"[The military could use this] for the detection of some kind of enemy target, but it could also have civilian applications."
Chair and Professor of Engineering Greg Sun is a member of a multi-university research group selected by the U.S. Department of Defense to receive $7.5 million in funding to develop high quality SiGeSn alloys for lighter, faster, and more energy efficient infrared imaging devices as the next generation infrared imaging technology.
Sun is part of the five-year DOD Multidisciplinary University Research Initiative (MURI) project “Understanding and Breaking the Material Barriers of SiGeSn Alloys for Infrared Devices,” which includes researchers from the University of Arkansas at Fayetteville, Arizona State University, Dartmouth University, and George Washington University. As Sun is doing the theoretical part of the project, he says the UMass Boston share is an estimated $570,000.
Sun’s research group is one of only 24 recipients to receive funding from the Department of Defense this year out of 295 proposals. The Air Force Office of Scientific Research awarded the grant.
“[The military could use this] for the detection of some kind of enemy target, but it could also have civilian applications,” Sun said. “Right now you do have infrared detectors, but usually those detectors are made from different semiconductors, and they don’t integrate with electronics well. They could be separate components and then you need some sort of physical connection between them. But when you put them in the same device, the connection time is a lot quicker and a lot faster, so the signal processing is a lot faster.”
Sun says past funding from the UMass president’s office paved the way for the group to go after this grant. The project, which will begin this fall, builds upon a larger effort in the Silicon photonics.
“Every 18 months to two years, the number of transistors on a [silicon] chip doubled, but we’re now coming to the end of that. The transistor size has become so small it is becoming very, very difficult to shrink it down any further,” Sun explained. “Seven nanometers—you can’t really put many atoms in it anymore, so people are realizing that we’re reaching kind of the end in terms of silicon electronics, but silicon as a material is still very useful. Can we do something else with silicon? So that something else becomes photonic devices.”
Sun says the problem with silicon is that although it is a perfect electronics material, it falls short when it comes to transmitting photons (light). So that’s why Sun and his collaborators on the DOD grant are looking at bringing not just germanium but tin into the silicon mix.
“By incorporating some tin into this material, it is possible we can get this property that we want for photonics,” Sun said. “Right now it’s all fundamental research, but the idea is hopefully to integrate all of this within silicon electronics. You build everything on a silicon substrate. The bottom layer is all silicon. On this bottom layer, you build silicon electronics, and next to it you build these photonic devices so they can talk to each other. …. What we’re thinking about is this highly integrated device that has the electronics component on it, and also the photonics component on it. That’s why being able to build everything on top of a silicon substrate is very, very important.”
This is the second award for Sun this semester. In March, he received an Advanced Materials Award from the nonprofit International Association of Advanced Materials (IAAM) for his research contributions.