Acrylate Optically\nClear Adhesives with Excellent\nOxygen Barrier for Organic Light-Emitting Devices

The organic light-emitting devices (OLEDs) sealed by\noptically\nclear adhesives (OCAs) always face the risk of luminescence loss due\nto the formation of dark spots caused by the oxygen attack, for which\nthe poor oxygen barrier property of the OCAs is responsible. To address\nthis issue, a new type of acrylate-based OCAs matrix was initially\nsynthesized; then the modified boron nitride (mBN) was integrated\nto create a physical “passive” barrier, and hydroxyl-terminated\npolybutadiene (HTPB) as an efficient chemical “active”\noxygen scavenger was also introduced to prepare acrylate-based OCAs\nwith superior oxygen barrier property. The oxygen permeability coefficient\nis as low as 4.76 cc·mil·m<sup>–2</sup>·day<sup>–1</sup>·0.1 MPa<sup>–1</sup>, which is 35.61\ntimes lower than that of the unmodified acrylate matrix, due to the\nsynergistic barrier effect of mBN and HTPB. Even after 6 months, the\nOCAs still maintain a good oxygen barrier performance, with an oxygen\npermeability coefficient of 103.43 cc·mil·m<sup>–2</sup>·day<sup>–1</sup>·0.1 MPa<sup>–1</sup>. The\nOCAs also exhibit excellent water barrier performance (11.26 g·mil·m<sup>–2</sup>·day<sup>–1</sup>), high light transmittance\n(>87%), strong peeling force (13.5 N/25 mm), and a remarkable strain\nrecovery ratio (73%). When testing the luminous performance of OLEDs\nat room temperature, the working time of OLEDs sealed by our OCAs\ncorresponding to a 5% decrease in relative luminous efficiency is\nextended by 10 h, compared to that of OLEDs sealed by commercial adhesives.\nFurthermore, when the OLEDs are stored at 85 °C for 7 days, the\nOLEDs sealed by our OCAs still exhibit luminous performance comparable\nto that of ones by commercial adhesives. Thus, this work presents\na novel approach to prepare OCAs with outstanding comprehensive performance,\nespecially the excellent oxygen barrier property, showing the significant\npotential for OLEDs sealing.