A Cadmium-Free Cu₂ZnSnS₄/ZnO Hetrojunction Solar Cell Prepared by Practicable Processes

Abstract

A cadmium-free Cu 2 ZnSnS 4 /ZnO hetrojunction solar cell with conversion efficiency of 4.29% has been obtained. The Cu 2 ZnSnS 4 absorber film was formed utilizing sulfurization of laminated metallic precursors, and the ZnO buffer layer was then deposited on it by ultrasonic spray pyrolysis. In comparison with a conventional Cu 2 ZnSnS 4 /CdS hetrojunction solar cell, the open circuit voltage as well as the relative quantum efficiency at the short-wavelength regions was increased. The in-plane homogeneity of p–n junction was improved by depositing the ZnO layer on Cu 2 ZnSnS 4 film via ultrasonic spray pyrolysis.