The effect of WO3 source stability on the properties of films deposited by electron beam deposition

This study investigates the impact of high temperature and vacuum on the properties of WO3 powder during electron beam deposition and evaluates the consequential effects on the as-deposited films. Therein, the grain size and the crystallinity of the source were observed to increase and become non-stoichiometric tungsten oxide (WO3−x) due to the high temperature and vacuum during the first deposition. As a result of these changes in the source, the optical band gap, Eg, of the deposited film decreased from 3.11 eV to 3.07 eV, and the absorbance was observed to increase. The coloration efficiencies of the deposited films decreased from 23 to 16 cm2 C−1. WO3-incorporated carbon nanotubes (WO3/CNT) were observed in the source after electron beam deposition if there were some initial carbon impurities in the source prior to deposition.