Design and Fabrication of a Cone Array Absorber with Ultra‐High Light Absorptance for Solar Energy Utilization

Abstract Efficient utilization of solar energy urgently demands high‐performance light‐absorbing materials. Constructing surface light‐trapping cavity structures can significantly enhance light absorption. However, fabricating high‐precision periodic cavity structures through a simple, scalable method remains challenging. Herein, a novel ultrahigh‐absorption periodic cone array absorber is designed and fabricated using a template replication method. This study pioneers the application of computer numerical control (CNC) drilling technology for fabricating high‐absorption material templates, enabling precise control over macrocavity geometric parameters. Benefiting from the cone macrocavity structure and the integration of high‐absorption absorbents, the cone array absorber exhibits an ultrahigh integral absorptance of 99.58% within the 400–2000 nm wavelength range. Under one‐sun solar irradiation, the absorber effectively absorbs solar energy, achieving a photothermal conversion efficiency of 85.13%. The solar‐thermal‐electric generation (STEG) system based on this absorber demonstrates a high output power density of 480 µW cm ⁻² . The cone array absorber also exhibits exceptional flexibility, chemical stability, and thermal shock resistance. This work provides a straightforward and scalable approach to manufacturing high‐performance light absorbers for efficient solar energy harvesting and utilization.