Navigation Links
What can happen when graphene meets a semiconductor
Date:11/22/2013

For all the promise of graphene as a material for next-generation electronics and quantum computing, scientists still don't know enough about this high-performance conductor to effectively control an electric current.

Graphene, a one-atom-thick layer of carbon, conducts electricity so efficiently that the electrons are difficult to control. And control will be necessary before this wonder material can be used to make nanoscale transistors or other devices.

A new study by a research group at the University of Wisconsin-Milwaukee (UWM) will help. The group has identified new characteristics of electron transport in a two-dimensional sheet of graphene layered on top of a semiconductor.

The researchers demonstrated that when electrons are rerouted at the interface of the graphene and its semiconducting substrate, they encounter what's known as a Schottky barrier. If it's deep enough, electrons don't pass, unless rectified by applying an electric field a promising mechanism for turning a graphene-based device on and off.

The group also found, however, another feature of graphene that affects the height of the barrier. Intrinsic ripples form on graphene when it is placed on top of a semiconductor.

The research group, led by Lian Li and Michael Weinert, UWM professors of physics, and Li's graduate student Shivani Rajput, conducted their experiment with the semiconductor silicon carbide. The results were published in the Nov. 21 issue of Nature Communications.

The ripples are analogous to the waviness of a sheet of paper that has been wetted and then dried. Except in this case, notes Weinert, the thickness of the sheet is less than one nanometer (a billionth of a meter).

"Our study says that ripples affect the barrier height and even if there's a small variation in it, the results will be a large change in the electron transport," says Li.

The barrier needs to be the same height across the whole sheet in order to ensure that the current is either on or off, he adds.

"This is a cautionary tale," says Weinert, whose calculations provided the theoretical analysis. "If you're going to use graphene for electronics, you will encounter this phenomenon that you will have to engineer around."

With multiple conditions affecting the barrier, more work is necessary to determine which semiconductors would be best suited to use for engineering a transistor with graphene.

The work also presents opportunity. The ability to control the conditions impacting the barrier will allow conduction in three dimensions, rather than along a simple plane. This 3D conduction will be necessary for scientists to create more complicated nano-devices, says Weinert.


'/>"/>

Contact: Lian Li
lianli@uwm.edu
414-229-5108
University of Wisconsin - Milwaukee
Source:Eurekalert  

Related biology technology :

1. Remarkable Bed Bug Spray Plus Pictures of Bed Bugs Reduce Pest-Control Expense by 50%, My Cleaning Products Explains How It Happened
2. Infrared vision lets researchers see through -- and into -- multiple layers of graphene
3. UT Austin researchers grow large graphene crystals that have exceptional electrical properties
4. New techniques produce cleanest graphene yet
5. Researchers advance scheme to design seamless integrated circuits etched on graphene
6. Understanding interface properties of graphene paves way for new applications
7. Controlling magnetic clouds in graphene
8. Diamonds, nanotubes find common ground in graphene
9. Graphene joins the race to redefine the ampere
10. How graphene and friends could harness the Suns energy
11. Graphenes high-speed seesaw
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
What can happen when graphene meets a semiconductor
(Date:2/11/2016)... 11, 2016  Vermillion, Inc. (NASDAQ: VRML ), ... announced the formation of the Steering Committee for its ... --> Pelvic masses can present physicians and ... Once pregnancy is ruled out, pelvic masses may include ... endometriosis, benign ovarian tumors and gastrointestinal and urinary tract ...
(Date:2/11/2016)... , Feb. 11, 2016  Spectra BioPharma Selling ... (CSO) that provides biopharma companies the experience, expertise, ... and deploy outsourced sales teams. Created in concert ... addresses both the strategic and tactical needs of ... sales solutions through both personal and non-personal promotion. ...
(Date:2/11/2016)... Feb. 11, 2016  Dovetail Genomics™ LLC today announced ... program for a planned metagenomic genome assembly service. ... metagenomic genome assembly method in a talk on Friday, ... & Technology conference in Orlando, Fla. ... complex datasets is difficult. Using its proprietary ...
(Date:2/11/2016)... ... February 11, 2016 , ... Reichert Technologies, which has created ... pursue the highest level of accuracy and quality with the addition of two ... AR5 Refractometer. Accurate, reliable and tough enough for the most demanding applications, ...
Breaking Biology Technology:
(Date:1/18/2016)... Jan. 18, 2016  Extenua Inc., a pioneering ... the use and access of ubiquitous on-premise and ... with American Cyber.  ... leading transformational C4ISR and Cyber initiatives in support ... latest proven technology solutions," said Steve Visconti ...
(Date:1/13/2016)... , January 13, 2016 ... published a new market report titled - Biometric Sensors Market ... Forecast, 2015 - 2023. According to the report, the global biometric ... is anticipated to reach US$1,625.8 mn by 2023, expanding ... In terms of volume, the biometric sensors market is ...
(Date:1/11/2016)... , Jan. 11, 2016 Synaptics Incorporated ... interface solutions, today announced that its ClearPad ® ... (TDDI) products won two separate categories in the 8 ... Innovator and Best Technology Breakthrough. The Synaptics ® ... a simplified supply chain, thinner devices, brighter displays and ...
Breaking Biology News(10 mins):