A Flexible, Wear-Resistant, Ultrablack Coating Modified by an Antireflective Layer Prepared with a Dry-Wet Hybrid...

The development of ultrablack coatings with exceptional absorption (>98%) has historically faced significant scientific and engineering challenges, primarily due to limitations in material selection, structural design, and practical durability. Considering the difficulties in practical applications of ultrablack materials with micro/nano structures and the limitations of planar ultrablack coatings in optical performance, we introduce an innovative integration of conventional planar ultrablack coatings with a specifically engineered trilayer antireflection architecture. This hybrid system incorporates a refractive index distribution (1.6-1.8-1.3 from substrate to air interface) achieved through a "dry-wet hybrid" deposition methodology. This coating exhibits outstanding optical performance, achieving 99.1% average visible-light absorption and peak absorption reaching 99.9%, which is in excellent agreement with theoretical simulations. The hybrid fabrication strategy offers dual advantages: it maintains antireflection performance comparable to vacuum-deposited coatings while significantly enhancing mechanical robustness. After 20,000 bending cycles, the coating retains optical stability with less than 1% performance degradation, showing no delamination or microcracking. A subsequent SiO₂ chemical vapor deposition (5 nm) further improves surface durability, limiting optical loss to less than 0.5% while achieving tribological properties on par with those of commercial antireflective films. In addition, it also exhibits a remarkable ability to convert light into heat and is resistant to high temperatures and acid erosion. This breakthrough combines unparalleled optical performance with excellent mechanical properties, demonstrating substantial potential for advanced optical applications such as stray light suppression and photothermal conversion. The dry-wet hybrid approach establishes a paradigm for developing multifunctional optical coatings that surpass traditional single performance.