To extract the confined waveguided light in organic light-emitting diodes (OLEDs), inserting a low refractive index (RI) periodic structure between the anode and organic layer has been widely investigated as a promising technology. However, the periodic-structure-based light extraction applied inside devices has been shown to severely distort spectrum and affect EL characteristics. In this study, a simple light extraction technology using periodic low-RI nanodot array (NDA) as internal light extraction layer has been demonstrated. The NDA was fabricated simply via laser interference lithography (LIL). The structural parameters of periodic pattern, distance, and height were easily controlled by the LIL process. From computational analysis using finite-difference time-domain (FDTD) method, the NDA with 300 nm pitch and 0.3 coverage ratio per unit cell with 60 nm height showed the highest enhancement with spectral-distortion-minimized characteristics. Through both computational and experimental systematic analysis on the structural parameters of low-RI NDA-embedded OLEDs, highly efficient OLEDs have been fabricated. Finally, as representative indicators, hexagonal and rectangular positioned NDA-embedded OLEDs showed highly improved external quantum efficiencies of 2.44 (+29.55%) and 2.77 (+57.38%), respectively. Furthermore, the disadvantage originating from the nanoscale surface roughness on the transparent conductive oxide was minimized.

为了提取有机发光二极管（OLED）中的受限波导光，在阳极和有机层之间插入低折射率（RI）周期性结构作为一项有前途的技术已被广泛研究。然而，器件内部应用的基于周期结构的光提取已被证明会严重扭曲光谱并影响 EL 特性。在这项研究中，展示了一种使用周期性低折射率纳米点阵列（NDA）作为内部光提取层的简单光提取技术。 NDA 是通过激光干涉光刻 (LIL) 简单制造的。 LIL 过程可以轻松控制周期性图案、距离和高度的结构参数。通过时域有限差分（FDTD）方法的计算分析，间距为300 nm、高度为60 nm的每晶胞覆盖率为0.3的NDA表现出最高的增强效果和光谱失真最小化的特性。通过对低 RI NDA 嵌入 OLED 的结构参数进行计算和实验系统分析，已经制造出高效的 OLED。最后，作为代表性指标，六边形和矩形位置的 NDA 嵌入式 OLED 显示出显着提高的外量子效率，分别为 2.44 (+29.55%) 和 2.77 (+57.38%)。此外，源自透明导电氧化物上的纳米级表面粗糙度的缺点被最小化。