Spectroscopic characteristics of doped nanoporous aluminum oxide

In this work, we present photoluminescence characterization of rare earth ion doped nanoporous aluminum oxide synthesized by anodization process in different aqueous electrolyte solutions. We found that the luminescence of doped aluminum oxide strongly depends on the synthesis medium. When synthesized in inorganic acid only rare earth ions fluorescence is present, whereas nanoporous aluminum oxide synthesized in organic solvent presents two strong unexpected luminescence emission lines, one at 429 nm and the other at 491 nm, with quite long decay time when excited with long wavelength ultraviolet light. Theses results suggest that light simulation of primary colors and chromaticity control of the emitted light can be achieved by carefully doping aluminum oxide nanoporous with a combination of different rare earth ions.