Insight into Interfacial Heat Transfer of β-Ga₂O₃/Diamond Heterostructures via the Machine Learning Potential

Area of Science:

• Materials Science
• Semiconductor Physics
• Thermal Management

Background:

• Gallium Oxide (β-Ga₂O₃) is an ultrawide-band gap semiconductor ideal for high-power and UV optoelectronics.
• Low thermal conductivity hinders the performance of β-Ga₂O₃ devices.
• Integrating β-Ga₂O₃ with diamond heat sinks offers a solution, but interfacial thermal properties require further study.

Purpose of the Study:

• To investigate the crystal-orientation-dependent and interfacial-atom-dependent thermal boundary resistance (TBR) of β-Ga₂O₃/diamond heterostructures.
• To understand how different crystal orientations and interfacial atoms influence thermal properties.
• To propose optimization strategies for thermal management in these heterostructures.

Main Methods:

• Utilized molecular dynamics simulations powered by machine learning potentials.
• Analyzed thermal conductivity, thermal conductivity spectra, vibration density of states, and interfacial structures.
• Examined the impact of varying crystal orientations and interfacial atoms on TBR.

Main Results:

• Demonstrated that TBR in β-Ga₂O₃/diamond heterostructures is significantly influenced by crystal orientations and interfacial atoms.
• Provided detailed explanations for observed TBR differences based on material properties and interface characteristics.
• Identified key factors governing thermal transport across the heterostructure interface.

Conclusions:

• Gained a deeper understanding of how crystal orientation and interfacial atoms affect the thermal behavior of β-Ga₂O₃/diamond heterostructures.
• Proposed optimization strategies for selecting crystal orientations and interfacial atoms to enhance thermal management.
• The findings offer guidance for designing and improving β-Ga₂O₃-based devices with integrated diamond heat sinks.