Gold Nanocone Array with Wide Angles and High Absorptivity for Light Absorber

Nanocone arrays are promising candidates for broadband light absorption owing to their graded refractive index and multiwavelength resonance mechanisms. However, the bidirectional reflection distribution function (BRDF) and wide‐angle performance of plasmonic nanocones remain insufficiently explored. Herein, a gold nanocone array fabricated with the ion track method is reported, achieving exceptional light absorptivity (>0.98) across a wide incidence angle range (5°–75°). Combining finite‐difference time‐domain simulations and experimental BRDF measurement, it is revealed that nonspecular scattering governs the reflection behavior and exhibits excellent Lambertian properties. This study provides critical insights into the design of plasmonic absorbers for solar energy harvesting and optical sensing technologies.