Selenic acid anodizing of aluminium for preparation of 1D photonic crystals

Anodizing of aluminium under oscillating conditions is a reproducible, scalable, and low-cost method for the preparation of one-dimensional photonic crystals with photonic band gaps in the visible and near-infrared regions. For this purpose, sulfuric and oxalic acid electrolytes are used, because in such baths transparent anodic alumina films are formed. In the present study, selenic acid electrolyte is utilized for the fabrication of anodic alumina photonic crystals for the first time. The choice of a rational range of voltage/current modulation is performed on the basis of linear voltammetry. The dispersion of the effective refractive index and the porosity of prepared photonic crystals are measured. High transmittance of the anodic alumina obtained in selenic acid electrolyte makes this bath promising for the preparation of 1D photonic crystals with photonic band gaps from the ultraviolet to infrared regions. Keywords: Selenic acid, Anodization, Anodic alumina, One-dimensional photonic crystal, Q-factor, Refractive inde