Electrical calcium test for moisture barrier evaluation for organic devices
Electrical calcium test for moisture barrier evaluation for organic devices
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DOI：
10.1063/1.3633956
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发表时间：
2011-09-01
影响因子：
1.6
通讯作者：
Leo, K.
中科院分区：
文献类型：
--
作者：
Schubert, S.;Klumbies, H.;Leo, K.
我们讨论了电钙测试-一种方法来测量非常小的水蒸气渗透率通过阻隔膜与高吞吐量。我们设计的灵敏度范围为10（-5）~ 15 g/（m（2）d）。此外，仔细看看电极串联电阻的重要性：我们表明，渗透率被低估，如果它被忽略。考虑串联电阻和Fickian扩散，不仅可以拟合稳态渗透曲线，而且可以拟合瞬态渗透曲线。使用这种方法，具有不同的渗透率的渗透屏障进行评估，导致水蒸气透过率以及可比库仑测量。的钙层形态的原子力显微镜测量表明在降解过程中的微观不均匀性。电极材料和钙层厚度的变化进行检查它们对测得的渗透的影响。此外，光学和电学钙测试进行了比较。在时间依赖性的小差异进行观察和讨论。(C)2011年美国物理学会。[doi：10.1063/1.3633956]
We discuss the electrical calcium test - a method to measure very small rates of water vapor permeation through barrier films with high throughput. The sensitivity range for our design is found to be 10(-5) to 15 g/(m(2) d). Moreover, a closer look at the importance of electrodes series resistance is taken: We show that permeation rates are underestimated if it is neglected. Taking this series resistance and Fickian diffusion into account not only the steady, but also the transient state of the permeation curve can be fitted. Using this approach, permeation barriers with different permeabilities are evaluated leading to water vapor transmission rates well comparable to coulometric measurements. The calcium layer morphology is investigated by atomic force microscopy measurements indicating microscopical inhomogeneities during degradation. Variations of electrode material and calcium layer thickness are carried out to examine their influence on the measured permeation. Additionally, optical and electrical calcium tests are compared. Small differences in the time dependence are observed and discussed. (C) 2011 American Institute of Physics. [doi:10.1063/1.3633956]