纳米图形增强OLED出光效率研究

Study on Light Extraction Efficiency of Enhanced OLED with Nanopatterns

采用纳米结构是提高有机发光二极管(OLED)出光效率(LEE)的主要方法之一。当纳米结构位于有机层和氧化铟锡(ITO)阳极之间时,可以起到引导模式的重叠、增强散射、提高OLED出光效率的目的。采用金薄膜退火和湿法刻蚀技术在ITO玻璃片上制备随机分布的纳米图形用于橙光OLED器件,研究了纳米图形对器件发光性能的影响因素,同时制作了无纳米图形的标准OLED器件作为对比。实验结果表明,当金薄膜厚度为10 nm,退火温度为570℃,退火时间为240 s,刻蚀深度为30 nm时,与无纳米图形的OLED相比,有纳米图形的OLED的亮度提高17%,电流效率提高34%,功率效率提高32%,外量子效率提高35%,证明纳米图形可以显著地提高OLED器件的出光效率。

Applying nanostructure is one of the main approaches to improve the light extraction efficiency （LEE） of organic light-emitting diodes （OLED）. When the nanostructure is located between the organic layer and indium tin oxide（ITO） anode, the mode overlap can be guided, the scattering can be enhanced, and the LEE of OLED can be improved. Gold thin-film annealing technology and wet etching technology are adopted to prepare random distributed nanopatterns on the ITO glass for the orange OLED device. The influence factors of nanopatterns on the luminous performance of devices are studied. Meanwhile the standard OLED device is fabricated for contrast. The experimental results show that, compared with the OLED without nanopattern, the performance of OLED with nanopattern is improved in brightness by 17 %, current efficiency by 34 %, power conversion efficiency by 32 %, and external quantum efficiency by 35%, while the gold film thickness is 10 nm, the annealing temperature is 570 ℃, the annealing time is 240 s, and the etching depth is 30 nm. It is indicated that nanopatterns can effectively improve the LEE of OLED device.