dc.contributor.author | Yang, K. | eng |
dc.contributor.author | Shcerf, Ullrich | eng |
dc.contributor.author | Guha, Suchi | eng |
dc.date.issued | 2009 | eng |
dc.description.abstract | Inclusion of heavy metal atoms in a polymer backbone allows transitions between the singlet and triplet manifolds. Interfacial dissociation of triplet excitons constitutes a viable mechanism for enhancing photovoltaic (PV) efficiencies in polymer heterojunction-based solar cells. The PV efficiency from polymer solar cells utilizing a ladder-type poly (para-phenylene) polymer (PhLPPP) with trace quantity of Pd atoms and a fullerene derivative (PCBM) is much higher than its counterpart (MeLPPP) with no Pd atom. Evidence is presented for the formation of a weak ground-state charge-transfer complex (CTC) in the blended films of the polymer and PCBM, using photo-induced absorption (PIA) spectroscopy. The CTC state in MeLPPP:PCBM has a singlet character to it, resulting in a radiative recombination. In contrast, the CTC states in PhLPPP:PCBM are more localized with a triplet character. An absorption peak at 1.65 eV is observed in PhLPPP:PCBM blend in the PIA, which may be converted to weakly-bound polaron-pairs, contributing to the enhancement of PV efficiency. | eng |
dc.description.sponsorship | We gratefully acknowledge the support of this work through the National Science Foundation
under grant No. ECCS-0823563. | eng |
dc.identifier.citation | arXiv:0908.0956v1 | eng |
dc.identifier.uri | http://hdl.handle.net/10355/6798 | eng |
dc.language | English | eng |
dc.publisher | arXiv | eng |
dc.relation.ispartofcollection | University of Missouri--Columbia. College of Arts and Sciences. Department of Physics and Astronomy. Physics and Astronomy publications | eng |
dc.source.uri | http://arxiv.org/PS_cache/arxiv/pdf/0908/0908.0956v1.pdf | eng |
dc.subject | materials science | eng |
dc.subject | triplet excitons | eng |
dc.subject | photovoltaic efficiencies | eng |
dc.subject.lcsh | Exciton theory | eng |
dc.subject.lcsh | Solar cells -- Research | eng |
dc.subject.lcsh | Polymers -- Optical properties | eng |
dc.subject.lcsh | Triplet state | eng |
dc.title | The role of triplet excitons in enhancing polymer solar cell efficiency: a photo-induced absorption study | eng |
dc.type | Article | eng |