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

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. (paper)