Controlling excitons [Elektronische Ressource] : concepts for phosphorescent organic LEDs at high brightness / vorgelegt von Sebastian Reineke

Institut fur Angewandte PhotophysikFachrichtung PhysikFakult at Mathematik und Naturwissenschaftender Technischen Universit at DresdenControlling Excitons:Concepts for PhosphorescentOrganic LEDs at High BrightnessDISSERTATIONzur Erlangung des akademischen GradesDOCTOR RERUM NATURALIUMvorgelegt vonSebastian Reinekegeboren in Eisenach am 9. Dezember 1979November 20091. Gutachter: Prof. Dr. Karl Leo2.hter: Prof. Dr. Josef SalbeckDiese Arbeit wurde am 27. November 2009 eingereicht und am 1. Juli 2010 verteidigt."Junge, hast Du einen guten Vortrag gehabt?"{ In Erinnerung an meine Mutter Berit Reineke.AbstractThis work focusses on the high brightness performance of phosphorescent organiclight-emitting diodes (OLEDs). The use of phosphorescent emitter molecules inOLEDs is essential to realize internal electron-photon conversion e ciencies of 100 %.However, due to their molecular nature, the excited triplet states have orders ofmagnitude longer time constants compared to their uorescent counterparts which,in turn, strongly increases the probability of bimolecular annihilation. As a con-sequence, the e ciencies of phosphorescent OLEDs decline at high brightness { ane ect known as e ciency roll-o , for which it has been shown to be dominated bytriplet-triplet annihilation (TTA).In this work, TTA of the archetype phosphorescent emitter Ir(ppy) is investi-3gated in time-resolved photoluminescence experiments.