Gold nanocone array with wide angles and high absorptivity for light absorber

The gold nanocone array, fabricated with the ion track method, exhibits exceptionally high light absorptivity, making it a wide angle light absorber. The finite difference time domain (FDTD) method was employed to study the influence of the geometric parameters on total absorptivity and promote strategies to enhance the absorptivity of the gold nanocone array. Experimental measurements were concluded to assess the total absorption and bidirectional reflection distribution function (BRDF) properties of the gold nanocone array. The absorptivity measurement results demonstrate that the gold nanocone array exhibits a wide angle (5-75{\deg}) of incidence and high absorptivity properties, achieving an absorptivity over 0.98. The BRDF results show that the reflection of the gold nanocone array is predominantly attributed to non-specular reflections, and exhibits excellent Lambert properties. This study reveals the influence of structural parameters and light incidence angle on the absorptivity of the gold nanocone array, which plays an important role in further understanding the light absorption/reflection mechanism and enhancing the absorptivity.