Organic solar cells are a compelling thin-film photovoltaic technology in part because of their compatibility with flexible substrates and tunable absorption window. Belgium-based chipmaker imec has set a new conversion efficiency record of 8.4% for this type of cell by developing fullerene-free acceptor materials and a new multilayer semiconductor device structure.
Graphene is not the only ultrathin material that exhibits special electronic properties. Ultrathin layers made of tungsten and selenium have recently been created in Austria that show a high internal efficiency when used to gather sunlight. More than 95% of light passes straight through, but a tenth of what is stopped is converted to electricity.
Experts from the Univ. of Buffalo (UB), helped by colleagues from two Chinese universities, have developed an optical "nanocavity" that could help increase the amount of light absorbed by ultrathin semiconductors. The advancement could lead to the creation of more powerful photovoltaic cells and improvements in video cameras and even hydrogen fuel, as the technology could aid the splitting of water using energy from light.
The huge surface area and strong interactions between graphene layers causes facile “stacking” behavior that dramatically reduces available surface area, inhibiting graphene electronic properties. Researchers have tried to prevent this with carbon black, but this also carries undesirable property changes. By introducing protuberances on graphene during synthesis, researchers in China have found a solution to the stacking problem.
A team of researchers has developed a material that could help prevent blood clots associated with catheters, heart valves, vascular grafts and other implanted biomedical devices. Blood clots at or near implanted devices are thought to occur when the flow of nitric oxide, a naturally occurring clot-preventing agent generated in the blood vessels, is cut off. When this occurs, the devices can fail.
Ultraviolet light (UV) has not only harmful effects on molecules and biological tissue like human skin but it also can impair the performance of organic solar cells upon long-term exposure. Researchers in Germany have now developed a so-called plasmonic metamaterial which is compatible with solar technology and completely absorbs UV light despite being only 20 nm thin.
Researchers from North Carolina State Univ. have developed a superabsorbing design that may significantly improve the light absorption efficiency of thin-film solar cells and drive down manufacturing costs. The superabsorbing design could decrease the thickness of the semiconductor materials used in thin-film solar cells by more than one order of magnitude without compromising the capability of solar light absorption.
Only a few elements in the periodic table are inherently magnetic, but scientists have recently discovered that gold, silver, platinum, palladium and other transition metals demonstrate magnetic behavior when formed into nanometer-scale structures. Scientists at the RIKEN Center for Emergent Matter Science have now shown that this nanoscale magnetism in thin films of platinum can be controlled using an externally applied electric field.
Getting the blues is rarely a desirable experience—unless you’re a solar cell, that is. Scientists at Argonne National Laboratory and the Univ. of Texas at Austin have together developed a new, inexpensive material that has the potential to capture and convert solar energy—particularly from the bluer part of the spectrum—much more efficiently than ever before.
Researchers in Ireland and Germany have discovered a novel solid state reaction which lets kesterite grains grow within a few seconds and at relatively low temperatures. The work points towards a new pathway for the fabrication of thin microcrystalline semiconductor films without the need of expensive vacuum technology.
In only a few years, the efficiency of perovskite-based solar cells has increased from 3% to more than 16%. However, a detailed explanation of the mechanisms of operation within this photovoltaic system is still lacking. in recent work, scientists have now uncovered the mechanism by which these novel light-absorbing semiconductors transfer electrons along their surface.
Researchers at North Carolina State Univ. have shown that a one-atom thick film of molybdenum sulfide (MoS2) may work as an effective catalyst for creating hydrogen. The work opens a new door for the production of cheap hydrogen. Hydrogen holds great promise as an energy source, but the production of hydrogen from water electrolysis currently relies in large part on the use of expensive platinum catalysts.
Researchers have shown how to increase the efficiency of thin-film solar cells, a technology that could bring low-cost solar energy. The approach uses 3-D photonic crystals to absorb more sunlight than conventional thin-film cells. The synthetic crystals possess a structure called an inverse opal to make use of and enhance properties found in the gemstones to reflect, diffract and bend incoming sunlight.
It's known that electric vehicles could travel longer distances before needing to charge and more renewable energy could be saved for a rainy day if lithium-sulfur batteries can just overcome a few technical hurdles. Now, a novel design for a critical part of the battery has been shown to significantly extend the technology's lifespan, bringing it closer to commercial use.
For years engineers the world over have been trying to use inexpensive, carbon-rich molecules and plastics to create organic semiconductors. Two university research teams have worked together to produce the world’s fastest thin-film organic transistors, proving that this experimental technology has the potential to achieve the performance needed for high-resolution television screens and similar electronic devices.
Researchers in Switzerland are developing electronic components that are thinner and more flexible than before. They can even be wrapped around a single hair without damaging the electronics. This opens up new possibilities for ultra-thin, transparent sensors that are literally easy on the eye.
A spin-off company from Singapore’s A*STAR research institute, has invented a new plastic film using a nano-inspired process that makes the material thinner but as effective as aluminium foil in keeping air and moisture at bay. The stretchable plastic could be an alternative for prolonging shelf-life of pharmaceuticals, food, and electronics, bridging the gap of aluminium foil and transparent oxide films.
To manufacture plastic parts with high-end surfaces, the entire forming tool is heated to 110 C using a technique known as variothermic tempering. To retrieve the finished plastic part, the mold must be cooled by up to 30 C, consuming lots of energy. Researchers have now developed a new kind of tempering technique that is up to 90% more energy efficient than variothermic tempering approaches.
Scientists from NIST and Sandia National Laboratories have added something new to a family of engineered, high-technology materials called metal-organic frameworks (MOFs): the ability to conduct electricity. This breakthrough—conductive MOFs—has the potential to make these already remarkable materials even more useful, particularly for detecting gases and toxic substances.
Researchers from the NIST Center for Nanoscale Science and Technology (CNST) have demonstrated a new low-energy electron beam technique and used it to probe the nanoscale electronic properties of grain boundaries and grain interiors in cadmium telluride (CdTe) solar cells. Their results suggest that controlling material properties near the grain boundaries could provide a path for increasing the efficiency of such solar cells.
Semiconductors, the foundation of modern electronics used in flatscreen televisions and fighter jets, could become even more versatile as researchers make headway on a novel, inexpensive way to turn them into thin films. Their report on a new liquid that can quickly dissolve nine types of key semiconductors appears in the Journal of the American Chemical Society.
An international team of scientists have discovered a new type of quantum material whose lopsided behavior may lend itself to creating novel electronics. The material is called bismuth tellurochloride, or BiTeCl. It belongs to a class of materials called topological insulators that conduct electrical current with perfect efficiency on their surfaces, but not through their middles.
As microelectronics get smaller and smaller, one of the biggest challenges to packing a smartphone or tablet with maximum processing power and memory is the amount of heat generated by the tiny “switches” at the heart of the device. A complex metal-oxide film could help reduce the voltage required to switch electronic signals, and thus the excessive energy they require.
Active camouflage has taken a step forward at Harvard Univ., with a new coating that intrinsically conceals its own temperature to thermal cameras. In a laboratory test, a team placed the device on a hot plate and watched it through an infrared camera as the temperature rose. Initially, it behaved as expected, giving off more infrared light as the sample was heated.
Researchers at the Helmholtz Zentrum Berlin Institute for Silicon Photovoltaics have shown that graphene retains its impressive set of properties when it is coated with a thin silicon film. These findings have paved the way for entirely new possibilities to use in thin-film photovoltaics. Graphene has extreme conductivity and is completely transparent while being inexpensive and nontoxic.