Analysis on the Light-Extraction Efficiency of GaN-Based Light-Emitting Diodes With Deep-Hole Amorphous Photonic Crystals Structures

We demonstrated that amorphous photonic crystals can effectively improve the light extraction efficiency of GaN-based light-emitting diodes (LEDs) by the Anderson localization effect. The finite-difference time-domain method was employed to analyze the frequency dependence of the light localization characteristics in the amorphous photonic crystals structure. Numerical studies revealed that the localization modes become most efficient at certain frequencies, owing to the confinement by short-range order. With the action of these strong localization modes, the light that propagated in the horizontal direction was redirected and propagated in the z-direction. Compared with conventional LEDs, significant enhancement of the light extraction efficiency (5.83 times) was achievable from amorphous photonic crystals LEDs with optimized structural parameters. Finally, we analyzed the physical mechanisms by which amorphous photonic crystals can effectively improve light extraction.