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 team of researchers at Michigan State Univ. has developed a new type of solar concentrator that when placed over a window creates solar energy while allowing people to actually see through the window. It is called a transparent luminescent solar concentrator and can be used on buildings, cell phones and any other device that has a clear surface.
A team including scientists from Spain and from IBM Research in Switzerland have published work which describes an extremely simple method to obtain high quality nanographenes from easily available organic compounds. This method is based on the reactivity of a group of molecules named arynes, which can act as "molecular glue" to paste graphene fragments together.
Researchers in Australia have discovered how algae that survive in very low levels of light are able to switch on and off a weird quantum phenomenon that occurs during photosynthesis. The function in the algae of this quantum effect, known as coherence, remains a mystery, but it is thought it could help them harvest energy from the sun much more efficiently.
In semiconductor-based components, high mobility of charge-carrying particles is important. In organic materials, however, it is uncertain to what degree the molecular order within the thin films affects the mobility and transport of charge carriers. Using a new imaging method, researchers have shown that thin-film organic semiconductors contain regions of structural disorder that could inhibit the transport of charge and limit efficiency.
Normally, keeping glass clean and clear depends on repelling or wiping away water droplets. Or a coating attached to help do this. But researchers in Singapore have discovered that doing just the opposite, collecting water, is the key to keeping a surface clear. Their superhydrophilic coating attracts water to create a uniform, thin, transparent layer.
A dash of clay, a dab of fiber from crab shells, and a dollop of DNA: This strange group of materials are actually the ingredients of promising green fire retardants invented by researchers at NIST. Applied to polyurethane foam, the bio-based coatings greatly reduced the flammability of the common furniture padding after it was exposed to an open flame.
A team of students in California have created a roof tile coating that, when applied to an average-sized residential roof, breaks down the same amount of smog-causing nitrogen oxides per year as a car driven 11,000 miles. The inexpensive titanium dioxide-based coating removes up to 97% of smog-causing nitrogen oxides.
Investigated heavily since the 1970s, solar cells have been the great unfulfilled promise for unlimited, almost free energy to power the world. The reasoning is solid: The Earth absorbs almost as much energy per hour than the entire human race uses in a single year.
A porous material invented by the Rice Univ. lab of chemist James Tour sequesters carbon dioxide, a greenhouse gas, at ambient temperature with pressure provided by the wellhead and lets it go once the pressure is released. The material shows promise to replace more costly and energy-intensive processes.
Thermal systems use heat to produce cold, and vice versa. The human body demonstrates this function when it perspires, but what is lacking for devices that operate on this principle are materials capable of sufficiently discharging the water vapor quickly. Metal organic frameworks (MOFs) are well suited to this task. Researchers have built a new 3-D porous MOF from metals and organic linkers that substantially increases water absorption.
Researchers at the Univ. of California, Riverside have developed a new nanometer scale ruthenium oxide anchored nanocarbon graphene foam architecture that improves the performance of supercapacitors. They found that the new structure could operate safely in aqueous electrolyte and deliver two times more energy and power compared to supercapacitors commercially available today.
Scientists at IBM Research have used a new “computational chemistry” hybrid approach to accelerate the materials discovery process that couples laboratory experimentation with the use of high-performance computing. The new polymers are the first to demonstrate resistance to cracking, strength higher than bone, the ability to reform to their original shape (self-heal), and the ability to be completely recycled back to the starting material.
Using a material found in Silly Putty and surgical tubing, a group of researchers at the Univ. of California, Riverside Bourns College of Engineering have developed a new way to make lithium-ion batteries that will last three times longer between charges compared to the current industry standard. The innovation involves the development of silicon dioxide nanotube anodes.
A research team that figured out how to coat an organic material as a thin film wanted a closer look at why their spreadable organic semiconductor grew like it did. So Cornell Univ. scientists used their high-energy synchrotron x-ray source to show how these organic molecules formed crystal lattices at the nanoscale. These high-speed movies could help advance the technology move from the laboratory to mass production.
Scientists are facing a number of barriers as they try to develop circuits that are microscopic in size, including how to reliably control the current that flows through a circuit that is the width of a single molecule. Recent work at the Univ. of Rochester may have solved this problem through the addition of a second, inert layer of molecules that can act like a plastic casing on the wires.
Researchers in Finland have succeeded in creating a surface on nano-sized cellulose crystals that imitates a biological structure. The surface adsorbs viruses and disables them, preventing their spread into cells. The results could prove useful in the development of antiviral ointments and surfaces.
Chemists have found that cellulose, the most abundant organic polymer on Earth, can be heated in a furnace in the presence of ammonia and turned into the building blocks for supercapacitors. The new process produces nitrogen-doped, nanoporous carbon membranes, which act as the electrodes of a supercapacitor. The only byproduct is methane, which could be used immediately as a fuel or for other purposes.
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.
Photovoltaic spray paint could coat the windows and walls of the future if scientists are successful in developing low-cost, flexible solar cells based on organic polymers. Scientists at Oak Ridge National Laboratory recently discovered an unanticipated factor in the performance of polymer-based solar devices that gives new insight on how these materials form and function.
Massachusetts Institute of Technology chemists have devised a way to trap carbon dioxide and transform it into useful organic compounds, using a simple metal complex. More work is needed to understand and optimize the reaction, but one day this approach could offer an easy and inexpensive way to recapture some of the carbon dioxide emitted by vehicles and power plants.
A key to realizing commercial-scale artificial photosynthesis technology is the development of electrocatalysts that can efficiently and economically carry out water oxidation reaction that is critical to the process. Heinz Frei, a chemist Lawrence Berkeley National Laboratory, has been at the forefront of this research effort. His latest results represent an important step forward.
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.
A team of researchers with Lawrence Berkeley National Laboratory has demonstrated a micro-sized robotic torsional muscle/motor made from vanadium dioxide that for its size is a thousand times more powerful than a human muscle. It is able to catapult objects 50 times heavier than itself over a distance five times its length within just 60 milliseconds.
Researchers from the Max Planck Institute for Intelligent Systems in Stuttgart have developed a new method for the active degradation of organic pollutants in solution by using swimming microengines. These tiny “engines” are made from platinum and iron and are highly efficient in removing organic pollutants from water using hydrogen peroxide.
Supramolecular chemistry is just beginning to come into its own with the emergence of nanotechnology. Metal organic frameworks (MOFs) are commanding much of the attention because of their appetite for greenhouse gases, but a new player has joined the field—supramolecular organic frameworks (SOFs). Researchers have unveiled the first 2-D SOFs that self-assemble in solution.
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