Hybrid-state emission in a polythienylenevinylene derivative with an electron deficient moiety.
The photoluminescence (PL) of a novel imide-substituted poly(3-thienylenevinylene) derivative (imidePTV) was studied in film and solution. PL quantum efficiency was measured to be more than two orders of magnitude larger than its nonluminescent counterpart, namely, alkyl-substituted PTV and was interpreted as evidence for a near degeneracy of optically allowed 1(1)Bu and optically forbidden 2(1)Ag excitonic states. As a result, coexistence of 2(1)Ag and 1(1)Bu emissions was observed, and the predominance was found to be sensitive to temperature and morphological environment. PL of solutions in solvents of higher polarity and polarizability and from low-temperature films was dominated by the transition from the dipole allowed 1(1)Bu state. On the other hand, the PL spectra of films at high temperature and solutions in solvents of low polarity and polarizability were primarily from the 2(1)Ag state that obtains a finite transmission moment from an asymmetric perturbation mixing with the 1(1)Bu.
Department of Physics, University of South Florida, Tampa, Florida 33620, USA.
Evan
E
Lafalce
Department of Physics, University of South Florida, Tampa, Florida 33620, USA.
Xiaomei
X
Jiang
Department of Physics, University of South Florida, Tampa, Florida 33620, USA.
Jianjun
J
Pan
Department of Chemistry, University of South Florida, Tampa, Florida 33620, USA.
Christi
C
Whittington
Department of Chemistry, University of South Florida, Tampa, Florida 33620, USA.
Randy
R
Larsen
Department of Chemistry and Biochemistry, South Dakota State University, Brookings, South Dakota 57007, USA.
Logan P
LP
Sanow
Department of Chemistry and Biochemistry, South Dakota State University, Brookings, South Dakota 57007, USA.
Cheng
C
Zhang