Abstract: High quality Sb2S3 thin films were prepared by pulsed laser deposition (PLD) method. The thickness of the Sb2S3 thin film was adjusted by changing the deposition duration to investigate the thickness dependent power conversion efficiency in complete solar devices. It was found that the Sb2S3 solar cell achieved power conversion efficiency of 3.98% when the deposition time was 5 min. Based on external quantum efficiency and electrochemical impedance spectroscopy analysis, it was observed that the change of thickness affects both the light harvesting capacity of the Sb2S3 layer and non-radiative recombination of photo generated carriers, thus affecting the efficiency of the solar cell.