title: Absorption and Quantum Yield of Single Conjugated Polymer Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) Molecules.
abstract: We simultaneously measured the absorption and emission of single conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) molecules in a poly(methyl methacrylate) (PMMA) matrix using near-critical xenon to enhance the photothermal contrast for direct absorption measurements. We directly measured the number of monomers and the quantum yield of single conjugated polymer molecules. Simultaneous absorption and emission measurements provided new insight into the photophysics of single conjugated polymers under optical excitation: quenching in larger molecules is more efficient than in smaller ones. Photoinduced traps and defects formed under prolonged illumination lead to decrease of both polymer fluorescence and absorption signals with the latter declining slower.
authors.affiliation: LION, Huygens-Kamerlingh Onnes Laboratory, Leiden University , Niels Bohrweg 2, 2300RA Leiden, The Netherlands.
authors.forename: Lei
authors.initials: L
authors.lastname: Hou
authors.affiliation: LION, Huygens-Kamerlingh Onnes Laboratory, Leiden University , Niels Bohrweg 2, 2300RA Leiden, The Netherlands.
authors.forename: Subhasis
authors.initials: S
authors.lastname: Adhikari
authors.affiliation: Chemical Physics and Nano Lund, Lund University , P.O. Box 124, 22100 Lund, Sweden.|Key Laboratory of Mesoscopic Chemistry of MOE and School of Chemistry and Chemical Engineering, Nanjing University , 210023 Nanjing, China.
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Chemical Physics and Nano Lund, Lund University , P.O. Box 124, 22100 Lund, Sweden.
authors.forename: Ivan G
authors.identifier: 0000-0001-6059-4777
authors.initials: IG
authors.lastname: Scheblykin
authors.affiliation: LION, Huygens-Kamerlingh Onnes Laboratory, Leiden University , Niels Bohrweg 2, 2300RA Leiden, The Netherlands.
authors.forename: Michel
authors.identifier: 0000-0002-3607-3426
authors.initials: M
authors.lastname: Orrit
keywords: Conjugated polymer; absorption; photothermal; quantum yield; quenching