2025/05/23 by Zhong, Hong, Peng, Ying, Lin, Feng +8
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2505.18294
Cubic boron arsenide (c-BAs) has been theoretically predicted to exhibit thermal conductivity \kappa comparable to that of diamond, yet experimental measurements have plateaued at ~1300W/mK. We report room-temperature \kappa exceeding 2000W/mK in c-BAs, on par with single-crystal diamond. This finding is enabled by high-quality single crystals and a newly developed nanosecond, transducer-less time-domain thermoreflectance technique that allows spatial mapping of \kappa without metal transducers. Thermal conductivity correlates with crystal quality, as evidenced by stronger photoluminescence and longer photoluminescence lifetimes. However, the observed nanosecond lifetimes remain shorter than expected for an indirect bandgap semiconductor, suggesting room for further crystal quality improvement and higher \kappa. These results challenge current theoretical models and highlight c-BAs as a promising material for next-generation electronics.