Deep-potential enabled multiscale simulation of gallium nitride devices on boron arsenide cooling substrates

Abstract

High-efficient heat dissipation plays critical role for high-power-density electronics. Experimental synthesis of ultrahigh thermal conductivity boron arsenide (BAs, 1300 W m−1K−1) cooling substrates into the wide-bandgap semiconductor of gallium nitride (GaN) devices has been realized [Nature Electronics 4, 416-423 (2021)]. However, the lack of systematic analysis on the heat transfer across the BAs-GaN interface hampers the practical applications. In this study, by constructing the accurate and high-efficient machine learning interatomic potentials, we performed multiscale simulations of the BAs-GaN heterostructures. Ultrahigh interfacial thermal conductance (ITC) of 265 MW m−2K−1 is achieved, which lies in the well-matched lattice vibrations of BAs and GaN. Moreover, the competition between grain size and boundary resistance was revealed with size increasing from 1 nm to 100 µm. Such deep-potential equipped multiscale simulations not only promote the practical applications of BAs cooling substrates in electronics, but also offer new approach for designing advanced thermal management systems.

Strong anharmonicity and medium-temperature thermoelectric efficiency in antiperovskite Ca3XN (X = P, As, Sb, Bi) compounds

“…22,28 Furthermore, anharmonicity in both PV and APV materials from their cubic structures, proved by theoretical research, gives rise to possible phase transitions such as between a, d and g cubic phases above 500 K. [29][30][31] The difference between bulk and thin lm perovskite materials could also bring about non-trivial differences because of their scaling and surface effect, 32,33 and only bulk materials would be discussed in this work. Anharmonicity from the lattice takes a leading role in affecting their physical properties, e.g., phonon frequency shi, [34][35][36] temperature dependence of vibrational frequencies, 37 thermal expansion, [38][39][40] and Li-ion diffusion. 41 Additionally, it impacts nite-temperature phonon properties and transport properties, 42 directly inuencing thermoelectric (TE) properties.…”