Ultra-thin conformal deposition of CuInS2 on ZnO nanowires by chemical spray pyrolysis

Abstract

CuInS₂ (CIS) was deposited on ZnO nanowires by a chemical spray pyrolysis (CSP) method, resulting in an ultra-thin, conformal CIS coating on ZnO forming ZnO–CIS core–shell structures. A high-resolution transmission electron microscope and elemental mapping showed the excellent quality of the coating, while Raman spectroscopy revealed the purity of the materials after core–shell formation. A significant enhancement in band-edge emission of ZnO after CIS coating (also lower defect emissions) was observed, which is due to the peculiar band alignment of the ZnO–CIS combination. Further, the electrical behaviour of the single nanowire ZnO–CIS diode was studied, demonstrating the excellent interface between CIS and ZnO. This technique provides tremendous potential for the fabrication of low-cost nano-electronic devices.