Issei Mizuki

Photoluminescence of Anodic Oxide Films on Aluminium

A wide variety of anodic oxide films were investigated from the photoluminescent point of view. It was found that the phenomenon of photoluminescence appears only on the films anodically formed in organic acids instead of inorganic acids. In particular, thick oxalic acid films formed in low electrolyte concentration, with high current densities on high purity aluminium, gave intense photoluminescence. The luminescent centres were presumed to be the carboxylate ions which had been incorporated in the films during anodisation.

Yellow Electroluminescence from Al–Al2O3: Mn-Electrolyte System during Anodization of Al–Mn(1%) Alloy

Yellow electroluminescence during the anodization of an Al–Mn(1%) alloy in certain electrolytes has a peak at about 560 nm, and the optimum content of Mn as activator is ca. 1%. Electrolytes of the barrier forming type, such as ammonium borate of 0.1 mol, and 2000 HizAC formation are suitable for obtaining intensive EL. Thin Al2O3: Mn phosphors can be formed by the anodization of Al–Mn(1%) alloys, and yellow EL occurs due to the collision-excitation of Mn activators by injected electrons from the oxide-electrolyte interface.

Transparentization of Tunnel-Etched Al Foil by Anodic Oxidation

The transparentization of etched Al foil was achieved by anodic oxidation in acid solution. The anodization under a low-voltage condition in chromic acid electrolyte contributed to a decrease in the amount of residual Al and generated a transparent porous material in the visible-wavelength region. The obtained transparent porous foil can be used for the preparation of several functional optical devices that require a transparent porous substrate with a large surface area.

YELLOW ELECTROLUMINESCENCE FROM ANODIC Al2O3:Mn FILMS FORMED ON Al-Mn ALLOY

The electroluminescenct device was fabricated using an Al/Al2O3 :Mn film/ITO system in which the Al2O3:Mn phosphor layer was formed by anodization of Al-Mn (1.2%) alloy in a chromic acid electrolytic solution. The device emitted yellow electroluminescence under DC high electric field of 105 v/cm.