This paper reports the variation in the optical and geometrical properties of individual organic layers to be used for thermally damaged top-emission organic light-emitting diodes (TEOLEDs). The copper deposited on the back of TEOLEDs is employed as a thermal facilitator, and a certain thermal damage occurs to the organic layers and devices. The phosphorescent host material 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP) is rapidly damaged to a significant extent owing to the low glass transition temperature (T_g), which also changes its optical and geometrical surface properties. Although the optical properties of the hole transport layer, N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) were changed slightly, the surface morphology was changed significantly. Despite having a higher T_g, the exciton blocking layer, tris(4-carbazoyl-9-ylphenyl)amine (TCTA), shows notable variations in optical properties and surface morphology due to heat exposure. Surprisingly, the electroluminescence spectra and micro-cavity are affected by increasing temperature without any considerable changes in device performance. Hence, this study reveals that besides T_g, the surface morphologies and thicknesses of the organic layers are also important factors in the annealing process and play a vital role in causing thermal damage to TEOLEDs.

本文报告了用于热损伤顶发射有机发光二极管 (TEOLED) 的各个有机层的光学和几何特性的变化。TEOLED背面沉积的铜作为热促进剂，对有机层和器件产生一定的热损伤。由于低玻璃化转变温度 (T _g )，磷光主体材料 4,4'-双(N-咔唑基)-1,1'-联苯 (CBP) 被迅速破坏到显着程度，这也改变了其光学和几何表面特性。尽管空穴传输层的光学性质，N,N'-二(1-萘基)-N,N'-二苯基-(1,1'-联苯)-4,4'-二胺(NPB)略有变化，表面形貌发生了显着变化。尽管有更高的 T_g，激子阻挡层三（4-咔唑基-9-基苯基）胺（TCTA）由于受热而在光学性质和表面形态方面表现出显着变化。令人惊讶的是，电致发光光谱和微腔受到温度升高的影响，而器件性能没有任何显着变化。因此，这项研究表明，除了 T _g之外，有机层的表面形貌和厚度也是退火过程中的重要因素，并且在对 TEOLED 造成热损伤方面起着至关重要的作用。