Biomimetic subwavelength antireflective gratings on GaAs

Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
Optics Letters (Impact Factor: 3.29). 11/2008; 33(19):2224-6. DOI: 10.1364/OL.33.002224
Source: PubMed


We have developed a simple and scalable bottom-up approach for fabricating moth-eye antireflective coatings on GaAs substrates. Monolayer, non-close-packed silica colloidal crystals are created on crystalline GaAs wafers by a spin-coating-based single-layer reduction technique. These colloidal monolayers can be used as etching masks during a BCl(3) dry-etch process to generate subwavelength-structured antireflective gratings directly on GaAs substrates. The gratings exhibit excellent broadband antireflective properties, and the specular reflection matches with the theoretical prediction using a rigorous coupled-wave analysis model. These bioinspired antireflection coatings have important technological applications ranging from efficient solar cells to IR detectors.

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