title: Optimal overlayer inspired by Photuris firefly improves light-extraction efficiency of existing light-emitting diodes.
abstract: In this paper the design, fabrication and characterization of a bioinspired overlayer deposited on a GaN LED is described. The purpose of this overlayer is to improve light extraction into air from the diode's high refractive-index active material. The layer design is inspired by the microstructure found in the firefly Photuris sp. The actual dimensions and material composition have been optimized to take into account the high refractive index of the GaN diode stack. This two-dimensional pattern contrasts other designs by its unusual profile, its larger dimensions and the fact that it can be tailored to an existing diode design rather than requiring a complete redesign of the diode geometry. The gain of light extraction reaches values up to 55% with respect to the reference unprocessed LED.
authors: Research Center in Physics of Matter and Radiation, Department of Physics, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur, Belgium. annick.bay@fundp.ac.be
authors: Annick
authors: A
authors: Bay
authors: Nicolas
authors: N
authors: André
authors: Michaël
authors: M
authors: Sarrazin
authors: Ali
authors: A
authors: Belarouci
authors: Vincent
authors: V
authors: Aimez
authors: Laurent A
authors: LA
authors: Francis
authors: Jean Pol
authors: JP
authors: Vigneron
mesh_terms: D000818:Animals; D004867:Equipment Design; D048888:Fireflies / Q000737:chemistry*; D005708:Gallium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D008027:Light; D012031:Refractometry / Q000295:instrumentation*; D012666:Semiconductors
chemical_list: D007204:Indium; D005708:Gallium; C027235:gallium nitrate