Exciton dynamics in blends of phosphorescent emitters

• Published in: Physica Status Solidi (b) Vol. 245; no. 5; pp. 810 - 813
• Main Authors: Schütz, Christoph, Höfer, Bianca, Jaiser, Frank, Krueger, Hartmut, Thesen, Manuel, Janietz, Silvia, Köhler, Anna
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.05.2008; WILEY‐VCH Verlag; Wiley
• Subjects: 78.55.Kz; 81.05.Lg; Applied sciences; Electronics; Exact sciences and technology; Optoelectronic devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Performance evaluation; Exciton; Polymer blends; Brightness; System design; Polymer; Light emitting diode; Side chain; Optoelectronic device; Copolymer; Blue light; Green light; Energy transfer
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200743441

Cascading energy transfer is a usually undesired effect in organic‐host guest systems that are designed for light‐emitting purposes. Here we demonstrate a chemical approach to suppressing undesired energy transfer from the blue to the red emitter in multicomponent polymer blends. We have combined a red, green and blue emitting Ir‐complex each with charge transporting molecules to a side‐chain copolymer. The covalent attachment of the phosphorescent emitter is found to prevent cascading energy transfer through steric shielding. This approach approximately doubles the efficiency and brightness of polymer light emitting diodes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)