Solar Energy Materials and Solar Cells, Vol.128, 156-165, 2014
Synthesis of CZTSe nanoink via a facile one-pot heating route based on polyetheramine chelation
In this paper, we report a systematic study of the growth and evolution mechanism of quaternary Cu2ZnSnSe4 (CZTSe) nanocrystals (NCs) in a polyetheramine solvent. To the best of our knowledge, this is the first study on the growth mechanism of CZTSe NCs based on polyetheramine chelation. Pure-phase CZTSe NCs were synthesized by a facile one-pot heating process. High-quality CZTSe NCs were easily obtained by mixing the precursors and simply heating them to the reaction temperature. Synthesis parameters, including reaction temperature, reaction time, and precursor concentration, which influence the morphology, size, and monodispersity of CZTSe NCs, were studied in detail. Time- and temperature-dependent experiments were performed to observe the growth of CZTSe NCs. The final CZTSe NCs were evolved from triangle-like Cu2Se crystals to pure spherical crystals. On the basis of detailed time-dependent shape and elemental composition evaluations, a possible asynchronous doping growth and formation mechanism is proposed. Moreover, the optical and electrical properties of pure CZTSe NCs were also investigated. The band gap of CZTSe was approximately 1.57 eV, which is close to the optimum value for solar photoelectric conversion. Further, the investigation of the current-voltage characteristics and Hall effect revealed p-type conduction, and the hole carrier concentration, hole mobility, and resistivity were found to be 3.11 x 10(18) cm(-3), 8.28 cm(2)/V-s, and 0.24 Omega-cm, respectively. These results indicate that CZTSe NCs are suitable for use as an absorber layer in low-cost solar cells. (C) 2014 Elsevier B.V. All rights reserved.