The eyes and wings of some species of moth are covered in arrays of subwavelength pillars that have been tuned over millions of years of evolution to reflect as little sunlight as possible. We are investigating ways of exploiting this to reduce reflection from the surfaces of silicon solar cells. Here, we report on the experimental realization of biomimetic antireflective moth-eye arrays in silicon using a technique based on nanoimprint lithography and dry etching. Areas of 1cm x 1cm have been patterned and analysis of reflectance measurements predicts a loss in the performance of a solar cell of only 6.5% compared to an ideal antireflective coating. This compares well with an optimized single layer Si₃N₄ antireflective coating, for which an 8% loss is predicted.

Date Published: 21 August 2009
PDF: 12 pages
Proc. SPIE 7401, Biomimetics and Bioinspiration, 74010J (21 August 2009); doi: 10.1117/12.826201

Published in SPIE Proceedings Vol. 7401:
Biomimetics and Bioinspiration
Raul J. Martin-Palma; Akhlesh Lakhtakia, Editor(s)