TY - JOUR
T1 - Realizing tremendous electrical transport properties of polycrystalline SnSe2 by Cl-doped and anisotropy
AU - Wu, Shaohai
AU - Liu, Chengyan
AU - Wu, Zhengsen
AU - Miao, Lei
AU - Gao, Jie
AU - Hu, Xiaokai
AU - Chen, Junliang
AU - Zheng, Yanyan
AU - Wang, Xiuxia
AU - Shen, Chengjin
AU - Yang, Hengquan
AU - Zhou, Xiaoyuan
N1 - Funding Information:
This work was supported by National Natural Science Foundation of China [grant numbers 51572049 , 51562005 , 51772056 ]; Natural Science Foundation of Guangxi Province [grant numbers 2015GXNSFFA139002 , 2016GXNSFBA380152 ]; and Innovation Project of GUET Graduate Education [grant number 2017YJCX117 ].
Publisher Copyright:
© 2018 Elsevier Ltd and Techna Group S.r.l.
PY - 2019/1
Y1 - 2019/1
N2 - SnSe2 is regarded as an attractive thermoelectric material for its structural and chemical analogy to SnSe that is claimed with the highest ZT in single crystal. In this study, the pure and Cl-doped SnSe2 polycrystals (3%, 6%, 9% and 12% molar Cl content) were fabricated in four steps that are hydrothermal synthesis, heating purification, diffusion doping, and spark plasma sintering. The phase structure, lamellar morphology and crystallite orientation were studied for the synthesized SnSe2 powder and the sintered pellets. The structural evolution was traced from the SnSe2 hexagonal plates of powders to the (001) oriented grains in pellets. The Cl doping into SnSe2 was verified by phase composition, lattice parameter, element distribution, and chemical valance. The doped Cl increased both the carrier concentration and the mobility. The anisotropic thermoelectric properties of SnSe2 bulk materials were investigated as functions of temperature from 50 °C to 300 °C and the doping amount, respectively. The Seebeck coefficient was less anisotropic than the electrical and thermal conduction. The grain orientation influenced the anisotropy of the electrical and thermal conductivity at a similar ratio. The power factors were less dependent on temperature with an optimum in-plane 1.06 mW m−1 K−2 and out-of-plane 0.41 mW m−1 K−2. The highest ZTs of 0.3 were attained at 300 °C in both directions.
AB - SnSe2 is regarded as an attractive thermoelectric material for its structural and chemical analogy to SnSe that is claimed with the highest ZT in single crystal. In this study, the pure and Cl-doped SnSe2 polycrystals (3%, 6%, 9% and 12% molar Cl content) were fabricated in four steps that are hydrothermal synthesis, heating purification, diffusion doping, and spark plasma sintering. The phase structure, lamellar morphology and crystallite orientation were studied for the synthesized SnSe2 powder and the sintered pellets. The structural evolution was traced from the SnSe2 hexagonal plates of powders to the (001) oriented grains in pellets. The Cl doping into SnSe2 was verified by phase composition, lattice parameter, element distribution, and chemical valance. The doped Cl increased both the carrier concentration and the mobility. The anisotropic thermoelectric properties of SnSe2 bulk materials were investigated as functions of temperature from 50 °C to 300 °C and the doping amount, respectively. The Seebeck coefficient was less anisotropic than the electrical and thermal conduction. The grain orientation influenced the anisotropy of the electrical and thermal conductivity at a similar ratio. The power factors were less dependent on temperature with an optimum in-plane 1.06 mW m−1 K−2 and out-of-plane 0.41 mW m−1 K−2. The highest ZTs of 0.3 were attained at 300 °C in both directions.
KW - Anisotropy
KW - Cl-doped
KW - Electrical transport property
KW - SnSe
UR - http://www.scopus.com/inward/record.url?scp=85053685966&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85053685966&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2018.09.136
DO - 10.1016/j.ceramint.2018.09.136
M3 - Article
AN - SCOPUS:85053685966
VL - 45
SP - 82
EP - 89
JO - Ceramics International
JF - Ceramics International
SN - 0272-8842
IS - 1
ER -