title: Note: Inhibiting bottleneck corrosion in electrical calcium tests for ultra-barrier measurements.
abstract: A major failure mechanism is identified in electrical calcium corrosion tests for quality assessment of high-end application moisture barriers. Accelerated calcium corrosion is found at the calcium/electrode junction, leading to an electrical bottleneck. This causes test failure not related to overall calcium loss. The likely cause is a difference in electrochemical potential between the aluminum electrodes and the calcium sensor, resulting in a corrosion element. As a solution, a thin, full-area copper layer is introduced below the calcium, shifting the corrosion element to the calcium/copper junction and inhibiting bottleneck degradation. Using the copper layer improves the level of sensitivity for the water vapor transmission rate (WVTR) by over one order of magnitude. Thin-film encapsulated samples with 20 nm of atomic layer deposited alumina barriers this way exhibit WVTRs of 6 × 10(-5) g(H2O)/m(2)/d at 38 °C, 90% relative humidity.
authors.affiliation: Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Nehm
authors.affiliation: Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Müller-Meskamp
authors.affiliation: Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Klumbies
authors.affiliation: Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Leo