Permeation barrier properties of oxide layers on polymer film deposited by pulsed magnetron sputtering
Abstract
Solar cells based on organic absorber materials and Organic Light Emitting Diodes (OLEDs) require an encapsulation to ensure sufficient life time. Many work groups suggest multilayer stacks to meet the requirements. We have developed a concept to deposit multilayer stacks by an in-line combination of reactive pulsed sputtering and magnetron based PECVD. To enhance the barrier properties of the multilayer system, the single sputtered layers which provide the barrier performance of the multilayer system have been investigated. Aluminum oxide, titanium oxide and a mixture of both materials have been deposited on polymer film in a roll-to-roll coating unit by dual magnetron sputtering. The layers have been characterized regarding barrier properties and optical transparency. Additionally with zinc-tin-oxide a new sputtered high-barrier material is presented. It is shown that the water vapor permeation rates are as low as or even lower than the permeation rates of alumina layers. Thin films grown by magnetron-based plasma enhanced CVD process have been characterized regarding their film composition and their barrier properties.
