Thermal transport in Cu{sub 2}ZnSnS{sub 4} thin films

Journal Article · Sun Mar 06 23:00:00 EST 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4942661· OSTI ID:22597025

White, B. E. ^[1]; Nandur, Abhishek ^[2]

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1. Department of Physics, Binghamton University, 4400 Vestal Parkway East, Binghamton, New York 13902 (United States)
2. Materials Science and Engineering Program, Binghamton University, 4400 Vestal Parkway East, Binghamton, New York 13902 (United States)

The stability of kesterite Cu{sub 2}ZnSnS{sub 4} (CZTS) under a range of compositions leads to the formation of a number of stable defects that appear to be necessary for high efficiency photovoltaic applications. In this work, the impact of the presence of these defects on the thermal conductivity of CZTS thin films has been explored. Thermal conductivities of CZTS thin films, prepared by pulsed laser deposition with differing compositions, were measured from 80 K to room temperature using the 3ω-method. The temperature dependence of the thermal conductivity indicates that the phonon mean free path is limited by strain field induced point defect scattering from sulfur vacancies in sulfur deficient thin films. The sulfurization of these films in a 10% N{sub 2} + H{sub 2}S ambient at 500 °C increased the sulfur content of the films, reducing the concentration of sulfur vacancies, and produced a negligible change in grain size with an unexpected factor of 5 increase in phonon boundary scattering. This, along with anisotropies in the x-ray diffraction peak profiles of the sulfurized films, suggests that the phonon mean free path in sulfurized films is limited by the presence of cation exchange induced stacking faults. The resulting room temperature thermal conductivities for sulfurized and sulfur deficient thin films were found to be 4.0 W/m K and 0.9 W/m K, respectively.

• OSTI ID: 22597025
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 119; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CATIONS
CDZNTE SEMICONDUCTOR DETECTORS
CONCENTRATION RATIO
ENERGY BEAM DEPOSITION
GRAIN SIZE
HYDROGEN SULFIDES
ION EXCHANGE
LASER RADIATION
MEAN FREE PATH
NITROGEN
PHONONS
PHOTOVOLTAIC EFFECT
PULSED IRRADIATION
STACKING FAULTS
SULFUR
TEMPERATURE DEPENDENCE
THERMAL CONDUCTIVITY
THIN FILMS
VACANCIES
X-RAY DIFFRACTION