An (Al, Ga, In)N light emitting device in which high light generation efficiency occurs by fabricating the device using non-polar or semi-polar GaN crystals.
The thickness of the quantum well (QW) in conventional GaN-based LEDs and LDs is only around 2-5 nm, due to the c-axis oriented GaN crystals which limit the thickness of the QW that can be achieved without losing efficiency. Conventional LEDs also utilize mirrors to increase the light output power from the front side of the LED. Reflected emissions are partially re-absorbed by the LED, further reducing the output power and efficiency of the LED.
Researchers at UC Santa Barbara have developed an (Al, Ga, In)N light emitting device in which high light generation efficiency occurs by fabricating the device using non-polar or semi-polar GaN crystals. This geometry allows for a QW layer larger than 5 nm with low piezoelectric effects so that higher efficiencies at higher current densities can be achieved. The device also minimizes internal reflections within the LED by eliminating mirrors and/or mirrored surfaces, in order to minimize re-absorption of light by the emitting or active layer of the LED.
|United States Of America||Issued Patent||9,130,119||09/08/2015||2007-317|
indled, indssl, GaN, LED