By Josh Perry, Editor
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There have been a handful of reports coming from colleges across the U.S. about the potential of boron arsenide crystals in thermal management applications and the University of California Los Angeles (UCLA) established a new benchmark by creating defect-less crystals with a thermal conductivity of 1,300 W/mK.

Illustration of thermal management using the new semiconductor, boron arsenide.
(W. Wu, Y. Shi, and Y. Hu/UCLA)

This report came just days after researchers at the University of Texas at Dallas and the University of Houston announced boron arsenide that had a thermal conductivity of 1,000 W/mK.

According to a report from UCLA, the new material quickly dissipates heat from hotspots and performs three times better than silicon carbide and copper.

“For many decades, theorists consider that three-phonon process governs thermal transport, and the effects of four-phonon and higher-order processes were believed to be negligible, which actually is the true case for most common materials,” the article explained. “This study makes significant impact to the theory field by showing that high-order anharmonicity through four-phonon process makes important contribution in defect-free BAs single crystals.”

In addition, the researchers explored ballistic thermal transport physics and was able to demonstrate that the long phonon mean free paths of boron arsenide contributed to its enhanced thermal conductivity.

The research was recently published in Science. The abstract stated:

“Improving thermal management of small scale devices requires developing materials with high thermal conductivities. The semiconductor boron arsenide (BAs) is an attractive target due to ab initio calculation indicating single crystals have an ultrahigh thermal conductivity.

“We synthesized BAs single crystals with undetectable defects and measured a room temperature thermal conductivity of 1300 W/mK. Our spectroscopy study in conjunction with atomistic theory reveals that the unique band structure of BAs allows for very long phonon mean free paths and strong high-order anharmonicity through the four-phonon process. The single-crystal BAs has better thermal properties than other metals and semiconductors.

“Our study establishes BAs as a benchmark material for thermal management applications and exemplifies the power of combing experiments and ab initio theory in new materials discovery.”