Engineers are shining new light on an emerging family of solar-absorbing materials that could clear the way for cheaper and more efficient solar panels and LEDs. The materials, called perovskites, are particularly good at absorbing visible light, but had never been studied in their purest form: as perfect single crystals.
Imagine eyeglasses that can go quickly from clear to shaded and back again when you want them to, rather than passively in response to changes in light. Scientists report a major step toward that goal, which could benefit pilots, security guards and others who need such control, in ACS Applied Materials & Interfaces.
In Science, Los Alamos National Laboratory researchers reveal a new solution-based hot-casting technique that allows growth of highly efficient and reproducible solar cells from large-area perovskite crystals. The researchers fabricated planar solar cells from pervoskite materials with large crystalline grains that had efficiencies approaching 18%.
A potential avenue to quantum computing currently generating quite the buzz in the high-tech industry is “valleytronics,” in which information is coded based on the wavelike motion of electrons moving through certain 2-D semiconductors. Now, a promising new pathway to valleytronic technology has been uncovered by researchers with the Lawrence Berkeley National Laboratory.
Friction impacts motion, hence the need to control friction forces. Currently, this is accomplished by mechanistic means or lubrication, but experiments conducted by researchers at Oak Ridge National Laboratory have uncovered a way of controlling friction on ionic surfaces at the nanoscale using electrical stimulation and ambient water vapor.
Nature packs away carbon in chalk, shells and rocks made by marine organisms that crystallize calcium carbonate. Now, research suggests that the soft, organic scaffolds in which such crystals form guide crystallization by soaking up the calcium like an "ion sponge". Understanding the process better may help researchers develop advanced materials for energy and environmental uses, such as for removing carbon dioxide from the atmosphere.
Using one of the largest supercomputers in the world, a team of researchers led by the Univ. of Minnesota has identified potential materials that could improve the production of ethanol and petroleum products. The discovery could lead to major efficiencies and cost savings in these industries. The Univ. of Minnesota has two patents pending on the research and hopes to license these technologies.
Graphene has many desirable properties. Magnetism alas is not one of them. Magnetism can be induced in graphene by doping it with magnetic impurities, but this doping tends to disrupt graphene's electronic properties. Now a team of physicists at the Univ. of California, Riverside has found an ingenious way to induce magnetism in graphene while also preserving graphene's electronic properties.
A team of chemists at Nagoya Univ. has synthesized novel transition metal-complexed cycloparaphenylenes (CPPs) that enable selective monofunctionalization of CPPs for the first time, opening doors to the construction of unprecedented nanocarbons. The team has synthesized novel CPP chromium complexes and demonstrated their utility in obtaining monofunctionalized CPPs, which could be useful for making carbon nanotubes.
Researchers in Japan revealed that improvements should soon be expected in the manufacture of transistors that can be used, for example, to make flexible, paper-thin computer screens. The scientists reviewed the latest developments in research on photoactive organic field-effect transistors, devices that incorporate organic semiconductors, amplify weak electronic signals and either emit or receive light.
Scientists at the Univ. of Liverpool have controlled the structure of a material to simultaneously generate both magnetization and electrical polarization, an advance which has potential applications in information storage and processing. The researchers demonstrated that it's possible to unlock these properties in a material which initially displayed neither by making designed changes to its structure.
Theoretical physicists at Rice Univ. are living on the edge as they study the astounding properties of graphene. In a new study, they figure out how researchers can fracture graphene nanoribbons to get the edges they need for applications. New research shows it should be possible to control the edge properties of graphene nanoribbons by controlling the conditions under which the nanoribbons are pulled apart.
With its high electrical conductivity and optical transparency, indium tin oxide is one of the most widely used materials for touchscreens, plasma displays and flexible electronics. But its rapidly escalating price has forced the electronics industry to search for other alternatives. One potential and more cost-effective alternative is a film made with silver nanowires embedded in flexible polymers.
A research team has developed a new technique for determining the role that a material’s structure has on the efficiency of organic solar cells, which are candidates for low-cost, next-generation solar power. The researchers have used the technique to determine that materials with a highly organized structure at the nanoscale are not more efficient at creating free electrons than poorly organized structures.
One of the reasons solar cells are not used more widely is cost: The materials used to make them most efficient are expensive. Engineers are exploring ways to print solar cells from inks, but the devices don’t work as well. A team of engineers has developed a technique to increase the performance and electrical conductivity of thin films that make up these materials using nanotechnology.
Scientists have identified synthetic materials that may purify ethanol more efficiently and greatly improve the separation of long-chain hydrocarbons in petroleum refining. The results show that predictive modeling of synthetic zeolites is highly effective and can help solve some of the most challenging problems facing industries that require efficient ways to separate or catalyze materials.
Sound waves passing through the air, objects that break a body of water and cause ripples or shockwaves from earthquakes all are considered “elastic” waves. These waves travel at the surface or through a material without causing any permanent changes to the substance’s makeup. Now, researchers have developed a material that has the ability to control these waves.
Just because concrete is the most widely used building material in human history doesn’t mean it can’t be improved. A recent study conducted by researchers from NIST, the Univ. of Strasbourg and Sika Corp. using U.S. Dept. of Energy Office of Science supercomputers has led to a new way to predict concrete’s flow properties from simple measurements.
Reducing the amount of sunlight that bounces off the surface of solar cells helps maximize the conversion of the sun's rays to electricity, so manufacturers use coatings to cut down on reflections. Now scientists at Brookhaven National Laboratory show that etching a nanoscale texture onto the silicon material itself creates an antireflective surface that works as well as state-of-the-art thin-film multilayer coatings.
By zapping ordinary metals with femtosecond laser pulses researchers from the Univ. of Rochester have created extraordinary new surfaces that efficiently absorb light, repel water and clean themselves. The multifunctional materials could find use in durable, low maintenance solar collectors and sensors.
The discovery of "topologically protected" electrical conductivity on the surface of some materials whose bulk interior acts as an insulator was among the most sensational advances in the last decade of condensed matter physics, with predictions of numerous unusual electronic states and new potential applications. But many of these predicted phenomena have yet to be observed, until now.
Organic semiconductors are prized for light-emitting diodes, field effect transistors and photovoltaic cells. As they can be printed from solution, they provide a highly scalable, cost-effective alternative to silicon-based devices. Uneven performances, however, have been a persistent problem.
A new insight into the fundamental mechanics of the movement of molecules recently published by researchers at NIST offers a surprising view of what happens when you pour a liquid out of a cup. More important, it provides a theoretical foundation for a molecular-level process that must be controlled to ensure the stability of important protein-based drugs at room temperature.
A single layer of metallic nanostructures has been designed, fabricated and tested by a team of Penn State Univ. electrical engineers that can provide exceptional capabilities for manipulating light. This engineered surface, which consists of a periodic array of strongly coupled nanorod resonators, could improve systems that perform optical characterization in scientific devices, sensing or satellite communications.
A team of chemical engineering researchers has developed a technique that uses a new catalyst to convert methane and water into hydrogen and a fuel feedstock called syngas with the assistance of solar power. The catalytic material is more than three times more efficient at converting water into hydrogen gas than previous thermal water-splitting methods.