Researchers at the Fraunhofer Institute for Applied Solid State Physics IAF have developed a gallium nitride-(GaN-)based power electronics module for 800 V bidirectional direct current (DC) charging systems. The module is part of the GaN4EmoBiL project (“GaN Power Semiconductors for Electric Mobility and System Integration via Bidirectional Charging”) funded by the Federal Ministry for Economic Affairs and Energy (BMWE). Project partner Ambibox GmbH integrated the module into the demonstrator of a bidirectional, single-phase off-board charger for electric vehicles (EV).
The Fraunhofer IAF module uses 1200 V GaN devices fabricated on an insulating substrate. The superior properties of the devices are to be evaluated through their use in the demonstrator with battery voltages ranging from 150 V to a maximum of 920 V. The successful development underscores the enormous potential that GaN-based power electronics hold for the future of electric mobility.
Bidirectional, single-phase 800-V DC charger for 3 kW power
“The single-phase demonstrator of an off-board EV charger with up to 3 kW of bidirectional power addresses an existing gap in the trade-off between cost, flexibility, efficiency, and compactness for bidirectional charging,” explains Jun.-Prof. Dr. Stefan Mönch, coordinator of the GaN4EmoBiL project. Currently, electric vehicles are equipped with permanently installed on-board chargers to convert the alternating current (AC) from a household outlet or public charging station into the direct current (DC) required by the electric car, for example, at a power level of 11 or 22 kW for fast charging.
However, on-board chargers incur high costs due to their size, weight, and technical complexity. The off-board charger developed in GaN4EmoBiL represents a significantly more affordable and flexible alternative: Although its 3 kW power output results in a slower charging speed compared to on-board charging systems, it is mobile, much more compact, lighter, and versatile thanks to its CCS (Combined Charging System) plug and Schuko plug. The demonstrator has a total volume of 8.3 liters and a total weight (including plugs) of 5.7 kg.
Another advantage is its bidirectional charging capability. “Bidirectional charging at high reverse voltages, as enabled by the demonstrated GaN charging system, is a key pillar in making the energy system more flexible,” emphasizes Achim Lösch, Business Developer for High-Frequency and Power Electronics at Fraunhofer IAF. Through bidirectional charging, an electric car can function not only as a means of transportation but also as an energy storage device. During periods of oversupply, it draws power from the grid; during peak loads, it feeds power back into the grid.
GaN power Electronics for energy technology: Fraunhofer IAF at PCIM Expo & Conference 2026
“At Fraunhofer IAF, we are developing innovative GaN devices and integrated power circuits (GaN power ICs) that are not only efficient but also significantly advance miniaturization at the system level through functional integration,” explains Dr. Michael Basler, researcher in the field of GaN power electronics at Fraunhofer IAF. “At the same time, we are advancing the scalability of these technologies in terms of voltage class, current carrying capacity, and wafer size. Our goal: wide-bandgap performance at silicon prices.”
Fraunhofer IAF will provide an overview of its research and development activities in the field of GaN power electronics at this year’s PCIM Expo & Conference, which takes place from June 9 to 11, 2026, in Nuremberg and focuses on the topic “Power Electronics for Energy Technology” in 2026. At the exhibition, Fraunhofer IAF will showcase various GaN-based power electronic components and modules at Booth 260 in Hall 6—with the highlight being the bidirectional EV charging system demonstrator. During the conference, four researchers from Fraunhofer IAF will present their current work in lectures and poster sessions.
Of particular note is the keynote presentation by Dr. Michael Basler on June 9 at 9:45 a.m.: “The GaN Evolution: Lateral, Vertical, and Bidirectional – What’s Next?” This year, the presentation will open the PCIM Conference. In it, Basler will provide an overview of the development of GaN transistors for power electronics to date, explain their advantages, and look ahead to upcoming innovations.
Dr. Richard Reiner will give two presentations: On June 9 at 11:40 a.m., he will compare two different concepts for GaN devices (“GaN-HEMTs vs. GaN-‘Bricks’”), and on June 10 at 10:25 a.m., Reiner will speak on the Technology Stage about “Scaling Up the Power of GaN Technologies”. In addition, Reiner will participate in the panel discussion “What’s up, What’s Next for GaN?” hosted by Bodo’s Power Systems on June 11 at 11:45 a.m.
Jun.-Prof. Dr. Stefan Mönch will participate in the “Advanced Power Devices” poster session on June 10 between 12:45 p.m. and 2:15 p.m. in Hall 4A. He will present his poster “A 600 V Three-Phase Inverter as GaN Power Converter IC on Substrate Biasing-Free Isolating Substrate.” Daniel Fugmann will present his poster “The Influence of Field Plates on the Dynamic RON in GaN-Based Monolithic Bidirectional Switches” at the poster session “GaN Devices and Driving,” which will take place on June 10 between 3:30 p.m. and 5:00 p.m. in Hall 4A.
GaN Power Electronics for the All-Electric Society
One of the key technological requirements of the All-Electric Society is the continuous development of increasingly powerful and efficient power electronics—particularly in energy conversion and storage systems. In these applications, power electronic components represent a bottleneck: The maximum voltage a converter can handle is typically determined by the breakdown voltage of the semiconductors used, thereby defining a critical system limit. Accordingly, the performance of these components is decisive for the performance of the entire system.
Due to its physical properties, GaN enables significant advances in power electronics for energy conversion applications. GaN-based components enable the development of faster, more compact, and more efficient systems. In the field of electromobility, GaN opens the door to the use of power electronics in voltage classes up to 1200 V and, in the future, up to 1700 V, thanks to its combination of performance, efficiency, and reduced costs.
Such high-performance systems have a positive impact on both the range of electric vehicles and their cost-effectiveness. They help to further establish electric mobility across broader segment of society.
About the GaN4EmoBiL Project
The goal of the GaN4EmoBiL consortium is to demonstrate an intelligent and cost-effective bidirectional charging system using new semiconductor, component, and system technologies. To this end, the project partners are researching new semiconductor devices (GaN high-voltage transistors on cost-effective alternative substrates), component concepts (bidirectional blocking power switches), and new system components (on- and off-board AC and DC chargers), including their reliability for significantly extended operating durations.
Demonstrators are intended to address the remaining research and development gap that currently exists in the tension between cost, efficiency, compactness, functionality, power class, and voltage class (800 V batteries). In this way, GaN4EmoBiL makes an important contribution to large-scale bidirectional system integration in electric mobility.
The GaN4EmoBiL project is funded by BMWE as part of the “Elektro-Mobil” program.
About Fraunhofer IAF
The Fraunhofer Institute for Applied Solid State Physics IAF is one of the world’s leading research institutions in the fields of III-V semiconductors and synthetic diamond. Based on these materials, Fraunhofer IAF develops components for future-oriented technologies, such as electronic circuits for innovative communication and mobility solutions, laser systems for real-time spectroscopy, novel hardware components for quantum computing as well as quantum sensors for industrial applications. With its research and development, the Freiburg research institute covers the entire value chain — from materials research, design and processing to modules, systems and demonstrators. https://www.iaf.fraunhofer.de/en.html
Further information
Overview of Fraunhofer IAF research activities in the field of GaN power electronics: https://www.iaf.fraunhofer.de/de/kunden/elektronische-schaltungen/leistungselektronik.html
Project profile for GaN4EmoBiL: https://www.iaf.fraunhofer.de/de/forscher/elektronische-schaltungen/Leistungselektronik/gan4emobil.html
PCIM Conference: Presentations by Fraunhofer IAF
June 9, 9:45 a.m., Stage: Tokio, Level 3 [Keynote]
Michael Basler: »The GaN Evolution: Lateral, Vertical, and Bidirectional – What’s Next?«
June 9, 11:40 a.m., Stage: Tokio, Level 3
Richard Reiner: »GaN-HEMTs vs. GaN-›Bricks‹: A Device Concept Comparison«
June 10, 10:25 a.m., Technology Stage
Richard Reiner: »Scaling Up the Power of GaN Technologies: Paving the Way for the 1200 V Class and Beyond«
June 10, 12:45 p.m., Hall 4A, Poster Session »Advanced Power Devices«
Stefan Mönch: »A 600 V Three-Phase Inverter as GaN Power Converter IC on Substrate Biasing-Free Isolating Substrate«
June 10, 3:30 p.m., Hall 4A, Poster Session »GaN Devices and Driving«
Daniel Fugmann: »The Influence of Field Plates on the Dynamic RON in GaN-Based Monolithic Bidirectional Switches«