Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Electronics Get a Power Boost with the Addition of Simple Material


The tiny transistor is the heart of the electronics revolution, and Penn State materials scientist have just discovered a way to give the workhorse transistor a big boost, using a new technique to incorporate vanadium oxide, one of a family of materials called functional oxides, into the device.

“It’s tough to replace the current transistor technology, because semiconductors do such a fantastic job,” said Roman Engel-Herbert, assistant professor of materials science and engineering. “But there are some materials, like vanadium oxide, that you can add to existing devices to make them perform even better.”

Penn State MRI

Vanadium atoms (blue) and molecules containing vanadium oxide (orange) coat a 3 inch sapphire wafer.

The researchers knew that vanadium dioxide, which is just a specific combination of the elements vanadium and oxygen, had an unusual property called the metal-to-insulator transition. In the metal state, electrons move freely, while in the insulator state, electrons cannot flow. This on/off transition, inherent to vanadium dioxide, is also the basis of computer logic and memory.

The researchers had the idea that if they could add vanadium oxide close to the transistor it could boost the transistor’s performance. Likewise, by adding it to the memory cell, it could improve the stability and energy efficiency to read, write and maintain the information state.

The major challenge they faced was that vanadium dioxide of sufficiently high quality had never been grown in a thin film form on the scale required to be of use to industry, the so-called wafer scale. Although vanadium dioxide, the targeted compound, looks simple, it is very difficult to synthesize.

In order to create a sharp metal-to-insulator transition, the ratio of vanadium to oxygen needs to be precisely controlled. When the ratio is exactly right, the material will show a more than four-order-of-magnitude change in resistance, enough for a sufficiently strong on/off response.

In a paper in the online journal Nature Communications, the Penn State team reports for the first time the growth of thin films of vanadium dioxide on 3-inch sapphire wafers with a perfect 1:2 ratio of vanadium to oxygen across the entire wafer. The material can be used to make hybrid field effect transistors, called hyper-FETs, which could lead to more energy efficient transistors.

In a paper published earlier this year, also in Nature Communications (, the research group led by Prof. Suman Datta at Penn State showed that the addition of vanadium dioxide provided steep and reversible switching at room temperature, reducing the effects of self-heating and lowering the energy requirements of the transistor.

But there is more. The implementation of vanadium dioxide can also benefit existing memory technologies, a quest that Penn State researchers are actively pursuing.

“The metal-to-insulator property of vanadium dioxide can ideally enhance state-of-the-art non-volatile memories by using it as an augmentation device, which, interestingly, can also serve as a selector in some memory architecture,” said Sumeet Gupta, Monkowski assistant professor of electrical engineering and group leader of the Integrated Circuits and Devices Lab at Penn State.

A selector insures that reading or writing information on a memory chip is done within a single memory cell, without bleeding over into neighboring cells. The selector works by changing the resistivity of the cell, which vanadium dioxide does extremely well. In addition, the change in resistivity of vanadium oxide can be used to significantly increase the robustness of the read operation.

The current paper’s lead author, Hai-Tian Zhang, a PhD student in Engel-Herbert’s group, said, “To determine the right ratio of vanadium to oxygen, we applied an unconventional approach in which we simultaneously deposit vanadium oxide with varying vanadium-to-oxygen ratios across the sapphire wafer. Using this ‘library’ of vanadium-to-oxygen ratios, we can perform flux calculations to determine the optimal combination that would give an ideal 1:2 vanadium/oxygen ratio in the film. This new method will allow a rapid identification of the optimal growth condition for industrial applications, avoiding a long and tedious series of trial-and-error experiments.”

The vanadium dioxide thin film material grown with this method has also been used to make super high frequency switches, in collaboration with the Datta group at Penn State and Notre Dame, a technology important in communications. These switches show cut-off frequencies an order of magnitude higher than conventional devices. This work will be reported at the IEEE International Electron Device Meeting, the leading forum for reporting technological breakthroughs in the semiconductor and electronic device industry, in December.

“We are starting to realize that the class of materials exhibiting these on/off responses can be beneficial in various ways in information technology, such as increasing the robustness and energy efficiency of read/write and compute operations in memory, logic and communication devices,” Engel-Herbert said. “When you can make high quality vanadium dioxide on a wafer scale, people are going to have many excellent ideas on how it can be used.”

Today’s paper in Nature Communications, “Wafer scale growth of VO2 thin films using a combinatorial approach,” was coauthored by graduate students Hai-Tian Zhang, Lei Zhang, Debangshu Mukherjee, Ryan Haislmaier, and assistant professors Nasim Alem and Roman Engel-Herbert, all in the Department of Materials Science and Engineering and the Materials Research Institute at Penn State, and Yuan-Xia Zheng a graduate student in Penn State’s Department of Physics. ( )

The work was supported by the National Science Foundation and the Penn State Center for Nanoscale Science. Analysis and measurement was performed in the Penn State Materials Characterization Laboratory, a facility of the Materials Research Institute.
Contact Roman Engel-Herbert at

Contact Information
Walter Mills
Editor Publications
Phone: 814-865-0285

Walter Mills | newswise

More articles from Materials Sciences:

nachricht From ancient fossils to future cars
21.10.2016 | University of California - Riverside

nachricht Study explains strength gap between graphene, carbon fiber
20.10.2016 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>