Simplified Route for Deposition of Binary and Ternary Bismuth Sulphide Thin Films for Solar Cell Applications

For photovoltaic applications, undoped and Ni2+ doped Bi2S3 thin films were chemically deposited onto glass substrates at room temperature. Elemental diffraction analysis confirmed the successful Ni2+ incorporation in the range of 1.0 to 2.0 at. %, while X-ray Diffraction analysis revealed that orthorhombic crystal lattice of Bi2S3 was conserved while transferring from binary to ternary phase. Scanning electron microscopy images reported homogeneous and crack-free morphology of the obtained films. Optoelectronic analysis revealed that the bandgap value was shifted from 1.7 to 1.1 eV. Ni2+ incorporation also improved the carrier concentration, leading to higher electrical conductivity. Resultant optoelectronic behavior of ternary Bi2−x NixS3 thin films suggests that doping is proved to be an effectual tool to optimize the photovoltaic response of Bi2S3 for solar cell applications.