Small Tweaks to Its Recipe and "White Graphene" Could Change Electronics

Adding some small twists to chemical vapor deposition makes a hexagonal boron nitride that could make the perfect substrate for graphene

2 min read
Small Tweaks to Its Recipe and "White Graphene" Could Change Electronics
Structural characterization of hBN. Schematic illustration of a hBN monolayer.
Illustration: ORNL/Nature Nanotechnology

Strictly speaking, hexagonal boron nitride is a semiconductor, but its band gap is so big that, for all practical purposes, it behaves like an insulator.

It’s because of this pseudo-insulator characteristic that researchers have been interested in combining boron nitride with other two-dimensional materials such as graphene to create hybrid materials capable of doing what each constituent can’t do on its own.

Now researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have developed a process for producing a nearly perfect single layer of hexagonal boron nitride—dubbed “white graphene”—that the researchers believe could be a game changer for the use of the material in electronic applications.

In research published in the journal Chemistry of Materials, the ORNL researchers followed traditional chemical vapor deposition (CVD) steps, in which gaseous reactants are introduced into a furnace to form a film on a metal substrate that’s usually made of copper. However, they added a little something to the recipe that provided a more gentle and controllable way to introduce the reactants into the furnace and took better advantage of the conditions inside the furnace.

“I just thought carefully beforehand and was curious. For example, I remind myself that there are many conditions in this experiment that can be adjusted and could make a difference,” said ORNL’s Yijing Stehle, postdoctoral associate and lead author of a paper, in a press release. “Whenever I see non-perfect results, I do not count them as another failure but, instead, another condition adjustment to be made. This ‘failure’ may become valuable.”

The result of finding value in failure was a “white graphene” that has lived up to the material’s previously unachieved theoretical performance potential. What this means is that if white graphene were used as a substrate material for its carbon analogue, the electron mobility of the combined materials would be a thousand times higher than that of graphene on other substrate materials.

“Imagine batteries, capacitors, solar cells, video screens and fuel cells as thin as a piece of paper,” said Stehle in the press release. “Imagine your message being sent thousands of times faster.”

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Two Startups Are Bringing Fiber to the Processor

Avicena’s blue microLEDs are the dark horse in a race with Ayar Labs’ laser-based system

5 min read
Diffuse blue light shines from a patterned surface through a ring. A blue cable leads away from it.

Avicena’s microLED chiplets could one day link all the CPUs in a computer cluster together.


If a CPU in Seoul sends a byte of data to a processor in Prague, the information covers most of the distance as light, zipping along with no resistance. But put both those processors on the same motherboard, and they’ll need to communicate over energy-sapping copper, which slow the communication speeds possible within computers. Two Silicon Valley startups, Avicena and Ayar Labs, are doing something about that longstanding limit. If they succeed in their attempts to finally bring optical fiber all the way to the processor, it might not just accelerate computing—it might also remake it.

Both companies are developing fiber-connected chiplets, small chips meant to share a high-bandwidth connection with CPUs and other data-hungry silicon in a shared package. They are each ramping up production in 2023, though it may be a couple of years before we see a computer on the market with either product.

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