A team of researchers from the Massachusetts Institute of Technology (MIT) and other institutions has developed a new way to improve the performance of powerful electronic devices by using an ultrathin layer of diamond.
The breakthrough could help future technologies such as 6G wireless networks, satellite communications, radar systems, and even data centers operate faster and more efficiently.
Most of today’s computer chips are made from silicon.
While silicon has been extremely successful, it has limits when handling the high power needed for advanced wireless communication systems.
Because of this, researchers have been exploring another material called gallium nitride, or GaN.
Gallium nitride can handle much higher power and faster speeds than silicon, making it ideal for demanding applications.
However, there is a major challenge. A large amount of the energy flowing through GaN devices turns into heat.
As more transistors are packed onto a chip, certain areas can become extremely hot, reducing performance and shortening the device’s lifespan.
To solve this problem, the research team turned to diamond.
Diamond is not only beautiful as a gemstone—it is also the best known material for conducting heat. This means it can quickly move heat away from hot spots and spread it more evenly.
The researchers created tiny gallium nitride transistors, called “dielets,” and embedded them into an ultrathin layer of lab-grown single-crystal diamond. The diamond acts like a heat spreader, helping keep temperatures under control.
Previous attempts to combine diamond and gallium nitride often created unwanted electrical effects that slowed device performance. The new method avoids these problems while still providing excellent cooling.
Building the devices required extremely precise manufacturing. The team used a powerful femtosecond laser to cut tiny gallium nitride pieces from a wafer and create matching cavities in the diamond layer. The transistors were carefully placed into these openings and bonded with a very thin film that helps transfer heat efficiently.
Using this approach, the researchers built a power amplifier, a critical component found in wireless communication systems. Power amplifiers boost weak electrical signals so they can travel long distances.
The new amplifier delivered higher output power, better efficiency, and stronger signal gain than similar devices reported by the researchers and others. According to the team, it outperformed all comparable amplifiers they could find in the scientific literature.
The technology could have important uses in future wireless networks, space communications, industrial drones, and high-power radar systems. It may also help reduce energy use in data centers by improving the cooling of power-conversion electronics.
The researchers believe this advance brings the electronics industry one step closer to building more powerful and reliable next-generation devices.
What once seemed like science fiction, they say, may soon become a practical technology powering the communications systems of the future.
