Atmospheric deposition process for enhanced hybrid organic–inorganic multilayer barrier thin films for surface protection

Abstract

In this study, organic polymer poly-vinyl acetate (PVA) and inorganic aluminum oxide (Al2O3) have been used together to fabricate a hybrid barrier thin film for the protection of PET substrate. The organic thin films of PVA were developed through roll to roll electrohydrodynamic atomization (R2R-EHDA) whereas the inorganic thin films of Al2O3 were grown by roll to roll spatial atmospheric atomic layer deposition (R2R-SAALD) for mass production. The use of these two technologies together to develop a multilayer hybrid organic-inorganic barrier thin films under atmospheric conditions is reported for the first time. These multilayer hybrid barrier thin films are fabricated on flexible PET substrate. Each layer of Al2O3 and PVA in barrier thin film exhibited excellent morphological, chemical and optical properties. Extremely uniform and atomically thin films of Al2O3 with average arithmetic roughness (Ra) of 1.64nm and 1.94nm respectively concealed the non-uniformity and irregularities in PVA thin films with Ra of 2.9nm and 3.6nm respectively. The optical transmittance of each layer was∼80-90% while the water vapor transmission rate (WVTR) of hybrid barrier was in the range of∼2.3×10−2gm−2day−1 with a total film thickness of∼200nm. Development of such hybrid barrier thin films with mass production and low cost will allow various flexible electronic devices to operate in atmospheric conditions without degradation of their properties.