Nanostructured kesterite (Cu2ZnSnS4) for applications in thermoelectric devices

Kesterite (Cu2ZnSnS4, CZTS) powders were produced by reactive high-energy milling, starting from stoichiometric mixtures of the elemental components. CZTS forms fine crystals with a cubic structure, which evolves to the stable tetragonal form after thermal treatment. Tablets were produced by cold pressing of the ball milled powder, and sintered up to 660 degrees C. Seebeck coefficient, electrical resistivity, and thermal diffusivity were measured on the sintered tablets, pointing out the positive effect of CZTS nanostructure and of the rather large fraction of porosity: thermal conductivity is rather low (from similar to 0.8 W/(m K) at 20 degrees C to similar to 0.42 W/(m K) at 500 degrees C), while electrical conduction is not seriously hindered (electrical resistivity from similar to 8500 mu Omega m at 40 degrees C to similar to 2000 mu Omega m at 400 degrees C). Preliminary results of thermoelectric behavior are promising. (C) 2019 International Centre for Diffraction Data.