Benzocarbazole and diphenyltriazine derived hosts for red phosphorescent organic light-emitting diodes

Functionalized 1,3,5-triazine derivatives as components for photo- and electroluminescent materials

“…Compounds 43 , 44 were synthesized by Pd-catalysed amination reaction between monobrominated triphenyl- s -triazine and benzocarbazole, and thus obtained products exhibited excellent thermal stability ( T d > 400 °C). 39 Both compounds exhibited blue fluorescence in solutions ( λ em = 447 nm for 43 and 431 nm for 44 in THF) and phosphorescence with a triplet energy value of 2.52 eV, as well as promising ambient carrier transport properties.…”

“…Compounds 43, 44 were synthesized by Pd-catalysed amination reaction between monobrominated triphenyl-s-triazine and benzocarbazole, and thus obtained products exhibited excellent thermal stability (T d > 400 °C). 39 phorescent OLED exhibited excellent current efficiency of 75.9 cd A −1 and excellent quantum efficiency of 24.7%.…”

Highly Efficient Phosphorescent Organic Light-Emitting Diodes Using Benzo[4′,5′]imidazo[2′,1′:2,3]imidazo[4,5,1-jk]carbazole as a Rigid and Effective Electron Acceptor in Bipolar Host

“…Researchers have proposed that incorporating both hole- and electron-transporting units in bipolar host materials can enhance device performance more rapidly than using conventional unipolar hosts. – Scientists have developed multiple classes of bipolar host materials by combining various hole-and electron-transporting moieties. Carbazoles and arylamines have been widely employed as hole-transporting units, – while benzimidazole, oxadiazoles, phenanthroline, phosphine oxide, phosphine sulfide, pyridine, triazine, and triazole have been used as electron-transporting units. However, further exploration of building units of bipolar hosts is necessary to improve the device performance of PhOLEDs.…”

A universal bipolar host based on isonicotinonitrile and carbazole for efficient red, green and blue PhOLEDs

“…Luckily, the host–guest system was found to be effective to alleviate the concentration caused quenching issue by dispersing the heavy metal emitters homogeneously in a proper host. 6–12 Thus, the host materials are of equal importance compared to the emitters to achieve high electroluminescent (EL) performance.…”

“…Carbazole is a widely used building block for hole transport due to its good electron donating ability, high E T , easy modification on its backbone and high thermal stability. 10,11,15,18,26,27 Isonicotinonitrile, also known as 4-cyano substituted pyridine, which could benefit from the good electron transport ability and high thermal stability of both of the two groups, is a potential acceptor for constructing bipolar hosts and D–A type emitters. 28–30 Li et al introduced a 3-cyanopyridine unit to the widely used host 1,3-di(9 H -carbazol-9-yl)benzene (mCP) to construct a bipolar host 3-PyCNmCP and an EQE max of 24.7% was obtained when hosting green PhOLEDs.…”