Anodic Composite Nanostructure: Formation, Morphology, Optical and Photoluminescent Properties

Abstract

Two-layer Al/Nb (1000/200 nm) was deposited by sputtering using a DC magnetron method on Si wafers. The anodizing was in 0.2 M oxalic solution at 53 V, re-anodized in the 0.5 M boric acid in potentiodynamic mode at increase of potential until 400 V. For forming anodic composite nanostructure, the porous anodic aluminum oxide was partially removed in 50 % aqueous solution of phosphoric acid at 50°C for 1200 s. The morphology, photoluminescence, and optical reflection of an anodic composite nanostructure were investigated. The anodic composite nanostructure showed effective optical reflection in the wavelength range from 540 to 1000 nm, and the maximum reflective efficiency was observed at a wavelength of 850 nm, 52 % reflectance occurs. The photoluminescence maximum was observed at a wavelength of 453 nm.