p states of Sn at 16i and 24k sites together with the p states of M substitute contributed significantly to the maximum power factor, yet Cs atoms nearly did not. The dangling bonds of vacancies in Cs8Snn44□2 are also discussed. The power factors of p- and n-type CssMaSn42 and Cs8Sn44□2 at optimal temperature and carder concentration are predicted. Our results suggest that Cs8ZnaSn44□2 is a promising candidate at the 5.25 ×10^19 cm-3 hole carrier concentration as a high temperature thermoelectric material that is competitive to the state-of-art Ge-based clathrate thermoelectric materials.The site occupancies and thermoelectric properties of tin-based clathrates Cs8M4Sn44□2 （M = Zn, Cd, Hg） and CssSn44□2 were studied by the first principle calculations. We had provided an efficient way to probe the relationship between the crystalline structure and power factor. Detailed analyses indicated the p states of Sn at 16i and 24k sites together with the p states of M substitute contributed significantly to the maximum power factor, yet Cs atoms nearly did not. The dangling bonds of vacancies in Cs8Snn44□2 are also discussed. The power factors of p- and n-type CssMaSn42 and Cs8Sn44□2 at optimal temperature and carder concentration are predicted. Our results suggest that Cs8ZnaSn44□2 is a promising candidate at the 5.25 ×10^19 cm-3 hole carrier concentration as a high temperature thermoelectric material that is competitive to the state-of-art Ge-based clathrate thermoelectric materials.

关 键 词：the first principle THERMOELECTRIC boltzmann theory clathrate tin electronic structure 

分 类 号：TB34[一般工业技术—材料科学与工程]