Advance in energy storage could speed up development of next-gen electronics

February 19, 2014
Advance in energy storage could speed up development of next-gen electronics

Electronics are getting smaller all the time, but there's a limit to how tiny they can get with today's materials. Researchers now say, however, that they have developed a way to shrink capacitors—key components that store energy—even further, which could accelerate the development of more compact, high-performance next-gen devices. The study appears in the journal ACS Nano.

Takayoshi Sasaki and colleagues point out that many recent improvements have already downsized capacitors significantly. But current technology has almost reached its limit in terms of materials and processing, which in turn limits the performance that manufacturers can achieve. In response, researchers have gone to the nanoscale, but "nanocapacitors" are not easy to make.

They require harsh, difficult-to-use methods and even then, they may not work that well. So Sasaki's team developed an easier approach, and they use it to make high-performance "ultrathin" capacitors.

The researchers found that they could use gentle techniques and mild conditions to create a sandwich consisting of layers of two different types of oxide nanosheets to produce an ultrathin . In addition, the new capacitor has a capacitance density about 2,000 times higher than that of commercially available products. They say that, in the future, the ultrathin capacitors could be used in and in memory storage devices, for example.

Explore further: High-performance energy storage

More information: "All-Nanosheet Ultrathin Capacitors Assembled Layer-by-Layer via Solution-Based Processes" ACS Nano, Article ASAP. DOI: 10.1021/nn406367p

Abstract
All-nanosheet ultrathin capacitors of Ru0.95O20.2–/Ca2Nb3O10–/Ru0.95O20.2– were successfully assembled through facile room-temperature solution-based processes. As a bottom electrode, conductive Ru0.95O20.2– nanosheets were first assembled on a quartz glass substrate through a sequential adsorption process with polycations. On top of the Ru0.95O20.2– nanosheet film, Ca2Nb3O10– nanosheets were deposited by the Langmuir–Blodgett technique to serve as a dielectric layer. Deposition parameters were optimized for each process to construct a densely packed multilayer structure. The multilayer buildup process was monitored by various characterizations such as atomic force microscopy (AFM), ultraviolet–visible absorption spectra, and X-ray diffraction data, which provided compelling evidence for regular growth of Ru0.95O20.2– and Ca2Nb3O10– nanosheet films with the designed multilayer structures. Finally, an array of circular films (50 μm ) of Ru0.95O20.2– nanosheets was fabricated as top electrodes on the as-deposited nanosheet films by combining the standard photolithography and sequential adsorption processes. Microscopic observations by AFM and cross-sectional transmission electron microscopy, as well as nanoscopic elemental analysis, visualized the sandwich metal–insulator–metal structure of Ru0.95O20.2–/Ca2Nb3O10–/Ru0.95O20.2– with a total thickness less than 30 nm. Electrical measurements indicate that the system really works as an ultrathin capacitor, achieving a capacitance density of 27.5 μF cm–2, which is far superior to currently available commercial capacitor devices. This work demonstrates the great potential of functional oxide nanosheets as components for nanoelectronics, thus contributing to the development of next-generation high-performance electronic devices.

Related Stories

High-performance energy storage

July 3, 2007

North Carolina State University physicists have recently deduced a way to improve high-energy-density capacitors so that they can store up to seven times as much energy per unit volume than the common capacitor.

New capacitors to improve electric vehicles

August 2, 2013

Scientists from the National Physical Laboratory (NPL) have developed a new lead-free, high temperature ceramic capacitor that could improve the efficiency and reliability of electric and hybrid vehicles.

3Qs: Could circuits' face-lift mean faster, smaller phones?

January 15, 2014

Imagine a cell phone that's half the size with longer battery time and better performance. That could become a reality thanks to new research by Nian Sun, associate professor of electrical and computer engineering at Northeastern. ...

Recommended for you

Reshaping the solar spectrum to turn light to electricity

July 28, 2015

When it comes to installing solar cells, labor cost and the cost of the land to house them constitute the bulk of the expense. The solar cells—made often of silicon or cadmium telluride—rarely cost more than 20 percent ...

Could stronger, tougher paper replace metal?

July 24, 2015

Researchers at the University of Maryland recently discovered that paper made of cellulose fibers is tougher and stronger the smaller the fibers get. For a long time, engineers have sought a material that is both strong (resistant ...

Changing the color of light

July 23, 2015

Researchers at the University of Delaware have received a $1 million grant from the W.M. Keck Foundation to explore a new idea that could improve solar cells, medical imaging and even cancer treatments. Simply put, they want ...

Wafer-thin material heralds future of wearable technology

July 27, 2015

UOW's Institute for Superconducting and Electronic Materials (ISEM) has successfully pioneered a way to construct a flexible, foldable and lightweight energy storage device that provides the building blocks for next-generation ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

PPihkala
not rated yet Feb 21, 2014
I would like to know what is the working voltage for the tiny device?

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.