Template‐Made Ultrahigh, Broadband, and Omnidirectional Light Absorption Surface for Enhanced Solar Energy Harvesting and Utilization

Abstract The practical application of solar energy harvesting urgently calls for the facile preparation of high‐performance ultrablack surfaces with broadband and omnidirectional light absorption performance; however, some roadblocks still need to meet these requirements simultaneously. Herein, cone‐array ultrablack (CAUB) surfaces are prepared by combining feasible template replication and blade coating techniques. The elaborate micro‐sized cone structure and high absorptive materials (polydimethylsiloxane@carbon black, PDMS@CB) offer the CAUB extremely high, broadband, and omnidirectional light absorption over the solar spectrum with an average absorbance of 99.35%. Under one sun irradiation, the CAUB can efficiently absorb solar energy, reaching a surface temperature as high as 75 °C. A solar‐thermal‐electric generator (STEG) made from the CAUB film demonstrates real‐time solar‐heat‐electric conversion, achieving a high output power density of 330 µW cm −2 . The CAUB film possesses excellent water repellency, flexibility, chemical solvent resistance, and potential for large‐scale production, satisfying the application requirements of solar energy harvesting and utilization.