摘要
研究了由聚合物发光材料poly(2-methoxy,5-(2-ethylhexyloxy)-1,4-phenylene vinylene)(MEH-PPV)掺杂2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole(PBD)制成的发光层厚度为80, 170 nm的高分子发光器件(PLEDs)。研究了PBD不同掺杂浓度时器件的电流密度-电压(J-V)和亮度-效率-电压(L-E-V)特性,发现PBD除传输电子外,还阻挡空穴的注入和传输。研究发现,PBD的最优掺杂浓度为20%,掺入PBD后MEH-PPV的EL光谱红移且发生窄化,当PBD掺杂浓度为40%时MEH-PPV的EL光谱窄化最明显,EL光谱半峰全宽从100 nm减小到44 nm。
Polymer light-emitting diodes （PLEDs） have attracted great attention in recent years due to their potential advantages in fabrication, mechanical properties, and low cost. Balance of charge injection and transporting is a key factor that determines device performances such as efficiency and operating lifetime. Usually, carrier-transporting layer or block layer was inserted into the device to improve the balance of the injected carriers. In this paper, PLEDs with different thickness of luminescent layer were fabricated. The conjugated polymer poly （2-methoxy, 5- （2-ethylhexyloxy） -1,4-phenylene vinylene ） （ MEH-PPV ） was used as a luminescent layer. By blending PBD into the luminescent layer in different concentration, comparing and analysising their properties of Current density-voltage （J-V） and Luminance-efficiency-voltage （L-E-V）, we found that the PBD not only enhanced the transporting of the electrons but also blocked the injection of the holes and leading to a better balance of the carriers, which improves the performances of PLEDs. The optimum concentration of the PBD was found to be 20%. EL emissions of blend devices were red-shifted by about 7 nm from the peak emission at 589 nm of pure MEH-PPV device to around 596 nm of devices with the blend film as EML （emission layer）. The Full width at half maximum （FWHM） was narrowed from 100 nm to 44 nm.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2006年第5期684-688,共5页
Chinese Journal of Luminescence
基金
国家"973"计划资助项目(2002CB613405)
