Conventional silicon solar cells could have an inexpensive competitor in the near future. Researchers in Europe have examined the working principle of a cell where an organic-inorganic perovskite compound acts as a light absorber. The scientists observed that charge carriers accumulate in a layer in these photovoltaic elements. If this jam can be dissolved, the already considerable efficiency of these solar cells could be further improved.
Imagine being able to tune the properties of a solid material just by flashing pulses of light on it. That is one potential payoff of electrons and atoms interacting with ultrashort pulses of light. The technology of ultrafast spectroscopy is a key to understanding this phenomenon and now a new wrinkle to that technology, observations of electron self-energy, has been introduced by Lawrence Berkeley National Laboratory researchers.
Nanoparticles could revolutionize the medical industry, but they must first target a specific region in the body, be trackable, and perform their function at the right moment. Researchers in Japan have made progress in this direction with a new type of nanomaterial: the nanosheet. Specifically, they have designed a strong, stable and optically traceable smart 2-D material that responds to pH, or the acidity or basicity of its environment.
Arrays of tiny conical tips that eject ionized materials are being made at the Massachusetts Institute of Technology. The technology, which harnesses electrostatic forces, has a range of promising applications, such as spinning out nanofibers for use in “smart” textiles or propulsion systems for fist-sized “nanosatellites.” The latest prototype array that generates 10 times the ion current per emitter that previous arrays did.
Individuals in industrial associations, educational institutions and government organizations who are interested in composites, or materials made from constituent materials with different physical or chemical properties, now have free, 24/7 access to simulation tools through an online community with offices in the Purdue Research Park.
The world’s first “solar battery”, invented by researchers at Ohio State Univ., is a battery and a solar cell combined into one hybrid device. Key to the innovation is a mesh solar panel, which allows air to enter the battery, and a special process for transferring electrons between the solar panel and the battery electrode. Inside the device, light and oxygen enable different parts of the chemical reactions that charge the battery.
Nanostructures of virtually any possible shape can now be made using a combination of techniques developed to exploit the unique properties of so-called perovskites. The group based in the Netherlands, developed a pulsed laser deposition technique to create patterns in ultra thin layers, one atomic layer at a time. The perovskites’ crystal structure is undamaged by this soft lithography technique, maintaining electrical conductivity.
A Duke Univ. team has found that nanoparticles called single-walled carbon nanotubes accumulate quickly in the bottom sediments of an experimental wetland setting, an action they say could indirectly damage the aquatic food chain. According to the research, the risk to humans ingesting the particles through drinking water is slight, but aquatic food chains might be harmed by molecules "piggybacking" on the carbon nanoparticles.
Ice contains many atoms and molecules trapped inside its structure. A team of Univ. of Chicago and Loyola Univ. researchers has discovered a new mechanism they call "stable energetic embedding" of atoms and molecules within ice. This mechanism explains how some molecules, such as CF4, or "carbon tetrafluoride", interact with and become embedded beneath ice surfaces.
Thermal considerations are rapidly becoming one of the most serious design constraints in microelectronics, especially on submicron scale lengths. A study by researchers from the Univ. of Illinois at Urbana-Champaign has shown that standard thermal models will lead to the wrong answer in a 3-D heat-transfer problem if the dimensions of the heating element are on the order of one micron or smaller.
Droplets are simple spheres of fluid, not normally considered capable of doing anything on their own. But now researchers have made droplets of alcohol move through water, even moving through complex mazes. The droplets can be led to certain targets, using a surprisingly simple impetus. In the future, such moving droplets may deliver medicines, moving entire chemistries to targets.
In a rare case of having their cake and eating it too, scientists from NIST and other institutions have developed a toolset that allows them to explore the complex interior of tiny, multi-layered batteries they devised. It provides insight into the batteries’ performance without destroying them, which results in both a useful probe for scientists and a potential power source for micromachines.
A novel x-ray technique used at the U.S. Department of Energy’s Advanced Photon Source has revealed surprising dynamics in the nanomechanics of operating batteries and suggests a way to mitigate battery failures by minimizing the generation of elastic energy. The method could open a path to wider use of these batteries in conjunction with renewable energy sources.
A little change in temperature makes a big difference for growing a new generation of hybrid atomic-layer structures, according to scientists. Rice Univ. scientists led the first single-step growth of self-assembled hybrid layers made of two elements that can either be side by side and one-atom thick or stacked atop each other. The structure’s final form can be tuned by changing the growth temperature.
The key to creating a material that would be ideal for converting solar energy to heat is tuning the material’s spectrum of absorption just right: It should absorb virtually all wavelengths of light that reach Earth’s surface from the sun—but not much of the rest of the spectrum, since that would increase the energy that is reradiated by the material, and thus lost to the conversion process.
Confined photons have many potential applications, such as efficient miniature lasers, on-chip information storage, or tiny sensors on pharmaceuticals. Making a structure that can capture photons is difficult, but scientists in the Netherlands have recently devised a new type of resonant cavity inside a photonic crystal that imprisons light in all three dimensions.
Electricity and magnetism rule our digital world. Semiconductors process electrical information, while magnetic materials enable long-term data storage. A Univ. of Pittsburgh research team has discovered a way to fuse these two distinct properties in a single material, paving the way for new ultrahigh density storage and computing architectures.
Concrete can be better and more environmentally friendly by paying attention to its atomic structure, according to researchers at Rice Univ., the Massachusetts Institute of Technology and Marseille Univ. The international team of scientists has created computational models to help concrete manufacturers fine-tune mixes for general applications.
If it's true that good things come in small packages, then NIST can now make anyone working with nanoparticles very happy. The institute recently issued Reference Material (RM) 8027, the smallest known reference material ever created for validating measurements of man-made, ultrafine particles between 1 and 100 nm in size.
Scientists at the U.S. Naval Research Laboratory have introduced a new one-step process using, for the first time in these types of syntheses, potassium superoxide to rapidly form oxide nanoparticles from simple salt solutions in water. An important advantage of this method is the capability of creating bulk quantities of these materials, more than 10 g in a single step.
using an aberration-corrected scanning transmission electron microscope, researchers have recently understood how defects in 2-D crystals such as tungsten disulphide can move, or dislocate, to other locations in the material. Understanding how atoms "glide" and "climb" on the surface of 2-D crystals may pave the way for researchers to develop materials with unusual or unique characteristics.
Princeton Univ. researchers have developed a new method to increase the power and clarity of light-emitting diodes (LEDs). Using a new nanoscale structure made from flexible carbon-based sheet, the researchers increased the brightness and efficiency of LEDs made of organic materials by 57%.
Diamonds aren’t just a girl’s best friend, they’re also R&D’s best friend—or at least a new acquaintance. Many laboratories and companies are embracing synthetic diamond for its elevated super properties in applications ranging from analytical instruments and biomedical sensors to electronics and lasers to water purification.
In experiments using graphene, researchers in Switzerland have been able to demonstrate a phenomenon predicted by a Russian physicist more than 50 years ago. The observation of the Lifshitz transition, which describes a change in topology, depended on the creation of a double-layer graphene sample of unprecedented quality.
A common complaints about solar power is that solar panels are still too expensive. Efforts at making them more efficient or longer-lasting have been limited. A new method developed in Okinawa could solve the expense problem: A hybrid form of deposition is being used to create perovskite solar cells from a mixture of inexpensive organic and inorganic raw materials, eliminating the need for expensive crystallized silicon.