A high efficiency, and possibly highly directional, light emitting diode
(LED) with an optimized photonic crystal extractor. The LED is comprised
of a substrate, a buffer layer grown on the substrate (if needed), an
active layer including emitting species, one or more optical confinement
layers that tailor the structure of the guided modes in the LED, and one
or more diffraction gratings, wherein the diffraction gratings are
two-dimensional photonic crystal extractors. The substrate may be removed
and metal layers may be deposited on the buffer layer, photonic crystal
and active layer, wherein the metal layers may function as a mirror, an
electrical contact, and/or an efficient diffraction grating.