Shape optimization of a moth-eye structure for omnidirectional and broadband antireflection

Abstract

The shape optimization method was proposed to acquire omnidirectional and broadband antireflection properties of a moth-eye structure. Demonstrated by a poly(methyl methacrylate) substrate used for packaging material of solar cells, an average transmittance up to 0.936 has been achieved over the AM1.5 spectrum and incident angle from 0 to 90 degrees, showing a better antireflection performance compared with the most widely used shapes with conical, sinusoidal and parabolic profiles. The improvement is attributed to the optimized effective refractive index profile, leading to a smaller reflection in large incidence angles. The method can be applied to solar cells for higher light management efficiency.