Growth and characterization of electrosynthesized iron selenide thin films

Iron selenide (FeSe) thin films were electrodeposited onto indium doped tin oxide coated conducting glass (ITO) substrates at various bath temperatures from 30 °C to 90 °C in an aqueous electrolytic bath containing FeSO4 and SeO2. The deposition mechanism was investigated using cyclic voltammetry. The appropriate potential region where the formation of stoichiometric iron selenide thin films' occurs was found to be −1100 mV versus SCE. X-ray diffraction studies revealed that the deposited films are found to be hexagonal structure with a preferential orientation along (002) plane. The parameters such as crystallite size, strain, dislocation density are calculated from X-ray diffraction studies. Optical absorption measurements were used to estimate the band gap value of iron selenide thin films deposited at various bath temperatures. Scanning electron microscopy (SEM) was used to study the surface morphology. The composition of FeSe thin films was analyzed using an energy dispersive analysis by X-rays (EDX) set up attached with scanning electron microscopy. Preliminary studies for photoelectrochemical solar cells based on iron selenide thin films were carried out and the experimental observations are discussed.