Modification in cell structure for better performance of spray pyrolysed CuInS2/In2S3 thin film solar cell

We report a new structure for CuInS2/In2S3 solar cell, in which both absorber and buffer layers were deposited using chemical spray pyrolysis (CSP) technique. The usual superstrate structure, having buffer layer just above ITO, was not functioning mainly due to diffusion of Cu into In2S3 layer as seen from X-ray photoelectron spectroscopy (XPS) results. However, when the configuration of the cell was ITO/CuInS2/In2S3/Ag, cell parameters obtained were V-oc=0.45 V, J(sc)=44.03 mA/cm(2), fill factor (FF)=29.5% and eta=5.87%. Good results could be obtained by using indium sulfide thin films having maximum photosensitivity. The cell was characterized using X-ray diffraction, optical absorption, current-voltage and spectral response measurements.