Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DS: Fachverband Dünne Schichten
DS 39: Organic Electronics and Photovoltaics CPP-IV (jointly with CPP, HL, and O)
DS 39.4: Vortrag
Mittwoch, 16. März 2011, 15:00–15:15, ZEU 222
Exciton quenching in light emitting organic field-effect transistors studied by localized Spectroscopy — •Wouter Koopman, Stefano Toffanin, and Michele Muccini — ISMN-CNR, Via P. Gobetti 101, 40129 Bologna, Italy
The recent development of organic light-emitting transistors (OLETs) promises a new generation of light-emitting organic devices surpassing the efficiency of organic LEDs. The transistor structure prevents non-radiative processes connected to charge-carrier injection as for the ideal OLET the full recombination takes place inside the channel.
In this work we present an investigation of the influence of field-induced quenching on the luminescence intensity in OLETs based on N,N’ ditridecyl-perylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13H27) as a model compound. We have used localized photoluminescence and lifetime spectroscopy to study the quenching processes at the electrodes and in the channel region in working devices. Our measurements show a reduction of luminescence intensity up to 20% by applying a forward gate voltage, with a gate field in the order of 1×108Vm−1. Upon application of a reverse bias a counter-intuitive enhancement of the PL spectrum was found. Excluding polaron-injection by a dielectric barrier, we can identify field induced effects to be responsible for the observed effects.
These results clarify the role of external electric field induced exciton-quenching on the luminescence efficiency of OLETs and establish a bases for the understanding of the limiting processes in more complex devices.