Optical and structural properties of sol-gel derived materials embedded in porous anodic alumina

Structures comprising a xerogel, doped with lanthanide ions (erbium, terbium and europium), embedded in porous anodic alumina (PAA) have been fabricated and their optical and electrical characteristics have been studied. Erbium photoluminescence at 1.53 μm from titania xerogel/PAA was found to increase with the number of xerogel layers and erbium concentration for the excitation wavelength 532 nm, matching the area of transparency of both titania xerogel and PAA. Visible green and red electroluminescence was observed for terbium- and europium-doped In2O3 and SnO2 xerogels embedded in porous anodic alumina. The improvement of the electrical properties of the xerogel/PAA cell is discussed, taking into account the observed ability of conducting In2O3:Sn (ITO) nanoparticles to penetrate into the anodic alumina pores.