Gong Xiong, Benmansour Hadjar, Bazan Guillermo C, Heeger Alan J
Institute for Polymers and Organic Solids, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
J Phys Chem B. 2006 Apr 13;110(14):7344-8. doi: 10.1021/jp060436m.
The investigation of the optical properties, carrier injection, and transport into a soluble small molecule, 6,6'-dicarbazolyl-2,2'-dihexyloxy-1,1'-binaphthol (BA), was reported. The results demonstrated that BA is a blue-emitting molecule, which can be used as a host for the fabrication of electrophosphorescent light-emitting diodes (LEDs). The single-layer electrophosphorescent LEDs fabricated from toluene solution containing BA with tris[2,5-bis-2'-(9',9'-dihexylfluorene)pyridine-kappa(2)NC(3)(')]iridium(III) [Ir(HFP)(3)] emitted red light from Ir(HFP)(3) triplet emission. The results from photoluminescence (PL) and electroluminescence (EL) demonstrated that the dominated operational mechanism in EL was charge trapping rather than Förster transfer, which was the dominated mechanism in PL. The single-layer OLEDs with 1wt % of Ir(HFP)(3) have a luminance (L) of 1000 cd/m(2) at 22 V and a luminous efficiency (LE) of 0.88 cd/A at 11 mA/cm(2). Double-layer electrophosphorescent LEDs fabricated by casting the emitting layer from a solution of BA blended with Ir(HFP)(3) and subsequently thermally depositing tris(8-hydroxyquinoline) aluminum (Alq(3)) film as an electron injection and transport layer yielded L = 1830 cd/m(2) at 30 V and LE = 2.47 cd/A at 18 mA/cm(2). These results demonstrated that electrophosphorescent LEDs can be fabricated from BA via solution processing and that L and LE can be enhanced by changing the device architecture with the goal of better balancing the electron and hole currents.
报道了对可溶性小分子6,6'-二咔唑基-2,2'-二己氧基-1,1'-联萘酚（BA）的光学性质、载流子子注入注入及其传输的研究。结果表明，BA是一种蓝色发光分子，可作为主体用于制备电磷光发光二极管（LED）。由含有BA与三[2,5-双-2'-（9',9'-二己基芴基）吡啶-κ(2)NC(3)(')]铱(III) [Ir(HFP)(3)]的甲苯溶液制备的单层电磷光LED从Ir(HFP)(3)三重态发射发出红光。光致发光（PL）和电致发光（EL）结果表明，EL中的主导工作机制是电荷俘获而非Förster转移，后者是PL中的主导机制。含1wt% Ir(HFP)(3)的单层OLED在22 V时亮度（L）为1000 cd/m²，在11 mA/cm²时发光效率（LE）为0.88 cd/A。通过从BA与Ir(HFP)(3)混合溶液中浇铸发光层，随后热沉积三（8-羟基喹啉）铝（Alq(3)）薄膜作为电子注入和传输层制备的双层电磷光LED在30 V时L = 1830 cd/m²，在18 mA/cm²时LE = 2.47 cd/A。这些结果表明，可通过溶液加工由BA制备电磷光LED，并且通过改变器件结构以更好地平衡电子和空穴电流的目标可以提高L和LE。
