Abstract
Dissociation of photo-generated excitons into charge carriers (polarons) is the working principle of organic photovoltaic cells, whereas recombination of field-injected charge carriers into luminescent singlet excitons and nonradiative triplet excitons governs the efficiency of organic light emitting devices (OLED). In this paper, we address these processes in a single layer OLED based on para-hexaphenyl (PHP)1 by conventional and electric field- assisted femtosecond pump/probe measurements. Due to its well defined conjugation length and its chemical structure PHP exhibits well resolved photo-induced absorption (PA) features, that can be assigned to singlet, triplet and polaron absorption. This allows to monitor the dynamics of field-induced singlet dissociation2 and polaron recombination in a single layer OLED structure consisting of aluminum/PHP/lndium Tin Oxide (1TO) with 200 fs time resolution.
© 1999 Optical Society of America
PDF ArticleMore Like This
G. Cerullo, M. Nisoli, S. Stagira, S. De Silvestri, G. Lanzani, W. Graupner, E. J. W. List, and G. Leising
QWI4 International Quantum Electronics Conference (IQEC) 1998
T. Virgili, G. Lanzani, G. Cerullo, C. Gadermaier, L. Lüer, S. De Silvestri, and D.D.C. Bradley
WD31 International Conference on Ultrafast Phenomena (UP) 2002
Dirk Hertel and Klaus Meerholz
OPTuA2 Organic Photonics and Electronics (OPE) 2006