Journal
ADVANCED ENERGY MATERIALS
Volume 5, Issue 2, Pages -Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/aenm.201401109
Keywords
polymers; fullerene; triplet excitons; charge transfer; energy transfer
Categories
Funding
- FWO (fund for Scientific Research - Flanders) [G.0555.10N, G.0888.12N, LC3007]
- IWT (Institute for the Promotion of Innovation by Science and Technology in Flanders) via the SBO-project [090047]
- Flemish Hercules foundation [AUHA013]
- Dutch Technology Foundation (STW), which is part of the Netherlands Organization for Scientific Research (NWO)
Ask authors/readers for more resources
Triplet exciton (TE) formation pathways are systematically investigated in prototype bulk heterojunction (BHJ) super yellow poly(p-phenylene vinylene) (SY-PPV) solar cell devices with varying fullerene compositions using complementary optoelectrical and electrically detected magnetic resonance (EDMR) spectroscopies. It is shown that EDMR spectroscopy allows the unambiguous demonstration of fullerene triplet production in BHJ polymer:fullerene solar cells. EDMR triplet detection under selective photoexcitation of each blend component and of the interfacial charge transfer (CT) state reveals that low lying fullerene TEs are produced by direct intersystem crossing from singlet excitons (SEs). The direct CT-TE recombination pathway, although energetically feasible, is kinetically suppressed in these devices. However, high energy CT states in the CT manifold can contribute to the population of the fullerene triplet state via a direct CT-SE conversion. This undesirable energetic alignment could be one of the causes for the severe reduction in photocurrent observed when the open-circuit voltage of polymer:fullerene solar cells is pushed to 1.0 V or beyond.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available