Effect of Iron Doping on the Mineralogical, Microstructural, Optical,
and Photoelectrochemical Properties of WO3 Thin Films
Renu Dhunna*, Pramod Koshy, and Charles Christopher Sorrell
School of Materials Science and Engineering, The University of New South Wales,
Sydney,
NSW 2052, Australia;
*Email: r.dhunna@unsw.edu.au
Tungsten trioxide (WO3) thin films (undoped and Fe-doped) were deposited by spin
coating on glass substrates coated with FTO (F-doped tin oxide). Tungsten
hexachloride and iron chloride were used as the tungsten and iron sources,
respectively, in precursor solutions containing ethanol. The effects of annealing
temperature (200°-400°C) on the mineralogical, microstructural, optical properties,
and chemical properties of the thin films were investigated using glancing angle Xray
diffraction
(GAXRD),
laser
Raman
microspectroscopy,
UV-Vis
spectrophotometry, and X-ray photoelectron spectroscopy (XPS). GAXRD results
indicated that the recrystallisation of WO3 occurred during heat treatment at 400°C
for 2 h. However, when doped with iron, the recrystallisation was observed to occur
at the lower temperature of 300ºC.
The effects of doping on the
photoelectrochemical properties of the films were assessed using a custom-made
electrochemical cell using standard reference electrodes.