Thermoelectric properties of chalcopyrite type CuGaTe{sub 2} and chalcostibite CuSbS{sub 2}

Journal Article · Sat Dec 14 00:00:00 EST 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4842095· OSTI ID:22266158

Kumar Gudelli, Vijay; Vaitheeswaran, G. ^[1]; Svane, A.; Christensen, N. E. ^[2]

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1. Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500 046, Andhra Pradesh (India)
2. Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)

Electronic and transport properties of CuGaTe{sub 2}, a hole-doped ternary copper based chalcopyrite type semiconductor, are studied using calculations within the Density Functional Theory and solving the Boltzmann transport equation within the constant relaxation time approximation. The electronic band structures are calculated by means of the full-potential linear augmented plane wave method, using the Tran-Blaha modified Becke-Johnson potential. The calculated band gap of 1.23 eV is in agreement with the experimental value of 1.2 eV. The carrier concentration- and temperature dependent thermoelectric properties of CuGaTe{sub 2} are derived, and a figure of merit of zT = 1.69 is obtained at 950 K for a hole concentration of 3.7·10{sup 19} cm{sup −3}, in agreement with a recent experimental finding of zT = 1.4, confirming that CuGaTe{sub 2} is a promising material for high temperature thermoelectric applications. The good thermoelectric performance of p-type CuGaTe{sub 2} is associated with anisotropic transport from a combination of heavy and light bands. Also for CuSbS{sub 2} (chalcostibite), a better performance is obtained for p-type than for n-type doping. The variation of the thermopower as a function of temperature and concentration suggests that CuSbS{sub 2} will be a good thermoelectric material at low temperatures, similarly to the isostructural CuBiS{sub 2} compound.

• OSTI ID: 22266158
• Journal Information: Journal of Applied Physics, Vol. 114, Issue 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABUNDANCE
ANISOTROPY
BOLTZMANN EQUATION
CHALCOPYRITE
CONCENTRATION RATIO
COPPER
DENSITY FUNCTIONAL METHOD
DOPED MATERIALS
PERFORMANCE
RELAXATION TIME
SEMICONDUCTOR MATERIALS
TEMPERATURE DEPENDENCE
THERMOELECTRIC MATERIALS
THERMOELECTRIC PROPERTIES
WAVE PROPAGATION