The Mechanistic Investigation of Polycarbonate:Polystyrene and Poly(vinylidene fluoride):Polystyrene Micro–Nano Structures in Optimization Light Field Distribution and Viewing Angle Ratio of Organic Light-Emitting Diodes

In this study, we utilize the phase separation phenomenon between polycarbonate (PC), poly(vinylidene fluoride) (PVDF), and polystyrene (PS) to fabricate two types of micro-nano structures, PC:PS, and PVDF:PS. We investigate the optimization mechanisms of two micro-nano structures in green phosphorescent organic light-emitting diodes (OLEDs) by using electroluminescence (EL), normalized viewing angle ratio tests, and finite-difference time-domain (FDTD) simulations. The results confirm that improvements in both the viewing angle ratio and light extraction efficiency are due to the optimized internal light field distribution. By adjusting the component ratios of micro-nano structures, the external quantum efficiency (EQE) of two OLEDs incorporating these structures is improved by 69.2 and 61.7%, respectively. Furthermore, the viewing angle ratio is increased by 10.6% and 7.7%, respectively. Additionally, FDTD simulations of the light field distribution both inside and outside the OLEDs reveal that the PC:PS and PVDF:PS micro-nano structures are effective in shifting the internal light field toward the glass/air interface. This shift optimizes the viewing angle ratio within this range, thereby enhancing the light extraction efficiency of the OLEDs.