+44 (0)24 7671 8970
More publications     •     Advertise with us     •     Contact us
 
Loading...
{megaLeaderboard}
{normalLeaderboard}
News Article

Japanese use spectroscopy to reveal OPC charge formation efficiency

News

Organic photovoltaic cells, a type of solar cell that uses polymeric materials to capture sunlight, show tremendous promise as energy conversion devices, thanks to key attributes such as flexibility and low-cost production.

But one giant hurdle holding back organic photovoltaic technologies have been the complexity of their power conversion processes, which involve separate charge formation and transport processes.

To manoeuvre around this problem, a team of researchers in Japan has developed a method to determine the absolute value of the charge formation efficiency. The secret of their method, as they report in Applied Physics Letters, is the combination of two types of spectroscopy.

The two types the team uses are photo-induced spectroscopy to determine the change in absorption after femtosecond photo-pulse excitation, and electrochemical spectroscopy to examine the absorption change due to charge injection. "By qualitative analysis of the spectral change, we can deduce how many charges are produced by one photon -- its charge formation efficiency," said Professor Yutaka Moritomo, Institute of Materials Science at the University of Tsukuba.

"It's a huge step forward," said Moritomo. "The team also discovered that the charge formation efficiency remains high (0.55) even at low temperatures (80 K)."

"This was extremely surprising," Moritomo continued, since the positive and negative charges are strongly bound in an organic photovoltaic device as an exciton -- a bound state of an electron and hole, which are attracted to each other by the electrostatic Coulomb force.

"Its charge formation was believed to be too difficult without a thermal activation process," explained Moritomo. "But our work shows that the charge formation process of an organic photovoltaic device is purely quantum mechanical, and any theoretical model should explain the high charge formation efficiency at low temperatures."

The team's work will enable the high-throughput screening of organic materials for new organic photovoltaic devices. "Organic materials have several requirements -- including high charge formation efficiency and high charge transport efficiency -- so our method can be used to quickly screen the materials by charge formation efficiency," Moritomo said.

"Now that we have a method to determine the key physical parameter, charge formation efficiency, we're exploring the interrelation between it and the nanoscale structure of the organic photovoltaic device to clarify the mechanism of the charge formation," noted Moritomo.

 

Journal Reference
 "Effect of temperature on carrier formation efficiency in organic photovoltaic cells," is authored by Yutaka Moritomo, Kouhei Yonezawa and Takeshi Yasuda. It will appear in the journal Applied Physics Letters on August 19, 2014. After that date, it can be accessed at: http://scitation.aip.org/content/aip/journal/apl/105/7/10.1063/1.4892611

Schletter Group: 48 MWp Project in Italy
ENCAVIS Acquires Two More Solar Parks In Spain and Surpasses The Planned Expansion
Maximum profitability with KACO advanced technology for complex solar roofs
Enviromena wins contract to re-power three major solar farms ahead of the summer energy peak
New Swansea University Collaboration to Support Sustainable, Locally Manufactured Solar PV
New Swansea University Collaboration to Support Sustainable, Locally Manufactured Solar PV
Next2Sun Builds World's Largest Vertical PV Plant at Frankfurt Airport
DNV Publishes Bankability Study of Solcast Satellite Irradiance Data
Steel company SSAB switches to fossil-free energy in Italy with PV solution from Solnet
janom Investments enters the Croatian solar energy industry by investing in a 30 MW power plant project
Trina Solar Vertex S+ 505W n-type dual-glass modules enter mass production
BayWa r.e. and 3E sign partnership agreement for monitoring & analytics of global PV portfolio
Accelerating Spain's Energy Transformation: LONGi to supply Naturgy with 1 million modules in new deal
NTR announces corporate PPA with Almac Group to buy energy from Murley Wind Farm, Northern Ireland
Oxford PV sets new solar panel efficiency world record
Order Intake for the Construction of Wind Turbines in Turkey
Trilantic Europe acquires stake in AEROCOMPACT Group
Octopus Energy makes solar farm debut in Germany
Austria-based KOGA Energy, a solar EPC solutions provider, has kicked off.
Exus to acquire 625MW New Mexico solar portfolio
Capcora Accompanies SUSI Partners In Raising Senior Debt For a Polish Renewables Portfolio
Qualitas Energy acquires a 96 MW wind energy project pipeline in Germany
Nordex Group receives orders from the UK for approx. 150 MW
Trina Solar gains EPD certification from UL Solutions and EPDItaly for industry leading modules
Mandarin Oriental Hyde Park, London instals innovative solar tech to decarbonise heating
Efficiency First: The Road to Electrification
SCHLETTER Supplies Austria's Largest PV Roof System
E.ON partners with UK renewable heat innovator Naked Energy
Sonnedix signs innovative EUR500 million loan facility to finance construction of its renewable electricity pipeline in Europe and UK
Construction begins on Glennmont and Ørsted’s Borkum Riffgrund 3 offshore wind farm in Germany
ABB shores up reliable power supply at Southeast Asia’s largest floating solar plant
Sonnedix starts construction of 300MW UK solar PV portfolio

×
Search the news archive

To close this popup you can press escape or click the close icon.
Logo
×
Logo
×
Register - Step 1

You may choose to subscribe to the Solar + Power Magazine, the Solar + Power Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: