Image: imec |
The Belgian research center imec, together with Plextronics
and Solvay, presented an organic polymer-based single junction solar cell with
6.9% performance in an innovative inverted device stack. Combining imec’s
scalable inverted device architecture and Plextronics’ polymers, new levels of
cell efficiency were achieved. The polymer was also integrated into a module
resulting in excellent module level efficiencies of 5% for an aperture area of
25cm².
Organic solar cells are regarded as an emerging technology
to become one of the low-cost thin-film alternatives to the current dominating
silicon photovoltaic technology, due to their intrinsic potential for low-cost
processing (high-speed and at low temperature). Inverted architectures are
developed to extend the lifetime of organic solar cells, an investigation which
is currently ongoing for this new architecture. By combining architecture
improvements with optimizations to the active layer using different types of
polymers, imec aims at making the organic photovoltaic technology ready for
market introduction.
The dedicated inverted bulk heterojunction architecture
developed by imec improved the device performance by at least 0.5% over
standard architectures used for organic solar cells. In the active layer, a new
buffer layer was introduced to optimize the light management in the device.
Imec’s device architecture, combined with Plextronics’ low band-gap p-type
polymer with a fullerene derivate, resulted in a stabilized certified
conversion efficiency of 6.9%, which is the highest performance obtained for
this polymer material and, to our knowledge, the highest efficiency reported
for inverted architectures. In this new inverted device architecture, similar
performance boosts have also been achieved for other polymer materials. The
module level efficiencies confirm the suitability towards upscaling.
Tom Aernouts, R&D Team Leader Organic Photovoltaics at
imec says: “We are delighted to present these excellent results, achieved by
combining imec’s expertise and knowhow in organic photovoltaics R&D with
Plextronics’ innovative material. With further optimizations to the material as
well as to the architecture, for example by introducing a multi-junction
featuring different layers of different polymers each capturing another part of
the light spectrum, we envision organic solar cell lifetimes of over 10 years
and conversion efficiencies of 10% in two to three years, ultimately aiming at
industry-relevant solutions.”
