What is the path for silicon?

Silicon carbide is the oldest of the WBGs and has been in development as a transistor material for decades. In that time, engineers have started using younger WBG materials, such as gallium nitride, or GaN. In the 1980s, researchers used gallium nitride to create the world’s first bright blue LEDs. Blue light comprises high-energy photons; Gallium nitride, with its band gap, was the first semiconductor that could practically produce photons of sufficient energy. In 2014, three scientists received the Nobel Prize in Physics for that innovation, which became ubiquitous in devices like television screens and light bulbs.

Lately, researchers have begun to use gallium nitride to improve power electronics. The material reached its commercial fruition in recent years in adapters to charge phones and computers. These adapters are smaller, lighter, faster charging and more efficient than traditional ones that use silicon transistors.

“A typical charger you buy for your computer is 90 percent efficient,” said Jim Witham, chief executive of GaN Systems, a Canadian company that supplied the transistors in Apple’s gallium nitride laptop chargers, which were released last fall. “Gallium nitride is 98 percent efficient. It can reduce energy losses four times.”

Yole Développement estimates that the gallium nitride market will grow to $2 billion by 2027 from its total of around $200 million this year.

Wide bandgap materials are making their way into other applications as well. Data centers, large facilities filled with computer servers running the online services we all depend on, are notorious users of electricity. Compuware, a provider of high-end power supplies for data centers, says its gallium nitride-based power supplies reduce electricity waste by about 25 percent and take up 20 percent less space than conventional power supplies. conventional devices, allowing customers to run more servers in the same racks. The company also says that its gallium nitride power supplies are being used in data centers run by major companies around the world.

Engineers are also working on using WBG materials to better harness renewable energy sources. Solar cells and wind turbines rely on traction inverters to supply electricity to a house or to the grid, and many companies hope that gallium nitride will do the job better than silicon. Enphase, a provider of inverters for solar-powered installations, is currently testing gallium nitride-based inverters to ensure they can withstand harsh rooftop weather conditions for decades. In one test, Enphase submerges inverters underwater inside a pressure cooker, places the pressure cooker inside a sealed chamber, and swings the temperature between 185 degrees and minus 40 degrees Fahrenheit over the course of 21 days. If gallium nitride devices survive the challenges, Enphase co-founder Raghu Belur plans to make a quick switch to the new material. “It absolutely goes in that direction,” he said.

At an investor meeting last year, a senior Enphase engineer gave a more conclusive prediction, saying, “It’s the end of the road for silicon.”

Leave a Reply

Your email address will not be published.