Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

The influence of microstructure on the electrochromic properties of Li[sub [ital x]]WO[sub 3] thin films: Part I. Ion diffusion and electrochromic properties

Journal Article · · Journal of Materials Research; (United States)
; ; ;  [1]
  1. National Renewable Energy Laboratory, Golden, Colorado 80401-3393 (United States)
The chemical diffusion coefficients of lithium ions in Li[sub [ital x]]WO[sub 3] films were investigated as a function of lithium concentration and film porosity. Thin films were deposited with different porosities by thermal evaporation of WO[sub 3] powder in various partial water pressures. Our results indicate that diffusion coefficients increase with film porosity and decrease with increasing lithium concentration. Large diffusion coefficients which were found for small lithium concentrations appear to be due to the contribution of protons generated from ion exchange reactions between lithium and water incorporated in the film. Simultaneous electrical and [ital in] [ital situ] optical measurements were carried out to study the effect of porosity on the electrochromic properties of Li[sub [ital x]]WO[sub 3]. The coloring efficiency of porous WO[sub 3] films increases by approximately 70% when deposited in partial water pressure of 10[sup [minus]4] Torr, but decreases with further increments in water pressure.
DOE Contract Number:
AC02-83CH10093
OSTI ID:
6082725
Journal Information:
Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 8:10; ISSN JMREEE; ISSN 0884-2914
Country of Publication:
United States
Language:
English