Studies of photoexcited states in polyacetylene and poly(paraphenylenevinylene) by absorption detected magnetic resonance: The case of neutral photoexcitations

Journal Article · Mon Feb 03 04:00:00 EST 1992 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.68.666· OSTI ID:7207066

Wei, X; Hess, B C; Vardeny, Z V ^[1]; Wudl, F ^[2]

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1. Department of Physics, University of Utah, Salt Lake City, Utah 84112 (United States)
2. Institute of Polymers and Organic Solids and Department of Physics, University of California, Santa Barbara, California 93106 (United States)

Photoexcited states in {ital trans}polyacetylene ({ital t}-(CH){sub {ital x}}), and in alkoxy derivatives of poly(paraphenylenevinylene) (PPV) nondegenerate ground-state polymers, have been studied by the technique of absorption detected magnetic resonance. In addition to the stable {ital charged} photoexcitations, which are charged solitons in {ital t}-(CH){sub {ital x}} and bipolarons in PPV, we clearly identify {ital neutral} photoexcitations with {ital nonzero} spins. In {ital t}-(CH){sub {ital x}} these are spin-1/2 neutral solitons {ital S}{sup 0}({ital {bar S}} {sup 0}) with an optical transition at 1.35 eV. The neutral photoexcitations in PPV form triplet excitons which cannot dissociate into {ital S}{sup 0}{ital {bar S}} {sup 0} pairs due to the confinement caused by the nondegenerate backbone structure.

• DOE Contract Number: FG02-89ER45409
• OSTI ID: 7207066
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 68:5; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ABSORPTIVITY
CHARGE STATE
ELECTRIC CONDUCTORS
ENERGY LEVELS
EXCITED STATES
HYDROCARBONS
MAGNETIC RESONANCE
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
PHOTO-INDUCED TRANSIENT SPECTROSCOPY
PHYSICAL PROPERTIES
POLYACETYLENES
POLYENES
POLYMERS
QUASI PARTICLES
RELAXATION
RESONANCE
SPECTROSCOPY