Researchers claim to have identified a material with extraordinarily high thermal conductivity that could replace diamond as an effective thermal management material and lower the manufacturing costs of electronic devices.
Considered one of the best thermal conductors in the industry, with a room-temperature thermal conductivity of more than 2,000 watts per meter per Kelvin—five times higher than copper—diamond is often used to help remove heat from sensitive electronic devices such as high-power laser diodes and transistors.
However, diamond is rare and expensive, say the team of researchers from Boston College and the U.S. Naval Research Laboratory, and synthetic alternatives are costly to produce and often inferior to natural diamond because of the presence of impurities.
Now, new research published by the joint research team has found that the thermal conductivity of cubic boron arsenide—a chemical compound of boron and arsenic—is more than than 2,000 Watts per meter per Kelvin at room temperature, and even higher than diamond at higher temperatures, making boron arsenide a potential thermal conductor for high-temperature cooling applications.
The discovery was made somewhat by accident—according to study co-author David Broido, a professor of physics at Boston College, boron arsenide was not expected to be a good thermal conductor and had in fact been estimated, using conventional evaluation criteria, to have a thermal conductivity 10 times smaller than diamond.
Broido said the team used a recently-developed theoretical approach for calculating thermal conductivities, which had tested previously on other well-studied materials. Their findings are published in the journal Physical Review Letters.
“This work gives important new insight into the physics of heat transport in materials, and it illustrates the power of modern computational techniques in making quantitative predictions for materials whose thermal conductivities have yet to be measured,” Broido said. “We are excited to see if our unexpected finding for boron arsenide can be verified by measurement. If so, it may open new opportunities for passive cooling applications using boron arsenide, and it would further demonstrate the important role that such theoretical work can play in providing useful guidance to identify new high thermal conductivity materials.”
In addition to the development of new passive cooling solutions, says the team, the research may also provoke a reevaluation of the guidelines used to predict the thermal conductivity of materials.
