Cu2ZnSnS4 thin films: spin coating synthesis and photoelectrochemistry

Cu2ZnSnS4 (CZTS) has attracted great interest in both photovoltaic and photoelectrochemical applications as a low cost and environmentally-friendly solar absorber material. The development of a facile and green chemical route for the preparation of a well crystallized and stable CZTS photoelectrode still remains a challenge. We present here the preparation of well crystallized CZTS thin films using a facile spin-coating method based on methanol solution and their applications as photoelectrocathodes for hydrogen production. The bare CZTS thin films demonstrate outstanding photoelectrochemical (PEC) efficiency and chemical stability, which are further improved by surface modification of CdS and TiO2 layers using chemical bath and atomic layer deposition, respectively. The incident-photon-to-current efficiency (IPCE) and long term photoelectrochemistry of the CZTS thin films are measured. The characterization of XRD, Raman, SEM, and UV-vis absorption is also performed.