Broadband and wide-angle antireflection realized by multireflection effect in a micro-∧-shape array

Abstract

Antireflective surfaces are often realized by minimizing the refractive index contrast between the air and substrate using subwavelength microstructures. In this paper, we introduce another kind of geometry-induced antireflective surface using multireflection to suppress reflection to a very low extent. This surface is composed of micro-∧-shape array with the wedge size much larger than the wavelength of the incident light. Simulation and experimental results show that the micro-∧-shape array can effectively suppress the reflection within wide incident angles and large wavelength ranges. The enhanced light adsorption caused by the greatly increased light path length within the micro-∧-shape array is responsible for the antireflection phenomena. Such antireflective surface may find various applications, in solar cells, for example.