Soraa Chosen to Lead DOE ARPA-E Project on Bulk Gallium Nitride Substrates

August 07, 2012 by Jeff Shepard

Soraa, a developer of GaN on GaN™ (gallium nitride on gallium nitride) solid-state lighting technology, announced that it has been selected by Advanced Research Projects Agency-Energy (ARPA-E) to lead a project on the development of bulk gallium nitride (GaN) substrates.

Using GaN as a substrate holds promise for many industries, but has immediate applications for light-emitting diodes (LEDs), which Soraa manufactures. A major advancement in a commercially viable new substrate is a promising disruptive technology in the areas of higher efficiency and performance. GaN on GaN LEDs are of particular interest because they have demonstrated much higher performance than traditional lighting technologies and thus offer the potential for major energy savings.

Currently, this is the only ARPA-E funded light-emitting diode (LED) substrate project.

According to Soraa Founder Shuji Nakamura, who is praised as the "father of LEDs" even by competitors, breakthroughs in GaN substrates can have far-reaching implications. "I have spent many decades of my life working on gallium nitride for LEDs because I believe this is a very important development and holds great promise for more energy efficient technology in lighting, power electronics and more."

Gallium Nitride is described as a unique semiconductor used in the manufacture of all white, blue and green LEDs. Most of these LEDs today are made by depositing GaN on non-native substrates, typically sapphire or silicon carbide. By contrast, virtually all other semiconductor technologies are based on "native" substrates, such as silicon on silicon or gallium arsenide on gallium arsenide. Soraa is the only LED manufacturer in the world shipping products based on superior GaN on GaN LEDs. To date, adoption of GaN on GaN technology for large-scale applications has been inhibited by high costs due in part to the absence of inexpensive native GaN substrates. Creating a made-in-U.S.A. solution to the challenges of bulk GaN production will benefit the company, the LED industry, and the American consumer with more energy efficient, less expensive and more readily available components.

LEDs lend themselves well to the new substrate because it greatly enhances performance--as in the quality of the light--as a benefit in addition to energy efficiency. Because of innate physical properties of the compound, GaN on GaN LEDs can withstand higher power densities than diodes made with other substrates. This means a much brighter diode and only one LED light emitter per lamp. Other manufacturers using other substrates have to use three, four and even more to get the same brightness. Multiple sources of light within a lamp mean fuzzy shadows and not the crisp light required of an MR-16 for best use in commercial, museum or high-end consumer applications. The MR-16 lamps--or bulbs--are Soraa’s first commercially available product.

ARPA-E, a new agency within the U.S. Department of Energy that invests exclusively in transformational energy technologies, began funding Soraa as a consortium member for this project in 2011. ARPA-E’s recent decision to make Soraa the lead organization on the project means that Soraa will become the prime contractor working with ARPA-E to commercialize GaN substrate technology. Applications for GaN substrates have the potential to reduce U.S. energy consumption by over 30%. Those same applications represent potential markets, including laser diodes and power electronics, of over $50 billion annually, according a US Department of Energy study.

"It is clear to ARPA-E that Soraa’s system design and capabilities represent a breakthrough path toward the development of high-quality, low-cost GaN substrates," said Mark Johnson, ARPA-E Program Director. "We are excited to move forward in supporting their process development, crystal quality improvements, and device characterization."

"We are pleased and honored that ARPA-E has recognized the value and impact of Soraa’s true bulk GaN substrate technology. DOE’s recognition and support of this transformational technology is expected to accelerate a more energy efficient, higher performing US-based technology for LEDs and a host of additional applications," said Mark D’Evelyn, Soraa’s Principal Investigator on the project.

"Soraa is delighted to take the lead for this project and continue development of ammonothermal technology for bulk GaN substrates. This level of funding combined with the vote of confidence from the Department of Energy is a significant step forward to a future of lighting technology based on large-area, high-quality, low-cost GaN substrates, " said Mike Krames, Chief Technology Officer at Soraa.