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(PhysOrg.com) -- Researchers from the National Renewable Energy Laboratory (NREL) have reported the first solar cell that produces a photocurrent that has an external quantum efficiency greater than 100 percent when photoexcited with photons from the high energy region of the solar spectrum

Typically, a solar cell generates a single electron for each photon captured. However, by adding pentacene, an organic semiconductor, the solar cells can generate two electrons for every photon from the blue light spectrum. This could enable the cells to capture 44% of the incoming solar energy.

LEDsThe strange quantum state of entanglement isn't just challenging to think about, it's hard to create. This "spooky" phenomenon-in which two particles are linked, even if they're separated by distance-can be created by scientists in the lab using bulky lasers. But scientists published a study in Nature today in which they created a light-emitting diode (LED) that produces entangled photons.

This method may potentially be suitable for designing novel light sources resembling lasers that work in the x-ray range. Among other applications, they might allow building more powerful computer chips.

A new process that simultaneously combines the light and heat of solar radiation to generate electricity could offer more than double the efficiency of existing solar cell technology, say the engineers who discovered it and proved that it works. The process, called 'photon enhanced thermionic emission," or PETE, could reduce the costs of solar energy production enough for it to compete with oil as an energy source.

(PhysOrg.com) -- A group of physicists working out of Chalmers University of Technology in Gothenburg, Sweden, have succeeded in proving what was until now, just theory; and that is, that visible photons could be produced from the virtual particles that have been thought to exist in a quantum vacuum. In a paper published on arXiv, the team describes how they used a specially created circuit called a superconducting quantum interference device (SQUID) to modulate a bit of wire length at a roughly five percent of the speed of light, to produce visible "sparks" from the nothingness of a vacuum.

Researchers at LaserMotive have devised a way to beam lasers to power military bases and drones, possibly helping to save lives, since delivering fuel to battle zones can be a dangerous task in wartime. Although still largely in the R&D stage, laser power beaming has many other potential uses, which include powering vehicles, replacing electric power wiring and transmission lines in difficult places, and even launching rockets into orbit. The beam is about 8 inches wide as it leaves the transmitter - and then spreads wider as it travels. The beam emitter is located at a ground-based unit and operated by a person, who could control it from the same location or remotely from an entirely different place altogether. The operator uses the machine to fire the laser beam at a photovoltaic collector located on an unmanned autonomous vehicle (UAV), small plane, or helicopter. The current range of the system is about a kilometer. When the laser hits the photovoltaic device, the photons in the light beam are converted to electricity to fly the AUV. Topics: AI/Robotics | Energy | Physics/Cosmology | Survival/Defense

ScienceDaily (July 11, 2011) - Researchers at Columbia Engineering School have built optical nanostructures that enable them to engineer the index of refraction and fully control light dispersion.