Aluminum nitride is a promising next-generation semiconductor material, but its widespread adoption has been limited by technical challenges. Cornell researchers, collaborating with the Florida-based technology company Lit Thinking, are working to overcome some of these key limitations with a grant from the Defense Advanced Research Projects Agency (DARPA).

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Aluminum nitride is an ultrawide-bandgap semiconductor material recognized for its thermal conductivity, high breakdown voltage and strong electric field tolerance, making it an ideal material for high-power and high-frequency electronic devices. Achieving ultralow resistance in pin diodes – which help semiconductors handle high voltages and currents – is crucial for improving efficiency and performance.

The Cornell-led project will focus on developing aluminum nitride-based pin diodes with extremely low on-state electrical resistance, reducing power loss and heat generation in high-power applications.

“Because aluminum nitride is normally an excellent electrical insulator, making it conductive holds the key to exploiting its amazing properties” said principal investigator is Debdeep Jena, the David E. Burr Professor in electrical and computer engineering and in materials science and engineering. “In this DARPA program, our interdisciplinary team is investigating several new ideas to unlock the potential of this ultrawide bandgap semiconductor.”

Co-principal investigators from the Department of Materials Science and Engineering include Huili Grace Xing, the William L. Quackenbush Professor in electrical and computer engineering; Michael Thompson, the Dwight C. Baum Professor; Hari Nair, assistant research professor; and Leo Schowalter, CTO of Lit Thinking and a visiting professor.

The project will build on research published earlier this year by Jena and Xing, who demonstrated p–n heterojunction diodes through distributed polarization doping to achieve properties that are not possible in standard diodes.

“Aluminum nitride semiconductor substrates have also recently enabled the realization of the very first deep ultraviolet diode lasers,” said Schowalter. “This project has the potential to enable similar revolutionary electronic devices in the near future, including cost effective far-UVC optoelectronic sources for safe disinfection of public spaces.” 

The grant is part of the DARPA Microsystems Technology Office’s Ultra-Wide BandGap Semiconductors program, which aims to develop materials for a variety of commercial applications, including high-power radio frequency devices for radar and communications systems, high-voltage switches for power electronics, high-temperature electronics and sensors for extreme environments, and deep ultraviolet light emitting diodes and lasers.