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

• Published in: Organic electronics 2018-08, Vol.59, p.21-26
• Main Authors: Terlier, T., Maindron, T., Barnes, J.-P., Léonard, D.
• Format: Article
• Language: English
• Subjects: 8-Hydroxyquinoline aluminum; Analytical chemistry; Chemical Sciences; Depth profile; Device stability; Diffusion barrier; Organic light emitting diode; ToF-SIMS
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2018.04.031

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 AlQ3 film after an exposition at the ambient atmosphere permitted to identify the secondary ions that are potentially indicative of the hydrolysis reaction of AlQ3. 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. [Display omitted] •ToF-SIMS depth profiling analysis allows issues related to the development of organic electronics to be studied.•The secondary ions detected are potentially indicative of the hydrolysis reaction of AlQ3 consistent with the literature.•In the case of the double barrier layer the moisture diffusion was lower and more confined in agreement with performance results and the literature.