LAUSR

Abstract In this study, superstrate-type ITO/TiO2/In2S3/C2ZnSnS4 thin film solar cells were investigated. We obtained thin film solar cells by using the facile, vacuum-free solution process which has no require complex system. The C2ZnSnS4(CZTS) thin film was produced by solution process and dip-coating technique on the glass substrate and annealed at 515 °C for 30 min under argon condition. The CZTS thin film was characterized by means of XRD, micro-Raman, XPS, SEM-EDX, AFM and UV–Visible Spectrometer tools. The XRD result showed that the CZTS quaternary semiconductor crystallized in the kesterite phase formation. The Raman and X-ray photo-electron studies were conducted to support the formation of crystalline structure. The SEM and AFM images showed that the surfaces of substrate were covered with sub-micron sized CZTS absorber without any cracks. The optical study revealed that the CZTS has a suitable band gap energy about ∼1.65 eV for solar cell applications. All the layers of the CZTS solar cells including the transparent conductive oxide (TCO) ITO, TiO2/In2S3 buffers and CZTS absorber layers were also coated on the soda-lime glass by the solution process, respectively. The ITO/TiO2/In2S3/CZTS device exhibited the solar conversion efficiency of 0.7% which was the first device that all layers including TCO obtained by means of the non-vacuum processed solution method.