共轭聚合物中掺杂可溶性石墨烯对于OLED和OPV性能的影响

SPFGO effects on the electroluminescence and photovoltaic response in conjugated polymers

本文重点研究了不同浓度可溶性石墨烯(SPFGO)对于聚[2-甲氧基-5-(2-乙基己氧基)]对苯乙炔(MEHPPV)/SPFGO复合薄膜的光致发光(PL)、有机电致发光(OLED)和有机光伏(OPV)性能的影响.研究发现,在MEH-PPV中掺杂SPFGO之后,MEH-PPV/SPFGO复合薄膜的光致发光发生了非常强烈的猝灭,意味着MEH-PPV和SPFGO之间发生了非常强烈的载流子传输.当SPFGO的浓度较低的时候,能够提高OLED的性能,当SPFGO的浓度为0.2%时,OLED的性能达到最佳,而此时的OPV性能基本没有改变.当掺杂较高浓度的SPFGO之后,OPV的性能有了明显的提升,当浓度为15%时,OPV达到了最佳的性能,而此时的OLED发生了非常强烈的猝灭.通过实验数据可以看出,当SPFGO较低浓度的时候,起到增强载流子注入的作用,提升OLED亮度的同时降低了开路电压.而当SPFGO达到较高浓度时,SPFGO作为电子受体,可以起到改善MEH-PPV/SPFGO界面激子分裂和提高OPV性能的作用.因此,通过调节SPFGO浓度可以起到独立调控OLED性能和OPV性能的作用.

This paper studies the influence of poly [2-methoxy-5-（2＇-ethylhexyloxy）-l, 4-phenylenevinylene] （MEH-PPV） on solution- processable functionalized graphene oxide （SPFGO） composite film-based organic light emitting Diode （OLED） and organic pho- tovoltaic （OPV） performance for different SPFGO concentrations. There is a strong quenching of photoluminescence when MEH-PPV is doped with SPFGO, which means there is a strong transfer of electron and energy between MEH-PPV and SPFGO. Doping SPFGO in MEH-PPV can improve the performance of OLED at low concentration, and the performance will be the best when the concen- tration of SPFGO is 0.2%; however, the performance of OPV remains unchanged. The performance of OPV could be improved by high doping concentration of SPFGO, the performance will be the best when the concentration of SPFGO reaches 15%, and there is a quenching in the electroluminescence （EL） of OLED. As shown in the statistics of the experiment, SPFGO can increase the injectivity of carriers, and when the SPFGO is of low concentration, it can increase the luminous intensity of OLED and reduce the threshold voltage. SPFGO can act as an electron acceptor, and when the concentration of SPFGO is high, the exciton dissociation at MEH- PPV/SPFGO interface can be improved, and the performance of OPV can be also improved. Therefore, the concentration of SPFGO should be the main factor in adjusting the performance of OLED and OPV separately.