HDPE/EVOH Multilayered, High Barrier Films for Flexible Organic Photovoltaic Device Packaging

Transparent films composed of 65 alternating layers of high density polyethylene and ethylene/vinyl alcohol copolymer were produced and evaluated for their oxygen and water vapor barrier performance. Such high barrier films are of special interest for encapsulation of flexible organic electronic devices; these devices are extraordinarily sensitive to degradation by oxygen and/or water. In the present work, the multilayered films were produced using a layer multiplying process, and in some cases, they were further modified by applying organic and inorganic barrier coatings. An optimized film included coatings of both parylene C and alumina, achieving an oxygen transmission rate of <10–3 cc/m2·day and a water vapor transition rate of 4.6 × 10–4 g/m2·day; these values are useful in encapsulating organic photovoltaic devices.