Silicon has been the backbone of electronics for decades, but it has its limits—especially when it comes to energy efficiency.
Now, a breakthrough from researchers at Nagoya University in Japan could change that.
They have created a new way to build gallium oxide (Ga₂O₃) semiconductors that are stronger, more efficient, and able to carry twice as much current as before.
Semiconductors are the heart of electronic devices, and one of their most important parts is the diode.
Diodes are made by joining two layers of semiconductors: one with extra electrons (n-type) and one with missing electrons, or “holes” (p-type).
This junction allows electricity to flow in one direction and not the other, making diodes vital for controlling power in everything from smartphones to electric vehicles.
Gallium oxide has long been seen as a promising alternative to silicon because it can handle much higher voltages and waste less energy as heat.
That could mean better efficiency for power-hungry systems like renewable energy grids or EV charging stations. The problem, until now, was that while n-type gallium oxide layers were easy to make, p-type layers were nearly impossible.
The crystal structure of gallium oxide naturally rejects the atoms needed for p-type layers, making devices unreliable.
The team at Nagoya University finally cracked this problem.
Their solution was to inject nickel atoms into gallium oxide by bombarding the surface with atoms shot at high speed. After this, they carefully heated the material in two steps: first at 300°C using activated oxygen radicals, and then at 950°C in oxygen gas.
This process transformed the nickel into nickel oxide and bonded it securely within the gallium oxide structure, creating the long-sought p-type layer.
The result is the first functional gallium oxide pn diodes, capable of carrying twice the current of earlier gallium oxide devices while wasting less energy than silicon-based diodes. That means cooler, more efficient, and more cost-effective electronics.
Even more importantly, this method doesn’t require exotic equipment. It uses existing industrial tools, which means it can be scaled up for mass production.
“The implications for future energy efficiency and costs are substantial, particularly for electric vehicles and renewable energy industries,” said Professor Masaru Hori from the Center for Low-Temperature Plasma Sciences at Nagoya University.
Analysts estimate the gallium oxide semiconductor market could reach nearly 15 billion yen a year by 2035. With this new process, gallium oxide may finally move from research labs to the center of the world’s most advanced power systems.
