PT  - JOURNAL ARTICLE
AU  - Kang, Joon Sang
AU  - Li, Man
AU  - Wu, Huan
AU  - Nguyen, Huuduy
AU  - Hu, Yongjie
TI  - Experimental observation of high thermal conductivity in boron arsenide
AID  - 10.1126/science.aat5522
DP  - 2018 Aug 10
TA  - Science
PG  - 575--578
VI  - 361
IP  - 6402
4099  - http://science.sciencemag.org/content/361/6402/575.short
4100  - http://science.sciencemag.org/content/361/6402/575.full
SO  - Science2018 Aug 10; 361
AB  - 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. 549Improving the thermal management of small-scale devices requires developing materials with high thermal conductivities. The semiconductor boron arsenide (BAs) is an attractive target because of ab initio calculation indicating that single crystals have an ultrahigh thermal conductivity. We synthesized BAs single crystals without detectable defects and measured a room-temperature thermal conductivity of 1300 watts per meter-kelvin. Our spectroscopy study, in conjunction with atomistic theory, reveals that the distinctive band structure of BAs allows for very long phonon mean free paths and strong high-order anharmonicity through the four-phonon process. The single-crystal BAs has better thermal conductivity than other metals and semiconductors. Our study establishes BAs as a benchmark material for thermal management applications and exemplifies the power of combining experiments and ab initio theory in new materials discovery.