When the researchers tested the coated material they found that it had chemically stabilized the silicon surface. When they used it to make supercapacitors, they found that the graphene coating improved energy densities by over two orders of magnitude compared to those made from uncoated porous silicon and significantly better than commercial supercapacitors.
via New device stores electricity on silicon chips | Research News @ Vanderbilt | Vanderbilt University.
Like any other new entrant into the highly competitive solar-panel market, perovskites will have difficulty taking on silicon solar cells. The costs of silicon solar cells are falling, and some analysts think they could eventually fall as low as 25 cents per watt, which would eliminate most of the cost advantage of perovskites and lessen the incentive for investing in the new technology. The manufacturing process for perovskite solar cells—which can be as simple as spreading a liquid over a surface or can involve vapor deposition, another large-scale manufacturing process—is expected to be easy. But historically, it has taken over a decade to scale up novel solar-cell technologies, and a decade from now silicon solar cells could be too far ahead to catch.
via A Material That Could Make Solar Power “Dirt Cheap” | MIT Technology Review.
The resulting material displays all the electrical properties associated with a capacitor, meaning that it can charge and discharge its full capacity almost instantly. But it has a storage density that’s right at the low-end of the range seen in lead-acid batteries. It’s also stable over multiple charge/discharge cycles and holds on to 90 percent of its capacity even after being charged for 300 hours straight.
via Simple technique puts graphene capacitors on par with lead-acid battery | Ars Technica.
However, there’s a slight hitch to be overcome before fabbing magnetite computer chips is possible. To lock an electrical charge in place in the material, it has to be chilled to minus 190 degrees Celsius.
Kukreja said the next objective for the team will be to try out electrical switching with “more complex materials and room-temperature applications” through new experiments which “aim to identify exotic compounds and test new techniques to induce the switching and tap into other properties that are superior to modern-day silicon transistors.”
via Scientists Demonstrate Ultra-Fast Magnetite Electrical Switch | News & Opinion | PCMag.com.
In traditional circuits, transistors are laid down in a bed of silicon that acts as an insulator to prevent crosstalk between circuits. In circuits based on quantum tunneling, silicon is replaced by nanotubes made of boron nitride and electrical pathways consisting of quantum dots—carefully placed bits of gold as small as three nanometers across (PDF).
via Quantum-Tunneling Electrons Could Make Semiconductors Obsolete.
In 2009, researchers at Rutgers University in Piscataway, New Jersey, demonstrated2 that the material has a photovoltaic response to visible light — meaning that when it is hit by light, a voltage is created. The size of the voltage depends on which polarization state the material is in, and can be read out using electrodes or transistors. Crucially, shining light on the material doesn’t change its polarization, and so does not erase the data stored in it.
via Computer memory can be read with a flash of light : Nature News & Comment.
It takes less than 10 nanoseconds to write to and read the cells, and recording the data requires about 3 volts. The leading nonvolatile RAM technology, flash, takes about 10,000 times longer to read and write, and needs 15 volts to record.
Technically the LEDs produce light by passing electrons through a semiconductor material, in combination with materials called phosphors that glow when excited by radiation from the LED. “But it’s hard to get one phosphor that makes the broad range of colors needed to replicate the sun,” said John Budai, a scientist in ORNL’s Materials Science and Technology division in a release. “One approach to generating warm-white light is to hit a mixture of phosphors with ultraviolet radiation from an LED to stimulate many colors needed for white light.”
via Scientists growing new crystals to make LED lights useful for office, home.
What’s particularly neat about this new approach is that it can be used with any kind of sensor without modification; CMOS, CCD, or BSI. And the filters can be produced using the same materials and manufacturing processes in place today. Which means we’ll probably be seeing this technology implemented on cameras sooner rather than later. [DigInfo TV]
via Panasonic’s Developed a Simple Sensor Tweak That Vastly Improves Low Light Photography.
Once the oxide materials, which are innately insulating, are transformed into a conducting state, the IBM experiments showed that the materials maintain a stable metallic state even when power to the device is removed. This non-volatile property means that chips using devices that operate using this novel phenomenon could be used to store and transport data in a more efficient, event-driven manner instead of requiring the state of the devices to be maintained by constant electrical currents.
Conventional materials that turn light into electricity, like silicon and gallium arsenide, generate a single electron for each photon absorbed. Since a photon contains more energy than one electron can carry, much of the energy contained in the incoming light is lost as heat. Now, new research reveals that when graphene absorbs a photon it generates multiple electrons capable of driving a current. This means that if graphene devices for converting light to electricity come to fruition, they could be more efficient than the devices commonly used today.