Transforming energy more efficiently
Electronic devices based on “wide-band-gap semiconductors” offer a chance to boost the efficiency and power density of power electronics. This makes power-electronics components smaller, faster, more reliable and more efficient.
Smart energy supplies, electromobility, broadband communication systems and AI applications – the number of interacting and interconnected systems is growing all the time. However, as the number of systems and volume of data traffic continues to rise, so too does the primary energy consumption. Meanwhile, electrical energy almost always needs to be converted for it to be used by the various systems in question. According to estimates, more than three terawatt-hours of energy are lost every year in this conversion in Europe alone – equivalent to the electricity generated by a mid-sized, coal-fired power station.
Power electronics are the key to energy efficiency
For the reasons outlined above, efficient energy conversion is becoming a major challenge for applications in areas like Industry 4.0 and electromobility, where power electronics are absolutely key. Only by using these can renewable energy sources be integrated into electricity supply grids. Without them, electric vehicles would not be possible; they are an essential prerequisite for charging notebook computers, smartphones, etc., and they ensure that drive systems in the manufacturing and process industry operate reliably. Now, new power-electronics devices are ensuring that the voltage, current and frequency profiles required in each scenario can be generated with even lower energy losses and a much higher power density.
A higher power density with silicon carbide and gallium nitride
New electronic devices based on “wide-band-gap” (WBG) semiconductors in particular are boosting the efficiency and power density of power electronics. This makes power-electronics components smaller, faster, more reliable and more efficient than conventional, silicon-based counterparts. At present, both silicon carbide (SiC) and gallium nitride (GaN) are establishing themselves as key materials on the market.
Even though SiC and GaN might compete with one another in certain areas, it is still possible to roughly differentiate them according to areas of application: GaN-based components can be incorporated into smaller and lighter device structures that switch the current more efficiently. Power losses are reduced by up to fifty per cent. GaN can even withstand higher voltages and is particularly of interest for high-frequency circuits. Its switching speeds are up to 20 times faster than silicon, which enables a threefold power increase. For this reason, GaN power electronics were initially used mainly in high-performance premium applications for high-frequency circuits, where their low resistance and small form factor on a system level scored particularly well. Yet now, more and more smartphone manufacturers are integrating GaN-based inbox fast-chargers into their products – marking a milestone for GaN power electronics as they break into the high-volume consumer market as well.
On the other hand, SiC is primarily used for high-temperature applications due to its lower thermal expansion and its resilience in the face of harsh ambient conditions. With a price of USD 800 to 2,000 per metric ton, SiC is costly compared to other semiconductor materials. It therefore follows that market-research institute Yole claims that the automotive industry is currently the biggest driving force on the booming market for SiC power electronics: in 2025, it will hold a total market share of over 50 per cent. SiC semiconductors are primarily used for on-board chargers in electric vehicles.
Applications keep on coming
Yet the areas of application for SiC- and GaN-based power electronics are currently diversifying at breakneck speed. Renewable energy alone promises enormous growth thanks to WBG semiconductors’ high energy efficiency and very low power losses. According to Market Study Report, the market turnover for SiC and GaN power-electronics devices is anticipated to grow by an average of 33.7 per cent annually over the coming five years. As such, the global market will grow from around EUR 570 million in 2019 to over USD 1.8 billion by 2025.
