Isotope‐Enriched Cubic Boron Arsenide with Ultrahigh Thermal Conductivity

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-¹⁰BAs and c-¹¹BAs) 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-¹¹BAs. 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.