MIT professor Gang Chen was raided by FBI agents and arrested for allegedly hiding connections to Chinese entities, but all charges were dropped in January. Photo: MIT/Handout via Reuters
China-born MIT professor Gang Chen, whose name was cleared earlier this year following a high-profile investigation into his alleged China ties, has led a team to discover what they say is the best semiconductor ever found.
In a paper published in the journal Science last month, Chen and colleagues said that a material known as cubic boron arsenide could conduct heat 10 times better than silicon, the most widely used semiconductor.
The new material’s extraordinary thermal conductivity makes it a promising candidate for next-generation electronics, according to the paper by Chen and co-authors from MIT, the University of Houston and other US institutions.
It also performs three times better than silicon when it comes to electron hole mobility, a crucial property for conductivity.
“If you build a device, you want to have a material where both electrons and [electron] holes travel with less resistance,” he said in a news release on the MIT Department of Mechanical Engineering website.
Chen, whose expertise is in nanotechnology, heat transfer and energy conversion, made theoretical predictions about the unique electronic properties of cubic boron arsenide back in 2018.
Chen’s lab was able to conduct experiments and prove their hypothesis using samples prepared by a team from the University of Houston led by another China-born professor, Ren Zhifeng.
While the material appears to be an ideal semiconductor, Chen said they still needed to test other properties of cubic boron arsenide, including its long-term stability. They also hope to figure out how to produce and purify it so one day it may partially replace the ubiquitous silicon in industrial applications, according to the release.
Chen is the Carl Richard Soderberg Professor of Power Engineering and director of the Pappalardo Micro/Nano Engineering Laboratories at MIT. He is also a Fellow of the American Academy of Arts and Sciences and a Thomson Reuters Highly Cited Researcher.
After obtaining his master’s degree and briefly teaching at the Huazhong Institute of Technology, now Huazhong University of Science and Technology, in central China’s Hubei province, Chen received a fellowship from the K.C. Wong Education Foundation in Hong Kong to pursue his doctorate at the University of California Berkeley in the 1990s.
In January 2020, Chen was detained at Boston Logan International Airport. A year later, US Federal Bureau of Investigation agents raided his home in Cambridge and arrested him for allegedly hiding connections to Chinese entities when applying for federal research grants.
The US government dropped all charges against him in January due to a lack of evidence.
Chen was one of dozens of researchers – most of them of Chinese ethnicity – investigated under the US Justice Department’s China Initiative, launched in November 2018 with the goal of fighting espionage and intellectual property theft.
“I grew up in China and found my American dream at MIT … In January 2020, the dream turned into a nightmare,” Chen wrote in an editorial in Science five days after his case was dismissed.
“Earlier this year, I was finally exonerated. I am painfully aware, however, I am the luckiest among the unlucky.”
Chen was reportedly back in his lab the day after the charges were dropped. Since then, he has co-authored and published papers in prestigious journals including Nature, Science, Nature Communications and Physical Review B.
Even after the widely criticised China Initiative ended in February, China-born scientists have stood trial and been convicted for failing to report ties with the country, including chemical engineer Franklin Feng Tao from the University of Kansas, Lawrence and applied mathematician Xiao Mingqing from Southern Illinois University, Carbondale.