Nanostructures Trap Photons in Ultrathin Solar Cells
In the quest to make sun power more competitive, researchers are designing ultrathin solar cells that cut material costs. At the same time, they’re keeping these thin cells efficient by sculpting their surfaces with photovoltaic nanostructures that behave like a molecular hall of mirrors.
“We want to make sure light spends more quality time inside a solar cell,” says Mark Brongersma, a professor of materials science and engineering at Stanford and co-author of a review article in Nature Materials.
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.
Alexander Shestopalov, an assistant professor of chemical engineering at the Univ. of Rochester, has done just that, thereby taking us one step closer to nanoscale circuitry.
Americans generate nearly 300 million scrap tires every year, according to the EPA. Historically, these worn tires often end up in landfills or, when illegally dumped, become breeding grounds for disease-carrying mosquitoes and rodents. They also pose a potential fire hazard.
In recent years, however, interest has been growing in finding new, beneficial and environmentally friendly uses for discarded tires.
The ability to stick objects to a wide range of surfaces such as drywall, wood, metal and glass with a single adhesive has been the elusive goal of many research teams across the world, but now a team of Univ. of Massachusetts Amherst inventors has created a new, more versatile version of their creation, Geckskin, which can adhere strongly to a wider range of surfaces, yet releases easily, like a gecko’s feet.
“Imagine sticking your tablet on a wall to watch your favorite movie and then moving it to a new location when you want, without the need for pesky holes in your painted wall,” says polymer science and engineering professor Al Crosby. Geckskin is a “gecko-like,” reusable adhesive device that they had previously demonstrated can hold heavy loads on smooth surfaces such as glass.
Electrically Controlled Polymer Changes its Properties
Electrically controlled glasses with continuously adjustable transparency, new polarization filters and even chemosensors capable of detecting single molecules of specific chemicals could be fabricated thanks to a new polymer that unprecedentedly combines optical and electrical properties.
An international team of chemists from Italy, Germany and Poland developed a polymer with unique optical and electric properties. Components of this polymer change their spatial configuration depending on the electric potential applied. In turn, the polarization of transmitted light is affected. The material can be used, for instance, in polarization filters and window glasses with continuously adjustable transparency. Due to its mechanical properties, the polymer is also perfectly suitable for fabrication of chemical sensors for selective detection and determination of optically active (chiral) forms of an analyte.
When an earthquake and tsunami struck the Fukushima Daiichi nuclear plant complex in 2011, neither the quake nor the inundation caused the ensuing contamination. Rather, it was the aftereffects — specifically, the lack of cooling for the reactor cores, because of a shutdown of all power at the station — that caused most of the harm.
A new design for nuclear plants built on floating platforms, modeled after those used for offshore oil drilling, could help avoid such consequences in the future. Such floating plants would be designed to be automatically cooled by the surrounding seawater in a worst-case scenario, which would indefinitely prevent any melting of fuel rods, or escape of radioactive material.
Composite Materials Can Repeatedly Heal Themselves
Internal damage in fiber-reinforced composites, materials used in structures of modern airplanes and automobiles, is difficult to detect and nearly impossible to repair by conventional methods. A small, internal crack can quickly develop into irreversible damage from delamination, a process in which the layers separate. This remains one of the most significant factors limiting more widespread use of composite materials.
However, fiber-composite materials can now heal autonomously through a new self-healing system, developed by researchers in the Beckman Institute for Advanced Science and Technology’s Autonomous Materials Systems (AMS) Group at the Univ. of Illinois at Urbana-Champaign, led by Profs. Nancy Sottos, Scott White and Jeff Moore.
Engineers from UC San Diego have created new ceramic materials that could be used to store hydrogen safely and efficiently. The compounds are made from mixtures of calcium hexaboride, strontium and barium hexaboride. They also have demonstrated that the compounds could be manufactured using a simple, low-cost manufacturing method known as combustion synthesis.
The work is at the proof of concept stage and is part of a $1.2 million project funded by the National Science Foundation, a collaboration between UC San Diego, Alfred Univ. in upstate New York and the Univ. of Nevada, Reno. The manufacturing process for the ceramics is faster and simpler than traditional methods used to manufacture these types of materials. The researchers presented their work at the third International Symposium on Nanoscience and Nanomaterials in Mexico.
From dental implants that are light, strong and porous enough to bond with bone to surgical implants that dissolve over time, modified metals are dramatically extending biomedical potential.
A new nanostructuring technique being researched by Prof. Yuri Estrin at Monash Univ.’s Centre for Advanced Hybrid Materials promises metals with greater strength, better corrosion resistance and increased biocompatibility.
Zero-emission hydrogen fuel cell systems soon could be powering the forklifts used in warehouses and other industrial settings at lower costs and with faster refueling times than ever before, courtesy of a partnership between Sandia National Laboratories and Hawaii Hydrogen Carriers (HHC).
The goal of the project is to design a solid-state hydrogen storage system that can refuel at low pressure four to five times faster than it takes to charge a battery-powered forklift, giving hydrogen a competitive advantage over batteries for a big slice of the clean forklift market. The entire U.S. forklift market was nearly $33 billion in 2013, according to Pell Research.
A research team at the Univ. of Kansas has used high-powered lasers to track the speed and movement of electrons inside an innovative material that is just one atom thick. Their findings are published in the current issue of ACS Nano.
The work at KU’s Ultrafast Laser Lab could help point the way to next-generation transistors and solar panels made of solid, atomically thin materials.
A house window that doubles as a solar panel could be on the horizon, thanks to recent quantum-dot work by Los Alamos National Laboratory researchers in collaboration with scientists from Univ. of Milano-Bicocca (UNIMIB). Their project demonstrates that superior light-emitting properties of quantum dots can be applied in solar energy by helping more efficiently harvest sunlight.
“The key accomplishment is the demonstration of large-area luminescent solar concentrators that use a new generation of specially engineered quantum dots,” says lead researcher Victor Klimov of the Center for Advanced Solar Photophysics (CASP) at Los Alamos.
In dense, urban centers around the world, many people live and work in dim and narrow streets surrounded by tall buildings that block sunlight. And as the global population continues to rise and buildings are jammed closer together, the darkness will only spread.
To alleviate the problem, Egyptian researchers have developed a corrugated, translucent panel that redirects sunlight onto narrow streets and alleyways. The panel is mounted on rooftops and hung over the edge at an angle, where it spreads sunlight onto the street below.
Think of the pressure change you feel when an elevator zips you up multiple floors in a tall building. Imagine how you’d feel if that elevator carried you all the way up to the top of Mt. Everest — in the blink of an eye.
That’s similar to what many fish experience when they travel through the turbulent waters near a dam. For some, the change in pressure is simply too big, too fast and they die or are seriously injured. In an article in Fisheries, ecologists from the Department of Energy’s Pacific Northwest National Laboratory and colleagues from around the world explore ways to protect fish from the phenomenon, known as barotrauma.