Integrated synthesis and comprehensive characterization of TiO2/AgBi2S3 ternary thin films via SILAR method

Abstract

AgBi2S3, a copious and innocuous ternary metal chalcogenide affiliated with the I-V-IV group of semiconductors, was synthesized. With an energy gap of 1.2eV, it closely matches the optimal 1.39eV for solar cell absorbers. Importantly, this chalcogenide exhibits a high absorption coefficient of 105 cm−1 at 600 nm. Using the successive ionic layer adsorption and reaction (SILAR) method; we deposited an AgBi2S3 thin film onto a titanium dioxide (TiO2) thin film. Characterization techniques encompassed XRD, SEM, EDXS, UV–Vis, EIS, and PEC performance analyses. The resulting TiO2/AgBi2S3 composite film ranged in thickness from 8 μm to 13 μm, with particle sizes spanning 20 nm–265 nm. Notably, the deposition of AgBi2S3 onto the TiO2 film caused depreciation in the TiO2 energy gap from 3.1eV to 1.7eV. Furthermore, it significantly enhanced the TiO2 film's absorbance across the visible and near-infrared regions. Intriguingly, the TiO2/AgBi2S3 composite film also exhibited discernible photoelectrochemical behavior.

Keywords

• Ternary metal chalcogenide
• SILAR
• AgBi2S3
• UV visible spectroscopy
• Optical energy band gap
• Electrochemical impedance spectroscopy