Water/Oxygen Barrier Coatings on Polyethersulfone Substrates by Plasma-Enhanced Chemical Vapor Deposition

• Main Authors: Wun-Chi Lo, 羅文池
• Other Authors: Dong-Sing Wuu
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/87843275444213095334

碩士 === 國立中興大學 === 材料工程學研究所 === 92 === Traditional flat panel displays were built on the glasses substrate. But they do not have impact-resistance, flexibility and have the high weight and thickness. Recently, using plastic materials substrate becomes a trend in the present development to study the flexible organic light-emitting devices (FOLED). However, the high permeation of water vapors and oxygen through polymer substrate is an important problem in the FOLED applications. Most of the commercial plastic substrates cannot resist the transmission of water vapor, which can easily cause a great damage inside the display and reduces the electron injection in the OLED structure and thereby drastically decreases its performance. To resolve this problem, a gas barrier layer must be developed on the plastic substrate. In this study, the SiOX and SiNX thin film was deposited on polyethersulfone (PES) plastic substrate by plasma-enhanced chemical vapor deposition (PECVD). Details of the effects of deposition parameters (flow ratio, chamber pressure, and rf power density, temperature, thickness) on the barrier film properties in terms of deposition rate, refractive index, roughness, etch rate, film structure, microstructure, adhesion, contact angle, flexibility, and WVTR/OTR were described, expecting for FOLED application as water/oxygen barrier layer. The transparency of the barrier layer can achieve over 80 % after coating silica and silicon nitride on PES. Under optimum conditions, the WVTR and OTR for PES can be reduced from a level of 28 g/m2/day and 243 cc/m2/day (bare substrate) to 0.1 g/m2/day and 0.18 cc/m2/day after coating silica. The WVTR and OTR for PES can be reduced to 0.01 g/m2-day and 0.01 cc/m2/day after coating silicon nitride. As a result of experiments, the deposition of SiOX and SiNX thin film on PES plastic substrate indeed resists the oxygen and water vapor transmission sufficiently.