This Small Business Innovation Research (SBIR) Phase II project aims to develop a scalable, compact and rapid ammonothermal method to grow high-quality, low-cost bulk gallium nitride (GaN) substrates. A novel apparatus that is scalable to large volumes at modest cost will be utilized to achieve high-pressure, high-temperature conditions and grow single-crystal GaN. This project is expected to demonstrate the synthesis of ultrapure raw material and the growth of high-quality bulk GaN crystals with excellent crystallinity, improved transparency, a diameter of at least 1 inch and a process capable of rapid scale-up to larger sizes.<br/><br/>The broader/commercial impact of this project will be the potential to offer high-quality and significantly lower cost GaN substrates, which may enable their applications in next generation displays including light-emitting diodes (LEDs), green and blue laser diodes etc. Bulk GaN substrates, currently in use for 405 nm laser diodes only and grown by a vapor-phase technique, are projected to be a $405 million market in 2010. The availability of low-cost and high-quality bulk GaN substrates is anticipated to improve efficiency and reduce cost of GaN-based LEDs, which will enable a large reduction in electrical power consumption.