Ultrablack films with mechanical stability and weather resistance prepared by ion-source-assisted deposition

Ultrablack materials have excellent light absorption properties and are widely used in modern scientific and technological fields such as precision optics, aerospace, energy, and biomedicine. Current methods, such as sol-gel methods and nanoimprint lithography, can achieve high uniformity and nanostructure control of thin film materials, but the preparation process is complex, involving high-purity precursors and a variety of chemical materials. Additionally, the prepared materials have issues with mechanical stability and weather resistance. Here, this study proposes the use of ion-source-assisted deposition (IAD) to prepare <i>N</i><i>b</i><i>O</i><i>x</i> multilayer ultrablack films with high light absorption and environmental stability. The composite structure of the multilayer ultrablack film consists of a <i>N</i><i>b</i><i>O</i><i>x</i> absorption layer and a multilayer anti-reflective film. This film by IAD at 300°C exhibits an average reflectance of 0.68% and an absorption rate of 99.29% in the spectral range of 400-1000 nm. While the average reflectance is 0.75% and absorption is 99.07% at room temperature. In comparison, the films prepared under 300°C are more suitable for high-temperature resistant substrates, and the room temperature deposition is more suitable for non-high-temperature resistant substrates. Moreover, the <i>N</i><i>b</i><i>O</i><i>x</i> ultrablack absorbing film also exhibits excellent mechanical stability and weather resistance and successfully passes reliability testing, including grid testing, abrasion resistance testing, and water boiling testing, which are required for industrial applications. This study offers a viable solution for the low-cost and large-scale industrial application of ultrablack thin films, with 99.29% absorption rate and 0.68% reflectivity.