Research carried out by scientists from the School of Chemistry and Biochemistry, with the Centre for Organic Photonics and Electronics at the Georgia Institute of Technology, is leading to a theoretical framework that can improve dramatically the performance of devices based on what is known as "Plastic Electronics", among which are found as leading to OLED displays and certain types of organic solar cells. The paper talks about a method used to eliminate "energy traps" which falls a percentage of electrons, while the current flows within these polymer semiconductors. Find out all the details of the find in this article.
During his tenure in semiconductors, while giving rise to the phenomenon we know as "current flow", there is a proportion of electrons that are "stuck" in certain load traps are no longer useful, lowering the efficiency of OLED devices , for example. "This process reduces electron capture the circulating current (appears as a resistor) and generally, this type of energy traps are moved toward the center of the device, where the electrons are converted into photons or vice versa, for the For solar cells, "the team from the University of Groningen and the Georgia Institute of Technology. Although several mechanisms, or simulation models have been proposed to explain the workings and nature of such traps, until now, no one knew for sure how it occurred, its nature, nor how it could build an antagonistic mechanism, capable of neutralizing its negative effect in normal operation of a traditional semiconductor element.
"We set out to solve this puzzle by comparing the properties they acquired these traps in nine different types of polymers. The comparison showed that the traps in all materials, had a similar energy level," said Herman Nicolai , author of a paper on the subject in Nature Materials ("Unification of trap-limited electron transport in semiconducting polymers"). As part of development work, the Georgia Tech group, led by Jean-Luc Bredas, used as models to study the electronic structures in a wide range of possible pitfalls. "What we found out of the calculation is that the energy level of traps, measured experimentally, coincided with the effects that might induce a complex (or combination) of water and oxygen.
"Although the devices were fabricated Nicolai studied in an atmosphere of nitrogen "these" impurities "(water-oxygen), can easily be introduced during manufacture of semiconductor material, even if the process is done under controlled conditions. Nitrogen can not prevent the contamination with small amounts of oxygen and water. " According to these results, the traps that are now known to effectively thanks to these studies, have a similar energy level, therefore the flow of electrons in different plastic materials can be estimated more easily, and opens a possibility stronger to support the design and building materials free of traps.
"The energy of the trap is in the forbidden energy gap," said Nicolai. This interval is the gap (space) representing the energy difference of the outside of the circle in which electrons orbit the nucleus in its ground state, higher orbit and why they should move (or move) to become mobile charge carriers (those forming the electron current). For example, when a moving electron flows in the vicinity of the area inhabited by a "trick" that is mentioned in the energy space, fall into this trap because it has a lower energy level. "From this research, if the chemicals could (or could) design semiconducting polymers where the energy of the traps is greater than that of the superior orbital in which electrons move through the material, they would not fall into the traps reaching the effectiveness of a material far superior to those of today. "said Nicolai.
In both devices, LEDs, plastic and plastic solar cells, "The flow of electrons should not be hampered by power outages. From now on, with our discovery, the designs can be made with more efficient results." The experimental work was conducted at the Institute for Advanced Materials Zernike (ZIAM) in the Faculty of Mathematics and Natural Sciences, University of Groningen in the Netherlands.
Stanford researcher Yi Cui looked across the field of transparent electronics and saw that all was not equal. While all other major electronics components--things like transistors, displays, and other circuitry--have been made transparent, no one had taken the time and effort to create a transparent power source. And you can’t have a fully transparent device without a transparent battery. So Cui made one.
There are a few ways to make an electronic component transparent. One is to make it so thin that it doesn’t register with the human eye. Or you can make the component take the form of a pattern whose features are so small they are invisible. Some battery components are easy to render transparent by shrinking them, but electrodes are particularly difficult to make thin. A super-thin electrode isn’t energy dense, and therefore it doesn’t store up enough power to be useful in any realistic way.
So Cui opted for the second approach. He and his team figured that if you can pattern the electrode into a superfine mesh, you can still build an energy dense battery. With enough electrode material distributed across the mesh, a battery can still hold a significant charge.
So using a relatively straightforward lithography method, they built a framework for the mesh in a soft, clear, spongy material called PDMS. To make a complete battery, they simply need two of these layers filled with electrode material--in this case, they used the makings of a standard lithium-ion battery--with a gel electrolyte (also clear, of course) sandwiched in between. Encase the whole thing in plastic, and you’ve got a see-through battery.
In the lab, the batteries have been used to power a small LED light (which can be viewed straight through the battery itself). Cui thinks the batteries should be roughly half as energy dense as a equally-sized regular battery. So right now the prototype is about as powerful as a NiCad battery, but Cui says he and his team should be able to improve that by an order of magnitude by reducing inefficiencies in the prototype design and layering batteries one atop the other. Depending on how it scales, the Stanford team thinks such transparent batteries could be commercialized in just two to four years.
[via popularSCI]
But there's one category of 3D gear for the home that doesn't require a bank loan: 3D video cameras. I'm not talking about James Cameron's Pace camera rigs here; these are ordinary consumer-grade camcorders that are affordable and as easy to use as run-of-the-mill video cameras. They are a surprisingly accessible first step into 3D video. You can see the video�in 3D and without glasses on the cameras' own displays. It's no accident that some of these cameras' manufacturers are also selling 3D TVs they are banking on user generated content partially filling the void until Hollywood produces more 3D Blu-rays.
And that strategy may work: There are already subcultures of 3D enthusiasts shooting everything from homemade 3D nature clips to 3D music videos and distributing them online. As for the cameras themselves, there are several coming to market at prices from a few hundred bucks to just under two thousand. The rough patches have more to do with the half-evolved infrastructure of at-home 3D equipment and software than with the cameras themselves. the cameras. Pricewise, 3D cameras fall into two categories: For $1000 to $1700, you can get a full-feature 3D HD camcorder with optical zoom, high-end sensors and processors that can record at high bit rates which translate directly to higher video quality. Below $1000, there are several easy-to-use 3D video cameras, but what you get varies from device to device.
The most straightforward of the cheaper bunch is the Sony 3D Bloggie, a camera that resembles the once popular but now defunct Flip video camera, but with two stereoscopic lenses. Primarily a 3D video camera, it can shoot 3D stills as well. Reversing those priorities is the Fujifilm FinePix Real 3D W3, a 3D still camera that can also shoot 3D video. Perhaps the weirdest device in the group is the HTC Evo 3D, a full-feature smartphone with integrated 3D camera that takes both still photos and video. If the $1000-and-above 3D camcorders are analogous to SLR still cameras, then these more affordable cameras are comparable to pocket point-and-shooters.
