Self-assembled nanostructures using anodized alumina thin films for optoelectronic applications

Anodized aluminum has recently attracted much attention because of its desirable porous structure. The pore structure is a self-ordered hexagonal array of cells with cylindrical pores in an alumina matrix of variable sizes with diameters of 25 to 300 nm with depths exceeding 100 μm depending on the anodizing conditions used. These properties make anodized aluminum a desirable material for many optoelectronic devices including polarizers, photonic crystals, low threshold current lasers, and investigation of light-surface plasmon interactions in metals. The conventional approach to fabricate porous alumina is to use bulk or thin sheets of aluminum and then replicate this pattern into the desired substrate by one of several methods involving a tedious film transfer. However, in this work, a more convenient and practical method of fabricating the porous alumina structure using an evaporated film of aluminum on silicon and other substrates, subsequent pattern transfer, and its use in optoelectronic applications will be discussed