Startup Soraa emerged from stealth status back in February at the Strategies in Light Conference with gallium nitride (GaN)-on-GaN LED technology, and now announces that it will lead a DOE project focused on developing bulk GaN substrates. The US Department of Energy (DOE) agency called Advanced Research Projects Agency – Energy (ARPA-E) first funded Soraa on the project in 2011 and has now decided to make Soraa the prime contractor.

Soraa believes that GaN has immediate applicability for brighter LEDs and perhaps other industries as well. Using the same material for the substrate and epitaxial layers results in a better match of the crystalline structures. The result, according to Soraa, is the ability to drive LEDs at higher current with less droop.

As Soraa points out, other segments of the semiconductor industry use what are sometimes called native substrates, such as the silicon-on-silicon technology used to manufacture the bulk of digital ICs such as microprocessors. But the adoption of GaN-on-GaN in LEDs and other applications has been hampered by the high costs of the substrates. The ARPA-E agency hope to capitalize on an opportunity with a US-developed solution.

Soraa's founder Shuji Nakamura has long worked with GaN in his pioneering work developing high-power LEDs. Nakamura said, "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."

"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."

The DOE believes that applications for GaN substrates have the potential to reduce US energy consumption significantly. Moreover, the DOE estimates that GaN products such as LEDs, laser diodes, and power electronics have the potential of being worth over $50 billion annually.

"We are pleased and honored that ARPA-E has recognized the value and impact of Soraa’s true bulk GaN substrate technology," said Mark D’Evelyn, Soraa’s principal investigator on the project. "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."