Piezoelectric tuning of thermal conductivity in nano-architected gallium nitride metamaterials

Gallium nitride (GaN) is widely recognized for its high thermal conductivity and piezoelectric properties, making it a key material in high-power electronics and nanoelectronic devices. Efficient thermal management is essential for the reliability and longevity of such devices, yet existing methods to tune thermal conductivity often present challenges, including permanent alteration of material properties and the complexity of applying mechanical strain at the nanoscale. In this study, we propose a dynamic and reversible approach to tune the thermal conductivity of GaN using the piezoelectric effect where an applied electric field induces mechanical strain and alters the material’s atomic structure and thermal properties. Using molecular dynamics (MD) simulations, we explore the thermal conductivity of pristine GaN and nano-architected GaN metamaterials across three topological families: cubic, octahedron, and triply periodic minimal surfaces (TPMS). Our results demonstrate that nano-architected GaN metamaterials exhibit significantly reduced thermal conductivity compared to pristine GaN, with variations depending on the underlying architecture. Furthermore, we demonstrate that, due to the topology-dependent enhancement of piezoelectric property, nano-architected GaN metamaterials exhibit a broader range of thermal conductivity tunability by an electric field compared to the pristine GaN. This study highlights the potential of tailoring the topological featuring and resorting to the piezoelectricity effect in tuning the thermal conductivity of GaN, providing insights for developing programmable nanoelectronic devices.