title: Blue Light Emitting Polyphenylene Dendrimers with Bipolar Charge Transport Moieties.
abstract: Two light-emitting polyphenylene dendrimers with both hole and electron transporting moieties were synthesized and characterized. Both molecules exhibited pure blue emission solely from the pyrene core and efficient surface-to-core energy transfers when characterized in a nonpolar environment. In particular, the carbazole- and oxadiazole-functionalized dendrimer (D1) manifested a pure blue emission from the pyrene core without showing intramolecular charge transfer (ICT) in environments with increasing polarity. On the other hand, the triphenylamine- and oxadiazole-functionalized one (D2) displayed notable ICT with dual emission from both the core and an ICT state in highly polar solvents.D1, in a three-layer organic light emitting diode (OLED) by solution processing gave a pure blue emission with Commission Internationale de l'Éclairage 1931 CIExy= (0.16, 0.12), a peak current efficiency of 0.21 cd/A and a peak luminance of 2700 cd/m². This represents the first reported pure blue dendrimer emitter with bipolar charge transport and surface-to-core energy transfer in OLEDs.
authors: Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz D-55128, Germany. zhangg@mpip-mainz.mpg.de.
authors: Guang
authors: G
authors: Zhang
authors: Joanneum Research Materials, Institut für Oberflächentechnologien und Photonik, Franz-Pichler-Straße 30, Weiz 8160, Austria. Manuel.Auer-Berger@joanneum.at.
authors: Manuel
authors: M
authors: Auer-Berger
authors: Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz D-55128, Germany. Dominik.Gehrig@web.de.
authors: Dominik W
authors: DW
authors: Gehrig
authors: Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz D-55128, Germany. blom@mpip-mainz.mpg.de.
authors: Paul W M
authors: PW
authors: Blom
authors: Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz D-55128, Germany. martin.baumgarten@mpip-mainz.mpg.de.
authors: Martin
authors: M
authors: Baumgarten
authors: Institute für Organische Chemie, Johannes Gutenberg-Universität, Mainz D-55128, Germany. scholli@uni-mainz.de.
authors: Dieter
authors: D
authors: Schollmeyer
authors: Institut für Physik, Institut für Chemie, Humboldt-Universität zu Berlin, IRIS Adlershof, Unter den Linden 6, Berlin 10099, Germany. emil.list-kratochvil@hu-berlin.de.
authors: E J W
authors: EJ
authors: List-Kratochvil
authors: Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz D-55128, Germany. muellen@mpip-mainz.mpg.de.
authors: Klaus
authors: K
authors: Müllen
mesh_terms: D002227:Carbazoles / Q000737:chemistry; D050091:Dendrimers / Q000138:chemical synthesis* / Q000737:chemistry; D004579:Electron Transport; D004735:Energy Transfer; D008027:Light; D010069:Oxadiazoles / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*
chemical_list: D002227:Carbazoles; D050091:Dendrimers; D010069:Oxadiazoles; D011108:Polymers; C041514:carbazole; C041325:polyphenylene sulfide
keywords: bipolar charge transport; blue light emitter; polyphenylene dendrimer; surface to core energy transfer