A German team of scientists has developed a technique to treat nanoparticle
surfaces. This treatment boosts the efficiency of organic solar cells. Presented
in the journal Applied Physics Letters, the work shows how 2% efficiency was
obtained by using so-called quantum dots made up of cadmium selenide.
The researchers from the Institute of Microsystem Technology (IMTEK) and the
Freiburg Materials Research Center (FMF), both at the University of Freiburg
in Germany, succeeded in breaking the previously held efficiency ratings of
between 1% to 1.8%. The method is protected by patent.
The 'Dye and Organic Solar Cells' research group at Fraunhofer Institute for
Solar Energy Systems in Germany confirmed the measurements made by the Freiberg
scientists.
According to the team, hybrid solar cells are protected by a layer containing
a mixture of inorganic nanoparticles and an organic polymer. From a theoretical
perspective, the new technique can be used on many nanoparticles, and could
further fuel the efficiency of this type of solar cell.
Still in the developmental phase, organic solar cells are part of the third
generation of solar cells, the scientists said. Latest data show that the world
record for purely organic solar cells stands at 7% for layers created through
wet chemical methods. The photoactive layer of these organic solar cells is
made up of organic materials.
The energy market would benefit immensely from organic solar cell use. Energy
producers commonly use conventional silicon cells, but solar cells are significantly
thinner, more flexible, cheaper and quicker to produce.
The scientists said organic solar cells can be used to strengthen everyday
devices and systems that are not used consistently including electrical appliances.
Ultimately, organic solar cells could be used to significantly decrease people's
dependence on batteries and cables.
'The interdisciplinary orientation of the group is a clear advantage and has
led to rapid progress on the project,' explained IMTEK's Dr Michael Krüger,
who led the group. 'We were able to carry out all of the steps on our own: from
the synthesis of the nanoparticles to the modification of their surface and
integration into composite materials.'
The research group comprises physicists, chemists and engineers. They are currently
applying the technique to other materials with a lot of potential so as to refine
them further and get them ready for a technology market launch. Commercialisation
of the technique is dependent on better efficiency, improved durability of the
materials, and cheaper production costs.
Source: Cordis
Posted February 17th, 2010
