Novel solar cell could break conversion efficiency barrier

[ScienceRocks]

Novel solar cell could break conversion efficiency barrier

15 January 2013

Scientists from the US Naval Research Laboratory (NRL) have proposed a novel triple-junction solar cell with the potential to break the 50 per cent conversion efficiency barrier.

‘This research has produced a novel, realistically achievable, lattice-matched, multi-junction solar cell design with the potential to break the 50 per cent power conversion efficiency mark under concentrated illumination,’ said Robert Walters, PhD, NRL research physicist. ‘At present, the world record triple-junction solar cell efficiency is 44 per cent under concentration and it is generally accepted that a major technology breakthrough will be required for the efficiency of these cells to increase much further.’

The work was carried out in collaboration with Imperial College London and MicroLink Devices.

Read more: Novel solar cell could break conversion efficiency barrier | News | The Engineer

 

[waltky]

Lower solar panel prices fuels rise in renewable energy usage...

Cheaper solar panels fuel rise in renewable energy
Jun 12,`13 -- A dramatic drop in the price of solar power technology last year helped the continued growth of renewable energy, according to a U.N.-backed report published Wednesday.

Global energy-generating capacity from renewable sources rose by 115 gigawatts in 2012, compared with 105 gigawatts the previous year, the report by the Paris-based think tank REN21 showed. Installed renewable energy capacity rose to over 1,470 gigawatts, equivalent to about 1,500 nuclear reactors. Two thirds of all renewable capacity still comes from hydropower, but wind and solar have been gaining. The worldwide capacity of photovoltaic cells, which convert sunshine into electricity, reached 100 gigawatts last year, the report said.

The drop in solar prices - fuelled by Chinese manufacturers - helped bring the overall cost of investment in renewables down 12 percent to $244 billion from $279 billion in 2011, effectively boosting the amount of generating capacity investors can get for their money. "This is not only normal in a rapidly growing, high tech industry but is likely to lead to even more competition, with even bigger gains for consumers, the climate and wider sustainability opportunities," said Achim Steiner, the head of the U.N. Environment Program.

Whether this glut of cheap solar products can last is unclear. Last week the EU announced new import duties on Chinese-made solar panels, cells and wafers, alleging they were being sold abroad at a lower price than at home, or below the manufacturing cost. Last year, the United States imposed tariffs on Chinese solar panels following similar complaints.

UNEP said investment in renewables was strong in developing countries and Japan last year, but stagnated or fell in the United States and many European countries grappling with high government debt and uncertainty over future feed-in subsidies. China alone invested $67 billion in renewable energy last year, compared with $36 billion in the United States and almost $80 billion for all European countries combined.

Source

 

[whitehall]

Funny how the solar power people never told us that there was a 50% conversion efficiency barrier until now.

 

[Old Rocks]

Funny how the solar power people never told us that there was a 50% conversion efficiency barrier until now.

Funny that you are that ignorant. For silicon, the barrier is about 34%. For thin film, no barrier, just how to coax the current out of the panel. Were you actually to research a subject, instead of just flap-yapping about it, you would know of the various efficiency 'barriers' for each type of solar cell.

NRL Designs Multi-Junction Solar Cell to Break Efficiency Barrier - Yahoo! Finance

U.S. Naval Research Laboratory scientists in the Electronics Technology and Science Division, in collaboration with the Imperial College London and MicroLink Devices, Inc., Niles, Ill., have proposed a novel triple-junction solar cell with the potential to break the 50 percent conversion efficiency barrier, which is the current goal in multi-junction photovoltaic development.

“This research has produced a novel, realistically achievable, lattice-matched, multi-junction solar cell design with the potential to break the 50 percent power conversion efficiency mark under concentrated illumination,” said Robert Walters, Ph.D., NRL research physicist. “At present, the world record triple-junction solar cell efficiency is 44 percent under concentration and it is generally accepted that a major technology breakthrough will be required for the efficiency of these cells to increase much further.”

In multi-junction (MJ) solar cells, each junction is ‘tuned’ to different wavelength bands in the solar spectrum to increase efficiency. High bandgap semiconductor material is used to absorb the short wavelength radiation with longer wavelength parts transmitted to subsequent semiconductors. In theory, an infinite-junction cell could obtain a maximum power conversion percentage of nearly 87 percent. The challenge is to develop a semiconductor material system that can attain a wide range of bandgaps and be grown with high crystalline quality.

By exploring novel semiconductor materials and applying band structure engineering, via strain-balanced quantum wells, the NRL research team has produced a design for a MJ solar cell that can achieve direct band gaps from 0.7 to 1.8 electron volts (eV) with materials that are all lattice-matched to an indium phosphide (InP) substrate.