A New Material Could Be the Best Semiconductor Ever, But There’s a Catch

Researchers have found a better semiconductor than silicon, potentially allowing faster and smaller computer chips in the future. 

A new study, published in the Science journal last month, proved that cubic boron arsenide has significantly higher mobility to both electrons and their positively charged counterparts than silicon, the ubiquitous semiconductor used in electronics and computers.

The discovery was a major advancement in research on semiconductor material and a victory for Gang Chen, one of the researchers and a professor of mechanical engineering at the Massachusetts Institute of Technology, who was falsely accused by the FBI of hiding links with China.

Besides its high ambipolar mobility, cubic boron arsenide also outperforms silicon in terms of conducting heat, potentially reducing overheating and the need for cooling systems in devices. 

“Heat is now a major bottleneck for many electronics,” said Jungwoo Shin, a postdoc at MIT and the lead author of the paper. He cited how silicon carbide, which has three times higher thermal conductivity than silicon, is replacing silicon in power electronics in electric vehicles, including those made by Tesla. The more advanced semiconductor compound saves weight and gives the vehicles a longer range.

“Imagine what boron arsenides can achieve, with 10 times higher thermal conductivity and much higher mobility than silicon,” he said, calling the material a potential “gamechanger.”

It is the “best semiconductor material ever found,” and maybe the best possible one, the researchers said in a press release by the university.

The new study adds to evidence that cubic boron arsenide is a “unique and promising material for the next-generation of electronics,” Xi Chen, an assistant professor at the University of California, Riverside, told VICE World News. He was involved in a previous study with the same group in 2018 that confirmed cubic boron arsenide’s high thermal conductivity.

While cubic boron arsenide seems to tick all the boxes for an ideal semiconductor, it remains unknown whether it is a viable replacement for silicon as researchers have yet to find a practical way to produce quality cubic boron arsenide in bulk. 

“One major challenge is to grow high-quality cubic boron arsenide crystals,” Chen said. So far, researchers could only obtain crystals less than a centimeter in size, whose thermal and electrical properties are not uniform. 

In another recent study, he also identified impurities that reduced the mobility of the material. “To commercialize this material, I think more effort is needed to investigate the synthesis of high-purity crystals,” Chen added.

Until that is solved, if or how cubic boron arsenide can be applied is unclear, the study acknowledged. “Whether or where it’s going to actually be used, we do not know,” Gang Chen said. 

Chen, a naturalized U.S. citizen, was among dozens of scholars targeted by U.S. authorities under the China Initiative, a controversial scheme launched under the Trump administration to root out espionage activities on campus. After his arrest in early 2021, more than 100 faculty members of MIT signed an open letter expressing concerns that scientists of Chinese heritage were being ethnically profiled. “One cannot embrace science and facts while creating an atmosphere of fear for scientists,” they wrote. 

The U.S. authorities dropped all charges against him in January and ended the program a month later. “Rampant wrongful prosecutions terrorize innocent people—everywhere,” Chen wrote in an editorial in Science afterward. 

Individual academics like Chen and the Chinese scientist community in the U.S. shouldered the primary harm from “unjust scrutiny” in many cases in the China Initiative, Yangyang Cheng, a research scholar at Yale Law School, told VICE World News. 

“An immigrant Chinese scientist, or any immigrant, should enjoy freedom and equal protection as natural-born citizens because migration is a basic human right, regardless of one’s profession or perceived ‘contribution’ to society,” Cheng added.  

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