Characterization of advanced ALD-based thin film barriers for organic electronics using ToF-SIMS analysis

Abstract To address all the concerns of organic electronics device development and especially ageing issues, analytical techniques must be able to provide extremely fine characterization of the composition and thickness of layers and interfaces, while retaining appropriate spatial resolution. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is able to provide a detailed characterization of the in-depth composition of hybrid organic/inorganic multilayer structures which is crucial for such investigations. The study of an aged AlQ 3 film after an exposition at the ambient atmosphere permitted to identify the secondary ions that are potentially indicative of the hydrolysis reaction of AlQ 3 . The investigation of the organic/inorganic multilayer devices by ToF-SIMS depth profiling also confirmed a confinement of the moisture in the gas barrier layer(s). It was possible to determine the moisture ratio present in the different barrier architectures to compare the efficiency of the encapsulation. In particular, the double barrier layer has shown a lower and a more localized diffusion of the moisture in the barrier which was consistent with the results of the performance of the devices and with the data reported in the literature such as water vapor transmission rate ones.