Controlled synthesis of SnSxSe2-x thin films for solar energy water splitting.

Earth-abundant and ecofriendly minerals SnS x Se 2–x can be promising candidates for photoelectrochemical (PEC) cells because of their tunable band gaps and high absorption efficiency in the visible light range. In this paper, p type SnS thin films with sheet-like morphologies were successfully prepared by CBD method and then n-type SnS x Se 2-x thin films were achieved by selenization annealing of SnS thin films. The physical properties and PEC performances of SnS x Se 2-x thin films influenced by the annealing process were detailed studied. The photocurrent densities and stability of SnS x Se 2-x films were further improved by the deposition of p-type CdS:Cu buffer layer. And the fabrication of FTO/SnS x Se 2-x /CdS:Cu/TiO 2 /Pt photocathode improved the PEC performance further and the photocurrent as high as 10.5 mA/cm2 had been achieved. IPCE tests indicated that the FTO/SnS x Se 2-x /CdS:Cu/TiO 2 /Pt structure achieved a power conversion efficiency of 31.3 %. •SnS thin films were deposited by CBD method, and SnS x Se 2-x thin films were prepared by selenization annealing. •The effects of different selenization temperatures and different amounts of selenium powder on SnS x Se 2-x films were studied. •By introducing CdS: Cu buffer layer with different deposition times, TiO 2 protective layer with varying thickness, and precious metal Pt for surface modification, the photoelectric performance of SnS x Se 2-x thin films was optimized. [ABSTRACT FROM AUTHOR]