New PV cell generates electricity from IR and UV light

Mar 24, 2010 by Lin Edwards report
The PV cell prototyped at the Kyoto Institute of Technology by adding cobalt to a p-type GaN thin film and laminating an n-type material (right). The cell with an absorbing layer measures 10 x 10mm. The surrounding thin rectangular patterns are electrodes. And the p-type GaN thin film without cobalt (left). Image via: Tech on.

(PhysOrg.com) -- A prototype of a new type of photovoltaic (PV) cell that generates electricity from visible, infrared and ultraviolet light has been demonstrated by a group of Japanese scientists. It could lead to the development of a highly-efficient PV cell in the future, without needing multijunction cells.

The research was led by Associate Professor Saki Sonoda of the Kyoto Institute of Technology. The prototype cell has a high open voltage (Voc) at around two volts, but a low . Sonada and the team hope the conversion rates can be improved.

Photovoltaic materials convert light to electricity at the atomic level by absorbing photons of light and releasing electrons that can be captured to produce an electric current. Most PV cells are multijunction devices, with single junction cells stacked in descending order of band gap. The cell at the top captures high-energy photons, while those at the bottom with lower band gaps capture the lower energy photons. The new cell is able to capture photons with a wide range of energies in a single junction cell.

The team made the 10 mm square PV cell by adding elements such as manganese (Mn) or cobalt (Co) to the transparent (GaN). When the element is added, the absorption coefficient of GaN is higher, allowing a much wider spectrum of light to be absorbed, including infrared, visible and ultraviolet. A cell made from p-type GaN with added Mn or Co is transparent and black, whereas GaN without additions is not.

Manganese and cobalt are 3d transition metals, which are elements in which the number of electrons in the 3d orbit (inside the outermost orbit) increases as the number of protons in the nucleus (and hence the atomic number) increases. Other well-known 3d transition metals include titanium (Ti), (Fe), copper (Cu) nickel (Ni) and zinc (Zn).

The scientists tried several 3d transition metals with GaN and obtained good results with many of them, including manganese and cobalt. Other researchers have tried adding indium (In) to gallium nitride PV cells with the aim of narrowing the to enable it to absorb a wider wavelength band of visible light.

The prototype was demonstrated during a 90-minute lecture at the 57th Spring Meeting of the Japan Society of Applied Physics on March 19.

Explore further: Infineon offers application optimized bipolar power modules introducing cost-effective solder bond modules

Related Stories

More efficient devices on solar cells due to energy matching

Dec 07, 2006

Many wireless devices currently work on solar energy (photovoltaic = PV). Often the choice for PV cells seems merely to be based on the green image. Yet this technology can be used far more effectively if the elements from ...

New alloys key to efficient energy and lighting

Mar 22, 2010

A recent advance by Arizona State University researchers in developing nanowires could lead to more efficient photovoltaic cells for generating energy from sunlight, and to better light-emitting diodes (LEDs) that could replace ...

Hot Electrons Could Double Solar Cell Power Efficiency

Dec 18, 2009

Scientists have experimentally verified a theory suggesting that hot electrons could double the output of solar cells. The researchers, from Boston College, have built solar cells that successfully use hot ...

Recommended for you

A green data center with an autonomous power supply

57 minutes ago

A new data center in the United States is generating electricity for its servers entirely from renewable sources, converting biogas from a sewage treatment plant into electricity and water. Siemens implemented ...

After a data breach, it's consumers left holding the bag

1 hour ago

Shoppers have launched into the holiday buying season and retailers are looking forward to year-end sales that make up almost 20% of their annual receipts. But as you check out at a store or click "purchase" on your online shopping cart ...

Can we create an energy efficient Internet?

1 hour ago

With the number of Internet connected devices rapidly increasing, researchers from Melbourne are starting a new research program to reduce energy consumption of such devices.

Brain inspired data engineering

2 hours ago

What if next-generation ICT systems could be based on the brain's structure and its cognitive and adaptive processes? A groundbreaking paradigm of brain-inspired intelligent ICT architectures is being born.

E-Voting: Risky technology or great improvement?

3 hours ago

On this forthcoming weekend the Australian state election takes place, and in Victoria State they will be using a new e-voting system to improve secrecy, reliability and user-friendliness. But how secure are such systems? ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

Sci_Phys_observer
4 / 5 (3) Mar 24, 2010
There is a better article that give more useful information at :
http://www.semico...310.html
Im always amazed at how little useful information is disclosed here
Yogaman
5 / 5 (3) Mar 24, 2010
That url is missing a hyphen between semiconductor and today, SPo, possibly thanks to word wrap. A fixed version is at http://tinyurl.com/yghgl4g

I once shared your amazement, but constant repetition has dulled it.
Thanks for the pointer, though.
Eco_R1
not rated yet Mar 25, 2010
heat shielding + "free" energy, i'll take it!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.