Direct Observation of Ultrafast Field-Induced Charge Generation in Ladder-Type Poly(Para-Phenylene)

W. Graupner; G. Cerullo; G. Lanzani; M. Nisoli; E. J. W. List; G. Leising; S. De Silvestri

doi:10.1103/PhysRevLett.81.3259

Direct Observation of Ultrafast Field-Induced Charge Generation in Ladder-Type Poly(Para-Phenylene)

W. Graupner, G. Cerullo, G. Lanzani, M. Nisoli, E. J. W. List, G. Leising, and S. De Silvestri

Phys. Rev. Lett. 81, 3259 – Published 12 October 1998

Abstract

Electric field-induced charge photogeneration in ladder-type poly(para-phenylene) is investigated by field-assisted femtosecond pump-probe experiments carried out on light emitting diodes. The characteristic photoinduced absorption band at 1.9 eV allows one to directly monitor the polaron population. We find that polarons are formed by exciton fission without intermediate states on a time scale of 10 ps. The buildup kinetics of the polaron population suggests a dissociation driven by exciton diffusion during interchain thermalization.

Received 23 December 1997

DOI:https://doi.org/10.1103/PhysRevLett.81.3259

Authors & Affiliations

W. Graupner¹, G. Cerullo², G. Lanzani³, M. Nisoli², E. J. W. List¹, G. Leising¹, and S. De Silvestri²

¹Institut für Festkörperphysik, Technische Universität Graz, A-8010 Graz, Austria
²Istituto Nazionale per la Fisica della Materia, CEQSE-CNR, Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
³Istituto di Matematica e Fisica, Istituto Nazionale per la Fisica della Materia, Università di Sassari, I-07100 Sassari, Italy