Silicon Valley earned its name for a reason—you can find silicon, the semiconductor element, in nearly every computing device on the planet. While silicon has become the widely adopted material-of-choice, it has begun to fall short of modern technology and market demands. As with all technology, computer scientists seem to have reached silicon's theoretical limits. Now the question has become: what comes after silicon? Electronics industry researchers continue to actively investigate silicon alternatives, such as gallium nitride (GaN), and implement them in new technology.
What is Gallium nitride (GaN)?
Gallium nitride (GaN) is a compound comprised of gallium and nitrogen that work together to form a robust Wurtzite crystal structure. This structure is very strong and has a high melting point, 4532 degrees Fahrenheit, making it suitable for semiconductor base materials in high-temperature settings.
GaN's structure will accept magnesium to form an n-type semiconductor, and silicon or oxygen to form a p-type semiconductor. Although gallium nitride does not occur naturally, scientists can synthesize it using a mixture of pure gallium and ammonia. When these two components are exposed to a large amount of pressure and heat, gallium nitride and hydrogen gas will form.
Two arguable downsides to using GaN are its limitations in size and purity. Given its complex crystalline structure, gallium nitride is prone to high dislocation densities ranging from 10^8 to 10^10 defects.
What is Gallium nitride's role in blue LEDs?
Gallium nitride isn't a brand-new compound. In fact, GaN has been present in certain electronics since the early 1990s. Around that time, Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura discovered that when they doped GaN with excess amounts of magnesium, the compound emits a blue light in the form of an LED. The LED community hailed this development as a breakthrough, and the scientists' invention eventually won them the 2014 Physics Nobel Prize for the vast influence their discovery had on the world.
The advent of blue LEDs has led to a renaissance of lighting applications worldwide, retiring the need for inefficient incandescent light bulbs. Once the evasive blue LED entered the market, it paved the way for the arrival of white LEDs and color-changing LEDs. The blue LED was the final ingredient in the now-beloved RGB LED.
Gallium nitride also contributed to the development of Blu-ray optical discs, which ushered in a new era of data storage. Before Blu-rays, DVDs were the default method of data storage for visual media. However, DVDs utilize 650nm lasers to read and write the hosted information, which limits their storage abilities to around 5GB of data. With the invention of the blue LED, and subsequently blue lasers, Blu-ray discs were able to utilize a 405nm laser to read and write up to 100GB of data in the same amount of space. So yes, Blu-ray doesstand for something specific.
Gallium nitride semiconductors: Harnessing GaN's power
Although gallium nitride had already earned its claim to fame in other applications, it has become increasingly valuable in the semiconductor space over the last decade. Given its wide bandgap and high melting point, GaN is a powerful tool in the power electronics world, especially when it comes to:
- Power conversion
- Discrete semiconductor components
GaN's switching characteristics make it also advantageous; GaN can switch to 400V nearly ten times as fast as silicon, which means manufacturers can also use this compound to make historically silicon-based products significantly smaller.
Learn more about the difference between GaN and silicon.
Modern GaN-based products
You can find GaN-based power products in residential solar energy harvesting applications. As an example, the Japanese-based company Yaskawa built solar inverters that use gallium nitride-based power semiconductor systems. A variety of their photovoltaic inverters utilize GaN technology, and those inverters have achieved significant savings when compared to silicon-based counterparts. The GaN-based inverters are half the size, half the weight, and lose half as much energy as silicon-based inverters.
Most impressively, some GaN transformers are so efficient that they can operate at temperatures low enough to not require a cooling fan. Yasakawa's Enewell-SOL V1 model, which is a residential 4.5kW photovoltaic inverter, utilizes gallium nitride and boasts a 60% reduction in overall volume when compared to a comparable silicon-based inverter system.
A company called SUMOLIGHT offers another excellent example of using GaN-based technology to create innovative products. SUMOLIGHT which manufactures professional-grade studio lighting solutions, created an award-winning studio-lighting product that utilizes discrete GaN-based devices. These devices reduce the overall weight and size of their power supply solution. In fact, SUMOLIGHT's bespoke power supply design was so powerful and lightweight that they were able to build the power supply directly into the lighting housing of the fixture without compromising the light's brightness or controllability. The power supply product is also efficient enough to requires no active cooling mechanism. The device utilizes entirely passive cooling mechanisms.
Conclusion: Gallium nitride applications
Gallium nitride has proven highly useful in the electronics industry and continues to gain popularity in historically silicon-based power semiconductor applications. While it may be more capable than silicon in certain applications, technologists around the world have still been slow to adopt gallium nitride. This hesitation may be due to gallium nitride's cost as well as engineers' lack of familiarity with its capabilities. However, gallium nitride-based products boast impressive efficiency and an ability to support higher power circuitry than traditional silicon, which may eventually make it the saving grace for a wave of semiconductor technologies.