Fabrication of Ag injection in Bi₂S₃ (AgBiS₂) thin films for photoelectrochemical cell applications

The present investigation deals with the detailed analysis of opto-structural, morphological, electrical properties and photoelectrochemical cell performances of thermally evaporated Ag_xBi_2−xS_3−y thin film prepared for various x and y values (x = y = 0, 0.25, 0.50, 0.75 and 1). The cubic-structured AgBiS₂ along with orthorhombic-structured Bi₂S₃ as confirmed from X-ray diffraction (XRD) analysis. The Ag_xBi_2−xS_3−y (x = y = 0–1) films showed higher optical absorption coefficient (10⁵ cm⁻¹) in the visible region and band gap values were found to be decreased from 2.08 to 1.35 eV. Scanning electron microscope (SEM) images have visualized the uniform distribution of spherical particles. Carrier concentration of the films are better than x = y = 0 as observed from Mott–Schottky plots. The FTO/Ag_xBi_2−xS_3−y (x = y = 1) photoelectrochemical cell yields the photoconversion efficiency (PCE) of 7.03%.