Review of Organic/Inorganic Thin Film Encapsulation by Atomic Layer Deposition for a Flexible OLED Display

Recent trends in thin film encapsulations (TFEs), fabricating organic/inorganic encapsulation films are reviewed. Atomic layer deposited inorganic films have superior barrier performance and have advantages of excellent uniformity over large scales at relatively low deposition temperatures. However, organic film should be combined with a hybrid structure for improved flexibility and longer lag time. We introduce various organic deposition methods and mechanisms for enhancing barrier performance. However, stress engineering is required to achieve high performance TFEs for flexible devices, new materials and deposition methods. First, modulating the internal stress in TFEs should be considered to increase flexibility by adopting other layers that can reduce internal stress. Second, controlling the configuration of the hybrid structure can prevent degradation due to cracks. Third, the introduction of a neutral plane as the middle layer decreases the strain. The results summarize how the device can improve barrier performance under external stress. This paper can guide the improvements in barrier performance.