Nanoclast iconNanoclast

Molecular Electronics Takes Large Stride Forward

Molecular electronics has long promised a day when individual molecules would serve as the basic building blocks for electronics.

That day has moved a bit closer thanks to research out of the Columbia University School of Engineering and Applied Science. Researchers there have developed a new technique that makes it possible to produce a diode from a single molecule.

In research published in the journal Nature Nanotechnology,  the researchers claim that they have not only produced a single-molecule diode, but that it greatly outperforms all previous designs.

Read More

Graphene Overcomes Achilles' Heel of Artificial Muscles

In the world of biomimetic robotics, so-called artificial muscles have promised everything from the ability to make fish-like fins for underwater vehicles to devices to help the disabled in their rehabilitation.

These ionic polymer composites are attractive for their sheer simplicity. You just put two electrodes on the polymer and when you switch on the voltage, the ions migrate, deforming the polymer.

However, there was a problem with the metal electrodes. After being exposed to air and current, the electrodes would begin to crack, leaking ions and diminishing the muscle’s performance.

Scientists at the Korea Advanced Institute of Science and Technology (KAIST) have come up with a solution to that problem, and it involves graphene.

Read More

Graphene Composites Go Big

Graphene is a wonder material — flexible, transparent, light, strong, and electrically and thermally conductive, qualities that have led to research worldwide into weaving these atom-thick layers of carbon into advanced devices. Now scientists have demonstrated what they say is the first large-scale fabrication of a graphene composite—a material that combines graphene with another substance to form something with new properties.

Until now, labs could only incorporate tiny flakes of graphene or graphene-like materials into composites. The mechanical and electrical capabilities of these composites were never as good as scientists would have liked because of weak links between the flakes, and the flakes often clumped together, leading to irregularities across the composites.

Read More

New Memristors Could Usher in Bionic Brains

Last month we saw researchers in the US push the envelope of non-volatile memory devices based on resistance switching to the point where they are now capable of mimicking the neurons in the human brain.

Now researchers at the Royal Melbourne Institute of Technology (RMIT) in Australia have built on their previous work developing ultra-fast nano-scale memories. They used a functional oxide ultra-thin film to create one of the world’s first electronic multi-state memory cells. The researchers claim that the memristive devices they have developed mimic the brain’s ability to simultaneously process and store multiple strands of information.

Read More

Plasmonic Nanostructures Could Change the Landscape of Optoelectronics

Scientists have high hopes that the emerging field of plasmonics can improve technologies such as photovoltaicsLEDs, and other optoelectronics. It’s a natural fit: Plasmonics exploits the oscillations in the density of electrons that are generated when photons hit a metal surface.

However, it’s been studied in a bit too much isolation. Scientists have only looked at the phenomenon in isloated metal nanostructures and not the metal adhesion layer that glued the nanostructures to a metal substrate.

Now researchers at Rice University have expanded the understanding of plasmonics beyond just the nanostructure itself and down into the metal substrate. They expect that their increased ability to characterize and manipulate the plasmonic effect could make plasmonic devices viable alternatives for highly complex optoelectronic devices like optomechnical oscillators, which couple photons into mechanical resonators and are used in photonic and wireless communications applications.

Read More

Graphene Enables First Example of a Textile Electrode

Wearable electronics has been a hotly pursued research area for years now, but there has been precious little to show for all that effort in terms of electronic garments appearing on people’s backs. The reason for this is not entirely clear. Maybe it’s because the technologies that would enable fabric makers to weave in electronic components have been unwieldy, or maybe people just don’t feel that compelled to wear their electronic devices.

In any case, researchers have recently been able to leverage the properties of graphene to bring the long-promised future of wearable electronics closer to the present. We’ve already seen graphene woven into a yarn-like material that acts as a supercapacitor to power wearable electronics both here and here.

Now, an international research team from the University of Exeter in the U.K. and the Institute for Systems Engineering and Computers, Microsystems and Nanotechnology (INESC-MN) in Lisbon, the Universities of Lisbon and Aveiro in Portugal and the Belgian Textile Research Centre (CenTexBel) has managed to coat textile fibers with graphene in a way that turns them into electrodes.

Read More

Perovskite Transistors Made for First Time

The last couple of years have seen the emergence of a new “wonder material” in photovoltaics: perovskite. Recently, we’ve seen that perovskite’s wonders are not limited to just solar cells; they can create 100-percent efficient lasers and can be manipulated to carry both electric and magnetic polarization.

Even without any particular manipulation, perovskites are a class of material with attractive PV properties such as high charge-carrier mobility, long diffusion lengths, and low cost. With these as motivation, research has pushed perovskite energy conversion efficiency up from 5 percent to 20 percent in just a few years.

Despite its spectacular development in photovoltaics, there has been no way to directly measure perovskits charge-transport properties for other applications. Now a team of researchers from both Wake Forest University and the University of Utah has overcome this limitation. The researchers have shown that it’s possible to make a field-effect transistor (FET) out of perovskite, showing for the first time that anyone can directly measure the material’s electronic properties at room temperature.

Read More

2-D Materials Produce Optically Active Quantum Dots for First Time

Tungsten diselenide (WSe2), which belongs to a class of 2-D crystals known as transition metal dichalcogenides, is proving to be an attractive platform for producing solid-state quantum dots for emitting light.

While graphene has become increasingly used for optoelectronic applications, researchers at the University of Rochester claim that the work they have done with tungsten diselenide represents the first time that 2-D materials have produced optically active quantum dots.

The researchers believe that this research, details of which were published in the journal Nature Nanotechnology, could serve as a basis for integrating quantum photonics with solid-state electronics. The result could be a new way to produce so-called integrated photonics.

In the research, the Rochester team laid atomically thin sheets of the semiconductor tungsten diselenide one on top of the next, creating defects in the semiconducting material. These defects are what create the quantum dots: nanoscale semiconductor crystals that are sometimes described as “artificial atoms” because, like atoms, when they absorb the right amount of energy they subsequently give off energy as colored light.

The researchers discovered that the quantum dots they created by engineering the tungsten diselenide defects did not impact the electrical or optical performance of the semiconductor. Further, they found that they could control the electrical and optical properties of the quantum dots by applying either an electrical or magnetic field.

In this way, the researchers were able to control the brightness of the quantum dot’s light emissions simply by applying a voltage. In future iterations of the technology, the researchers believe they will also be able to tune the color of the emitted photons using a voltage, which will open up these quantum dots to applications including nanophotonic devices.

Another possibility opened up by the quantum dots having been produced in this way is a potential use in “spintronics,” where the spin of an electron is used to encode information rather than a charge.

"What makes tungsten diselenide extremely versatile is that the color of the single photons emitted by the quantum dots is correlated with the quantum dot spin," said Chitraleema Chakraborty, one of the authors of the Nature Nanotechnology paper, in a press release.

The researchers believe that the easy interaction between the spin and the photons should make them attractive for quantum information applications.

Light Reveals the Spin of Electrons

Spintronics—in which the spin of electrons is used to encode information rather than chargeis the foundational technology for the read heads in the hard drives of our computers and is the focus of extensive research in creating the logic devices based on the spin of electrons that could lead to quantum computing.

While there has been some recent research in which electric fields are used to manipulate the spin of electrons, the predominant way to read the spin of an electron is to use extremely powerful magnetic fields.

Now researchers at the London Centre for Nanotechnology (LCN) have put aside both magnetic and electrical fields and have demonstrated that it’s possible to read the spin of an electron with a laser.

Read More

Novel Process Promises Atomically Thin Semiconductors for Electronics

Researchers at Cornell University have developed a process for producing transition metal dichalcogenides (TMDs) with spatial uniformity—a key attribute for thin films in electronics—on wafers. This development could ultimately translate into atomically thin semicondutor layers that could pave the way for atomic-scale minutarization of electronics.

Read More


IEEE Spectrum’s nanotechnology blog, featuring news and analysis about the development, applications, and future of science and technology at the nanoscale.

Dexter Johnson
Madrid, Spain
Rachel Courtland
Associate Editor, IEEE Spectrum
New York, NY
Load More