Abstract

Solution processing of crosslinkable small molecular thin films is potentially attractive for the fabrication of large-area display panels based on organic light-emitting diodes (OLEDs). The characteristics of a wet-processed film made of a thermally crosslinked small-molecular material can be controlled by simply adding a cosolvent to its solution. The surface morphology of a nanometer-scale thin film made of N4,N4′-di(naphthalen-1-yl)-N4,N4′-bis(4-vinylphenyl)biphenyl-4,4′-diamine (VNPB), dissolved in chlorobenzene, improved dramatically after the addition of 20% cyclohexanone. At the same time, better resistance of the crosslinked layer to a number of solvents frequently used in the fabrication of the adjacent emitting layer was achieved. Moreover, the maximum current efficiency in the binary solvent device increased significantly to 22.2 Cd/A, compared to 9.7 Cd/A in the reference device without VNPB, and the device lifetime was extended by up to 74.8%. This illustrates a simple and additive-free strategy to prevent the formation of defects in solution processed thin-film stacks made of small-molecular materials. The insights gained will be helpful in the solution-based manufacture of large-area OLEDs and other optoelectronic components.

Graphic Abstract

中文翻译：

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固溶处理有机发光二极管对热交联小分子薄膜的二元溶剂效应

摘要

可交联的小分子薄膜的溶液处理对于基于有机发光二极管（OLED）的大面积显示面板的制造具有潜在的吸引力。由热交联的小分子材料制成的湿处理膜的特性可以通过简单地在其溶液中添加助溶剂来控制。由N 4，N 4'-二（萘-1-基）-N 4，N 4制成的纳米级薄膜的表面形态加入20％环己酮后，溶于氯苯的4'-双（4-乙烯基苯基）联苯-4,4'-二胺（VNPB）显着改善。同时，获得了交联层对在相邻发光层的制造中经常使用的多种溶剂的更好的耐受性。此外，与没有VNPB的参考设备中的9.7 Cd / A相比，二元溶剂设备中的最大电流效率显着提高到22.2 Cd / A，并且设备寿命延长了74.8％。这说明了一种简单且无添加剂的策略，可以防止在由小分子材料制成的溶液处理薄膜堆叠中形成缺陷。获得的见解将有助于大面积OLED和其他光电组件的基于解决方案的制造。

图形摘要