Photoluminescence properties of heat-treated porous alumina films formed in oxalic acid
Abstract
Photoluminescence and optical properties of as-anodized and heat-treated at 500°C porous alumina films formed in a 0.3M oxalic acid at 40V have been studied. The FTIR indicates that the oxalate ions are embedded in the anodic alumina as chelating bidentate structures and further heating up to 500°C does not cause any change in ion coordination. The results of time-resolved spectroscopy show the presence of two luminescence centers both in the as-anodized and heat-treated anodic alumina films with lifetimes of about 0.25 and 4.0ns. The F+-centers in anodic alumina are responsible for the luminescence peak at about 420nm, with a lifetime of about 4.0ns. The luminescence peak at about 480nm, with lifetime of about 0.25ns, can be attributed to the luminescence of carboxylate ions existing in bulk of anodic alumina.
- Publication:
-
Journal of Luminescence
- Pub Date:
- May 2011
- DOI:
- 10.1016/j.jlumin.2010.12.027
- Bibcode:
- 2011JLum..131..938V
- Keywords:
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- Porous alumina;
- Photoluminescence spectroscopy;
- Fourier transform infrared spectroscopy (FTIR);
- Lifetime of luminescence centers