阴极耦合层对顶发射白光OLED器件光电性能影响

Effect of refractive index matching layers on optical and electrical properties of top-emitting organic white light emitting devices

为了研究不同厚度C60阴极耦合层对顶发射白光OLED器件光电性能的影响,实验数值计算了半透明阴极组成的多层膜系(ETL/EIL/Mg∶Ag/C60)的透过率;同时,采用共阴极结构设计制备了顶发射白光OLED器件,并对不同厚度的C60折射率匹配层制备的顶发射白光OLED器件的光电特性进行了研究。结果表明,不同C60厚度的多层膜系透过率差异较大,在C60膜层厚度为30~40 nm时,多层膜在较宽波段范围内均有高的透过率,且透过率光谱的色坐标最接近白光等能点;通过分析不同阴极耦合层制备的顶部发光OLED器件的光电性能,发现采用适当厚度的C60阴极耦合层材料,可以有效提高器件外量子效率,并在一定程度上能够有效改善器件的色坐标,实现接近等能白光的顶发光OLED器件制备。

In order to analyze the effect of different thickness of C60 on optical and electrical properties of top-emitting OLED,in experiment,the transmittance of ETL/EIL/Mg∶Ag/matching layers were numerically calculated and two top OLED with common cathode configurations were fabricated.The optical and electrical properties of OLED devices prepared with different thickness of C60 refractive index matching layers were analyzed.The results showed,the complex films with different C60 thickness have different transmittance,the complex films have high transmittance in wide range of wavelengths when C60 film thickness is 30~40 nm,the CIE x and CIE y values of transmittance spectra are extremely near to the equal energy(0.33,0.33).In addition,it can be found that the electroluminescence spectra and the chromaticity coordinates of OLED devices are also heavily related to the thickness of C60 refractive index matching layers,which is consistent with the numerical results of transmission spectrum of multilayer(ETL/EIL/Mg∶Ag/C60)at different thickness of C60 thin films and indicate that the luminous brightness and the color coordinates of top-emitting white light devices can be adjusted by different thickness of C60 refractive index matching layer to achieve white light emission close to equal energy.