Quantum dots are nano-sized semiconductor particles whose emission color can be tuned by simply changing their dimensions. New research at Los Alamos National Laboratory aims to improve quantum dot-based light-emitting diodes by using a new generation of engineered quantum dots tailored specifically to have reduced wasteful charge-carrier interactions that compete with the production of light.
Semiconductor Research Corporation (SRC) has launched a new research program on hybrid bio-semiconductor systems that they hope will provide insights and opportunities for future information and communication technologies. The Semiconductor Synthetic Biology (SSB) program will initially fund research at six universities.
Amy Prieto, a chemist at Colorado State Univ. leads a start-up company with the goal of developing a lithium-ion battery that should be safer, cheaper, faster-charging, and more environmentally friendly than conventional batteries now on the market. The key to the technology is copper foam which is easy to manufacture and has high power density.
In new research, scientists have demonstrated that the efficiency of all solar panel designs could be improved by up to 22% by covering their surface with aluminium studs that bend and trap light inside the absorbing layer. At the microscopic level, the studs make the surface of the solar panels look similar to the interlocking building bricks played with by children across the world.
Although the amount of data that can be stored has increased immensely during the past few decades, it is still difficult to actually store data for a long period of time. A researcher has recently demonstrated a way to store data for extremely long periods, even millions of years, using an etched wafer made of tungsten encapsulated by silicon nitride. The material is resistant to both time and elevated temperatures.
Vanadium dioxide is one of the few known materials that acts like an insulator at low temperatures but like a metal at warmer temperatures starting around 67 C. This temperature-driven metal-insulator transition, the origin of which is still intensely debated, could be induced by the application of an external electric field. Beamline studies at the Advanced Light Source has shed some light on this potential avenue for faster electronics.
People often customize the size and shape of materials like textiles and wood without turning to specialists like tailors or carpenters. In the future this should be possible with electronics, according to computer scientists who have developed a printable multi-touch sensor whose shape and size can be altered by anybody.
Renewable sources like sun and wind aren’t always productive. But waves in the ocean are never still, prompting Georgia Institute of Technology scientists to find a way to produce energy by making use of contact electrification between a patterned plastic nanoarray and water. They have introduced an inexpensive and simple prototype of a triboelectric nanogenerator that could be used to produce energy and as a chemical or temperature sensor.
Researchers in Japan have developed a new photodiode that can detect in just milliseconds a certain type of high-energy ultraviolet light, called UVC, which is powerful enough to break the bonds of DNA and harm living creatures. The new device shows promise for space-based communication and monitoring ozone depletion.
Researchers in Germany are showing the way toward low-cost, industrial-scale manufacturing of a new family of electronic devices. Gas sensors that could be integrated into food packaging to gauge freshness, new types of solar cells and flexible transistors, and sensors that could be built into electronic skin: All can be made with carbon nanotubes, sprayed like ink onto flexible plastic sheets or other substrates.
A new, environmentally-friendly electronic alloy consisting of 50 aluminum atoms bound to 50 atoms of antimony may be promising for building next-generation "phase-change" memory devices. Phase-change memory is being actively pursued as an alternative to the ubiquitous flash memory for data storage applications, because flash memory is limited in its storage density and phase-change memory can operate much faster.
Using colloidal lead sulfide nanocrystal quantum dot (QD) substances, U.S. Naval Research Laboratory (NRL) research scientists and engineers have recorded an open-circuit voltage of 692 mV using the QD bandgap of a 1.4 eV under one-sun illumination. The achievement highlights the potential for improvements in QD solar cells by employing smaller quantum dots.
Measuring the band offset faced by electrons jumping from one material to another is a key component of a nanoscale design process because it guides redesign and prototyping. Current methods don’t work on the nanoscale, however. Using laser-induced current in a nanowire device and its dependence on the wavelength of the laser, a team at Drexel Univ. devised a new method to derive the band offset.
Electronic devices with touchscreens rely on transparent conductors made of indium tin oxide, or ITO. But cost and the physical limitations of this material are limiting progress in developing flexible touchscreens. A research collaboration between the Univ. of Pennsylvania and Duke Univ. is exploring the use of nanowires to replace ITO, and are using simulation tools to determine how they might work.
Researchers not only confirmed several theoretical predictions about topological crystalline insulators (TCIs), but made a significant experimental leap forward that revealed even more details about the crystal structure and electronic behavior of these newly identified materials. The findings reveal the unexpected level of control TCIs can have over electrons by creating mass.
Titanium dioxide is an inexpensive, yet versatile material. The use of titanium oxide in the electronics industry is currently being investigated. An international team of researchers has confirmed theoretically-predicted interactions between single oxygen molecules and crystalline titanium dioxide and the implications of these findings could be important for a variety of applications.
Quantum point contacts in electrical circuits are narrow constrictions that can impede the passage of electrons in unexpected ways. Using a combination of experimental measurements and numerical modeling, physicists have recently provided the first detailed microscopic explanation of the associated conductance anomalies.
Researchers from the RIKEN Center for Life Science Technologies and Chiba Univ. have developed a high-temperature superconducting wire with an ultrathin polyimide coating only 4 micrometers thick, more than 10 times thinner than the conventional insulation used for high-temperature superconducting wires. The breakthrough should help the development of more compact superconducting coils for medical and scientific devices.
In recent years, thermoelectric materials have enabled the re-use of otherwise wasted thermal energy as electrical power. But this ability is limited to materials, typically complex crystals, exhibiting high electrical conductivity and low thermal conductivity. Scientists have now discovered a way of suppressing thermal conductivity in sodium cobaltate, opening new paths for energy scavenging.
A RMIT Univ. research collaboration with top scientists in Australia and Japan is advancing next-generation solar cells. Currently, cadmium or lead elements dominate colloidal nanocrystals synthesis, despite toxicity concerns. In its research, the team has discovered a new selective synthesis of tetrahedrite and famatinite copper antimony sulphide nanocrystals, which could be promising for printable solar cell applications.
Most solar cells today are inorganic and made of crystalline silicon. These cells tend to be expensive, rigid and relatively inefficient when it comes to converting sunlight into electricity. Work by a team of chemical engineers at Penn State Univ. and Rice Univ. may lead to a new class of inexpensive organic solar cells, one that skips difficult-to-scale fullerene acceptors and relies on molecular self-assembly instead.
A team led by Oak Ridge National Laboratory’s Amit Goyal, a former R&D Scientist of the Year, has demonstrated that superconducting wires can be tuned to match different operating conditions by introducing small amounts of non-superconducting material, or defects, that influences how the overall material behaves. A wire sample grown with this process exhibited new levels of performance in terms of engineering critical current density.
Researchers in Israel have developed a simple magnetization progress that depends on electron spin to eliminate the need for permanent magnets in memory devices. The new technique, called magnetless spin memory (MSM), drives a current through chiral material and selectively transfers electrons to magnetize nanomagnetic layers or nanoparticles.
Polymer, or plastic, solar cells contain Earth-abundant and environmentally benign materials, can be made flexible and lightweight, and can be fabricated using roll-to-roll technologies. But the cells’ power-conversion efficiency has been limited. A Northwestern Univ. research reports the design and synthesis of new polymer semiconductors a plastic solar cells with fill factors of 80%. This number is close to that of silicon solar cells.
Flexible thin film solar cells that can be produced by roll-to-roll manufacturing are a highly promising route to cheap solar electricity. Researchers in Switzerland report that they have designed a low-cost cadmium telluride solar cell technology based on metal foil substrates. By doping the cells with cooper, they have elevated efficiency from 8 to 11.5%.