Luminescent Imaging on the Basis of Porous Anodic Alumina

Luminescence of Lanthanides from Xerogels Embedded in Mesoporous Matrices

“…High-transparency of anodic alumina oxide on the one hand and strong optical anisotropy on the other hand may be the reasons of growing interest to exploit this material as a cage for light-emitting species. Filling the channels of the pores of anodic alumina films with silica [36][37][38], titania [23,[39][40][41][42], alumina [43][44][45] xerogels doped with lanthanide ions Er [37][38][39], Tb [23,38,44] and Eu [35,[40][41][42]45], organic dyes [46], semiconductor nanocrystals [47,48], polymers [ 49,50], quantum dots [51,52], and biological samples [53] was investigated, and strong luminescence of optically active species incorporated in voids of anodic alumina or, probably, in its walls [54,55] was reported.…”

“…However, deposition of the sols and even suspension of semiconductive nanoparticles [56] or quantum dots [52] by spinning promotes their penetration deep into the pore volume even if the channels of the pores are opened from the top only, like for the PAA films fabricated on aluminium, silicon, quartz, or other substrates.…”

“…Some PAA samples fabricated in oxalic acid exhibit blue PL visible to the naked eye with a strong band at about 450 nm [52,[62][63][64]. The origin of the blue PL from PAA grown in oxalic acid is associated with generation of F-centres during anodizing of aluminium or excitation of residual chemical components absorbed from the electrolytes.…”