Effect of iron doping on tin oxide thin films

Abstract

In this study, Undoped tin oxide (SnO2) and iron (Fe) doped tin oxide thin films were deposited on heated glass using spray pyrolysis technique. SnCl2 and FeCl3 were used as sources of SnO2 and Fe doping respectively. Effects of dopant on the optical, structural and opto-electrical properties of 0,0.2 and 0.4 wt.% Fe-doped SnO2 thin films were investigated. Optical transmittance spectra of the thin films showed high transparency of about 80-90% in visible region. The optical gap of 0,0.2and 0.4 wt. % Fe-doped SnO2 thin films were found to be in 3.78-3.67 eV range. X-ray diffraction patterns showed that both undoped SnO2 and Fe-doped SnO2 thin films, were polycrystalline with cassiterite tetragonal crystal structure. The preferential orientation for undoped SnO2 was along (211) plane whereas Fe-doped SnO2 preferential orientations were along (110) planes. The calculated grain sizes were in 35.63- 30.03 nm average. Fe-doped SnO2 thin films are promising to be used as smart windows , gas sensor and water treatment