Spectroscopic Ellipsometry and Optical Modelling of Structurally Colored Opaline Thin-Films

Abstract

The method of spectroscopic ellipsometry is applied to complex periodic nanomaterials, consisting of shear-ordered polymeric nanosphere composites, with intense resonant structural color. A corresponding multilayer optical quasi-model of the system, parametrizing the inherent degree of sample disorder and encompassing key properties of effective refractive-index and index-contrast, is developed to elucidate the correlation between the ∆ and Ψ ellipsometric parameters and the shear-induced opaline crystallinity. These approaches offer reliable means of in-line tracking of the sample quality of such “polymer opals” in large scale processing and applications.

Transparent Polymer Opal Thin Films with Intense UV Structural Color

“…Fabrication of the thin films is discussed further in Section 3. Polymer opals displaying visible structural color have been characterized extensively [29][30][31][32][33], with the tunability of the structural color with sphere geometry and size being particularly well documented. However, we believe our work to be among the first reports of these systems being engineered toward the ultraviolet band of the electromagnetic spectrum, thus forming the primary focus of this paper.…”