Eu⁺イオン注入陽極アルミナ発光素子のEL強度への結晶形態の影響

抄録

It is known that an anodic oxide film on aluminum shows a weak electroluminescence (EL) characteristic during anodization in a sulfuric acid solution or in an oxalic acid solution. Anodic alumina films doped with Mn or Tb show a strong yellow or green EL, respectively.
Next, the application of ion doped alumina films to a solid-state EL device with rare earth (RE) supported by the barrier type anodic alumina films was investigated, because anodic alumina films implanted with RE show continuous and uniform luminescence. The rare earth metals are implanted into the barrier type anodic aluminum oxide film by an ion accelerator. The red luminescence of Eu³⁺ can especially be confirmed if Eu⁺ was implanted.
The influence of the crystalline structures of Eu⁺ implanted alumina on the emission intensity was investigated. Three kinds of structures α, γ and γ'-alumina were selectively produced by adjusting process parameters at the anodization of aluminum.
As a result, the specimen of γ'-alumina showed the strongest EL intensity among them. It can be expected that a higher intensity and longer life EL device will be obtained by the combination of γ'-alumina films and ion implanted RE metals.