Dandelion-Like Carbon Nanotubes for Near-Perfect Black Surfaces

A variety of complex and expensive techniques, which usually work efficiently in the visible range only, have been developed to make a near-perfect blackbody. In this work, novel hierarchical dandelion-like flower carbon nanostructure (FCNTs) are synthesized by using a two-step growth protocol. FCNTs show near-perfect absorption of ≥99.9% in the wavelength range of 300–2000 nm at varying beam angles (10° to 60°). Coupled with the emissivity of 0.98, FCNTs are qualified as one of the darkest artificial materials. The observed behavior originates from multiple scattering and subsequent trapping of incident beam inside the FCNT microstructure. The contact angle (172°) and roll-off angle (2°) of water droplets reveal the superhydrophobic and self-cleaning behavior of the fabricated surface. The combination of properties demonstrated by FCNTs are envisaged to be a significant step toward developing better materials for stray light absorption and a light trapping layer in a photovoltaic system.