Optics Express, Vol. 21, Issue 14, pp. 16319-16330 (2013).
C. Fuchs, T. Schwab, T. Roch, S. Eckardt, A. Lasagni, S. Hofmann, B. Lussem, L. Muller-Meskamp, K. Leo, M. C. Gather, and R. Scholz.
Institut fur Angewandte Photophysik, Technische Universitat Dresden, George-Bahr-Straße 1, 01069 Dresden, Germany and
Institut fur Fertigungstechnik, Technische Universitat Dresden, George-Bahr-Straße 3c, 01069 Dresden, Germany and
Fraunhofer-Institut fur Werkstoff- und Strahltechnik IWS Dresden, Winterbergstr. 28, 01277 Dresden, Germany.
Bragg scattering effects in bottom-emitting organic light-emitting diodes (OLEDs) grown on corrugated aluminum-doped zinc oxide electrodes are analyzed. Periodic corrugation is introduced by structuring the oxide electrode via UV laser ablation, a process that enables flexible adjustment of the period and height of corrugation. We demonstrate that fabrication of stable and electrically efficient OLEDs on these rough substrates is feasible. Sharp spectral features are superimposed onto the broad emission spectra of the OLEDs, providing clear evidence for Bragg scattering of light from guided modes into the air cone. Theoretical analysis based on an emissive dipole model and conservation of momentum considerations allows a quantitative description of scattering and the associated dispersion relations.
© 2013 OSA