While much of the public focus in the EV industry revolves around sleek autonomous features or record-breaking range, a quieter yet equally profound revolution is unfolding at the heart of the electric powertrain. It involves not high-performance motors or AI-enabled driving systems, but a material science breakthrough—wide bandgap semiconductors (WBGs), particularly silicon carbide (SiC) and gallium nitride (GaN).
From Tesla’s traction inverters to Bosch’s chip foundries and Lucid’s record-setting efficiency, major players across the U.S. and Europe are quietly but aggressively betting on WBG power electronics. These materials promise a new paradigm: smaller, cooler, faster-switching devices that can handle much higher voltages and power densities than traditional silicon.
This story traces its roots back to 2017, when the U.S. Department of Energy’s U.S. DRIVE partnership set targets for the future of EV power electronics: 100 kW/l power density at a unit cost no greater than $2.70 per kW, with a system life of 300,000 miles or 15 years. By 2024, that benchmark was already outdated. The new roadmap set a 2025 target of 150 kW/l at $1.80 per kW, on 600-volt architectures. Longer term goals are even more ambitious—200 kW/l at $1.35 per kW on 800V systems by 2030, and 225 kW/l at $1.20 by 2035.
At the core of these improvements is a physical property called bandgap—the amount of energy needed to move an electron from the valence band to the conduction band. Silicon’s bandgap is 1.1 electron volts (eV). SiC and GaN boast values of 3.3 and 3.4 eV respectively, enabling much higher breakdown voltages, lower conduction losses, and significantly reduced heat generation.
Dr. Burak Ozpineci, Section Head of Vehicle and Mobility Systems at Oak Ridge National Laboratory (ORNL), explained the advantage plainly: “With SiC, we’ve built inverters in the lab that reach over 98.5% efficiency—sometimes even 99%—compared to 97% with silicon. That’s a two-thirds reduction in power loss.”
The implications for EVs are enormous. Higher efficiency directly translates into longer range—Bosch estimates gains of up to 6%—or enables manufacturers to downsize batteries, cutting cost and weight.
ORNL recently built an inverter that meets 2025 U.S. DRIVE targets and is one-eighth the size of a similar device from 2015. That reduced size also impacts supporting systems: smaller cooling loops, fewer ancillaries, and more compact power electronics layouts across the vehicle.
SiC has emerged as the current leader, with Bosch preparing to enter serial production of its third-generation SiC chips while developing fourth- and fifth-generation versions. According to Jens Baringhaus, Bosch’s Chief Expert for WBG Technologies, SiC “has found its sweet spot at 800V,” making it the go-to material for traction inverters, onboard chargers, and high-voltage architectures.
Meanwhile, GaN—although slightly ahead of SiC in bandgap—is still catching up in real-world deployment. Commercial GaN devices are lateral, meaning current moves across the surface, which limits their voltage handling compared to SiC’s vertical current paths.
GaN’s strengths lie in high switching frequency and compactness, making it ideal for applications like DC-DC converters. However, the industry is racing to develop vertical GaN devices using native GaN substrates, which, if successful, could unlock even higher performance—but at a significant cost premium.
“There are major technical challenges,” Baringhaus noted. “Vertical GaN still struggles with manufacturing costs. Reaching cost parity with SiC will be extremely difficult unless alternative substrates emerge with the right cost-performance tradeoffs.”
Despite these challenges, the industry is optimistic. “GaN is going through what SiC went through 20 years ago,” said Ozpineci. “We saw defects and reliability issues then too. But we solved them. GaN will get there—it’s just a matter of time.”
Cost remains the central hurdle for both materials. WBG semiconductors are more expensive than silicon—both in raw materials and in processing complexity. However, these costs are often recouped when viewed at the system level: smaller form factors, lower cooling requirements, and fewer support components add up to meaningful savings for OEMs.
One major way the industry is addressing cost is through wafer scaling. Most SiC devices are currently made on 150mm wafers. Players like Infineon and Bosch are transitioning to 200mm and even 300mm wafers, significantly improving die yield per wafer. For example, moving from 150mm to 200mm can increase the number of usable dies by 1.8x, and 200mm to 300mm by another 2.3x. GaN is also heading toward 300mm production, with some prototypes already in place.
Environmental considerations are also shaping the future. In response to EU restrictions on PFAs (per- and polyfluoroalkyl substances), manufacturers are moving toward silver and copper sintering, which not only increases heat tolerance but reduces the use of “forever chemicals” in chip packaging.
AI, of course, is playing an increasingly pivotal role. “AI is already widely used in process control and simulation,” Baringhaus said. “We’ll see more development tools and design processes become AI-driven in the coming years.”
Looking forward, integration is the next frontier. Engineers are working on ways to co-package multiple SiC devices, sensors, and controllers into highly compact, robust modules. This is especially important as power devices shrink in size: managing thermal performance and maintaining system-level reliability becomes exponentially more difficult.
There are also cooling challenges. Traditional water-ethylene glycol (WEG) systems may not be sufficient for the next generation of compact power modules. New liquid or even vapor-based cooling systems are being explored to meet the demands of these dense, high-power systems.
What’s emerging is not just a better chip—but an entirely rethought EV architecture. In the age of 800V platforms, ultra-fast charging, and autonomous controls, power electronics is no longer an invisible component—it’s the cornerstone of performance, efficiency, and long-term reliability.
As Bosch, Wolfspeed, Infineon, and dozens of automakers race toward commercial maturity for fourth- and fifth-generation WBG chips, it’s clear that SiC and GaN aren’t just supporting characters—they’re becoming the stars of the show.