Zhang, ManZhang, HangfengJiang, QinghuiGao, FengChen, RiqingZhang, DouReece, Michael J.Yang, BinViola, GiuseppeYan, Haixue2022-02-162022-02-162021-11-02Zhang, M., Zhang, H., Jiang, Q., Gao, F., Chen, R., Zhang, D., Reece, M. J., Yang, B., Viola G., & Yan, H. (2021). Terahertz characterisation of lead-free dielectrics for different applications. ACS Applied Materials & Interfaces, 13, 45, 53492-53503. https://doi.org/10.1021/acsami.1c145831944-824410.1021/acsami.1c14583http://hdl.handle.net/10034/626696“This document is the Accepted Manuscript version of a Published Work that appeared in final form in [ACS Applied Materials & Interfaces], copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see [https://pubs.acs.org/doi/10.1021/acsami.1c14583].”In this Spotlight on Applications, we describe our recent progress on the terahertz (THz) characterization of linear and non-linear dielectrics for broadening their applications in different electrical devices. We begin with a discussion on the behavior of dielectrics over a broadband of frequencies and describe the main characteristics of ferroelectrics, as an important category of non-linear dielectrics. We then move on to look at the influence of point defects, porosity and interfaces, including grain boundaries and domain walls, on the dielectric properties at THz frequencies. Based on our studies on linear dielectrics, we show that THz characterization is able to probe the effect of porosities, point defects, shear planes and grain boundaries to improve dielectric properties for telecommunication applications. Further, we demonstrate that THz measurements on relaxor ferroelectrics can be successfully used to study the reversibility of the electric field-induced phase transitions, providing guidance for improving their energy storage efficiency in capacitors. Finally, we show that THz characterization can be used to characterize the effect of domain walls in ferroelectrics. In particular, our studies indicate that the dipoles located within domain walls provide a lower contribution to the permittivity at THz frequencies than the dipoles present in domains. The new findings could help develop a new memory device based on non-destructive reading operations using a THz beam.CC0 1.0 Universalhttp://creativecommons.org/publicdomain/zero/1.0/terahertzferroelectricdielectricdomain walldefectsArticle1944-8252ACS Applied Materials and Interfaces