Effects of Zn precursors on solvothermal synthesis of Cu2ZnSnSe4 nanocrystals

Cu2ZnSnSe4 (CZTSe) has potential applications in thin film solar cells and thermoelectric devices. The synthesis of stoichiometric CZTSe nanocrystals by the solvothermal process is still a challenge. In this work, the effects of different Zn precursors on the synthesis of pure and stoichiometric CZTSe nanocrystals via a facile solvothermal process were explored. The products were characterized using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and UV-vis spectroscopy. The present study showed that with the Zn(CH3COO)(2) precursor pure and stoichiometric CZTSe nanocrystals were readily synthesized, while with the ZnCl2 precursor the synthesized nanocrystals were Zn-deficient and composed of CZTSe and Cu2SnSe3 phases. This result can be attributed to the chelating effect of the acetate anion in the solvothermal reaction. (C) 2012 Elsevier B.V. All rights reserved.