Abstract
Ag2S thin films have been deposited onto fluorinated tin oxide (FTO)-coated conducting glass substratesusing chemical bath deposition (CBD) method. Photoelectrochemical (PEC) cell, optical properties, surface morphology, structural properties, compositional analysis and electrical properties of Ag-2 thin films have been investigated. The PEC measurements indicate that the deposited Ag2S layers are n-type in electrical conduction. The transmittance of deposited layer is obtained to be about 13-87%. The absorbance of the films is found to decrease with increasing wavelength. The bandgap of the Ag2S thin film is estimated to be 1.8 eV. It is observed from scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements that the substrates are well-covered with the deposited Ag2S layers without cracks and pin holes. The grain size of Ag2S thin films is estimated from SEM measurements to be in the range 100-210 nm. The mean roughness of Ag2S films is found from AFM measurements to be in the range 7.20-15nm. X-ray diffraction shows that the films are well-crystallized and the deposited layers are mainly consisting of Ag2S phase with (-103) preferential plane. EDX analysis shows that an early stoichiometric composition of Ag2S is obtained. The resistivity is estimated to be in the range 3.5-7.0 Omega-cm.