Novel fluorine-containing X-branched oligophenylenes: structure–hole blocking property relationships
作者:Zhong Hui Li、Ka Lap Tong、Man Shing Wong、Shu Kong So
DOI:10.1039/b512517k
日期:——
Four fluorine-containing X-branched oligophenylenes, X-OPP(5)-Fn, n = 1,2,3 and X-OPP(5)-CF3, have been synthesized and studied as potential hole-blocking materials. These molecular materials exhibit a low HOMO energy level (ca. 6.5 eV) and a large energy gap (ca. 3.5 eV), indicating that they can be employed as effective hole-blockers in blue-emitting organic EL devices. Four-layer organic EL devices consisting of CuPc as a hole injection layer, α-NPD as a hole-transporting and emitting material, X-OPP(5)-Fn or X-OPP(5)-CF3 as a hole-blocker, and Alq3 as an electron-transporter sandwiched between indium tin oxide (ITO) and LiF/Al electrodes were fabricated, and their performance was examined and compared with the widely used hole-blocker bathocuproine (BCP), the non-fluorine-containing X-branched analogue X-OPP(5)-H and the X-branched analogue with one less phenyl ring, X-OPP(3)-F2. The preliminary results show that these new molecular materials, especially X-OPP(5)-F2, are excellent hole-blockers for blue-emitting organic EL devices.
作为潜在的空穴阻断材料,我们合成并研究了四种含氟 X 支链低聚亚苯基,即 X-OPP(5)-Fn(n = 1、2、3)和 X-OPP(5)-CF3。这些分子材料表现出较低的 HOMO 能级(约 6.5 eV)和较大的能隙(约 3.5 eV),表明它们可以在蓝色发光的有机 EL 器件中用作有效的空穴阻滞剂。我们制作了四层有机电致发光器件,包括作为空穴注入层的 CuPc、作为空穴传输和发光材料的 α-NPD 、作为空穴阻滞剂的 X-OPP(5)-Fn 或 X-OPP(5)-CF3 以及夹在铟锡氧化物(ITO)和 LiF/Al 电极之间作为电子传输剂的 Alq3、并将它们的性能与广泛使用的空穴阻滞剂bathocuproine (BCP)、不含氟的 X-支链类似物 X-OPP(5)-H 和少一个苯基环的 X-支链类似物 X-OPP(3)-F2 进行了研究和比较。初步研究结果表明,这些新分子材料,尤其是 X-OPP(5)-F2 是蓝光有机 EL 器件的优良空穴阻断剂。