Electroluminescence from lattice defects of photonic crystal slabs in blue-light-emitting diodes

Lattice defect structures embedded into perfect photonic crystal slabs have been fabricated onto the GaN surfaces of InGaN/GaN multi-quantum-well light-emitting diodes. The photonic crystal slab with a triangular lattice constant of 230 nm showed suppressed light extraction for the electroluminescence at a peak of 464 nm, but the light radiated through lattice defects. The perfect photonic crystal slab shows the cooperative phenomenon of a light scattering similar to Wood's anomaly in a metallic grating, and lattice defects result in the leaky modes of light extractions by breaking the symmetry of cooperative light scattering.