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Title: Defect-modulated thermal transport behavior of BAs under high pressure

Boron arsenide (BAs) is a covalent semiconductor with a theoretical intrinsic thermal conductivity approaching 1300 W/m K. The existence of defects not only limits the thermal conductivity of BAs significantly but also changes its pressure-dependent thermal transport behavior. Using both picosecond transient thermoreflectance and femtosecond time-domain thermoreflectance techniques, we observed a non-monotonic dependence of thermal conductivity on pressure. This trend is not caused by the pressure-modulated phonon–phonon scattering, which was predicted to only change the thermal conductivity by 10%–20%, but a result of several competing effects, including defect–phonon scattering and modification of structural defects under high pressure. Our findings reveal the complexity of the defect-modulated thermal behavior under pressure.

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American Institute of Physics
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Journal Name:
Applied Physics Letters
Medium: X
Sponsoring Org:
National Science Foundation
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