Suspicion Confirmed: Flat Molecules Better for Conducting Electricity

Aug 25, 2006
Suspicion Confirmed: Flat Molecules Better for Conducting Electricity
Conductance vs. Conformance: The diagram above illustrates how the conductance of the molecule (the green, yellow or red structure in the center of each model) drops as its two benzene rings are rotated relative to one another. On the far left the molecule is shown in its flattest form, and has the highest conductance. Diagram courtesy of L. Venkataraman.

Columbia research scientist Latha Venkataraman has demonstrated that in creating single-molecule electronic devices, flatter molecules conduct electricity better. That principle has long been suspected, but to demonstrate it definitively required an innovation to existing methods for measuring conductance in nano-scale objects.

The field of nanotechnology involves designing machines and devices on a nanoscale. One of the main challenges for scientists had been in figuring out how to test the conductance of electronic components that consist of a single molecule. Scientists have come up with a number of techniques, but the large fluctuations in the results produced by these techniques have made it difficult to predict how individual molecules will behave as electronic devices.

In her previous research, Venkataraman -- together with her colleagues Jennifer Klare, Colin Nuckolls, Mark Hybertsen and Michael Steigerwald from Columbia’s Nanoscale Science and Engineering Center -- came up with a refinement of one of the prevailing methods for measuring conductance in a molecule. She used a novel amine-gold link to attach single molecules to the gold electrodes (published in Nano Letters in March 2006).

Venkataraman et al. have now applied this technique to provide definitive evidence to support a long-held belief that flatter molecules conduct electricity better than twisted ones.

“Overall, the discovery of the amine-gold link chemistry has been a significant breakthrough in the field of molecular electronics,” said Venkataraman. “It has enabled detailed and systematic studies of single molecule conductance as a function of molecular properties and we can now design, make and test single molecule devices with innovative properties.”

Go to full text of the Nature paper:
Dependence of single-molecule junction conductance on molecular conformation

Source: Columbia University

Explore further: Solving molybdenum disulfide's 'thin' problem

add to favorites email to friend print save as pdf

Related Stories

Scientists develop cool process to make better graphene

Mar 18, 2015

A new technique invented at Caltech to produce graphene—a material made up of an atom-thick layer of carbon—at room temperature could help pave the way for commercially feasible graphene-based solar cells ...

Supercomputers help solve puzzle-like bond for biofuels

Mar 16, 2015

One of life's strongest bonds has been discovered by a science team researching biofuels with the help of supercomputers. Their find could boost efforts to develop catalysts for biofuel production from non-food ...

Will next-generation wearable sensors make us healthier?

Mar 10, 2015

There is certainly no shortage of headlines on wearable sensors these days. "A contact lens measures your glucose level." "New electronic tattoos could help monitor health during normal daily activities." A "headband can read your brainwaves." Numerous wearable sensors are cu ...

When temperature goes quantum

Mar 06, 2015

A UA-led collaboration of physicists and chemists has discovered that temperature behaves in strange and unexpected ways in graphene, a material that has scientists sizzling with excitement about its potential ...

Recommended for you

Solving molybdenum disulfide's 'thin' problem

16 hours ago

The promising new material molybdenum disulfide (MoS2) has an inherent issue that's steeped in irony. The material's greatest asset—its monolayer thickness—is also its biggest challenge.

Snowflakes become square with a little help from graphene

Mar 25, 2015

The breakthrough findings, reported in the journal Nature, allow better understanding of the counterintuitive behaviour of water at the molecular scale and are important for development of more efficient techno ...

Nanostructure complex materials modeling  

Mar 25, 2015

Materials with chemical, optical, and electronic properties driven by structures measuring billionths of a meter could lead to improved energy technologies—from more efficient solar cells to longer-lasting ...

User comments : 0

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.