杂质
热导率
材料科学
硼
声子
散射
电子迁移率
凝聚态物理
半导体
分析化学(期刊)
声子散射
化学
光电子学
光学
物理
复合材料
有机化学
色谱法
作者
Xi Chen,Chunhua Li,Youming Xu,Andrei Dolocan,Gareth Seward,Ambroise van Roekeghem,Fei Tian,Jie Xing,Shucheng Guo,Ni Ni,Zhifeng Ren,Jianshi Zhou,Natalio Mingo,David Broido,Li Shi
标识
DOI:10.1021/acs.chemmater.1c02006
摘要
Cubic boron arsenide (BAs) is a promising compound semiconductor for thermal management applications due to its high thermal conductivity, exceeding 1000 W m–1 K–1 at room temperature in high-quality samples. However, the as-grown BAs crystals usually exhibit large variations in thermal and electronic transport properties. The origin of these large variations has thus far been inconclusive. Here, we investigate the effects of impurities on the thermal and electrical properties of BAs. Time-of-flight secondary ion mass spectrometry and electron probe microanalysis measurements reveal the presence of several impurities in BAs, including Si, C, O, H, Te, Na, and I. Some of these impurities, especially Si, C, and H, could serve as shallow acceptors, leading to the p-type conducting behavior commonly measured in BAs. The thermal conductivity and hole mobility are reduced more in the samples with higher impurity concentrations due to the enhanced impurity scattering of phonons and holes, respectively. First-principles calculations are used to determine the thermal conductivity reduction induced by different impurities. The calculated results confirm the experimental trends. The substitution of O for As leads to a large bond distortion resulting from the breaking of the Td symmetry, which yields unusually strong phonon scattering with a correspondingly large reduction in thermal conductivity. Our results offer useful insights into the impurity-sensitive transport properties of BAs.
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