Photonic crystals, in the form of closed-packed nano-pillar arrays patterned by nanosphere lithography, have been formed on the n-faces of InGaN thin-film vertical light-emitting diodes (LEDs). Through laser lift-off of the sapphire substrate, the thin-film LEDs conduct vertically with reduced dynamic resistances, as well as reduced thermal resistances. The photonic crystal plays a role in enhancing light extraction, not only at visible wavelengths but also at infrared wavelengths boosting heat radiation at high currents, so that heat-induced effects on internal quantum efficiencies are minimized. The observations are consistent with predictions from finite-difference time-domain simulations.
Observation of enhanced visible and infrared emissions in photonic crystal thin-film light-emitting diodes
Y. F. Cheung, K. H. Li, R. S. Y. Hui, H. W. Choi; Observation of enhanced visible and infrared emissions in photonic crystal thin-film light-emitting diodes. Appl. Phys. Lett. 18 August 2014; 105 (7): 071104. https://doi.org/10.1063/1.4893739
Download citation file: