Solution-based synthesis of wurtzite Cu2ZnSnS4 nanoleaves introduced by α-Cu2S nanocrystals as a catalyst

Abstract

Cu₂ZnSnS₄ is a promising solar absorbing material in solar cells due to its high absorption coefficient and abundance on earth. We have demonstrated that wurtzite Cu₂ZnSnS₄ nanoleaves could be synthesized through a facile solution-based method. Detailed investigation of the growth process indicates that α-Cu₂S nanocrystals are first formed and then serve as a catalyst to introduce the Cu, Zn, and Sn species into the nanoleaf growth for fast ionic conduction. The structure of the as-synthesized nanoleaves is characterized by powder X-ray diffraction, high-resolution transmission electron microscopy, fast Fourier transform, and energy dispersive X-ray spectroscopy mapping. Photoresponses of Cu₂ZnSnS₄ nanoleaves are evaluated by I–V curves of a Cu₂ZnSnS₄ nanoleaf film. It is believed that the enhancement of the photoresponse current of the Cu₂ZnSnS₄ nanoleaf film can be attributed to fast carrier transport due to the single crystalline nature and enhanced light absorption resulting from larger absorption areas of the Cu₂ZnSnS₄ nanoleaves.