Houston Daily

University of Houston researchers, working with colleagues from the University of California, Santa Barbara, and Boston College, have found that boron arsenide crystals can achieve thermal conductivity levels that may surpass diamond. The findings challenge established theories about heat conduction in materials.

The research team discovered that high-quality boron arsenide crystals can reach thermal conductivity values above 2,100 watts per meter per Kelvin (W/mK) at room temperature. Diamond has long been considered the best heat conductor among isotropic materials. The results were published on October 10 in Materials Today.

Zhifeng Ren, a professor in the Department of Physics at UH’s College of Natural Sciences and Mathematics and director of the Texas Center for Superconductivity, said: “We trust our measurement; our data is correct and that means the theory needs correction. I'm not saying the theory is wrong, but an adjustment needs to be made to be consistent with the experimental data.”

Previous theoretical models had suggested boron arsenide could match or exceed diamond’s thermal conductivity. However, revised models introduced more complex calculations and capped its potential below what this new study observed. According to Ren, many earlier samples contained defects, limiting their performance. By using purer source materials and refining synthesis techniques, the researchers produced cleaner crystals with record-breaking properties.

Ren stated: “We trust our measurement; our data is correct and that means the theory needs correction.”

Boron arsenide offers several advantages for use in electronics and heat management applications. It is easier and less expensive to manufacture than diamonds because it does not require extreme temperatures or pressures. In addition to its exceptional thermal conductivity, it functions as an effective semiconductor. Its properties include a wider band gap and higher carrier mobility compared to silicon, as well as a well-matched coefficient of thermal expansion.

“This new material, it's so wonderful,” said Ren. “It has the best properties of a good semiconductor, and a good thermal conductor — all sorts of good properties in one material. That has never happened in other semiconducting materials.”

The project received funding through a $2.8 million National Science Foundation grant led by Bolin Liao at UC Santa Barbara with participation from UH, Notre Dame, and University of California, Irvine. Industrial sponsor Qorvo also provided partial support for work at UH.

Ren encouraged theorists to revisit their models: “You shouldn’t let a theory prevent you from discovering something even bigger, and this exactly happened in this work.”