Hierarchical Pyramid‐Array‐Based Robust Superblack Sheets With Excellent Mechanical Durability for Broadband and Wide‐Angle Absorption

ABSTRACT Ultrablack materials with high absorption have emerged as fundamentally crucial absorption layers for stray light suppression. Despite significant advances, large‐scale production of blackbody sheets with periodic array architectures and excellent mechanical durability over broadband and large angles still remained great challenges in state‐of‐the‐art light‐absorbing materials. Rational light‐trapping structure design was essential to reduce reflectance. Here, we proposed a simple two‐step procedure of micromachining and replica moulding, verified by theoretical simulation, to fabricate robust superblack materials. The resultant ultrablack showed periodic micro‐pyramid arrays with precise nanoscale structures. The vertically aligned micro‐pyramids enabled multiple internal light reflection which significantly exceeded the wavelength of interest endowed the low‐reflection properties over broad wavelengths. Furthermore carbon black nanoparticles achieved reduced backscattering. Meanwhile, nanometrically features of pyramids hindered diffuse photon escape effectively. The hemispherical reflectance below 0.004 of hierarchical black sheets was achieved. The sheets maintained high resilience modulus and exceptional mechanical endurance. ‌This preparation method was applied to fabricate a barrel shading hood of lens from epoxy resin composites. Integration of this method with a roll‐to‐roll process made industrial‐scale production possible, indicating their application potential. This work provided a novel perspective for robust ultrablack sheets with highly effective absorption, ‌large‐scale preparation, and excellent ‌abrasion resistance.