Highly efficient flexible organic light-emitting diodes (OLEDs) fabricated by utilizing inkjet printing technique are demonstrated in this work. A strategy of hybrid hole injection layer is employed to improve the device efficiency, where the polyethylene glycol (PEG) is used to modify the energy level and conductivity of the conventional hole injection layer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), which regulates the amount of holes entering the organic light-emitting layer, realizes the injection balance of carriers, and nearly doubles the green device efficiency with the record high maximum external quantum efficiency (EQE) of 9.45% and the current efficiency of 28 cd/A. Moreover, the introduction of PEG improves the mechanical properties of PEDOT: PSS and improves the bending resistance of the device. A highly efficient flexible white OLED device is realized by using inkjet printing based on the PEG-modified PEDOT:PSS hole injection layer, achieving the maximum EQE of 4.8%. In addition, a 1-inch white OLED array device is realized on the flexible substrate, which further confirm the feasibility of large-scale production for inkjet printed flexible devices.

在这项工作中展示了利用喷墨印刷技术制造的高效柔性有机发光二极管（OLED）。采用混合空穴注入层的策略来提高器件效率，其中使用聚乙二醇（PEG）来改变常规空穴注入层聚（3,4-乙撑二氧噻吩）：聚（苯乙烯磺酸盐）的能级和电导率（PEDOT：PSS）可以调节进入有机发光层的空穴数量，实现载流子的注入平衡，并使绿色器件的效率几乎翻倍，最大的外部量子效率（EQE）为9.45％，创历史新高。电流效率为28 cd / A。此外，PEG的引入改善了PEDOT：PSS的机械性能，并改善了设备的抗弯曲性。通过使用基于PEG修饰的PEDOT：PSS空穴注入层的喷墨打印，可以实现一种高效的柔性白色OLED器件，最大EQE为4.8％。另外，在柔性基板上实现了1英寸的白色OLED阵列器件，这进一步证实了大规模生产用于喷墨印刷的柔性器件的可行性。