TY - JOUR
T1 - Enhanced thermoelectric transport properties of n-type InSe by Sn doping
AU - Choo, Sung Sil
AU - Hong, Seok Won
AU - Kim, Hyun Sik
AU - Kim, Sang Il
N1 - Publisher Copyright:
Copyright © The Korean Institute of Metals and Materials.
PY - 2020/5
Y1 - 2020/5
N2 - Layered post transition metal chalcogenides such as SnSe, SnSe2, In2Se3, and In4Se3 have attracted attention as promising thermoelectric materials due to their intrinsically low lattice thermal conductivities. Recently, n-type indium selenide (InSe) based materials have also been suggested as good candidates for thermoelectric materials by optimizing their electrical properties, i.e., increasing carrier concentration. Here, we report enhancement of the thermoelectric properties of n-type InSe by Sn substitutional doping at the In site. A series of In1-xSnxSe for x = 0, 0.03, 0.05, 0.15 and 0.2 was examined. The carrier concentration and electrical conductivity increased due to the Sn substitution, since Sn behaves as a shallow electron donor in InSe, while the Seebeck coefficient decreased moderately. In addition, it was found that effective mass was increased by more than 10 times by Sn doping. As a result, the power factor was enhanced from 0.07 mW/ mK2 to 0.13 mW/mK2 at 800 K. The total thermal conductivity was unchanged despite Sn doping because the electrical contribution to the total thermal conductivity was very small. Consequently, Sn doping in InSe enhanced the dimensionless thermoelectric figure of merit zT from 0.04 to 0.14 at 800 K, mainly due to enhanced electrical properties.
AB - Layered post transition metal chalcogenides such as SnSe, SnSe2, In2Se3, and In4Se3 have attracted attention as promising thermoelectric materials due to their intrinsically low lattice thermal conductivities. Recently, n-type indium selenide (InSe) based materials have also been suggested as good candidates for thermoelectric materials by optimizing their electrical properties, i.e., increasing carrier concentration. Here, we report enhancement of the thermoelectric properties of n-type InSe by Sn substitutional doping at the In site. A series of In1-xSnxSe for x = 0, 0.03, 0.05, 0.15 and 0.2 was examined. The carrier concentration and electrical conductivity increased due to the Sn substitution, since Sn behaves as a shallow electron donor in InSe, while the Seebeck coefficient decreased moderately. In addition, it was found that effective mass was increased by more than 10 times by Sn doping. As a result, the power factor was enhanced from 0.07 mW/ mK2 to 0.13 mW/mK2 at 800 K. The total thermal conductivity was unchanged despite Sn doping because the electrical contribution to the total thermal conductivity was very small. Consequently, Sn doping in InSe enhanced the dimensionless thermoelectric figure of merit zT from 0.04 to 0.14 at 800 K, mainly due to enhanced electrical properties.
KW - Chalcogenide
KW - Density-of-states effective mass
KW - Doping
KW - InSe
KW - Thermoelectric
UR - http://www.scopus.com/inward/record.url?scp=85086749897&partnerID=8YFLogxK
U2 - 10.3365/KJMM.2020.58.5.348
DO - 10.3365/KJMM.2020.58.5.348
M3 - Article
AN - SCOPUS:85086749897
SN - 1738-8228
VL - 58
SP - 348
EP - 352
JO - Journal of Korean Institute of Metals and Materials
JF - Journal of Korean Institute of Metals and Materials
IS - 5
ER -