Thin films of polycrystalline AgInS2 were deposited on indium-tin oxide glass substrates by chemical bath deposition process. Various dipping cycles (1, 2, 3, 4 and 5) were taken into consideration. The influence of dipping cycle on structural, optical, electrical and photoelectrochemical characteristics of the AgInS2 thin films were investigated. The X-ray diffraction patterns indicated that all the samples revealed single phase of orthorhombic AgInS2 with polycrystalline structure. The thickness of samples in a range of 0.82-2.67 μm analyzed by α-step instrument. The optical band gap of all AgInS2 films were 1.94 eV calculated by transmittance spectra, respectively. All the samples revealed n-type semiconductor behaviors by Hall measurement. The carrier concentrations, mobility and resistivity of the AgInS2 films at room temperature were in the range of 1012-1015 cm-3, 1.9-15 cm 2 V-1 s-1 and 103-105 Ω cm, respectively. We found that the dipping 3 cycles AgInS2 film had a better photoelectrochemical performance with photocurrent density of 3.50 mA/cm2 bias 0.5 V vs. SCE reference electrode under a 300 W Xe lamp illumination with the intensity of 100 mW/cm2. This value was about 3 times higher than the dipping 5 cycles AgInS2 film. Observed higher photocurrent density was likely due to a suitable thickness, higher carrier mobility and lower charge transfer resistance.
- Chemical bath deposition
- Water splitting