2012-04-14T09:21:00.001-07:00

In Solar Cells, Tweaking the Tiniest of Parts Yields Big Jump in Efficiency

Electrical engineer Vladimir Mi tin and colleagues have significantly increased the electrical output of solar cells by embedding charged quantum dots in them.

Scientists from the University at Buffalo, Army Research Laboratory and Air Force Office of Scientific Research have developed a new, nano-materials-based technology that has the potential to increase the efficiency of photovoltaic cells up to 45 percent.

Specifically, the scientists have shown that embedding charged quantum dots into solar cells can improve electrical output by enabling the cells to harvest infrared light, and by increasing the lifetime of photo electrons. The technology can be applied to a number of different photovoltaic structures.A new company the scientists founded, Optoelectronic Nano devices LLC. (OPEN LLC), is commercializing this technology.

BUFFALO, N.Y. -- By tweaking the smallest of parts, a trio of University at Buffalo engineers is hoping to dramatically increase the amount of sunlight that solar cells convert into electricity.

With military colleagues, the UB scientists have shown that embedding charged quantum dots into photovoltaic cells can improve electrical output by enabling the cells to harvest infrared light, and by increasing the lifetime of photo electrons.

The research appeared online last May in the journal Nano Letters. The research team included Vladimir Mi tin, Andrei Sergeev and Nizami Vagidov, faculty members in UB's electrical engineering department; Kitt Reinhardt of the Air Force Office of Scientific Research; and John Little and advanced nano fabrication expert Kimberly Sablon of the U.S. Army Research Laboratory.........

New laser technology could kill viruses and improve DVDs

A team led by a professor at the University of California, Riverside Bourns College of Engineering has made a discovery in semiconductor nano wire laser technology that could potentially do everything from kill viruses to increase storage capacity of DVDs.

Ultraviolet semiconductor diode lasers are widely used in data processing, information storage and biology. Their applications have been limited, however, by size, cost and power. The current generation of ultraviolet lasers is based on a material called gallium nitride, but Jianlin Liu, a professor of electrical engineering, and colleagues have made a breakthrough in zinc oxide nano wire waveguide lasers, which can offer smaller sizes, lower costs, higher powers and shorter wavelengths.

Until now, zinc oxide nano wires couldn't be used in real world light emission applications because of the lack of p-type, or positive type, material needed by all semiconductors. Liu solved that problem by doping the zinc oxide nano wires with antimony, a Metallica element, to create the p-type material.

The p-type zinc oxide nano wires were connected with n-type, or negative type, zinc oxide material to form a device called p-n junction diode. Powered by a battery, highly directional laser light emits only from the ends of the nano wires..

Better than the human eye

cientists from Northwestern University and the University of Illinois at Urban-Champaign are the first to develop a curvilinear camera, much like the human eye, with the significant feature of a zoom capability, unlike the human eye.

The "eyeball camera" has a 3.5x optical zoom, takes sharp images, is inexpensive to make and is only the size of a nickel. (A higher zoom is possible with the technology.).

While the camera won't be appearing at Best Buy any time soon, the tunable camera -- once optimized -- should be useful in a number of applications, including night-vision surveillance, robotic vision, endoscopic imaging and consumer electronics."We were inspired by the human eye, but we wanted to go beyond the human eye," said Yong-gang Huang, Joseph Cummings Professor of Civil and Environmental Engineering and Mechanical Engineering at Northwester's McCormick School of Engineering and Applied Science. "Our goal was to develop something simple that can zoom and capture good images, and we've achieved that".

The tiny camera combines the best of both the human eye and an expensive single-lens reflex (SLR) camera with a zoom lens. It has the simple lens of the human eye, allowing the device to be small, and the zoom capability of the SLR camera without the bulk and weight of a complex lens. The key is that both the simple lens and photo detectors are on flexible substrates, and a hydraulic system can change the shape of the substrates appropriately, enabling a variable zoom..

Advance could change modern electronics

CORVALLIS, Ore. Scientists at Oregon State University have solved a quest in fundamental material science that has eluded researchers since the 1960s, and could form the basis of a new approach to electronics.

The discovery, just reported online in the professional journal Advanced Materials, outlines the creation for the first time of a high-performance "metal-insulator-metal" diode.

"Scientists have been trying to do this for decades, until now without success," said Douglas Keszler, a distinguished professor of chemistry at OSU and one of the nation's leading material science researchers. "Diodes made previously with other approaches always had poor yield and performance.

"This is a fundamental change in the way you could produce electronic products, at high speed on a huge scale at very low cost, even less than with conventional methods," Keszler said. "It's a basic way to eliminate the current speed limitations of electrons that have to move through materials".

A patent has been applied for on the new technology, university officials say. New companies, industries and high-tech jobs may ultimately emerge from this advance, they say.

The research was done in the Center for Green Materials Chemistry, and has been supported by the National Science Foundation, the Army Research Laboratory and the Oregon Nano-science and Micro-technologies Institute.

Power gorilla: portable charger

I have been testing a Power-gorilla portable charger for a few weeks now, mainly as a phone charger for extended trips rather than a laptop charger, and one thing sticks out – this is not your average power block. The massive 21000mAh capacity battery pack for standard 5V USB devices is absolutely superb, and means you can keep all your gadgets charged on the move, without having to worry about finding a mains power socket at all.

I’ve successfully used it to keep my phone charged for 10 days with no hassle. The array of connectors is impressive, as is the flexibility of the power output options, from 5V up to 24V for heavy devices such as laptops or video cameras. It’s kind of like carrying around your own power station in a bag. It’s not lightweight at 700g, but worth the lug if you’re always finding yourself out of power when it counts.The company also promotes the Solar-gorilla solar charger as an optional accessory to keep the Power gorilla charged up in the field, but when I tried I found the output of the solar unit so weak (it took an hour to add 10% juice to my phone) that I gave up almost instantly. I guess you need to be in Africa to get the most out of it, and really if you’re serious about solar you’ll need to carry around one of those hefty suitcase products to get the job done.

However, the power-gorilla unit really shines as a power source on the run, and for £150.00 it’s not too heavy on the wallet. It’ll deliver around 2 to 3 hours of power for your laptop and the blurb says 20 hours for your phone from one recharge of the unit, which could be a lifesaver in extreme emergency.

Then simply hook up your gadget and away you go! You can even daisy-chain, so whilst the power-gorilla is charging your laptop, you can charge the power-gorilla from the mains power supply. Or you can charge your laptop and your mobile phone simultaneously! One-touch button technology means the power-gorilla charger for laptops is easy to use and its sleek, aluminum casing with shock resistant rubber protection strips makes it totally robust.

Technology

In Solar Cells, Tweaking the Tiniest of Parts Yields Big Jump in Efficiency

New laser technology could kill viruses and improve DVDs

Better than the human eye

Advance could change modern electronics

Power gorilla: portable charger