9/11/2024 Cassandra Smith
Written by Cassandra Smith
Materials science & engineering Ph.D. student Adrian Birge has been on a roll with wins regarding his work in solar cells. He recently was awarded “Best Presentation Prize” at the IEEE Photovoltaic Specialists Conference in Seattle, Washington.
Birge gave a presentation on “High-efficiency MBE-grown 1 eV InGaAs solar cells.” In this work, Adrian grew single- crystal thin films of compound semiconductors using molecular beam epitaxy (MBE). MBE works by directing beams of high-purity elements towards a heated crystal substrate, where it is energetically favorable for them to form bonds and grow high-quality films. Adrian took on the challenge of growing the first InGaAs solar cells on GaAs by MBE and succeeded in obtaining very high device efficiencies. Recently, Birge was awarded a NASA fellowship to expand his research on this topic. To expand his knowledge on solar cells, Adrian applied for and was selected to participate in a workshop was held at the National Renewable Energy Laboratory in Golden, Colorado.
There, Birge had the opportunity to experience five days of education and networking. He got to explore the laboratories within NREL, talk with the scientists who work within those labs and learn about their techniques for making and testing the world’s most efficient solar cells.
At the conference in Seattle, he gave a 15-minute oral presentation about the materials growth challenges he faced in his work along with the innovative methods he used to obtain high-performance devices. “It was really cool to have people in the audience where I’ve read a lot of their papers and who I hold them in very high esteem in terms of the research they’ve done.” He heard from other researchers who work in his area but also learned from colleagues who focus on other areas of photovoltaics.
Attending both the conference and the workshop left him invigorated for the journey ahead. “[I] feel like the conference got me really excited about my specific research and my topic, and then the workshop got me really excited about solar energy and photovoltaics in general.” And he hopes that energy continues as the semester begins. In addition to his NASA-funded research, he is taking a class called Point and Line Defects. He said this class will be beneficial in relation to his own research. “My research involves growing thin films with a different crystal size of what I’m growing it on, so that causes line defects to form.” He is also a teaching assistant for a materials science course surrounding thin films.
Birge is also working on extending the research of a group member who recently defended their thesis. The research involves growing gallium arsenide phosphide solar cells on silicon. “Because silicon wafers are huge, there’s a giant infrastructure of silicon from the electronics industry,” said Birge. Birge attributes his recent success not just to his personal dedication to research, but also the high performance of the cleanroom and facilities staff who keep their labs in top condition.
Birge’s cells are grown and fabricated in the Holonyak Micro and Nanotechnology Lab clean room. He noted that it is convenient to have everything he needs in one building instead of going to several locations around campus to use various instruments to further his research. He appreciates that as well as the staff who help maintain that equipment. “When I’m having an issue, I can ask them for advice on troubleshooting, which is really, really great. I think that’s been really helpful in facilitating my research.”
Birge has been working with HMNTL director Minjoo Larry Lee, a professor of electrical and computer engineering, for two years. His connection with Professor Lee was one of the sticking points for attending the University of Illinois Urbana-Champaign for his graduate program.
When looking at U. of I., Birge met with several professors. He said they were brief chats, except for his meeting with Lee. “I ended up chatting with Larry for an hour and a half just on a weeknight...and it went really well.” They talked about Birge’s undergraduate research and his goals for the future. “And so, from that I could tell he was going to be a really good fit, a really good advisor. The next week, he offered me a position in his lab. I didn’t really hesitate at all.” Not only was his willingness to spend time with Birge something that he appreciated, Lee’s solar work also lined up with Birge’s desire to work in that area.
Compatibility between an advisor and advisee is of the utmost importance, according to Birge. The same idea applies to lab mates as well. “The part that makes it enjoyable is the group members I have around me,” said Birge. “They’re friendly, and we collaborate well, and my advisor, who’s supportive, we also get along well.”
He urges graduate students looking into programs to do their research before applying and get to know professors and their research. If you find someone of interest, reach out to see if they have space in their lab and if they want to bring on another person. He urged applicants to have their CVs ready in case they want to see it and then keep you in mind when you do apply.