Synergistic Photonic Management for High-Efficiency Inverted Organic Light-Emitting Diodes

Inverted organic light-emitting diodes (IOLEDs) offer improved environmental stability and simplified encapsulation relative to conventional architectures, yet their external quantum efficiency (EQE) has remained comparatively limited. To address this challenge, we present a comprehensive photonic management strategy that concurrently suppresses surface plasmon polariton (SPP) losses and enhances light extraction. A 210 nm optical decoupling layer is first introduced to convert SPP modes at the metal anode into waveguided and substrate modes. In addition, a low-hardness textured substrate with a high refractive index (n = 1.68) is employed to effectively outcouple the redistributed waveguided/substrate modes. By synergistically integrating these designs, green phosphorescent IOLEDs achieve a peak EQE of 30.1%, representing a 2.3-fold improvement over the control device (13.3%). This work establishes a scalable photonic-engineering framework for high-efficiency IOLEDs, substantially narrowing their performance gap compared to conventional OLED architectures.