Cubic boron arsenide: A transformative material reshaping modern electronics and thermal management

Cubic boron arsenide (c-BAs) has emerged as a promising III-V semiconductor owing to its combination of ultrahigh lattice thermal conductivity and attractive electronic properties. First-principles calculations demonstrate that BAs could rival diamond in thermal conductivity and have recently been experimentally validated. High-quality single crystals now routinely achieve 1000–1300 Wm −1 K −1 at room temperature, reaching ~1500 Wm −1 K −1 in isotope-engineered samples. Cubic BAs is a wide-gap semiconductor (~1.8 eV) with high elastic modulus, low thermal expansion comparable to equivalent III-V semiconductors such as GaN, and exceptionally high ambipolar carrier mobility (>1600 cm 2 . V −1 s −1 ), positioning it as a premier candidate for electronics thermal management and high-power devices. At the device level, BAs has enabled record-performance thermal interfaces and heat-dissipating substrates, including integration beneath GaN or Ga 2 O 3 electronics, where its high interfacial conductance and bulk thermal conductivity enable it to surpass diamond as a substrate in power cooling performance. Beyond bulk, theory and emerging experiments on hexagonal BAs nanosheets reveal mechanically and dynamically stable semiconductors with tuneable band gaps, anisotropic optical response, promising thermoelectric performance, and applications in flexible, low power memristors. In this article, we present the key challenges in scalable synthesis of defect-controlled crystals and epitaxial thin films, impurity management, and integration with mainstream semiconducting platforms by reviewing the latest advancements in boron arsenide. Experimental measurements of BAs provide a definitive validation of joint three-phonon and four-phonon scattering theory, establishing the material as a benchmark for ultrahigh-thermal conductivity applications. Furthermore, its versatile electronic, optoelectronic, and nanoscale properties enable transformative use in advanced heat dissipating substrates and active layers for next-generation high-power and high-frequency electronics.