polymers blended with electron-accepting fullerene derivatives have reached high ... shown in Figure 2A, with the typical signatures for ground-state bleaching .... excited state, caused by electronic relaxation through a manifold of delocalized ...
Article pubs.acs.org/JACS
Charge Separation Pathways in a Highly Efficient Polymer: Fullerene Solar Cell Material Arun Aby Paraecattil and Natalie Banerji* Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), SB ISIC GR-MO, Station 6, CH-1015 Lausanne, Switzerland S Supporting Information *
ABSTRACT: PBDTTPD is one of the best conjugated polymers for solar cell applications (up to 8.5% efficiency). We have investigated the dynamics of charge generation in the blend with fullerene (PCBM) and addressed highly relevant topics such as the role of bulk heterojunction structure, fullerene excitation, and excess energy. We show that there are multiple charge separation pathways. These include electron transfer from photoexcited polymer, hole transfer from photoexcited PCBM, prompt (
