Enhanced Light Extraction by Photonic Quasi-Crystals in GaN Blue LEDs

Univ. of Bath, Bath, UK
IEEE Journal of Selected Topics in Quantum Electronics (Impact Factor: 2.83). 09/2009; 15(4):1269 - 1274. DOI: 10.1109/JSTQE.2009.2016674
Source: IEEE Xplore


The far-field profile of photonic quasi-crystal patterned and unpatterned LEDs, fabricated from commercial epitaxial substrates by electron beam lithography, has been measured prior to lapping and dicing. Emission enhancements reach a maximum of 62%, and are strongly dependent on the filling factor. Qualitative agreement is achieved between 2-D finite-difference time-domain calculations and the experimental data.

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    • "Photonic quasi-crystal cladding results in unusual characteristics which are not noticeable in photonic crystal cladding. Over the years, photonic quasi-crystals have been playing an indispensable role for enhancing the light extraction in III-Nitrides based light-emitting diodes (LEDs) [17], [18] and Organic LEDs [19]. In addition, they also help increase the light trapping capability in thin film silicon solar cell [20]. "
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