[Paper] High Temperature Tolerant Barrier Films with Stacking Barrier Layers by Sputtering and ALD

Abstract

Barrier films are key components of organic electronics devices such as OLEDs, OPVs, OTFTs, etc. Novel barrier films with high temperature tolerance were developed by applying the alternatingly stacked barrier layers with Si₃N₄ deposited by sputtering and Al₂O₃ deposited by ALD (Atomic Layer Deposition) to simultaneously biaxially stretched polyetheretherketone (EXPEEK) films. The WVTR (Water Vapor Transmission Rate) values of single and various stacking barrier layers on EXPEEK were investigated by Ca corrosion method. While the single barrier layers with Si₃N₄ or Al₂O₃ showed poor barrier abilities, the several alternatingly stacked layers with Si₃N₄ and Al₂O₃ achieved high gas barrier ability with WVTR values of the order of 10^-5g/m²/day. The results implies that defects and pinholes of Si₃N₄ layer deposited by sputtering are effectively covered by Al₂O₃ layer deposited by ALD, which has excellent defect coverage. In addition, flexible OLED devices were fabricated using the developed barrier films.