Photoelectrochemical performances of AgInS2 film electrodes fabricated using the sulfurization of Ag–In metal precursors

Ternary silver-indium-sulfide samples were deposited on various substrates using the sulfurization of Ag–In metal precursors. A new procedure for the deposition of AgInS2 samples is reported. The effect of the [Ag]/[In] molar ratio in metal precursors on the structural, morphological, and photoelectrochemical properties of the samples was examined. X-ray diffraction patterns of samples show that the films are in the polycrystalline AgInS2 phase. The thickness and direct band gap of the films were in the ranges of 1.1–1.2 μm and 1.92–1.94 eV, respectively. The conduction type of all samples was n-type. The carrier concentration, mobility, and resistivity of samples were in the ranges of 1.5×1013–7.0×1013 cm−3, 2.6–14.8 cm2V−1s−1, and 2.6×104–3.5×104 Ωcm, respectively. It was found that the samples with an [Ag]/[In] molar ratio of 0.89 in Ag–In metal precursors had a maximum photo-enhancement current density of 2.43 mAcm−2 at an applied bias of +0.5 V vs. an Ag/AgCl electrode in contact with electrolyte containing 0.5 M K2SO4. The results show that high-quality AgInS2 films can be obtained using the sulfurization of Ag–In metal precursors for photoelectrochemical (PEC) applications.