Effect of humidity on structure and electrochromic properties of sol-gel-derived tungsten oxide films
IR@NPL: CSIR-National Physical Laboratory, New Delhi
View Archive InfoField | Value | |
Title |
Effect of humidity on structure and electrochromic properties of sol-gel-derived tungsten oxide films
|
|
Creator |
Deepa, M
Singh, P. Sharma, S. N. Agnihotry, S. A. |
|
Subject |
Energy Fuels
Materials Science Applied Physics/Condensed Matter |
|
Description |
The influence of varying relative humidity (RH similar to 55 and 75%) during thin film deposition from an oxalato-acetylated peroxotungstic acid sol by dip coating, on the microstructure and electrochromic properties of pristine tungsten oxide (WO3) films obtained upon annealing is presented. The films fabricated under a relative humidity of 55% are amorphous whereas the ones cast under a substantially humid atmosphere (RH similar to 75%) are characterized by interconnected nanocrystallites with a triclinic phase and a nanoporous surface morphology as well. Upon lithium insertion, larger integrated values of transmission modulation and coloration efficiency are observed over the photopic and solar regions, for the films prepared under a RH-75% as compared to that observed for the films deposited under a RH of 55%. Functional improvements are due to the larger surface area of nanocrystallites and a porous microstructure, a consequence of a higher degree of hydration and hydroxylation in the former films in contrast to the non-porous and a rather featureless structure of the latter films. Faster switching kinetics between the clear and blue states, a greater current density for lithium intercalation, a higher diffusion coefficient for lithium and a superior cycling stability, again shown by the film fabricated under a 75% RH confirm that the WO3 film microstructure is most conducive for a more facile ion insertion-extraction process, which hints at its potential for electrochromic window applications.
|
|
Publisher |
Elsevier
|
|
Date |
2006
|
|
Type |
Article
PeerReviewed |
|
Format |
application/pdf
|
|
Identifier |
http://npl.csircentral.net/2458/1/45.pdf
Deepa, M and Singh, P. and Sharma, S. N. and Agnihotry, S. A. (2006) Effect of humidity on structure and electrochromic properties of sol-gel-derived tungsten oxide films. Solar Energy Materials and Solar Cells, 90 (16). pp. 2665-2682. ISSN 0927-0248 |
|
Relation |
http://npl.csircentral.net/2458/
|
|