Solar cell prototypes combining TiO2 and electrodeposited CuInS2

Y. DI IORIO; M. BERRUET; M. VAZQUEZ

Rio de Janeiro

Congreso; XIV Brazilian Materials Research Society Meeting; 2015

SBPMAT

The aim of this work is to prepare np junctions suitable for solar energy conversion using exclusively low-cost techniques, such as electrodeposition and spray pyrolysis. Both have common features: are cost-effective, do not require high vacuum, can be implemented on top of a wide variety of substrates and are suitable for industrial production.TiO2 and CuInS2 (CIS) are used as n and p-type semiconductor respectively. These layers are combined in superstrate configuration on conducting glass substrates (FTO).Spray deposition is used to deposit a thin film of TiO21. CIS was electrodeposited at pH 8, room temperature and at constant potential in a three electrode electrochemical cell2.The morphology, thickness, crystalline structure and chemical composition of FTO/TiO2/CIS were analyzed by SEM, XRD, Raman spectroscopy and EDX. The energy gap (Eg) was evaluated from UV -Vis spectra. Current-Voltage curves were performed in the dark and under illumination with a solar simulator in order to analyze the response and efficiency of the photovoltaic cell.Preliminary solar cell prototypes show a clear photo-response, although the open circuit potential is still low. Current studies are focused on introducing a buffer layer of In2S3 prepared by spray pyrolysis. These results are taken as a starting point, from which conversion efficiency might be increased by fine-tuning some of the multiple variables involved.