Effect of molybdenum doping on the electrochromic properties of tungsten oxide thin films by RF magnetron sputtering

• Published in: Ionics 2014-12, Vol.20 (12), p.1737-1745
• Main Authors: Madhavi, V., Kumar, P. Jeevan, Kondaiah, P., Hussain, O. M., Uthanna, S.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Energy Storage; Optical and Electronic Materials; Original Paper; Renewable and Green Energy
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-014-1073-8

Thin films of pure and molybdenum (Mo)-doped tungsten trioxide (WO 3 ) were deposited on indium tin oxide (ITO)-coated glass and Corning glass substrates by RF magnetron sputtering technique. The effect of Mo doping on the structural, morphological, optical and electrochromic properties of WO 3 films was studied systematically. The energy dispersive X-ray analysis (EDAX) revealed that the films consist of molybdenum concentrations from 0 to 2 at.%. X-ray diffraction (XRD) studies indicated that with the increase of Mo concentration the structural phase transformation takes place from polycrystalline to amorphous phase. The crystallite size of the films decreased from 24 to 12 nm with increase of doping concentration of Mo in WO 3 . Scanning electron microscope (SEM) analysis revealed that Mo dopant led to significant changes in the surface morphology of the films. The electrochemical and electrochromic performance of the pure and Mo-doped WO 3 were studied. The WO 3 films formed with 1.3 at.% Mo dopant concentration exhibited high optical modulation of 44.3 % and coloration efficiency of 42.5 cm 2 /C.