Localized triplet excitations and the effect of photo-oxidation in ladder-type poly-phenylene) and oligo-phenylene)
- 15 April 2000
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 61 (16) , 10807-10814
- https://doi.org/10.1103/physrevb.61.10807
Abstract
The photophysics of methyl-bridged poly(para-phenylene)-type ladder polymer (m-LPPP) and oligomer films and solutions is described and discussed. The spin sensitive properties, such as the formation and properties of polaron pairs and triplet excitons (TE’s) were studied using X-band photoluminescence (PL) detected magnetic resonance (PLDMR). The PLDMR results and quantum chemical calculations show unambiguously that the TE wave-function extent is much smaller than that of the singlet exciton (SE). The weaker vibronic structure of the triplet photoinduced absorption (PA) band of m-LPPP relative to the singlet absorption is assigned to the small energy difference between the geometry of the lowest lying and excited triplet states. This is an additional indication of the strong localization of the triplet wave-function as compared to that of the SE. Finally, the influence of photo-oxidation on the PLDMR and PA is analyzed and discussed in relation to the photoconductivity of the materials.Keywords
This publication has 38 references indexed in Scilit:
- Electro-optical studies of a soluble conjugated polymer with particularly low intrachain disorderPhysical Review B, 1999
- Photogeneration and recombination processes of neutral and charged excitations in films of a ladder-type poly(para-phenylene)Physical Review B, 1999
- Photogeneration Action Spectroscopy of Neutral and Charged Excitations in Films of a Ladder-Type Poly(Para-Phenylene)Physical Review Letters, 1999
- Spontaneous and stimulated emission from a ladder-type conjugated polymerPhysical Review B, 1999
- Single-mode picosecond blue laser emission from a solid conjugated polymerApplied Physics Letters, 1998
- Efficient white light-emitting diodes realized with new processable blends of conjugated polymersApplied Physics Letters, 1997
- Blue green stimulated emission from a high gain conjugated polymerApplied Physics Letters, 1997
- Efficient red- and orange-light-emitting diodes realized by excitation energy transfer from blue-light-emitting conjugated polymersPhysical Review B, 1997
- Electric-field-induced luminescence quenching in an electroluminescent organic semiconductorPhysical Review B, 1997
- Highly efficient electroluminescence of new wide band gap ladder-type poly(para-phenylenes)Applied Physics Letters, 1996