Assessment of thermoelectric performance of Cu2ZnSnX4, X=S, Se, and Te

A recent experiment on In-doped Cu2ZnSnSe4 [X. Y. Shi et al., Appl. Phys. Lett. 94, 122103 (2009)] has shown promising thermoelectric performance characteristics. In this letter, we analyze relevant electronic and transport properties of Cu2ZnSnSe4 and similar compounds, Cu2ZnSnS4 and Cu2ZnSnTe4, to assess their potential as thermoelectric materials. Using density functional theory and Boltzmann transport equations, we determine Seebeck coefficients, conductivities, and power factors of closely related polymorphs with space groups, I (4) over bar, I (4) over bar 2m, and P (4) over bar 2m for each compound. Based on their electronic structure and transport properties, we conclude that other two compounds could have similar potential as thermoelectric materials. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3222862]