Photogeneration Action Spectroscopy of Neutral and Charged Excitations in Films of a Ladder-Type Poly(Para-Phenylene)

Journal Article · Thu Apr 01 00:00:00 EST 1999 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.82.3344· OSTI ID:700958

Wohlgenannt, M; Vardeny, Z V ^[1]; Graupner, W ^[2]; Wohlgenannt, M; Graupner, W; Leising, G ^[3]

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1. Department of Physics, University of Utah, Salt Lake City, Utah 84112 (United States)
2. Department of Physics, Virginia Tech, Blacksburg, Virginia 24061-0435 (United States)
3. Institut fuer Festkoerperphysik, Technische Universitaet Graz, Petersgasse 16, A-8010 Graz (Austria)

The photogeneration quantum efficiency action spectra of long-lived neutral and charged excitations in films of a ladder-type poly(para-phenylene) were measured. We found that both triplet and polaron action spectra show, in addition to a step function increase at the optical gap, a monotonic rise at higher energies. For triplets this rise is explained by singlet exciton fission into triplet pairs from which the triplet exciton energy in the gap was obtained; this energy was also confirmed by measuring the weak phosphorescence band. For polarons the photogeneration increase at high energies is modeled by a novel hot electron interchain tunneling process. {copyright} {ital 1999} {ital The American Physical Society}

• OSTI ID: 700958
• Journal Information: Physical Review Letters, Vol. 82, Issue 16; Other Information: PBD: Apr 1999
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
POLYMERS
POLYPHENYLS
THIN FILMS
EXCITONS
POLARONS
ENERGY GAP
PHOSPHORESCENCE
EMISSION SPECTRA