Brunner, R.R.BrunnerKraus, M.M.KrausHirte, J.J.HirteDiao, Z.Z.DiaoWeishaupt, K.K.WeishauptSpatz, J.P.J.P.SpatzHarzendorf, T.T.HarzendorfTrost, M.M.TrostMunser, A.S.A.S.MunserSchröder, S.S.SchröderBär, M.M.Bär2022-03-062022-03-062020https://publica.fraunhofer.de/handle/publica/26488410.1364/OE.406150Diffuse reflecting (white) and highly absorbing (black) fused silica based materials are presented, which combine volume modified substrates and surfaces equipped with antireflective moth-eye-structures. For diffuse reflection, micrometer sized cavities are created in bulk fused silica during a sol-gel process. In contrast, carbon black particles are added to get the highly absorbing material. The moth-eye-structures are prepared by block copolymer micelle nanolithography (BCML), followed by a reactive-ion-etching (RIE) step. The moth-eye-structures drastically reduce the specular reflectance on both diffuse reflecting and highly absorbing samples across a wide spectral range from 250 nm to 2500 nm and for varying incidence angles. The adjustment of the height of the moth-eye-structures allows us to select the spectral position of the specular reflectance minimum, which measures less than 0.1%. Diffuse Lambertian-like scattering and absorbance appear nearly uniform across the selected spectral range, showing a slight decrease with increasing wavelength.enBlock Copolymerycarbon blackmicellesreactive ion etchingreflection620621journal article