Two dimensions are better than three

December 17, 2018, University of Pittsburgh
Cross sectional view of the stack of two-dimensional materials. The monolayer electrolyte in the middle allows the ions (pink spheres) to be toggled between two locations. The location of the ions sets the state of the memory. Credit: Fullerton Group

For the past sixty years, the electronics industry and the average consumer have benefited from the continuous miniaturization, increased storage capacity and decreased power consumption of electronic devices. However, this era of scaling that has benefited humanity is rapidly coming to end. To continue shrinking the size and power consumption of electronics, new materials and new engineering approaches are needed.

Susan Fullerton, assistant professor of chemical and petroleum engineering at the University of Pittsburgh's Swanson School of Engineering, is tackling that challenge by develop next-generation electronics based on all . These "all 2-D" materials are similar to a sheet of paper—if the paper were only a single molecule thick. Her research into these super-thin materials was recognized by the National Science Foundation with a $540,000 CAREER award, which supports early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.

"The advent of new computing paradigms is pushing the limit of what traditional semiconductor devices can provide," Dr. Fullerton said. "For example, will require nanosecond response speeds, sub-volt operation, 1,000 distinct resistance states, and other aspects that no existing device technology can provide.

"We've known for a long time that ions—like the ones in —are very good at controlling how charge moves in these ultra-thin semiconductors," she noted. "In this project, we are reimagining the role of ions in high-performance electronics. By layering successive molecule-sized layers on top of each other, we aim to increase , decrease power consumption, and vastly accelerate processing speed ."1

To build this all 2-D device, Fullerton and her group invented a new type of ion-containing material, or electrolyte, which is only a single molecule thick. This "monolayer electrolyte " will ultimately introduce new functions that can be used by the electronic materials community to explore the fundamental properties of new semiconductor materials and to develop electronics with completely new device characteristics.

Schematic of nanoionic memory device to be developed in this CAREER award. Molecularly thin sheets are stacked on top of each other to create an ultra-thin memory based on ions interacting with two-dimensional materials. Credit: Fullerton Group

According to Dr. Fullerton, there are several important application spaces where the materials and approaches developed in this CAREER research could have an impact: information storage, brain-inspired computing, and security, in particular.

In addition to developing the monolayer electrolytes, the NSF award will support a Ph.D. student and postdoctoral researcher, as well as an outreach program to inspire curiosity and engagement of K-12 and underrepresented students in materials for next-generation electronics. Specifically, Dr. Fullerton has developed an activity where students can watch the polymer electrolytes used in this study crystallize in real-time using an inexpensive camera attached to a smart phone or iPad. The CAREER award will allow Dr. Fullerton to provide this microscope to classrooms so that the teachers can continue exploring with their students.

"When the students get that portable microscope in their hands—they get really creative," she said. "After they watch what happens to the polymer, they go exploring. They look at the skin on their arm, the chewing gum out of their mouth, or the details of the fabric on their clothing. It's amazing to watch this relatively inexpensive tool spark curiosity in the materials that are all around them, and that's the main goal."

Dr. Fullerton noted that her research takes a truly novel approach to ion utilization, which has traditionally been avoided by the semiconductor community.

"Ions are often ignored because if you cannot control their location, they can ruin a device. So the idea of using ions not just as a tool to explore fundamental properties, but as an integral device component is extremely exciting and risky," explained Dr. Fullerton. "If adopted, ions coupled with 2-D materials could represent a paradigm shift in high-performance computing because we need brand with exciting new physics and properties that are not longer limited by size."

Explore further: New materials are powering the battery revolution

Related Stories

New materials are powering the battery revolution

October 4, 2018

There are more mobile phones in the world than there are people. Nearly all of them are powered by rechargeable lithium-ion batteries, which are the single most important component enabling the portable electronics revolution ...

Part-organic invention can be used in bendable mobile phones

October 5, 2018

Engineers at ANU have invented a semiconductor with organic and inorganic materials that can convert electricity into light very efficiently, and it is thin and flexible enough to help make devices such as mobile phones bendable.

New method benchmarks organic mixed conductors

November 27, 2017

Within the past five years, Northwestern University's Jonathan Rivnay has noticed a surge in the development of new organic mixed conductors—polymer materials that can transport both electrons and ions. Lighter, more flexible, ...

Recommended for you

The powerful meteor that no one saw (except satellites)

March 19, 2019

At precisely 11:48 am on December 18, 2018, a large space rock heading straight for Earth at a speed of 19 miles per second exploded into a vast ball of fire as it entered the atmosphere, 15.9 miles above the Bering Sea.

Revealing the rules behind virus scaffold construction

March 19, 2019

A team of researchers including Northwestern Engineering faculty has expanded the understanding of how virus shells self-assemble, an important step toward developing techniques that use viruses as vehicles to deliver targeted ...

Nanoscale Lamb wave-driven motors in nonliquid environments

March 19, 2019

Light driven movement is challenging in nonliquid environments as micro-sized objects can experience strong dry adhesion to contact surfaces and resist movement. In a recent study, Jinsheng Lu and co-workers at the College ...

Levitating objects with light

March 19, 2019

Researchers at Caltech have designed a way to levitate and propel objects using only light, by creating specific nanoscale patterning on the objects' surfaces.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.