Isotope‐Enriched Cubic Boron Arsenide with Ultrahigh Thermal Conductivity

Abstract High thermal conductivity materials are critical for advanced thermal management applications. The semiconductor cubic boron arsenide (c‐BAs) has drawn significant attention due to its ultrahigh thermal conductivity. In this study, high‐quality isotope‐enriched cubic boron arsenide (c‐ ¹⁰ BAs and c‐ ¹¹ BAs) crystals are synthesized to further enhance the thermal conductivity of c‐BAs and measured a room temperature thermal conductivity of 1500 W m ⁻¹ K ⁻¹ for the c‐ ¹¹ BAs. This value is the highest thermal conductivity for isotope‐enriched c‐BAs reported so far. The experimental study, together with ab initio calculation, verifies the high quality with reproducibility of the crystals. The exceptionally high thermal conductivity of the isotope‐enriched BAs, combined with their semiconductor properties, holds significant potential for improving thermal management in semiconductor devices and electronics packaging applications.