Aperiodic biomimetic Vogel spirals as diffractive optical elements for tailored light distribution in functional polymer layers

Merkel M, Schemme T, Denz C

Abstract

The biomimetic, deterministic aperiodic golden angle Vogel spiral lacks both translational and rotational symmetry and exhibits circularly symmetric scattering rings in Fourier space. We present a versatile and low cost method for maskless fabrication of a Vogel spiral relief grating by illumination of a photoresist with laser light complexly structured using a spatial light modulator and subsequent transfer of its negative into a polymer layer via replica molding. We investigate its diffractive properties and present as one application its implementation as a surface structure, leading to an efficiency enhancement of 18% in an organic solar cell.