News Article

Increasing Efficiency And Shrinking GaN Devices

Fraunhofer ISE has explored the limits of a new technology with gallium nitride power transistors

Scientists at the Fraunhofer Institute for Solar Energy Systems ISE have successfully tested new types of power transistors made of gallium nitride in power electronic systems.

With these transistors, the size of charging inverters for electric vehicles and the weight of power converters for aircrafts can be reduced and power supplies for server farms could gain efficiency.

Fraunhofer ISE 1MHz LLC resonant converter

Gallium nitride (GaN) has been in the centre of interest of many semiconductor researchers for a long time.

“With power transistors made of GaN, significantly higher switching frequencies are achievable than with ordinary silicon power transistors. In contrast to SiC, GaN is particularly suited for the lower voltage range. Especially resonant topologies can fully utilise the advantages of GaN power transistors," says Bruno Burger, head of the department “Power Electronics" at Fraunhofer ISE.

Despite the substantial need for research, impressing results have been obtained in an internal study. A DC/DC converter with rated output power of one kilowatt was operated at a switching frequency of one megahertz providing 94 percent peak efficiency. “With regard to the 600V GaN transistor the switching frequency and also the efficiency of the DC/DC converter could have been raised to an even higher level. The limiting factor was the high-frequency transformer," points out Arne Hendrik Wienhausen who performed the experiments.

Until today, only transistors made of silicon have been used in power electronic systems with voltages up to 600V. Switching and conduction losses of these transistors are significantly higher than those of transistors made of GaN. Therefore high losses are generated in the transistors which need to be dissipated in a complex way.

In addition to the higher efficiency, GaN provides the opportunity of increasing the switching frequency to exceed the state-of-the-art multiple fold. As a result, the passive components like inductors, transformers and capacitors can be much smaller leading to more compact and light-weight designs and expensive materials can be saved.

The scientists at Fraunhofer ISE predict that GaN will permanently change the world of power electronics. In all applications where system weight and volume are crucial, power transistors made of GaN and operated at high frequency offer great advantages over other technologies. It can be assumed that the switching frequency of one megahertz demonstrated in the DC/DC converter is only a first step towards much higher switching frequencies while maintaining high efficiency.

Converter efficiency of the 1MHz LLC resonant converter

The GaN power transistors used in the converter were produced by Panasonic.

AngelTech Live III: Join us on 12 April 2021!

AngelTech Live III will be broadcast on 12 April 2021, 10am BST, rebroadcast on 14 April (10am CTT) and 16 April (10am PST) and will feature online versions of the market-leading physical events: CS International and PIC International PLUS a brand new Silicon Semiconductor International Track!

Thanks to the great diversity of the semiconductor industry, we are always chasing new markets and developing a range of exciting technologies.

2021 is no different. Over the last few months interest in deep-UV LEDs has rocketed, due to its capability to disinfect and sanitise areas and combat Covid-19. We shall consider a roadmap for this device, along with technologies for boosting its output.

We shall also look at microLEDs, a display with many wonderful attributes, identifying processes for handling the mass transfer of tiny emitters that hold the key to commercialisation of this technology.

We shall also discuss electrification of transportation, underpinned by wide bandgap power electronics and supported by blue lasers that are ideal for processing copper.

Additional areas we will cover include the development of GaN ICs, to improve the reach of power electronics; the great strides that have been made with gallium oxide; and a look at new materials, such as cubic GaN and AlScN.

Having attracted 1500 delegates over the last 2 online summits, the 3rd event promises to be even bigger and better – with 3 interactive sessions over 1 day and will once again prove to be a key event across the semiconductor and photonic integrated circuits calendar.

So make sure you sign up today and discover the latest cutting edge developments across the compound semiconductor and integrated photonics value chain.



Search the news archive

To close this popup you can press escape or click the close icon.
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.

Please subscribe me to:


You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in:
Live Event