A Superior Encapsulation Strategy for Large-Sized Flexible Top-Emission OLEDs

In this paper, the “face seal” encapsulation was developed for large-sized flexible top-emission OLEDs. Before that, the encapsulants including barrier film and UTG were verified to exhibit high performance in the optical properties, mechanical properties and barrier capabilities to moisture, which suggest a promising application in flexible encapsulation. Then, we fabricated four 16.9-inch top-emission OLED panels with different encapsulation structures. It was found that comparing with the pure TFE, the added barrier film shows prolonged RA lifetime at accelerated condition of 85 °C and 85% RH. In addition, the pressure sensitive adhesive (PSA), which attach the encapsulants to the OLED substrates, was inserted with hygroscopic filler to further improve the edge barrier moisture ability, and the RA lifetime was significantly boosted to over 700 h in barrier film based panels. Furthermore, the UTG based panels show the best RA lifetime of over 1000 h. Our research affords a superior “face seal” encapsulation strategy for large-sized flexible top-emission OLEDs, and the lamination process can be used to fabricate them with reduced manufacturing cost and time for mass production.