Photovoltaic Investigation of New Co-polymers Based on Thiophene, Fluorine and Phenylene
Conferences & Talks

• Natasha Yamamoto, Universidade Federal do Parana (presenter)
• Leah Lavery
• Gregory Whiting
• Ana Arias

2010 Materials Research Society Fall Meeting

30 November 2010
10:30am
Boston, Massachusetts

description

We have investigated a series of new electron donor co-polymers (LaPPS-35)  in organic thin-film solar cells.  Copolymerization allows us to create new materials by tailoring unit ratios with a combination of  properties and behaviors of different materials. The co-polymers used in this study were composed of thiophene, phenylene and fluorine units, where the thiophene content was kept constant while the fluorine/phenylene ratio was varied.  For every copolymer ratio, we report results in three different structures: monolayer, bilayer and bulk heterojunction.  Using vapor-deposited C60 as the electron acceptor in bilayer structures, we show the effect of altering the thickness of both the copolymer and fullerene films.  Bilayer devices were further analyzed using a model for charge transport, which indicated a dependence of effective mobility on film thickness.  For the bulk heterojunction system [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) was used as the electron acceptor.  For both the bilayer and heterojection cells it was found that a 1:1 ratio of phenylene:fluorine units led to the highest device performance, and initial bulk hetereojunction devices using this polymer showed a peak external quantum efficiency of 33% and a AM1.5 power conversion efficiency of 0.7%.