Efficient Solid-State Lighting Using Inverted InGaN/GaN Structures
Our group is interested in fabricating high efficiency blue-green LEDs for lighting applications. Solid-state lighting promises to produce the most efficient light sources and significantly reduce our energy consumption in the USA. It is important to realize that 20 % of the electricity produced in this nation is used for lighting. Therefore, a more efficient light source can substantially contribute at reducing our energy needs. Our structure utilizes a unique p-down Ga-polar structure to control the intrinsic polarization fields in the structure and achieve a better carrier injection in the quantum well. Our group has made significant progress in optimizing both p and n contacts to GaN. Recently we have obtained very promising results on dry-etched p-type GaN sample. Our n-i-p structure is grown by MBE on a thick GaN template in order to reduce the dislocation density. We now have started making and optimizing LEDs.
The University of Maryland has established a close collaboration with the Army Research Lab in Adelphi.