Optoelectronic, structural and morphological analysis of Cu3BiS3 sulfosalt thin films

Abstract

Sulfosalts are well known naturally occurring mineral species since the surprise mineralogy and are well reported for a variety of applications including photovoltaics. In the current study Cu3BiS3 (wittichinite mineral), a member of the sulfosalt family was crystallized by a simplified route through chemical bath deposition. To elaborate the experimental design and deposition mechanism and for the sake of comparison, Bi2S3 thin films were also deposited. X-Ray Diffraction, Scanning Electron Microscopy, Atomic Force Microscopy, UV–Vis Spectroscopy, and the Hall effect were used to explore the structural, morphological, and optoelectronic behaviour of synthesized materials in the form of thin films. The thickness of the films was measured by ellipsometry. XRD analysis confirmed the Bi2S3 for the first bath, while for the rest of the films Cu3BiS3 phase emerged. Optical bandgap values of 1.0 eV and 1.25 eV were achieved for Bi2S3 and Cu3BiS3 thin films respectively. Results revealed that Cu3BiS3 thin films deposited for 6 h at room temperature demonstrated Hall mobility of 34.9 cm2 v−1 s−1, the charge carrier concentration of 6.07 × 1016 cm−3 and 7.22 O-cm resistivity with the thickness of 126 nm, hence validating the potential of synthesized materials for photovoltaic applications.