Evolution of excitons and polarons in polythiophene from femtoseconds to milliseconds

Journal Article · Mon Jul 20 00:00:00 EDT 1992 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.69.538· OSTI ID:7110235

Kanner, G S; Wei, X; Hess, B C; Chen, L R; Vardeny, Z V ^[1]

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1. Department of Physics, University of Utah, Salt Lake City, Utah 84112 (United States) Department of Physics, California State University, Fresno, California 93740 (United States) Division of Engineering, Brown University, Providence, Rhode Island 02912 (United States)

We have studied the photoexcitation dynamics in electrochemically polymerized polythiophene thin films using transient photomodulation (PM) spectroscopy measured from 100 fs to 20 ms in the spectral range from 0.25 to 2.2 eV, and by the novel technique of absorption-detected magnetic resonance (ADMR). Our results show that photogenerated exciton polarons are formed within 300 fs; they subsequently decay in the nanosecond time domain by 1D diffusion toward recombination centers The dominant excitations after about 250 ns are charged polarons and bipolarons, which are identified by optical transitions correlated with a spin-1/2 ADMR signal at {ital g}=2.003.

• DOE Contract Number: FG02-89ER45409
• OSTI ID: 7110235
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 69:3; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
DYNAMICS
ELECTRONIC STRUCTURE
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITONS
FILMS
HETEROCYCLIC COMPOUNDS
LUMINESCENCE
MAGNETIC RESONANCE
MECHANICS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHOTO-INDUCED TRANSIENT SPECTROSCOPY
PHOTOLUMINESCENCE
POLARONS
POLYMERS
QUASI PARTICLES
RELAXATION TIME
RESONANCE
SPECTROSCOPY
THIN FILMS
THIOPHENE