934466-45-2Relevant academic research and scientific papers
Highly efficient simple-structure blue and all-phosphor warm-white phosphorescent organic light-emitting diodes enabled by wide-bandgap tetraarylsilane-based functional materials
Gong, Shaolong,Sun, Ning,Luo, Jiajia,Zhong, Cheng,Ma, Dongge,Qin, Jingui,Yang, Chuluo
, p. 5710 - 5718 (2014)
Two host materials of {4-[diphenyl(4-pyridin-3-ylphenyl)silyl]phenyl}diphenylamine (p-PySiTPA) and {4-[[4-(diphenylphosphoryl)phenyl](diphenyl)silyl] phenyl}diphenylamine (p-POSiTPA), and an electron-transporting material of [(diphenylsilanediyl)bis(4,1-phenylene)]bis(diphenylphosphine) dioxide (SiDPO) are developed by incorporating appropriate charge transporting units into the tetraarylsilane skeleton. The host materials feature both high triplet energies (ca. 2.93 eV) and ambipolar charge transporting nature; the electron-transporting material comprising diphenylphosphine oxide units and tetraphenylsilane skeleton exhibits a high triplet energy (3.21 eV) and a deep highest occupied molecular orbital (HOMO) level (-6.47 eV). Using these tetraarylsilane-based functional materials results in a high-efficiency blue phosphorescent device with a three-organic-layer structure of 1,1-bis[4-[ N,N- di(p-tolyl)-amino]phenyl]cyclohexane (TAPC)/ p-POSiTPA: iridium(III) bis(4′,6′- difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate (FIr6)/SiDPO that exhibits a forward-viewing maximum external quantum efficiency (EQE) up to 22.2%. This is the first report of three-organic-layer FIr6-based blue PhOLEDs with the forward-viewing EQE over 20%, and the device performance is among the highest for FIr6-based blue PhOLEDs even compared with the four or more than four organic-layer devices. Furthermore, with the introduction of bis(2-(9,9-diethyl-9 H-fluoren-2-yl)-1-phenyl-1 H-benzoimidazol- N,C3) iridium acetylacetonate [(fbi)2Ir(acac)] as an orange emitter, an all-phosphor warm-white PhOLED achieves a peak power efficiency of 47.2 lm W?1, which is close to the highest values ever reported for two-color white PhOLEDs.
