Large-Area Semipolar Ammonothermal GaN Substrates for High-Power LEDs

Soraa proposes to develop low-cost, large area semipolar ammonothermal true bulk GaN substrates. Semipolar bulk GaN substrates are expected to be transformative for high power blue, green, and/or yellow LEDs, enabling high efficiency, high power density LEDs at costs below $3/kilolumen. The large cost reduction will enable widespread implementation of high-efficiency semipolar LEDs, enabling energy savings for general illumination in residential and commercial buildings of up to 1 quad/year by 2030. Semipolar crystallographic orientations of bulk GaN offer key advantages over conventional orientations for mid-spectrum light emission but are currently much too small and far too expensive to be relevant to LED manufacturing. The objectives for this Phase I project include: 1. Survey the growth properties of a range of semipolar orientations in Soraas novel high-rate SCoRA ammonothermal bulk crystal growth process, identifying at least one orientation with stable long-term growth and surface morphology characteristics and a growth rate enabling low-cost manufacturing upon scaleup. 2. Fabricate semipolar bulk GaN crystals with an area equivalent to a 1 inch diameter by means of a method that can be scaled up to 4 & quot; within two years. Soraa envisions that scale-up of the semipolar bulk GaN technology to 4 & quot; diameter, together with reduction of dislocation densities to below 104 cm-2, enabling further efficiency improvements, would be carried out during a follow-on Phase II effort