Applied Surface Science, Vol.383, 90-97, 2016
Fabrication of Cu2ZnSn(SxSe1-x)(4) solar cells by ethanol-ammonium solution process
In this paper, Cu2ZnSn(SxSe1-x)(4) precursor films were produced by doctor blade process from SnS-Cu2O-ZnS slurry. To prepare the slurry, SnS, ZnS and Cu2O precipitates, which are outgrowths of stacked layer ZnS/Cu/SnS by CBD (chemical bath deposition)-annealing route, were dissolved in the mixture solvent of ethanol and NH3 center dot H2O. Synthesized precursor films were then annealed at different conditions. The post annealed films were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman measurements and UV-vis-NIR spectroscopy. SEM studies reveal that the rough and relatively compact absorber thin films are obtained via the sulfidation and sulfidation-selenization processes. X-ray diffraction and Raman spectrum results verify that the obtained films are composed of Cu2ZnSnS4 and Cu2ZnSnSe4 phases, which have high absorbance in visible range and direct band gap energy of 1.01-1.47 eV. The best devices yield total area power conversion efficiency of 1.99% and 2.95% corresponding to Cu2ZnSnS4 and Cu2ZnSn(SxSe1-x)(4) thin film solar cells under AM1.5 illumination without any anti-reflection layer. (C) 2016 Published by Elsevier B.V.