Open AccessStudy on electrochromic performances of amorphous WO3 films
Author(s) -
Dai Fu-Ping,
Shiqi Lu,
Bin Feng,
Jiang Shengrui,
Chong Chen
Publication year - 2003
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.52.1003
Subject(s) - electrochromism , materials science , amorphous solid , tungsten , partial pressure , sputtering , transmittance , electrochromic devices , oxygen , analytical chemistry (journal) , annealing (glass) , diffraction , ion , thin film , chemical engineering , electrode , composite material , nanotechnology , optoelectronics , optics , crystallography , metallurgy , chemistry , physics , organic chemistry , chromatography , engineering
A series of WO3 films are prepared by rf-sputtering under different partial pressures of oxygen. It is found that the films with oxygen partial pressure ratio 1∶10 have better electrochronic(EC) properties than others. Microstructural and compositional characteristics of WO3 films are studied by x-ray diffraction, atomic force microscopy and x-ray photo electro spectroscopy. It is obvious that the samples are amorphous and have more pores that are beneficial for Li+ to inject and eject. The original-state films are composed of tungsten and oxygen. After electrochemical reactions the main component becomes LixWO3 in which tungsten ions normally exhibit both W6+ and W5+ oxidation states. The films are annealed in air at 230 and 400℃ for 90 min. The cyclic voltammograms and optical transmittance show that the films annealed at 400℃ after more than 10 cycles present better EC properties.