Electrochromism in nickel oxide films

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1991

OSTI ID:7114779

Wruck, D A

Optical absorption in a thin-film nickel oxide electrode depends on the state of charge of the electrode; the effect has been called electrochromism, and it may have practical applications in low-speed light modulation devices. In this dissertation, the physical and chemical processes which lead to the change in optical properties are investigated. Preparation of NiO film electrodes by reactive sputtering of a Ni target in an Ar + O[sub 2] gas mixture is described, and the electrochromic response is correlated to film growth conditions. Structural, electronic, and electrochemical properties of the NiO films are characterized by x-ray diffraction, infrared absorption, x-ray photoemission, optical absorption, electrical conductivity, and electrochemical measurements. It is proposed that the electrochromism results from the adsorption and desorption of protons at the oxygen-rich surface of a granular and porous NiO film. The surface electronic levels are then modified by the presence or absence of the O-H bonds, and the effect on the film electronic properties is discussed. A general discussion is also given of the current-limiting processes at the NiO film electrodes.

• Research Organization: California Univ., Berkeley, CA (United States)
• OSTI ID: 7114779
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400 -- Electrochemistry
CHALCOGENIDES
CHEMISTRY
ELECTRICAL PROPERTIES
ELECTRO-OPTICAL EFFECTS
ELECTROCHEMISTRY
ELECTROCHROMISM
FILMS
NICKEL COMPOUNDS
NICKEL OXIDES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STRUCTURAL CHEMICAL ANALYSIS
THIN FILMS
TRANSITION ELEMENT COMPOUNDS