IndiaNanoResearchers(INR)

In simple terms, FETs can be thought as high-speed switches, composed of two metal electrodes and a semiconducting channel in between. Electrons (or holes) move from the source electrode to the drain electrode, flowing through the channel. While 3D FETs have been scaled down to nanoscale dimensions successfully, their physical limitations are starting to emerge. Short semiconductor channel lengths lead to a decrease in performance: some electrons (or holes) are able to flow between the electrodes even when they should not, causing heat and efficiency reduction. To overcome this performance degradation, transistor channels have to be made with nanometer-scale thin materials. However, even thin 3D materials are not good enough, as unpaired electrons, part of the so-called "dangling bonds" at the surface interfere with the flowing electrons, leading to scattering. Passing from thin 3D FETs to 2D FETs can overcome these problems and bring in new attractive properties. ...

A key step in unlocking the potential for greener, faster, smaller electronic circuitry was taken recently by a group of researchers led by UAlberta physicist Robert Wolkow. The research team found a way to delete and replace out-of-place atoms that had been preventing new revolutionary circuitry designs from working. This unleashes a new kind of silicon chips for used in common electronic products, such as our phones and computers. "For the first time, we can unleash the powerful properties inherent to the atomic scale," explained Wolkow, noting that printing errors on silicon chips are inevitable when working at the atomic scale. "We were making things that were close to perfect but not quite there. Now that we have the ability to make corrections, we can ensure perfect patterns, and that makes the circuits work. It is this new ability to edit at the atom scale that makes all the difference." Think of a typing mistake and the ability to go back and white ...

View of the bismuthene film through the scanning tunnelling microscope. The honeycomb structure of the material (blue) is visible, analogous to graphene. A conducting edge channel (white) forms at the edge of the insulating film (on the right). Credit: Felix Reis It's ultra-thin, electrically conducting at the edge and highly insulating within -- and all that at room temperature: Physicists from the University of Würzburg have developed a promising new material. The material class of topological insulators is presently the focus of international solids research. These materials are electrically insulating within, because the electrons maintain strong bonds to the atoms. At their surfaces, however, they are conductive due to quantum effects. What is more: The electron has a built-in compass needle, the spin, whose orientation is capable of transmitting information very efficiently. It is protected against scattering when moving through these surface channels. Wi...

Engineers at Caltech have for the first time developed a light detector that combines two disparate technologies -- nanophotonics, which manipulates light at the nanoscale, and thermoelectrics, which translates temperature differences directly into electron voltage -- to distinguish different wavelengths (colors) of light, including both visible and infrared wavelengths, at high resolution. Light detectors that distinguish between different colors of light or heat are used in a variety of applications, including satellites that study changing vegetation and landscape on Earth and medical imagers that distinguish between healthy and cancerous cells based on their color variations. The new detector, described in a paper in  Nature Nanotechnology on May 22, operates about 10 to 100 times faster than current comparable thermoelectric devices and is capable of detecting light across a wider range of the electromagnetic spectrum than traditional light detectors. In traditional lig...

Researchers at the University of Connecticut have found that reducing oxygen in some nanocrystalline materials may improve their strength and durability at elevated temperatures, a promising enhancement that could lead to better biosensors, faster jet engines, and greater capacity semiconductors. "Stabilizing nanocrystals at elevated temperatures is a common challenge," says Peiman Shahbeigi-Roodposhti, a postdoctoral research scholar with UConn's Institute of Materials Science and the study's lead author. "In certain alloys, we found that high levels of oxygen can lead to a significant reduction in their efficiency." Using a special milling process in an enclosed glove box filled with argon gas, UConn scientists, working in collaboration with researchers from North Carolina State University, were able to synthesize nano-sized crystals of Iron-Chromium and Iron-Chromium-Hafnium with oxygen levels as low as 0.01 percent. These nearly oxygen-free alloy ...

A discovery of how to control and transfer spinning electrons paves the way for novel hybrid devices that could outperform existing semiconductor electronics. In a study published in  Nature Communications , researchers at Linkoping University in Sweden demonstrate how to combine a commonly used semiconductor with a topological insulator, a recently discovered state of matter with unique electrical properties. Just as the Earth spins around its own axis, so does an electron, in a clockwise or counter-clockwise direction. "Spintronics" is the name used to describe technologies that exploit both the spin and the charge of the electron. Current applications are limited, and the technology is mainly used in computer hard drives. Spintronics promises great advantages over conventional electronics, including lower power consumption and higher speed. In terms of electrical conduction, natural materials are classified into three categories: conductors, semiconductors and insul...

In today's increasingly powerful electronics, tiny materials are a must as manufacturers seek to increase performance without adding bulk. Smaller also is better for optoelectronic devices -- like camera sensors or solar cells -- which collect light and convert it to electrical energy. Think, for example, about reducing the size and weight of a series of solar panels, producing a higher-quality photo in low lighting conditions, or even transmitting data more quickly. However, two major challenges have stood in the way: First, shrinking the size of conventionally used "amorphous" thin-film materials also reduces their quality. And second, when ultrathin materials become too thin, they become almost transparent and actually lose some ability to gather or absorb light. Now, in a nanoscale photodetector that combines a unique fabrication method and light-trapping structures, a team of engineers from the University of Wisconsin-Madison and the University at Buffalo ha...

Information technologies of the future will likely use electron spin -- rather than electron charge -- to carry information. But first, scientists need to better understand how to control spin and learn to build the spin equivalent of electronic components, from spin transistors, to spin gates and circuits. Now, researchers have developed a technique to control and measure spin voltage, known as spin chemical potential. The technique, which uses atomic-sized defects in diamonds to measure chemical potential, is essentially a nanoscale spin multimeter that allows measurements in chip-scale devices. The research is published in  Science . "There is growing interest in insulating materials that can conduct spin," said Amir Yacoby, Professor of Physics in the Department of Physics and of Applied Physics at Harvard John A. Paulson School of Engineering and Applied Sciences and senior author of the paper. "Our work develops a new way to look at these spins in material...

Transistors, as used in billions on every computer chip, are nowadays based on semiconductor-type materials, usually silicon. As the demands for computer chips in laptops, tablets and smartphones continue to rise, new possibilities are being sought out to fabricate them inexpensively, energy-saving and flexibly. The group led by Dr. Christian Klinke has now succeeded in producing transistors based on a completely different principle. They use metal nanoparticles which are so small that they no longer show their metallic character under current flow but exhibit an energy gap caused by the Coulomb repulsion of the electrons among one another. Via a controlling voltage, this gap can be shifted energetically and the current can thus be switched on and off as desired. In contrast to previous similar approaches, the nanoparticles are not deposited as individual structures, rendering the production very complex and the properties of the corresponding components unreliable, but, instead, the...

Tiny particles found in televisions and tablets could be used to provide relief from eye infections. Researchers are investigating the use of tiny particles found in the latest electronic displays to fight eye infections.  Quantum dots are small semiconductor particles that are a key component in nanotechnology.  A new study, published in  ACS Nano , reported on the use of quantum dots as an ingredient in eye drops for the treatment of bacterial keratitis. Researchers manufactured quantum dots by heating spermidine, a compound that boosts the effectiveness of antibiotics.  They found that the quantum dots disrupted bacterial cells while leaving animal cells unscathed. The authors conclude that the new quantum dots are a potential alternative to conventional eye drop treatments for bacterial keratitis.  Current treatments for the eye infection include steroid drops, but these can result in scarring of the cornea. 

Current semiconductor logic devices within our computers use the flow and control of electronic charge for information processing. Spintronic memory devices use the intrinsic properties of electron spin to store information. For future devices, researchers are searching for ways to integrate both information processing and storage in one device unit. "Graphene is an excellent medium for spin transport at room temperature, due to its low atomic mass. However, an unsolved challenge was to control the spin current at ambient temperature" explains Saroj Dash, group leader and Associate Professor at Chalmers University of Technology. The Graphene Flagship researchers Andre Dankert and Saroj Dash have now shown that it is possible to electrically manipulate the spin properties of graphene in a controlled manner at room temperature. This not only could open many new possibilities in spin logic operations but also integration with magnetic memory elements in a single device. W...

 State University report they have created a TI film just 25 atoms thick that adheres to an insulating magnetic film, creating a "heterostructure." This heterostructure makes TI surfaces magnetic at room temperatures and higher, to above 400 Kelvin or more than 720 degrees Fahrenheit. The surfaces of TI are only a few atoms thick and need little power to conduct electricity. If TI surfaces are made magnetic, current only flows along the edges of the devices, requiring even less energy. Thanks to this so-called quantum anomalous Hall effect, or QAHE, a TI device could be tiny and its batteries long lasting, Shi said. Engineers love QAHE because it makes devices very robust, that is, hearty enough to stand up against defects or errors, so that a faulty application, for instance, doesn't crash an entire operating system. Topological insulators are the only materials right now that can achieve the coveted QAHE, but only after they are magnetized, and therein lies the ...

Ever since the 2015  Consumer Electronics Show ,  quantum dots  have been in a market struggle to displace light-emitting diodes (LEDs) as a backlight source for liquid crystal displays (LCDs). Now an advance by a team of researchers from the University of Illinois at Urbana–Champaign, the Electronics and Telecommunications Research Institute in South Korea, and Dow Chemical may turn the display market on its head by eliminating the need for backlights in LCD devices. They have  produced a LED pixel out of nanorods capable of both emitting and detecting light . In the video below, you can get a further description of how the nanorods manage to both detect and emit light as well as some pretty attractive future applications, like mobile phones that can “see” without the need of a camera lens or communicate with each other using Light Fidelity (Li-Fi) Technology  Its different from the use of quantum dots as backlight,” explained Moonsub Shim, a ...

In a major breakthrough for optoelectronics, researchers at Columbia University have made the smallest yet integrated photonic circuit. In the process, they have managed to attain a high level of performance over a broad wavelength range, something not previously achieved. The researchers believe their discovery is equivalent to replacing vacuum tubes in computers with semiconductor transistors—something with the potential to completely transform optical communications and optical signal processing. The research community has been feverishly trying to build i ntegrated photonic circuits  that can be shrunk to the size of integrated circuits (ICs) used in computer chips. But there’s a big problem: When you use wavelengths of light instead of electrons to transmit information, you simply can’t compress the wavelengths enough to work in these smaller chip-scale dimensions. In research described in the journal  Nature Nanotechnology , the integrated ...

Three decades of steady increases in fiber-optic transmission capacity have powered the growth of the Internet and information-based technology. But  sustaining that growth has required increasingly complex and costly new technology . Now, a new experiment has shown that an elegant bit of laser physics called a  frequency comb—which earned Theodor Hänsch and John Hall the 2005 Nobel Prize in Physics —could come to the rescue by greatly improving optical transmitters.  x A pair of silicon-nitride microresonator frequency combs to transmit 50 terabits of data through 75 kilometers of single-mode fiber using 179 separate carrier wavelengths. They also showed that microresonator frequency combs could serve as local oscillators in receivers, which could improve transmission quality, and lead to petabit-per-second (1000 terabit) data rates inside data centers. The German and Swiss researchers’ transmission scheme is similar to many of today's fiber-optic netwo...