Enhanced performance of quantum dots sensitized solar cell utilizing copper indium sulfide and reduced-graphene oxide with the presence of silver sulfide

Abstract

In this study, rGO/CuInS2 has been successfully prepared onto TiO2 thin film using solvothermal method followed by Ag2 S deposition layer by successive ionic layer adsorption and reaction deposition (SILAR) technique. The morphology, structural, and optical properties of TiO2 /rGO/CuInS2 thin film were investigated by using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscope (AFM), X-ray diffraction (XRD) and ultra-violet-visible near infrared spectrophotometer (UV-Vis). For electrical properties, electrochemical impedance spectra (EIS) and current-voltage (I-V) test investigated the interfacial charge-transfer resistances and the conversion efficiency of the samples. Results showed that the average particles size of the samples ranged from ±46.52 to ±53.97 nm in diameter. UV-VIS analysis indicated that TiO2 /rGO/CuInS2 thin film showed better light absorption capability with the presence of Ag2 S deposition layers. The rGO/CuInS2 quantum dot sensitized with Ag2 S layers exhibit a photovoltaic power conversion efficiency of 0.33%, which has great improvement of short circuit current (ISC) comparing with that of rGO/CuInS2 quantum dot sensitized without Ag2 S deposition layers.