A highly transparent laminated composite cathode for organic light-emitting diodes
A highly transparent laminated composite cathode for organic light-emitting diodes
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一种用于有机发光二极管的高透明层状复合阴极
DOI：
10.1063/5.0057184
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发表时间：
2021-08
影响因子：
4
通讯作者：
Xiaotian Chen;Dan Wu;Jintao Wang;Yibin Zhou;Ziyu Zhang;Chuannan Li;Jian Zhang;Ping Chen;Y. Duan
中科院分区：
文献类型：
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作者：
Xiaotian Chen;Dan Wu;Jintao Wang;Yibin Zhou;Ziyu Zhang;Chuannan Li;Jian Zhang;Ping Chen;Y. Duan
透明导电电极是有机光电器件的重要组成部分之一。Mg：Ag合金由于其高电导率和相对低的功函数而被广泛用作顶部发射有机发光二极管（OLED）或透明OLED（TrOLED）的半透明阴极。然而，它们的低透射率使得光提取效率相对较低。在这项研究中，一个高度透明的（84.6%在可见光范围内），导电，层状阴极与结构的ZnO/Mg：Ag/ZnO通过原子层沉积（ALD）制造。ALD沉积的ZnO用于保护易受损伤的Mg：Ag合金层，同时保持其整个结构的低功函数。特别地，底部ZnO层用作ETL，其可以在阴极层和发射层之间提供合理的能量对准，并防止金属颗粒渗透到下面的有机层中。在本研究中通过使用层压阴极制备的顶部发射OLED显示出85.8%的亮度增加，在4.0 V下的电流密度为11.2 mA/cm 3，这与用Mg：Ag阴极制成的器件相比是超低电压。此外，与使用Mg：Ag阴极的器件相比，TrOLED的总亮度提高了34.4%。此外，器件的可见光平均透射率仍高达77.19%。
Transparent conductive electrodes are one of the important components of organic optoelectronic devices. Mg:Ag alloys have been widely used as a semi-transparent cathode for top-emitting organic light-emitting diodes (OLEDs) or transparent OLEDs (TrOLEDs) due to their high conductivity and relatively low work function. However, their low transmittance makes the light-extraction efficiency to be comparatively low. In this study, a highly transparent (84.6% in the visible light range), conductive, laminated cathode with the structure of ZnO/Mg:Ag/ZnO was fabricated via atomic layer deposition (ALD). ALD-deposited ZnO is used to protect the vulnerable ultrathin Mg:Ag-alloy layer, while preserving its low work function for the entire structure. In particular, the bottom ZnO layer is used as an ETL, which can provide reasonable energy alignment between the cathode layer and the emission layer and prevent metal particles from penetrating into the underlying organic layer. The top-emission OLED, which is prepared in this study by using the laminated cathode, showed an 85.8% increase in brightness, with a current density of 11.2 mA/cm3 at 4.0 V, which is an ultra-low voltage compared with devices made with Mg:Ag cathodes. In addition, the total luminance of TrOLEDs increases 34.4% compared with devices using Mg:Ag cathodes. Furthermore, the average transmittance of the device was still as high as 77.19% for visible light.