A research team from City University of Hong Kong (CityU) recently successfully achieved lattice-mismatch-free construction of III-V/chalcogenide core-shell heterostructure nanowires for electronic and optoelectronic applications. This breakthrough addresses crucial technological challenges related to the lattice mismatch problem in the growth of high-quality heterostructure semiconductors, leading to enhanced carrier transport and photoelectric properties.
Category: nanotechnology – Page 52
Nanoscale transistors are in demand for efficient digital circuits, and biasing of each device is critical. These stringent biasing conditions can be relaxed by obtaining precise values of the threshold voltages of the transistor. This leads to more tolerant logic states to the electrical noise.
To meet the requirements of reduced power consumption, CMOS field-effect transistors (FETs) are fabricated such that they operate in enhancement (E) mode, i.e., there are no free charge carriers in the channel at zero gate voltage. On the other hand, depletion (D) mode transistors have higher currents than enhancement mode due to ample charge carrier density.
In contrast to switching applications of FET, for high-frequency applications, off-state of FET is not a compulsory requirement. In fact, the presence of a channel at zero gate bias is advantageous to obtain high transconductance at lower voltages. For Si FETs, the enhancement or depletion modes were determined at the fabrication step of ion implantation doping. However, it is challenging to implement this solution for the new generation of thin materials like organic semiconductors and 2D materials.
Invisible vacuum energy is all around us. We could use it to power propulsion, enhance nanostructures, and build levitating devices.
An international research team led by RMIT University has designed and manufactured a virus-killing surface that could help control disease spread in hospitals, labs, and other high-risk environments. The surface made of silicon is covered in tiny nanospikes that skewer viruses on contact.
Lab tests with the hPIV-3 virus – which causes bronchitis, pneumonia, and croup – showed 96% of the viruses were either ripped apart or damaged to the point where they could no longer replicate to cause infection. These impressive results, featured on the cover of top nanoscience journal ACS Nano, show the material’s promise for helping control the transmission of potentially dangerous biological material in laboratories and healthcare environments.
Stanford materials engineers have 3D printed tens of thousands of hard-to-manufacture nanoparticles long predicted to yield promising new materials that change form in an instant.
Stanford materials engineers have 3D printed tens of thousands of hard-to-manufacture nanoparticles long predicted to yield promising new materials that change form in an instant.
A study from the Instituto de Astrofísica de Canarias (IAC) which combines laboratory chemistry with astrophysics, has shown for the first time that grains of dust formed by carbon and hydrogen in a highly disordered state, known as HAC, can take part in the formation of fullerenes, carbon molecules which are of key importance for the development of life in the universe, and with potential applications in nanotechnology. The results are published in the journal Astronomy & Astrophysics.
Two-dimensional transition metal carbides (MXene) possess attractive conductivity and abundant surface functional groups, providing immense potential in the field of electromagnetic wave (EMW) absorption. However, high conductivity and spontaneous aggregation of MXene suffer from limited EMW response. Inspired by dielectric–magnetic synergy effect, the strategy of decorating MXene with magnetic elements is expected to solve this challenge.
As transistors get smaller, they become increasingly inefficient and susceptible to errors, as electrons can leak through the device even when it is supposed to be switched off, by a process known as quantum tunneling. Researchers are exploring new types of switching mechanisms that can be used with different materials to remove this effect.
In the nanoscale structures that Professor Jan Mol, Dr. James Thomas, and their group study at Queen Mary’s School of Physical and Chemical Sciences, quantum mechanical effects dominate, and electrons behave as waves rather than particles. Taking advantage of these quantum effects, the researchers built a new transistor.
The transistor’s conductive channel is a single zinc porphyrin, a molecule that can conduct electricity. The porphyrin is sandwiched between two graphene electrodes, and when a voltage is applied to the electrodes, electron flow through the molecule can be controlled using quantum interference.
Now Flinders University researchers have discovered a light-responsive, inexpensive sulfur-derived polymer receptive to low power, visible light lasers—which promises a more affordable and safer production method in nanotech, chemical science and patterning surfaces in biological applications.
Details of the novel system have just been published in Angewandte Chemie International Edition, featuring a laser-etched version of the famous “Mona Lisa” painting and micro-Braille printing even smaller than a pin head.
“This could be a way to reduce the need for expensive, specialized equipment, including high-power lasers with hazardous radiation risk, while also using more sustainable materials. For instance, the key polymer is made from low-cost elemental sulfur, an industrial byproduct, and either cyclopentadiene or dicyclopentadiene,” says Matthew Flinders Professor of Chemistry Justin Chalker, from the Flinders University.