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Unusual high thermal conductivity in boron arsenide bulk crystals

2018; American Association for the Advancement of Science; Volume: 361; Issue: 6402 Linguagem: Inglês

10.1126/science.aat7932

1095-9203

Fei Tian, Bai Song, Xi Chen, Navaneetha K. Ravichandran, Yinchuan Lv, Ke Chen, Sean E. Sullivan, Jaehyun Kim, Yuanyuan Zhou, Te‐Huan Liu, Miguel Goni, Zhiwei Ding, Jingying Sun, Geethal Amila Gamage, Haoran Sun, Hamidreza Ziyaee, Shuyuan Huyan, Liangzi Deng, Jianshi Zhou, Aaron J. Schmidt, Shuo Chen, C. W. Chu, Pinshane Y. Huang, David Broido, Li Shi, Gang Chen, Zhifeng Ren,

Advanced Thermoelectric Materials and Devices

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.