Highly efficient pure blue electroluminescence from 1,4-bis[2-(3-N-ethylcarbazoryl)vinyl]benzene

Abstract

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Optical and electroluminescent properties of 3,4,6-triphenyl-α-pyrone

“…For example, lithium tetra (2-methyl-8-hydroxy-quinolate) boron and bis(2-methyl-8-quinolinolate) aluminum(III) hydroxide have been found to be efficient blue emitters with emission bands at 470 and 485 nm, respectively [6][7][8]. In addition, a number of blue-emitting materials have been synthesized and utilized in OLEDs, such as poly(alkylfluorene) [9], 4,4-bis(2,2-diphenylvinyl)biphenyl [10], 1,4-bis[2-(3-N-entylcarbazoryl) vinyl]benzen [11,12], 9,10-bis-(b-naphtyl)-anthrene [13], 9,10-bis(2 0 -naphthyl)anthracene [14], 2,6-diphenyl-1,5-diaza-1,5-dihydro-s-indacene (indacene) [15], iridium(b)bis[(4,6-di-fluorophenyl)pyridinato-N,C 20 ]picolinate [16,17], iridium(b)bis(4 0 ,6 0 ,-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate [18] and poly(9-vinylcarbazole) (PVK) doped with iridium(b) complexes [19]. However, pure blue OLEDs are reported infrequently.…”

Highly efficient red electrophosphorescent devices at high current densities

“…The energy transfer from host CBP to guest Btp 2 ir(acac) is proved to possibly occur by the PL measurement of CBP:Btp 2 Ir(acac) (6.0 wt%) system in which the excitation is nearly completely contributed by CBP (Ref. [12]) and the emission by Btp 2 Ir(acac) as shown in Fig. 3.…”

“…Here, TPD (N,N 0 -diphenyl-N,N 0 -bis(3-methyl-phenyl)-1,1 0 biphenyl-4,4 0 diamine) is used as a hole-transporting layer, CBP (4,4 0 -N,N 0 -dicarbazole-biphenyl) as a host, Btp 2 Ir(acac) as a dopant (6.0 wt%), BAlq (10 nm) in device (a) as a hole and exciton blocker, Alq 3 (tris-(8-hydroxy-quinolinato)aluminum) as an electron transporting layer, Liq (8-hydroxy-quinolinato lithium) as an electron injection layer [13] and Al as a cathode, respectively. In addition, BAlq also acts as a step barrier to assist electron injection [12]. All layers including Al cathode were evaporated onto the substrates by conventional resistive heating in same vacuum chamber ($1 Â 10 À3 Pa), and their thicknesses controlled by using a quartz crystal thickness monitor.…”

Synthesis, structures, and property studies on Zn(II), Ni(II), and Cu(II) complexes with a Schiff base ligand containing thiocarbamide group

“…However, it is much more difficult to obtain highly efficient blue-light emission due to its intrinsic characteristic of the large band gap of the emitting material. Although many blue fluorescent dyes exhibiting excellent performance, such as distyrylarylene derivatives, have been explored so far, the common way to improve efficiency and stability of organic light-emitting diodes (OLEDs) is to use the fluorescent dye doping technique [2][3][4][5]. In practical application, however, the doping method is rather sophisticated and inconvenient for device fabrication because it is difficult to control the deposition rate in co-evaporation process and the doping ratio.…”