-
- News
- Books
Featured Books
- pcb007 Magazine
Latest Issues
Current IssueInventing the Future with SEL
Two years after launching its state-of-the-art PCB facility, SEL shares lessons in vision, execution, and innovation, plus insights from industry icons and technology leaders shaping the future of PCB fabrication.
Sales: From Pitch to PO
From the first cold call to finally receiving that first purchase order, the July PCB007 Magazine breaks down some critical parts of the sales stack. To up your sales game, read on!
The Hole Truth: Via Integrity in an HDI World
From the drilled hole to registration across multiple sequential lamination cycles, to the quality of your copper plating, via reliability in an HDI world is becoming an ever-greater challenge. This month we look at “The Hole Truth,” from creating the “perfect” via to how you can assure via quality and reliability, the first time, every time.
- Articles
- Columns
- Links
- Media kit
||| MENU - pcb007 Magazine
Researchers Control the Properties of Graphene Transistors Using Pressure
May 17, 2018 | Columbia UniversityEstimated reading time: 3 minutes

A Columbia University-led international team of researchers has developed a technique to manipulate the electrical conductivity of graphene with compression, bringing the material one step closer to being a viable semiconductor for use in today’s electronic devices.
“Graphene is the best electrical conductor that we know of on Earth,” said Matthew Yankowitz, a postdoctoral research scientist in Columbia’s physics department and first author on the study. “The problem is that it’s too good at conducting electricity, and we don’t know how to stop it effectively. Our work establishes for the first time a route to realizing a technologically relevant band gap in graphene without compromising its quality. Additionally, if applied to other interesting combinations of 2D materials, the technique we used may lead to new emergent phenomena, such as magnetism, superconductivity, and more.”
The study, funded by the National Science Foundation and the David and Lucille Packard Foundation, appears in the May 17 issue of Nature.
The unusual electronic properties of graphene, a two-dimensional (2D) material comprised of hexagonally-bonded carbon atoms, have excited the physics community since its discovery more than a decade ago. Graphene is the strongest, thinnest material known to exist. It also happens to be a superior conductor of electricity – the unique atomic arrangement of the carbon atoms in graphene allows its electrons to easily travel at extremely high velocity without the significant chance of scattering, saving precious energy typically lost in other conductors.
But turning off the transmission of electrons through the material without altering or sacrificing the favorable qualities of graphene has proven unsuccessful to-date.
“One of the grand goals in graphene research is to figure out a way to keep all the good things about graphene but also create a band gap – an electrical on-off switch,” said Cory Dean, assistant professor of physics at Columbia University and the study’s principal investigator. He explained that past efforts to modify graphene to create such a band gap have degraded the intrinsically good properties of graphene, rendering it much less useful. One superstructure does show promise, however. When graphene is sandwiched between layers of boron nitride (BN), an atomically-thin electrical insulator, and the two materials are rotationally aligned, the BN has been shown to modify the electronic structure of the graphene, creating a band gap that allows the material to behave as a semiconductor – that is, both as an electrical conductor and an insulator. The band gap created by this layering alone, however, is not large enough to be useful in the operation of electrical transistor devices at room temperature.
In an effort to enhance this band gap, Yankowitz, Dean, and their colleagues at the National High Magnetic Field Laboratory, the University of Seoul in Korea, and the National University of Singapore, compressed the layers of the BN-graphene structure and found that applying pressure substantially increased the size of the band gap, more effectively blocking the flow of electricity through the graphene.
“As we squeeze and apply pressure, the band gap grows,” Yankowitz said. “It’s still not a big enough gap – a strong enough switch – to be used in transistor devices at room temperature, but we have gained a fundamentally better understanding of why this band gap exists in the first place, how it can be tuned, and how we may target it in the future. Transistors are ubiquitous in our modern electronic devices, so if we can find a way to use graphene as a transistor it would have widespread applications.”
Yankowitz added that scientists have been conducting experiments at high pressures in conventional three-dimensional materials for years, but no one had yet figured out a way to do them with 2D materials. Now, researchers will be able to test how applying various degrees of pressure changes the properties of a vast range of combinations of stacked 2D materials.
“Any emergent property that results from the combination of 2D materials should grow stronger as the materials are compressed,” Yankowitz said. “We can take any of these arbitrary structures now and squeeze them and the strength of the resulting effect is tunable. We’ve added a new experimental tool to the toolbox we use to manipulate 2D materials and that tool opens boundless possibilities for creating devices with designer properties.”
-By Jessica Guenzel
Testimonial
"In a year when every marketing dollar mattered, I chose to keep I-Connect007 in our 2025 plan. Their commitment to high-quality, insightful content aligns with Koh Young’s values and helps readers navigate a changing industry. "
Brent Fischthal - Koh YoungSuggested Items
Fresh PCB Concepts: Designing for Success at the Rigid-flex Transition Area
08/28/2025 | Team NCAB -- Column: Fresh PCB ConceptsRigid-flex PCBs come in all shapes and sizes. Manufacturers typically use fire-retardant, grade 4 (FR-4) materials in the rigid section and flexible polyimide materials in the flex region. Because of the small size, some rigid-flex PCBs, like those for hearing aid devices, are among the most challenging to manufacture. However, regardless of its size, we should not neglect the transition area between the rigid and flexible material.
Global Sourcing Spotlight: How to Evaluate Supplier Capabilities Worldwide
08/20/2025 | Bob Duke -- Column: Global Sourcing SpotlightIn global sourcing, the difference between a competitive edge and a catastrophic disruption often comes down to how well you vet your suppliers. Sourcing advanced PCBs, precision components, or materials for complex assemblies demands diligence, skepticism, and more than a little time on airplanes. Here’s how to do your due diligence when evaluating international suppliers and why cutting corners can cost you more than money.
Insulectro and Electroninks Sign North American Distribution Agreement
08/12/2025 | InsulectroElectroninks, a leader in metal organic decomposition (MOD) inks for additive manufacturing and advanced semiconductor packaging, today announced a strategic collaboration and distribution partnership with Insulectro, a premier distributor of materials used in printed electronics and advanced interconnect manufacturing.
Happy’s Tech Talk #41: Sustainability and Circularity for Electronics Manufacturing
08/13/2025 | Happy Holden -- Column: Happy’s Tech TalkI attended INEMI’s June 12 online seminar, “Sustainable Electronics Tech Topic Series: PCBs and Sustainability.” Dr. Maarten Cauwe of imec spoke on “Life Cycle Inventory (LCI) Models for Assessing and Improving the Environmental Impact of PCB Assemblies,” and Jack Herring of Jiva Materials Ltd. spoke on “Transforming Electronics with Recyclable PCB Technology.” This column will review information and provide analysis from both presentations.
Dymax Renews Connecticut Headquarters Lease, Reinforces Long-Term Commitment to Local Community
08/08/2025 | DymaxDymax, a global manufacturer of rapid light-curing materials and equipment, is pleased to announce the renewal and extension of its corporate lease at its 318 Industrial Lane, Torrington, headquarters.