Facile one-step nanoporous alumina for modifying the surface optical properties of ITO glass

Abstract

Structure color is a useful technique with good brightness, variuos color, and friendly environmental properties, compared with the dyes and pigments colors. However, the structure colors are based on the micro- or nano structures, which is still a challenge for fabricating the desired colors. Anodic aluminum oxide (AAO) is a common nanomaterial for fabricating the structure colors because of the properties of hardness, stability, and the self-assembly. However, current techniques mostly manufactured the structure color on the aluminum foils or the alloy, which limited these techniques from the glass-based applications. Additionally, current technologies usually require a time-consuming fabrication process lasting several tens of hours. In this study, a facile method is proposed for producing structure colors on transparent ITO glass through AAO coating with a short fabrication time. The vibrant structure colors result from constructive interference of visible light due to the nanoporous AAO film on the ITO glass substrate. Furthermore, a correlation between the anodization time of AAO and color is established, enabling the prediction of anodization time to achieve the desired color without resorting to a trial-and-error approach. A spectrum of colors within the visible light range, spanning wavelengths from 420 to 740 nm, is successfully demonstrated on the ITO glass using this uncomplicated one-step anodization process.