Electrodeposition and characterization of Fe doped CdSe thin films from aqueous solution

摘要

Thin films of Cadmium selenide (CdSe) and Ferrous (Fe) doped Cadmium selenide (CdSe:Fe) have been deposited on indium doped tin oxide coated conducting glass (ITO) substrates using potentiostatic electrodeposition technique.The mechanism of formation of CdSe and CdSe:Fe have been analyzed in the potential range between -1500 and +1500mV versus SCE. X-ray diffraction pattern reveals that the deposited films possess hexagonal structure with preferential orientation along (002) plane. The dependency of microstructural parameters such as crystallite size, strain and dislocation density with FeSO_4 concentration for CdSe:Fe thin films are studied. Surface morphology and film composition shows that films with smooth surface and well defined stoichiometry is obtained at 0.01 M dopant (FeSO_4) concentration. Optical parameters such as band gap, refractive index and extinction coefficient for CdSe and CdSe:Fe thin films are estimated using optical absorption measurements. Photoelectrochemical solar cells are constructed using CdSe and CdSe:Fe as photocathode in 1 M each of Na_2S, S and NaOH as redox electrolyte and their power output characteristics are studied.