Interfacial Interaction Governs Wettability and Thermal Transport at Liquid Ga/SiC Interfaces

Abstract In liquid-metal thermal management and SiC-based power-device packaging, the wettability and thermal transport across Ga/SiC interfaces are critical for efficient heat dissipation. However, the fundamental role of SiC crystal orientation and surface termination in governing interfacial wettability and thermal conductance remains unclear. In this study, we investigate nanoscale wetting and thermal transport of liquid Ga on SiC surfaces with different crystal planes and terminations by molecular dynamics simulations. The results show that liquid Ga exhibits non-wetting behavior on ideal oxide-free SiC surfaces at 350 K. Among all considered interfaces, Si-terminated surfaces and the (111) crystal plane display stronger Ga−SiC interactions and consequently better wettability than other crystal planes. Although increasing temperature from 305 to 500 K improves liquid spreading, it does not alter the non-wetting nature of the interface. In addition, interfacial thermal conductance increases with interfacial interaction strength and wettability. The 111-Si interface exhibits the highest interfacial thermal conductance of 15.50 MW·m−2·K−1. Vibrational density of states analysis further identifies the largest interfacial spectral overlap at 111-Si, providing complementary insight into interfacial vibrational coupling. These results demonstrate that interfacial interaction strength governs both wettability and interfacial thermal transport. This work establishes a direct correlation between interfacial structure, wettability, and heat transfer, providing atomistic guidance for applications of liquid gallium in thermal management.