Researchers from MIT and elsewhere have found a material that can perform much better than silicon. The next step is finding practical and economic ways to manufacture it. Silicon is one of the most plentiful elements on Earth, and in its pure form, the semiconductor material has become the found
MIT researchers say cubic boron arsenide is the best semiconductor material ever found, and maybe the best possible one. Credit: Christine Daniloff, MITand elsewhere have found a material that can perform much better than silicon. The next step is finding practical and economic ways to manufacture it.
Now, a team of scientists from MIT, the University of Houston, and other institutions has carried out experiments showing that a material called cubic boron arsenide overcomes both of these limitations. In addition to providing high mobility to both electrons and holes, it has excellent thermal conductivity. It is the best semiconductor material ever found, and maybe the best possible one, according to the researchers.
The earlier experiments demonstrated that the thermal conductivity of cubic boron arsenide is almost 10 times greater than that of silicon. “So, that is very attractive just for heat dissipation,” Chen says. They also showed that the material has a very good bandgap, a property that gives it great potential as a semiconductor material.
“Heat is now a major bottleneck for many electronics,” says Shin, the paper’s lead author. “Silicon carbide is replacing silicon for power electronics in major EV industries including Tesla, since it has three times higher thermal conductivity than silicon despite its lower electrical mobilities. Imagine what boron arsenides can achieve, with 10 times higher thermal conductivity and much higher mobility than silicon. It can be a gamechanger.
Not only is the material’s thermal conductivity the best of any semiconductor, but the scientists also say it has the third-best thermal conductivity of any material — next to diamond and isotopically enriched cubic boron nitride. “And now, we predicted the electron and hole quantum mechanical behavior, also from first principles, and that is also proven to be true,” Chen says., that has all these properties,” he says. “And this is a bulk material that has these properties.
And while the thermal and electrical properties have been shown to be excellent, there are many other properties of a material that have yet to be tested, such as its long-term stability, Chen says. “To make devices, there are many other factors that we don’t know yet.”