Scientists have developed a new synthesis process to produce a corrosion-resistant coating with additional properties that are ideal for faster, longer-lasting electronics. The team, led by researchers from the University of Pennsylvania, published their work in the journal Nature Communications.

Two-dimensional (2D) semiconductor materials, which control the flow of electricity in electronic devices, are particularly problematic because any corrosion can render the atomically thin material useless.

Traditional methods used to protect these materials from rust include oxide-based coatings, but these processes often use water, which ironically can accelerate the very oxidation they are designed to prevent.

A team led by Pennsylvania State University professor Joshua Robinson has developed a new synthesis method that uses amorphous boron nitride (a-BN) as a coating. The material is known for its high thermal stability and electrical insulating properties, making it ideal for use in semiconductors.

“One of the biggest challenges we face in modern 2D semiconductor research is that the materials oxidize rapidly. Because they are used in transistors or sensors that must last for years, their long-term reliability must be ensured. Currently, these materials do not last more than a week in the open air,” says Joshua Robinson, professor of materials science and engineering and co-author of the paper.

According to Robinson, a-BN’s high dielectric strength is comparable to the best available dielectrics, and it doesn’t require water to make. The team also developed a new two-step atomic layer deposition method that allows two-dimensional materials to be uniformly coated with an a-BN layer.

“We wanted to avoid using water in this process, so we started thinking about what two-dimensional materials we could make without using water in the process, and amorphous boron nitride is one of them,” Robinson said.

Using this new method, the team was able to create a uniform a-BN coating on two-dimensional semiconductors, resulting in a 30% to 100% improvement in transistor performance (depending on the transistor design).

“When you put 2D semiconductors between amorphous boron nitride, you get a smoother electron path, even though it’s amorphous, which allows for advanced electronics,” Robinson said. “Electrons can pass through a 2D material faster than they can through other dielectric materials.”

Despite its high dielectric strength, Robinson noted that researchers have only scratched the surface of a-BN’s potential as a dielectric material for semiconductor devices. “While it outperforms other dielectric materials, we have room for improvement,” he said. “The main thing we’re trying to do right now is improve the overall quality of the material and then integrate it into some of the more complex structures that will be seen in future electronics.”