Bae Eun-Jeong, Kim Yeon-Sik, Choi Geun-Su, Ju Byeong-Kwon, Baek Dong-Hyun, Park Young-Wook
Nano and Organic-Electronics Laboratory, SunMoon University, Asan 31460, Republic of Korea.
Display and Nanosystem Laboratory, Department of Electrical Engineering, Korea University, 145, Anam-ro, Seoul 02841, Republic of Korea.
Nanomaterials (Basel). 2023 Jul 30;13(15):2216. doi: 10.3390/nano13152216.
In this study, we demonstrated organic light-emitting diodes (OLEDs) outcoupling with a flexible polydimethylsiloxane (PDMS) film with a micro-convex structure using the breath figure (BF) method. We can easily control the micro-convex pattern by adjusting the concentration of polystyrene and the humidity during the BF process. As process conditions to fabricate the micro-convex structure, polymer concentrations of 10, 20, 40, and 80 mg/mL and 60, 70, and 80% relative humidity were used. To evaluate the optical properties, we analyzed the transmission, diffusion, and electroluminescence with or without the micro-convex structure on the OLEDs. The shape and density of the micro-convex structure are related to its optical properties and outcoupling and we have experimentally demonstrated this. By applying a micro-convex structure, it achieved up to a 42% improvement in the external quantum efficiency compared to bare OLEDs (without any light extraction film). We expect the fabricated flexible light extraction film to be effective for outcoupling and applicable to flexible devices.
在本研究中，我们展示了利用呼吸图案（BF）法，通过具有微凸结构的柔性聚二甲基硅氧烷（PDMS）薄膜实现有机发光二极管（OLED）的光出射耦合。我们可以通过在BF过程中调节聚苯乙烯的浓度和湿度来轻松控制微凸图案。作为制造微凸结构的工艺条件，使用了10、20、40和80mg/mL的聚合物浓度以及60%、70%和80%的相对湿度。为了评估光学性能，我们分析了有无微凸结构的OLED上的透射、扩散和电致发光情况。微凸结构的形状和密度与其光学性能和光出射耦合相关，并且我们已经通过实验证明了这一点。通过应用微凸结构，与裸OLED（无任何光提取薄膜）相比，外部量子效率提高了高达42%。我们期望所制备的柔性光提取薄膜对光出射耦合有效，并适用于柔性器件。
