MoO3掺杂有机半导体NPB光电性质研究

在典型有机空穴传输材料胺类衍生物NPB(N,N'-diphenyl-N,N'-bis(1-naphthyl) (1,1'-biphenyl)-4,4'diamine)中引入过渡金属氧化物MoO₃制备了只有空穴传输的单载流子器件.结果表明:MoO₃的引入明显提升了NPB的导电性能,在约2.0 V的外加电压下,100 nm厚纯NPB薄膜电流密度仅为1.28 mA/cm²,而同样厚度的掺杂薄膜NPB∶MoO₃ (50 wt.%)电流密度达到了2 530 mA/cm².同样掺杂比例的NPB∶MoO₃薄膜吸收谱显示位于500 nm附近存在既不同于NPB也不同于MoO₃的额外吸收峰,表明体系中产生了电荷转移复合物NPB^＋-MoO^-₃,从而产生了额外的空穴载流子,进而提升了掺杂体系的导电性能.进一步的荧光分析表明,MoO₃的引入对NPB自身荧光具有明显的猝灭作用.NPB∶MoO₃(30 wt.%)薄膜的荧光强度比纯NPB薄膜荧光强度降低了2个数量级,NPB∶MoO₃ (50 wt.%)掺杂薄膜的荧光强度降低为零.

Study of optical and electrical properties of MoO3doped organic semiconductor NPB

Hole only single carrier devices were prepared by introducing transition metal oxide MoO₃ into the typical organic hole transport material amine derivative NPB (N,N'-diphenyl-N,N'-bis(1-naphthyl) (1,1'-biphenyl)-4,4'diamine). The results showed that the introduction of MoO₃ significantly enhances the conductivity of NPB, at an applied voltage of about 2.0 V, thecurrent density for a 100-nm-thick pure NPB device is only 1.28 mA/cm², while that for NPB∶MoO₃ (50 wt.%) device with the same film thickness is as high as 2 530 mA/cm². The absorption spectrum of the NPB∶MoO₃ film with the same doping ratio showed that there is an additional absorption peak near 500 nm, which is different from that of NPB or MoO₃, indicating that a charge transfer complex NPB⁺-MoO^-₃ has been formed in the doped system, resulting in additional hole carriers and thus enhancing the conductivity of the doped film. Further fluorescence analysis showed that the introduction of MoO₃ has a significant quenching effect on the fluorescence of NPB. The fluorescence intensity of the NPB∶MoO₃ (30 wt.%) films is reduced by two orders of magnitude compared to the pure NPB films, while that of the NPB∶MoO₃ (50 wt.%) film was essentially reduced to zero.