Moving the heat aside with BAs Thermal management becomes increasingly important as we decrease device size and increase computing power. Engineering materials with high thermal conductivity, such as boron arsenide (BAs), is hard because it is essential to avoid defects and impurities during synthesis, which would stop heat flow. Three different research groups have synthesized BAs with a thermal conductivity around 1000 watts per meter-kelvin: Kang et al., Li et al., and Tian et al. succeeded in synthesizing high-purity BAs with conductivities half that of diamond but more than double that of conventional metals (see the Perspective by Dames). The advance validates the search for high-thermal-conductivity materials and provides a new material that may be more easily integrated into semiconducting devices. Science, this issue p. 575, p. 579, p. 582; see also p. 549 Boron arsenide has an ultrahigh thermal conductivity, making it competitive with diamond for thermal management applications. Conventional theory predicts that ultrahigh lattice thermal conductivity can only occur in crystals composed of strongly bonded light elements, and that it is limited by anharmonic three-phonon processes. We report experimental evidence that departs from these long-held criteria. We measured a local room-temperature thermal conductivity exceeding 1000 watts per meter-kelvin and an average bulk value reaching 900 watts per meter-kelvin in bulk boron arsenide (BAs) crystals, where boron and arsenic are light and heavy elements, respectively. The high values are consistent with a proposal for phonon-band engineering and can only be explained by higher-order phonon processes. These findings yield insight into the physics of heat conduction in solids and show BAs to be the only known semiconductor with ultrahigh thermal conductivity.

中文翻译：

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砷化硼块状晶体异常高的热导率

随着我们减小设备尺寸并提高计算能力，热管理变得越来越重要。砷化硼 (BA) 等具有高导热性的工程材料很硬，因为在合成过程中必须避免缺陷和杂质，这会阻止热流。三个不同的研究小组合成了热导率约为 1000 瓦/米-开尔文的 BA：Kang 等人、Li 等人和 Tian 等人。成功合成了高纯度 BA，其导电性是金刚石的一半，但是传统金属的两倍以上（参见 Dames 的观点）。这一进展证实了对高导热材料的探索，并提供了一种可以更容易地集成到半导体器件中的新材料。科学，这个问题 p。575 页。579 页。582; 另见第。549 砷化硼具有超高的导热性，使其在热管理应用中可与金刚石相媲美。传统理论预测，超高晶格热导率只能出现在由强键合的轻元素组成的晶体中，并且受到非谐三声子过程的限制。我们报告了偏离这些长期标准的实验证据。我们测量了块状砷化硼 (BA) 晶体的局部室温热导率超过 1000 瓦/米-开尔文，平均体积值达到 900 瓦/米-开尔文，其中硼和砷分别是轻元素和重元素。高值与声子带工程的建议一致，只能通过高阶声子过程来解释。