The material, technically known as hexagonal boron nitride, is said to feature better transparency than graphene, is chemically inert, and atomically smooth. It also features high mechanical strength and thermal conductivity. Unlike graphene, however, it is an insulator instead of a conductor of electricity, making it useful as a substrate and the foundation for the electronics in mobile phones, laptops, tablets and many other devices.
"Imagine batteries, capacitors, solar cells, video screens and fuel cells as thin as a piece of paper," said ORNL postdoctoral associate Yijing Stehle. She and her colleagues are also working on a graphene hexagonal boron 2D capacitor and fuel cell prototype that is not only ‘super thin’ but also transparent.
With white graphene as a substrate, the researchers believe they can unleash the full potential of graphene while further reducing the thickness and increasing the flexibility of electronic devices.
While graphene, which is stronger and stiffer than carbon fibre, is a promising material for data transfer devices, graphene on a white graphene substrate features several thousand times higher electron mobility than on other substrates. That feature could enable data transfers that are much faster than what is currently available.
Stehle noted that this work is especially significant because it takes the material beyond theory. A recent theoretical study led by Rice University, for instance, proposed the use of white graphene to cool electronics. Stehle and colleagues have made high-quality layers of hexagonal boron nitride they believe can be cost-effectively scaled up to large production volumes.
"Various hexagonal boron nitride single crystal morphology formulations have been mentioned in theoretical studies, but for the first time we have demonstrated and explained the process," Stehle said.
That process consists of standard atmospheric pressure chemical vapour deposition with a similar furnace, temperature and time. The difference is what Stehle describes as "a gentle, controllable way to release the reactant into the furnace and figuring out how to take advantage of inner furnace conditions. These two factors are almost always neglected."