The order-disorder transition in Cu{sub 2}ZnSnS{sub 4}: A theoretical and experimental study
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany)
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin (Germany)
In this work the Cu/Zn order-disorder transition in Cu{sub 2}ZnSnS{sub 4} kesterites on Wyckoff positions 2c and 2d was investigated by a structural and electronic analysis in theory and experiment. For experimental investigations stoichiometric samples with different Cu/Zn order, annealed in the temperature range of 473–623 K and afterwards quenched, were used. The optical gaps were determined using the Derivation of Absorption Spectrum Fitting (DASF) method. Furthermore, the order-disorder transition was examined by DFT calculations for a closer analysis of the origins of the reduced band gap, showing a good agreement with experimental data with respect to structural and electronic properties. Our studies show a slight increase of lattice parameter c in the kesterite lattice with increasing disorder. Additionally, a reduced band gap was observed with increasing disorder, which is an effect of newly occurring binding motifs in the disordered kesterite structure. - Highlights: • Experimental and theoretical investigation on the order-disorder transition in kesterites. • Slight enlargements of lattice constants due to disorder in experiment and theory. • Strong band gap fluctuations with decreasing order. • Electronic structure deviations due to changing binding motifs. • Disorder as possible main source of low open-circuit voltages.
- OSTI ID:
- 22658298
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 250; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
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