聚合物级联发光器件

发布时间：2019-04-18 13:34

【摘要】：基于溶液加工方法制备了聚乙撑二氧噻吩-聚(苯乙烯磺酸盐)(PEDOT:PSS)/氧化锌(ZnO)/乙氧基化聚乙烯亚胺(PEIE)电荷产生层的聚合物级联发光器件,发现PEDOT:PSS层电导和厚度对器件的电流-电压特性影响较小,不同PEDOT:PSS对器件发光效率的影响主要来自于其对发光层激子不同的猝灭作用,PEDOT:PSS厚度为60 nm的级联器件比PEDOT:PSS厚度为30 nm的级联器件的发光效率稍高,原因是PEDOT:PSS较厚时,其表面形貌更均匀。级联器件的发光效率和驱动电压分别与发光子单元的发光效率和驱动电压之和相近,说明在较低的电压下电荷产生层就能够有效产生电荷并注入到发光子单元中,级联器件的发光光谱中包含两个发光子单元的发光光谱,说明两个发光子单元在级联器件中都能正常工作。通过对电荷产生层的电容-电压(C-V)特性的测试,确认了在电荷产生层中存在电荷的积累过程。证明了PEDOT:PSS/ZnO/PEIE为有效的电荷产生层。首次报道了包含三个SY-PPV发光单元的级联器件,三个发光子单元发光效率之和与级联器件的发光效率相当,其最大发光效率和最大外量子效率分别为21.7 cd·A~(-1)和6.95%。在器件亮度为5 000 cd·m~(-2)时,器件的发光效率和外量子效率分别为20.5 cd·A~(-1)和6.6%。说明并没有由于发光子单元数目增加而影响级联器件的发光效率。并且其发光光谱和发光子单元的发光光谱相接近。通过进一步降低CGL中空穴注入层对级联器件的影响有望提高级联器件的发光效率。
[Abstract]:Poly (ethylenedioxythiophene)-poly (styrene sulfonate) (PEDOT:PSS) / zinc oxide (ZnO) / ethoxylation polyethylene imine (PEIE) charge generation layer was prepared by solution processing method. It is found that the conductivity and thickness of the PEDOT:PSS layer have little effect on the current-voltage characteristics of the device. The effect of different PEDOT:PSS on the luminous efficiency of the device is mainly due to its different quenching effect on the exciton of the emitting layer. The light-emitting efficiency of cascaded devices with PEDOT:PSS thickness of 60 nm is slightly higher than that of cascade devices with PEDOT:PSS thickness of 30 nm, because the surface morphology of cascaded devices with thicker PEDOT:PSS is more uniform than that of cascaded devices with PEDOT:PSS thickness of 30 nm. The light-emitting efficiency and driving voltage of cascaded devices are similar to those of photon-emitting units and driving voltages respectively, indicating that the charge generation layer can effectively generate charges and inject them into photon-emitting units at lower voltages. The photoluminescence spectra of cascaded devices contain the luminescence spectra of two photon emitting units, which indicate that the two photon emitting units can work normally in cascaded devices. The charge accumulation process in the charge generation layer is confirmed by the measurement of the capacitance-voltage (C _ () V) characteristics of the charge generation layer. It is proved that PEDOT:PSS/ZnO/PEIE is an effective charge generation layer. A cascade device consisting of three SY-PPV light emitting units is reported for the first time. The total luminous efficiency of the three photon emitting units is equal to that of the cascaded devices. The maximum luminescence efficiency and external quantum efficiency are 21.7 cd 路A ~ (- 1) and 6.95%, respectively. When the brightness of the device is 5 000 cd 路m ~ (- 2), the luminous efficiency and external quantum efficiency of the device are 20.5 cd 路A ~ (- 1) and 6.6%, respectively. It is shown that the luminous efficiency of cascaded devices is not affected by the increase of the number of photon emitting units. The luminescence spectra of the photons are similar to those of photons-emitting units. By further reducing the effect of hole injection layer on cascade devices in CGL, it is expected to improve the luminous efficiency of cascade devices.
【作者单位】：西南大学物理科学与技术学院;
【基金】：国家自然科学基金项目(61177030,11474232)资助
【分类号】：TN383.1

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