193017-42-4Relevant academic research and scientific papers
Influence of polyhedral oligomeric silsesquioxanes (POSS) on blue light-emitting materials for OLED
Zhang, Tianfu,Wang, Jinze,Zhou, Manxi,Ma, Li,Yin, Guangzhong,Chen, Guangxin,Li, Qifang
, p. 2478 - 2486 (2014)
By using Heck polycondensation, we have synthesized carbazole-based alt-copolymers tethered with polyhedral oligomeric silsesquioxanes (POSS), which had well-defined architectures, similar polymerization degrees and the different contents of POSS. The effect of POSS content and the length of the side chain containing POSS on the electroluminescence properties of these polymers were investigated. POSS particles in these alt-copolymers showed excellent dispersity and prevented the interchain aggregation of polymers in film state well. Besides, POSS benefited charge balance by increasing the electron current density, which led to a higher luminance and current efficiency, as well as purer blue light-emitting.
Fluorescent pyrene-centered starburst oligocarbazoles with excellent thermal and electrochemical stabilities
Ren, Ming-Guang,Guo, Hui-Jun,Qi, Fei,Song, Qin-Hua
, p. 6913 - 6916 (2011/11/04)
A series of pyrene-centered starburst oligocarbazoles (1-3) have been synthesized and well characterized. Based on photophysical, thermal and electrochemical studies in solutions and as thin films, all starburst molecules reveal a sky blue emission with a high efficiency (ΦF = 0.99 - 0.81) and excellent thermal and electrochemical stabilities. As OLED materials, these superior properties are helpful to enhance device stability and lifetime.
Carbazole Compounds as Host Materials for Triplet Emitters in Organic Light-Emitting Diodes: Tuning the HOMO Level without Influencing the Triplet Energy in Small Molecules
Brunner, Klemens,Van Dijken, Addy,Boerner, Herbert,Bastiaansen, Jolanda J. A. M.,Kiggen, Nicole M. M.,Langeveld, Bea M. W.
, p. 6035 - 6042 (2007/10/03)
A series of novel carbazole compounds was synthesized and tested for their suitability as host for triplet emitters in an organic-light emitting diode (OLED). In these compounds, a carbazole unit is either connected to other carbazole units to form carbazole dimers and trimers or to fluorene and oxadiazole derivatives to form mixed compounds. The HOMO level of carbazole compounds can be tuned by substitution at the 3, 6, and/or 9 positions. Making oligomers by connecting carbazole molecules via their 3 (3′) positions shifts the HOMO level to higher energy, while replacing alkyl groups at the 9 (9′) positions by aryl groups shifts the HOMO level to lower energy. Furthermore, it has been found that the triplet energy of these compounds is determined by the presence of poly(p-phenyl) chains in the molecular structure. By identifying the longest poly(p-phenyl) chain, one can predict whether a compound will be a suitable host for a high-energy triplet emitter. An overview of HOMO levels, singlet and triplet levels, and exchange energies is given for all carbazole compounds synthesized. Finally, OLEDs employing two selected carbazole compounds as host and fac-tris(2-phenylpyridine)-iridium (Ir(ppy) 3) as guest were constructed and characterized electrically.
