Information technology and its wide applications in automation have been progressing rapidly and, as a result, electricity consumption is increasing. It is about time for the power industry to focus on making electronic devices that are more efficient and cost-effective.
Since the 1950s, the power electronic industry relied on silicon as the material of choice for the semiconductor, not only because of its fundamentally superior electrical properties but also because it is relatively inexpensive to produce. The silicon transistor has reached its limit, though, as it is becoming difficult to make further improvements to it. That’s why there’s an increasing need for new material that has better physical limits.
Gallium nitride (GaN), a material that operates in ways similar to silicon but has tremendous performance and size advantages, has caught the attention of the power industry.
ROBUST AND STABLE
GaN, a compound of gallium and nitrogen, is a hard material that is thermally robust, chemically stable, and good at handling high temperatures. The GaN energy gap of 3.4 electron volts is greater than that of silicon, whose band gap is only 1.1 eVs. The energy gap range is a major factor in determining the electrical conductivity of any semiconductor.
GaN is smaller than silicon, and its mobility is 1,000 times faster. It can be manufactured at a lower cost than traditional semiconductors.
Semiconductors with wide band gaps provide many potential advantages when used in power electronic devices, including quicker switching, high-conduction capabilities, low resistance, and less capacitance—which means less loss and less power required to operate.
THE NEXT SEMICONDUCTOR
GaN semiconductors have been around since the early 2000s. They are commonly found in LEDs. Recently they have been used in power amplifier adapters, power supplies, solar inverters, fast-charging power adaptors, LiDAR, and electric vehicles and hybrid electric vehicles (EVs/HEVs). But the technology also could be used for high‐power RF electronics as well as optoelectronics, quantum computers, radio applications, traffic-enforcement cameras, air traffic control systems, and space and military applications.
The GaN market is growing. According to a recent Yole Power SiC report, the GaN market could reach US $450 million by 2023.
Apple is considering using GaN for wireless charging. The adoption of the technology by Apple or another large smartphone manufacturer would dramatically change the market.
Panasonic has used GaN technology to produce transistors in a number of applications including power converters. BMW i Ventures recently invested in GaN solutions for its EV/HEV technology, according to the company’s investment portfolio.
NASA announced last year that it was studying the use of GaN crystals in some of its space applications. The European Space Agency has been looking into GaN to replace silicon due to its robustness against the radiation in space. The Japanese chip company Renesas plans to use GaN power conversion ICs for satellites. Texas Instruments is researching how to make GaN more efficient and accessible.
Although GaN might seem like a perfect choice, it will not replace silicon in all applications, at least not for a few years.
IEEE Senior Member Qusi Alqarqaz is an electrical engineer with more than 28 years of experience in the power industry. He writes about technology, works as a consultant, and mentors younger engineers and students. He is a contributor to The Institute as well as the Analog, a newsletter for the IEEE Central Texas Section. He previously worked in Qatar and the United Arab Emirates.