Boron Arsenide Surpasses Diamond in Heat Conductivity, Paving Way for Advanced Electronics

Scientists find that boron arsenide can be a better conductor of heat than diamond, which has so far been the best-known material for dissipating heat. By reducing crystal impurities and optimising synthesis methods, a team of researchers at the University of Houston reported BAs samples that have thermal conductivity above 2,100 watts per meter per Kelvin (W/mK) at room temperature -- higher than previously reported or theorised. The discovery upends long-held notions about how heat moves in things and could make possible new materials where high thermal conductivity and semiconductor-like transparency for electricity flow can be tuned.

Flawless Boron Arsenide Crystals Surpass Diamond, Paving Way for Next-Gen Electronics

According to a report in Materials Today, the team obtained this result by removing defects in BAs crystals, which had left the conductivity as a bottleneck. Previous models predicted that BAs might outperform diamond, but experimental imperfections have left many unconvinced of the material's potential. These nearly perfect crystalline structures, grown using state-of-the-art synthesis methods, confirmed that purity underlies maximum thermal performance. Zhifeng Ren, professor of physics and the lead author of the paper, said the results suggest that theoretical models need to be updated to accommodate experimental conditions.

Its discovery could greatly contribute to electronics from high-power computers to smartphones and data centres, offering a material that can shed heat as well as trap electricity as a top-of-the-range semiconductor. Superior to diamond, BAs can be more easily fabricated while possessing a high mobility of carriers, a wide bandgap, and matching thermal expansion that enables them as excellent candidates for future devices.

This joint effort between the University of Houston, UC Santa Barbara, and Boston College, with support from NSF and Qorvo, is motivated to improve BA synthesis as well as review advanced material models.