Hot-wire Chemical Vapor Deposition of WO{sub}3 and MoO{sub}3 Nanoparticles and the Performance of Nanostructured WO{sub}3 Electrochromic Films

摘要

High-density crystalline WO{sub}3 nanoparticle bulk synthesis using a simple hot-wire chemical vapor deposition (HWCVD) technique has been previously demonstrated. Recent efforts have been focused on incorporation of WO{sub}3 nanoparticles into a thin film to determine its electrochromic (EC) performance. Compared to state-of-the-art amorphous films, nanostructured WO{sub}3 films show greater charge density for proton intercalation. Optical measurements indicate coloration efficiency (CE) values comparable to amorphous films and significantly better than crystalline films. New data also suggest enhancement in the EC performance for more sub-stoichiometric nanostructured WO{sub}3 films. Finally, we have also employed HWCVD technique for MoO{sub}3 nanoparticle synthesis. Depending on synthesis conditions, nanospheroids having diameters between~5-20nm and nanorods having diameters between~20-50nm and lengths between~100-400nm are obtained as indicated by transmission electron microscopy (TEM). Raman spectroscopy revealed the nanoparticles are highly crystalline α-phase MoO{sub}3.