Transparent oxygen impermeable AlOx thin films on polycarbonate deposited by reactive ion beam sputtering

The AlOx thin films were deposited on the polycarbonate by reactive ion beam sputtering (RIBS) at different oxygen partial pressures where the AlOx thin film with O/Al ratio of 1.5 was formed when oxygen partial pressure increased from 4 10 5 to 2 10 4 Torr. As a result, oxygen transmission rate (OTR) of the barrier significantly decreased from 24 cm3/m2 day to around 2 cm3/m2 day with increase in oxygen partial pressure. Optical transmittances of the films were in the 86–88% range at 550 nm versus 89% for the pure polycarbonate film.