Capacitance Measurement for Evaluating the Initial Top-Electrode-Damage-Induced Degradation of Organic Devices

The formation of bubbles and fractures on the top electrode surface is one of the key factors that leads to the degradation of organic devices. This degradation can be directly observed through optical microscopy but only in low spatial resolution of several micrometers due to limited optical contrast between the bubbles and their surroundings. Here, we present a nonintrusive capacitance method to characterize electrode damage with improved accuracy and testing efficiency. For serious degradation with a large damage area at the top electrode (almost more than 10 μm), the relative drop in capacitance after degradation is consistent with the results derived by optical microscopy. For initial degradation with a damage area below the resolution of optical microscopy (even less than 1 μm), our proposed capacitance method still works well, which is validated by atomic force microscopy results.