Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

  • Arkadiusz Jarosław GOSZCZAK Mads Clausen Institute, NanoSYD, University of Southern Denmark
  • Horst-Günter RUBAHN Mads Clausen Institute, NanoSYD, University of Southern Denmark
  • Morten MADSEN Mads Clausen Institute, NanoSYD, University of Southern Denmark
Keywords: Al concaves, enhanced absorption, imprinting, PAA

Abstract

In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al films evaporated via e-beam evaporation on Si substrates. The template formation leads to natural patterning of the underlying Al layers that are used as rigid masters for stamp fabrication, after selective etching of the porous anodic alumina. PDMS stamps were made after replicating the Al concave patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption that is attributed to field enhancement and diffuse scattering, leading to efficient light trapping for a selected active layer material (P3HT:PCBM).

DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14188

Published
2017-03-01
Section
ELECTRONIC AND OPTICAL MATERIALS