Pressure-driven anomalous thermal transport behaviors in gallium arsenide

High-pressure has been widely utilized to improve material performances such as thermal conductivity κ and interfacial thermal conductance G. Gallium arsenide (GaAs) as a functional semiconductor has attracted extensive attention in high-pressure studies for its technological importance and complex structure transitions. Thermal properties of GaAs under high pressure are urgent needs in physics but remain elusive. Herein, we systematically investigate κGaAs and GAl/GaAs of multi-structure up to ∼23 GPa. We conclude that: (1) in pressurization, phonon group velocity, lattice defects, and electrons play a central role in κGaAs in elastic, plastic, and metallization regions, respectively. The increased phonon density of states (PDOS) overlap, group velocity, and interfacial bonding enhances GAl/GaAs. (2) In depressurization, electrons remain the dominant factor on κGaAs from 23 to 13.5 GPa. GAl/GaAs increases dramatically at ∼12 GPa due to the larger PDOS overlap. With decompressing to ambient, lattice defects including grain size reduction, arsenic vacancies, and partial amorphization reduce κGaAs to a glass-like value. Remarkably, the released GAl/GaAs is 2.6 times higher than that of the initial. Thus our findings open a new dimension in synergistically realizing glass-like κ and enhancing G, which can facilitate thermoelectric performance and its potential engineering applications.