Process Parameter Optimization of a Polymer Derived CeramicCoatings for Producing Ultra-High Gas Barrier

Abstract

Silica is one of the most efficient gas barrier materials, and hence is widely used as anencapsulating material for electronic devices. In general, the processing of silica is carried out at hightemperatures, i.e., around 1000◦C. Recently, processing of silica has been carried out from a polymercalled Perhydropolysilazane (PHPS). The PHPS reacts with environmental moisture or oxygen andyields pure silica. This material has attracted many researchers and has been widely used in manyapplications such as encapsulation of organic light-emitting diodes (OLED) displays, semiconductorindustries, and organic solar cells. In this paper, we have demonstrated the process optimization ofthe conversion of the PHPS into silica in terms of curing methods as well as curing the environment.Various curing methods including exposure to dry heat, damp heat, deep UV, and their combinationunder different environments were used to cure PHPS. FTIR analysis suggested that the quickestconversion method is the irradiation of PHPS with deep UV and simultaneous heating at 100◦C.Curing with this method yields a water permeation rate of 10−3g/(m2·day) and oxygen permeationrate of less than 10−1cm3/(m2·day·bar). Rapid curing at low-temperature processing along withbarrier properties makes PHPS an ideal encapsulating material for organic solar cell devices and avariety of similar applications.