Effect of surface states of WO3 on the operating characteristics of thin film electrochromic devices
| Autor: | Tetsuzo Yoshimura, Masaki Watanabe, Yoshio Koike, Tanaka Masao, Kohei Kiyota |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Materials science
business.industry Metals and Alloys Oxide Surfaces and Interfaces Semiconductor device Electrochromic devices Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound Adsorption chemistry Depletion region Electrochromism Materials Chemistry Optoelectronics Thin film business Surface states |
| Zdroj: | Thin Solid Films. 101:141-151 |
| ISSN: | 0040-6090 |
| DOI: | 10.1016/0040-6090(83)90266-3 |
| Popis: | The effect of gas adsorption at the WO 3 -MgF 2 interface on the operating characteristics of a thin film electrochromic device consisting of WO 3 and MgF 2 were investigated, and the results were discussed from the viewpoint of surface states of the WO 3 film. As a result of gas adsorption the coloration speed and efficiency are increased, the threshold characteristics for coloration become sharp, the open- circuit memory becomes long and the leak current is reduced. These effects were obvious only when the adsorption was performed at the WO 3 -MgF 2 interface and water adsorption is essential to the effects. The film thickness dependence of the conductivity of as-grown WO 3 film revealed that the depletion layer of WO 3 , whose thickness is about 5000 A in vacuum, vanishes when MgF 2 film is deposited onto it. We concluded that the effect of gas adsorption can be attributed to the surface states and the depletion layer induced by the surface states of WO 3 . Using the analogy of a metal/oxide/semiconductor device, we proposed an energy band model for electrochromic devices which can explain the effects of gas adsorption systematically. |
| Databáze: | OpenAIRE |
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