A single molecule device for mobile phones

September 2, 2014 by Ans Hekkenberg
Negative differential resistance
Resonant tunneling device based on a single molecule: initially starting from zero, the current increases with voltage. However, for higher voltages, the current decreases thereby showing negative differential resistance. The calculated drawn red line is in good agreement with the data. Credit: Fundamental Research on Matter (FOM)

Researchers from the Delft University of Technology, Groningen University and the FOM Foundation have designed a single molecule which can act as a useful building block in nanometer-size circuits. They found that the molecule functions as a resonant tunneling device, an essential component in mobile phones and WiFi. In conventional semiconductor technology, these devices have a complicated design consisting of several layers of different materials. This is the first time that such a device has been realized on the smallest imaginable scale, thus providing an interesting option within the continuing down-scaling of electronic components by the conventional industry. The results are published online this week in Nature Nanotechnology.

Molecular electronics

Molecules have a typical size of a few nanometers, making them the ultimate limit for down-sizing present-day , such as diodes, transistors, and so called resonant tunneling devices. Radio-frequency electronics, as for instance used in mobile phones and WiFi, rely on the use of resonant tunneling devices. These devices exhibit negative differential conductance, which means that an increase in voltage across the device results in a decrease in electric current through it. This effect can be used to amplify electric signals.

Pulling

The negative differential conductance measured in the single molecule considered by the research teams in Delft and Groningen, was very prominent and tunable by mechanically manipulating the molecule. The degree of bending of the molecule could be varied by pulling at it by adjusting the distance between the electrodes to which the molecule is attached (see GIF file).

Design rules

The trapping of a molecule between two gold electrodes: When measuring at the same time the current through the molecule, negative differential resistance appears. The molecular structure is calculated in every step based on the forces between the atoms.

From these observations new design rules were derived for implementing complex electronic functionalities in single . As a result, the researchers were able to demonstrate the smallest known resonant tunneling device with a pronounced negative differential conductance. Moreover, the results pave the way for the design of an efficient single-molecule rectifier (which converts AC into DC). It can be built based on the same resonant tunneling principle.

This research was carried out with financial support from the FOM Foundation, NWO/OCW, and the European FP7-framework programme.

Explore further: Single molecule electronics and 'chemical soldering'

More information: Large negative differential conductance in single-molecule break junctions, Nature Nanotechnology (2014), DOI: 10.1038/nnano.2014.177

Related Stories

Single molecule electronics and 'chemical soldering'

May 13, 2011

(PhysOrg.com) -- Single molecule electronics is a division of nanotechnology utilizing single molecules as electronic components and its study has the ultimate goal of reducing the size of common electrical circuits. Since ...

An advance toward ultra-portable electronic devices

July 20, 2011

Scientists are reporting a key advance toward the long-awaited era of "single-molecule electronics," when common electronic circuits in computers, smart phones, audio players, and other devices may shrink to the size of a ...

S-t-r-e-t-c-h-i-n-g electrical conductance to the limit

December 5, 2011

Individual molecules have been used to create electrical components like resistors, transistors and diodes, that mimic the properties of familiar semiconductors. But according to Nongjian (NJ) Tao, a researcher at the Biodesign ...

Recommended for you

Electrical circuit made of gel can repair itself

August 25, 2015

(Phys.org)—Scientists have fabricated a flexible electrical circuit that, when cut into two pieces, can repair itself and fully restore its original conductivity. The circuit is made of a new gel that possesses a combination ...

Scientists grow high-quality graphene from tea tree extract

August 21, 2015

(Phys.org)—Graphene has been grown from materials as diverse as plastic, cockroaches, Girl Scout cookies, and dog feces, and can theoretically be grown from any carbon source. However, scientists are still looking for a ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

PPihkala
5 / 5 (1) Sep 02, 2014
I wonder if these could be used for rectantenna, to capture sunlight directly to DC.

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.