Fate of excitations in conjugated polymers: single-molecule spectroscopy reveals nonemissive "dark" regions in MEH-PPV individual chains.
Single chains of the conjugated polymer MEH-PPV (poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene)) were studied with wide-field fluorescence microscopy (dispersion in inert polymer matrices) and with fluorescence correlation spectroscopy (chloroform solution). The fluorescence yield of individual molecules in matrices was found to be 1-2 orders of magnitude lower than that in solution and it decreased substantially with increasing chain length. It suggests that isolation of MEH-PPV molecules in polymer matrices creates favorable conditions for photogeneration of nonemissive primary excited states.
Lin
Hongzhen
H
Chemical Physics and Pure and Applied Biochemistry, Lund University, Box 124, 22100 Lund, Sweden.
Tian
Yuxi
Y
Zapadka
Karolina
K
Persson
Gustav
G
Thomsson
Daniel
D
Mirzov
Oleg
O
Larsson
Per-Olof
PO
Widengren
Jerker
J
Scheblykin
Ivan G
IG
D008027:Light; D011108:Polymers / Q000737:chemistry*; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014753:Vinyl Compounds / Q000737:chemistry*
D011108:Polymers; D014753:Vinyl Compounds; C520682:poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene)