Photonic crystal microcavity enhanced LEDs

One of the main motivations of pursuing research into photonic crystals is to modify the spontaneous emission rate in active material. In particular, the aim is to a) increase the extraction efficiency in LEDs, which is typically around 3-5% in commercial devices and b) to decrease the spontaneous emission lifetime, which is currently in the ns-regime, in order to enable high speed modulation. These goals can be achieved by suppressing the undesired electromagnetic modes into which the emitter can radiate, and by, concurrently, enhancing the desired modes [1].