Characterization of CuInS2 thin films prepared by chemical bath deposition and their implementation in a solar cell

•CuInS2 films were formed by chemical bath deposition followed by a heat treatment.•Prepared CuInS2 thin films can work as an effective absorbing layer in a solar cell.•A complete solar cell structure was made by a chemical bath deposition method.

CuInS2 thin films were formed by the sequential deposition of In2S3–CuS layers on glass substrates, by chemical bath deposition technique, and heating these multilayer 1 h at 350 °C and 400 mPa. The morphology and thickness of the CuInS2 thin films were analysed by scanning electron microscopy, showing particles with elongated shape and length about 40 nm, and thickness of 267 and 348 nm for samples from 15 and 24 h of deposition time in the chemical bath of In2S3, respectively. The energy band gap values of the films were around 1.4 eV, whereas the electrical conductivity showed values from 64.91 to 4.11 × 10− 3 Ω− 1 cm− 1 for the samples of 15 and 24 h of In2S3 deposition bath, respectively. The obtained CuInS2 films showed appropriate values for their application as an absorbing layer in photovoltaic structures of the type: glass/SnO2:F/CdS/Sb2S3/CuInS2/PbS/C/Ag. The whole structure was obtained through chemical bath deposition technique. The solar cell corresponding to 15 h of In2S3 deposition duration bath showed energy-conversion efficiency (η) of 0.53% with open circuit voltage (Voc) of 530 mV, short circuit current density (Jsc) of 2.43 mA cm− 2, and fill factor (FF) of 0.41. In the case of the structure with 24 h of deposition of In2S3 bath, η = 0.43% was measured with the following parameters: Voc = 330 mV, Jsc = 4.78 mA cm− 2 and FF = 0.27.