Electrically Detected Magnetic Resonance (EDMR) was used to investigate the influence of dye doping molecules on spin-dependent exciton formation in Aluminum (III) 8-hydroxyquinoline (Alq₃) based OLEDs with different device structures and temperature ranges. 4-(dicyanomethylene)-2-methyl-6-{2-[(4-diphenylamino-phenyl]ethyl}-4H-pyran (DCM-TPA) and 5,6,11,12-tetraphenylnaphthacene (Rubrene) were used as dopants. A strong temperature dependence have been observed for doped OLEDs, with a decrease of two orders of magnitude in EDMR signal for temperatures above ~200 K. The signal temperature dependence were fitted supposing different spin-lattice relaxation processes. The results suggest that thermally activated vibrations of dopants molecules induce spin pair dissociation, reducing the signal.

Date Published: 22 February 2012
PDF: 7 pages
Proc. SPIE 8333, Photonics and Optoelectronics Meetings (POEM) 2011: Optoelectronic Devices and Integration, 83331B (22 February 2012); doi: 10.1117/12.918246

Published in SPIE Proceedings Vol. 8333:
Photonics and Optoelectronics Meetings (POEM) 2011: Optoelectronic Devices and Integration
Erich Kasper; Jinzhong Yu; Xun Li; Xinliang Zhang; Jinsong Xia; Junhao Chu; Zhijiang Dong; Bin Hu; Yan Shen, Editor(s)