Traditional materials for power electronics, such as SiC and GaN, are reaching their limits in terms of performance, prompting the search for new materials that can overcome these barriers. Ultrawide bandgap semiconductors, such as β-Ga₂O₃ and AlN, offer exceptional higher breakdown voltages, making them ideal candidates for the next generation of power devices.

In response to these challenges, researchers at PHELIQS, in collaboration with LMGP, Institut Néel and MEM, have developed a method to grow ultra-smooth layers of aluminum nitride (AlN) on β-Ga₂O₃ substrates using plasma-assisted molecular beam epitaxy (PAMBE), a deposition technique that operates with a relatively low thermal budget [1]. By tweaking the balance between aluminum and nitrogen during growth, they achieved high quality AlN films with sharp, clean interfaces. The AlN/β-Ga₂O₃ interface is positively charged, which attracts a high density of electrons that accumulate in the interface plane. This high density allows the electrons to achieve high mobility in this plane, thereby improving electrical performance.

This discovery is not just about growing crystals; it is about providing a new technology to power the modern world. The improved electron flow can lead to:

• Faster, more efficient electric vehicle chargers,
• Enhanced efficiency and reduced energy consumption in motor control systems (e.g. industrial automation, robotics), to regulate the speed and torque of electric motors,
• Energy-saving power converters for renewable energy systems.

By mastering the growth of AlN on β-Ga₂O₃, scientists are paving the way for electronic devices that are not just smaller and faster, but also greener and more reliable. The next steps involve exploring new device designs that can fully harness this technology. The ultimate goal? Power electronics that keep up with the demands of our fast-paced, energy-hungry world.