Bipolar hosts and non-doped deep-blue emitters (CIE_y= 0.04) based on phenylcarbazole and 2-(2-phenyl-2H-1,2,4-triazol-3-yl)pyridine groups

Abstract

Four bipolar materials using 1,2,4-triazol derivative as an acceptor and carbazole as a donor were synthesized. They can be used not only as emitters to fabricate deep-blue OLEDs, but also as hosts to construct PhOLEDs.

Violet-Blue Aggregation-Induced Emission Emitters for Non-Doped OLEDs with CIEy Smaller than 0.046

“…It is also worth noting the outstanding EQE value of the TPBCzC1-baesd OLED also represents the best results for violet-blue OLEDs with CIEy < 0.046 based on fluorescent materials ( Figure 6C and Table 2). [44][45][46][47][48][49] Moreover, all devices exhibit a very low efficiency roll-off probably because the radiative transition channels are activated and the non-radiative transition channels are inhibited in the aggregate state, confirming the excellent efficiency stabilities of the devices (Figures 6A and S7).…”

Rational design of quinoxaline-based bipolar host materials for highly efficient red phosphorescent organic light-emitting diodes

“…2a, the absorption of M1 and M2 exhibits bands in the range from 250 to 430 nm (247, 298, 387 nm for M1; 254, 303, 378 nm for M2), attributed to the p-p* electronic transition of the quinoxaline and carbazole unit. 33,34,[40][41][42] M1 and M2 show almost the same absorption spectra in spite of the larger p-electron conjugation of compound M2, implying that the introduction of the phenyl spacer almost has little effect on the absorption properties of these donor-acceptor systems.…”

“…However, the LUMO energy of compound M1 (À3.09 eV) were higher than that of M2 (À3.21 eV), implying that the phenyl spacer have evident inuence on the LUMO of these donor-acceptor systems. [40][41][42] Red phosphorescent OLEDs…”

“…Many bipolar host materials have been explored in highly efficient red phosphorescent OLEDs, especially in the design of acceptor moieties. [40][41][42] Recently, diphenylquinoxaline derivatives showing excellent electron-transportation property also have been selected as the novel acceptor moiety to realize the bipolar host materials. 33,34 For instance, Cheng et al designed an excellent bipolar host material which is composed of two 6Hindolo [2,3-b]quinoxaline unit bridged by the tetraphenylsilane core realizing high-efficiency red phosphorescent OLEDs.…”

Donor and Acceptor Fused 16,16‐Dimethyl‐11,16‐dihydrodibenzo[2,3:5,6]pyrrolizino[1,7‐ab]acridine as a Blue‐Emitting Chromophore for High External Quantum Efficiency and Long Lifetime

“…Majority of these reports were mainly confined to two strategies such as directly linked D‐A structure or D‐π‐A structure with a π linker. [ 6–10 ] Various acceptors such as imidazole, [ 11 ] phenanthroimidazole, [ 12–14 ] oxadiazole, [ 15 ] and borane, [ 16–18 ] and donors such as carbazole, [ 17,19 ] diphenylamine, [ 20 ] acridine, [ 21,22 ] etc. have been used for this purpose.…”