One-step fabrication of ultra-wideband TiAlN light absorber coating by magnetron sputtering

Abstract

It is challenging to produce ultra-wideband light absorber coatings by a cost-effective one-step route for numerous industrial applications, like solar energy harvesting, stealth technology, thermal regulation, stray light suppression, etc. Nanostructured refractory materials possess excellent characteristics, can completely absorb incident photons in the subwavelength range, and are durable in adverse environments. This work presents a novel dc magnetron sputtering approach to fabricate large-area single-layered TiAlN-based nearly perfect black absorber coatings. The manipulation of incident photons in the absorber coatings is attributed to their vertical columnar nanostructure, where light is randomized and absorbed. The substrate-independent coatings revealed low emissivity and optimum absorption of almost 99.5% in the visible wavelength range. In contrast, the single-layered near-perfect black absorber showed absorption of 91% in the broad wavelength range (250–2500 nm), which further improved to 97% on depositing an anti-reflecting coating over the absorber layer. The wideband absorption achieved in this work is higher than any other reported work on sputtering-based absorber coatings. Moreover, the fabricated sputtering-based blackbody absorbers with integrated nanophotonic structures have the potential to withstand adverse environments, which testify to their practical applications.