Superjunction Silicon-Based Devices vs. Vertical GaN Devices: Multi-Physics Co-Optimization Strategies for New Energy Vehicle Inverters

New energy vehicle inverter, as the "heart" of the electric drive system power conversion unit, has its material technology directly impacting the efficiency and power density of the entire system. Currently, silicon-based super junction (SJ-Si) devices have occupied the medium-voltage market. Wide-band semiconductors such as silicon carbide (SiC) and gallium nitride (GaN), despite their high-frequency and high-voltage performance advantages, face delayed industrialization due to material defects and cost issues. This paper analyzes SJ-Si and vertical GaN power devices using multi-physics co-optimization to assess their potential for high-performance, cost-effective inverters in new energy vehicles. It employs multi-scale simulations and machine learning to compare their electric field management, electro-thermal characteristics, and fabrication costs, and reviews the latest literature on high-voltage power devices. The findings show that SJ-Si is suitable for cost-sensitive medium-voltage applications, while vertical GaN is more suitable for high-frequency and high-power density applications. The two can complement each other's performance through partition collaboration and intelligent design tools, providing new ideas for the evolution of next-generation inverter technology.