A new benzimidazole/carbazole hybrid bipolar material for highly efficient deep-blue electrofluorescence, yellow–green electrophosphorescence, and two-color-based white OLEDs

Synthesis, photophysical and electro-optical properties of bis-carbazolyl methane based host material for pure-blue phosphorescent OLED

“…Many highly efficient red/green/blue color PHOLEDs have already been reported in the literatures, however, the high efficiency device was hardly reported in pure-blue PHOLEDs, especially [5][6][7][8][9][10][11]. In order to be a good host material for increasing the efficiency of the device, its triplet energy must be higher than that of the guest molecules to prevent backward energy transfer during operation and it must have good morphological and chemical stabilities to extend the operation lifetime of the device.…”

High performance hybrid white OLEDs based on new platinum complexes and new blue fluorescence host

“…In order to achieve stable WOLEDs and yet having easy fabrication, fluorescence (F)-phosphorescence (P) hybrid WOLEDs have been demonstrated before. 9 Recently, the hybrid of blue fluorescence and yellow 10,11 or orange 12,13 phosphorescence has attracted much attention in generating white EL with long stability and simplified device structure. However, most of such hybrid WOLEDs have been based on iridium complex phosphorescent dopant.…”

Highly efficient bipolar host material based-on indole and triazine moiety for red phosphorescent light-emitting diodes

“…[6-8] Besides the appropriate triplet energy level, the M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 5 carrier transport property is another criteria to be met, as the occurrence of charge hopping in the emission layer would decrease the carrier recombination zone and directly lower the device efficiency. [9] To meet this requirement, both electron accepter moieties such as benzimidazole, [10] phosphine oxide, [11] triazine, [12] and oxadiazole [13] and electron donors groups like carbazole, [14] amine, [15] fluorine [16] and dibenzothiophene [17] should be introduced to modify the bipolar carrier abilities of hosts. In addition, a desired host material should still possess a high glass transition temperature (T g ) that could enhance the thermal and morphological stability and consequently extend the operational lifetime of the device.…”