We propose a plasmonic ultrathin metal grid electrode as a promising light outcoupling strategy in a flexible organic light-emitting device (OLED). The plasmonic ultrathin metal grid electrode consists of an ultrathin Au grid film incorporating with plasmonic subwavelength corrugations, which was fabricated by lithography and nanoimprint technologies, demonstrates excellent optical and electrical properties as the substitute of ITO transparent electrode in flexible OLED. The transmittance of the plasmonic ultrathin Au grid electrode is 88.5% at 550 nm and the sheet resistance is about 36 Ω/sq. The periodic subwavelength corrugations of the plasmonic ultrathin Au grid electrode excite the surface plasmon-polariton (SPP) resonance which is an adverse optical mode with power loss in OLED, and the photons trapped in SPP mode are effectively outcoupled and extracted by the plasmonic corrugations. Compared to the ITO-based device, OLED based on plasmonic ultrathin Au grid electrode realizes a desirable enhancement of 60.3% in current efficiency. In addition, the flexible OLED based on the proposed electrode also exhibits decent mechanical robustness and flexibility with stable electroluminescence performances.

我们提出等离子超薄金属栅电极作为柔性有机发光器件（OLED）中有希望的光输出耦合策略。等离子超薄金属栅电极由超薄Au栅膜和等离子亚波长波纹组成，该膜是通过光刻和纳米压印技术制造的，具有出色的光学和电学性能，可替代ITO在柔性OLED中使用。等离子体超薄金栅格电极在550 nm处的透射率为88.5％，薄层电阻约为36Ω/ sq。等离子体超薄金Au栅电极的周期性亚波长波纹会激发表面等离子体激元（SPP）共振，这是一种不利的光学模式，会降低OLED的功率损耗，捕获在SPP模式下的光子通过等离子体波纹有效地耦合和提取。与基于ITO的设备相比，基于等离子超薄Au栅电极的OLED实现了电流效率60.3％的理想提升。此外，基于提出的电极的柔性OLED还表现出不错的机械强度和柔韧性以及稳定的电致发光性能。