Transparent high barrier coatings for electronic encapsulation

Barrier coatings are a category of functional films designed to enhance enduse properties to the underlying substrate. When used for electronic applications (such as flexible displays, digital paper, lighting, OLEDs and solar cells), the barrier characteristics are meant to protect the device from environmental influence, especially the permeation of oxygen and water vapour that can degrade and corrode the active layers of the devices (causing mal-functioning). In this project, silicon oxide barrier layers were deposited onto a non-treated BO-PET via plasma enhanced chemical vapour deposition, using a pilot scale roll-to-roll coater. The aim was to optimise the deposited coatings by understanding the effect of the deposition parameters on the barrier properties (oxygen and water vapour barrier) and the surface properties (i.e. topography, chemistry, structure, thickness, mechanical properties) of the coatings. For encapsulation in electronic devices such as OLEDS and photovoltaics cells, the barrier coatings must remain transparent and flexible, which is one of the challenges of this project. This project has demonstrated that the moisture barrier performance of silicon oxide coated BO-PET is dependent on film structure (i.e. porosity), which are linked to the plasma conditions of the deposited film. Lower WVTR could be reached (10-2×g/m2/day) for film produced at high input power (1.6kW), low webspeed (