Interface Optimization and Electrical Properties of 0.5Ba(Zr_0.2Ti_0.8)O₃–0.5(Ba_0.7Ca_0.3)TiO₃Thin Films Prepared by a Sol–Gel Process

Abstract

In this work, 0.5Ba(Zr 0.2 Ti 0.8 )O 3 −0.5-(Ba 0.7 Ca 0.3 )TiO 3 (0.5BZT−0.5BCT) thin films were synthesized at 500 °C by introducing a seed layer. Low interfacial diffusion and high (100) orientation were simultaneously achieved. Minimal leakage current density, dielectric constant, and loss were obtained owing to low crystallization temperature and low interfacial diffusion. The pyroelectric coefficient remained relatively high because of the high orientation, which resulted in superior pyroelectric figures of merit compared with previously reported films. This study demonstrates that low-temperature crystallization can suppress interfacial diffusion and extend film applications by integrating the films with silicon substrates and that thin films annealed at 500 °C are good candidates for application in uncooled infrared detectors.

Lead-Free Ferroelectric Thin Films

“…8. The process starts with the preparation of the precursor solution from Ba and Sr carboxylates, usually acetates, and Zr and Ti alkoxides, mostly propoxides and butoxides (Chen et al 2016;Chi et al 2013Chi et al , 2014Huang et al 2016;Li et al 2013Li et al , 2015cLin et al 2012;Wang et al 2014aWang et al , 2015. In most of the cases, acetic acid and 2-methoxyethanol are used as solvents.…”

“…Some groups reported the existence of a metastable pyrochlore phase (Chen et al 2016;Chi et al 2014;Kang et al 2012). Kang et al found that by modifying the solution chemistry, the fraction of the pyrochlore phase in BZT-0.5BCT films could be reduced.…”

“…Different perovskite seeding layers were implemented with the aim of obtaining pure perovskite BZT-BCT phase and/or decreasing the crystallization temperature of BZT-BCT films and thus possibly reducing integration problems (Chen et al 2016;Chi et al 2013Chi et al , 2014Li et al 2013Li et al , 2015c. Chi et al introduced a (100) oriented Pb 0.8 Ca 0.2 TiO 3 (PCT) seeding layer on the platinized silicon substrate.…”

Low temperature growth of (100)-oriented Ba(Zr0.2Ti0.8)O3- 0.5(Ba0.7Ca0.3)TiO3 thin films using a LaNiO3 seed layer

“…Mimura et al [17] prepared BCZT thin films fabricated on Pt/TiO x /SiO 2 /Si substrates at temperatures above 650 °C, and the temperature at which the films were well crystallized was maintained at approximately 700 °C. Furthermore, for this type of film, more and more researchers have focused on interface issues [18][19][20]. Chi et al [18,19] conducted an in-depth study of BCT-0.5BZT thin films, in which they synthesized BCT-0.5BZT thin films at 500 °C by introducing The next step was to deposit BZT-0.5BCT on top of the LNO coating and pyrolyze the material at 450 °C for 120 s on a hot-plate.…”

“…Furthermore, for this type of film, more and more researchers have focused on interface issues [18][19][20]. Chi et al [18,19] conducted an in-depth study of BCT-0.5BZT thin films, in which they synthesized BCT-0.5BZT thin films at 500 °C by introducing The next step was to deposit BZT-0.5BCT on top of the LNO coating and pyrolyze the material at 450 °C for 120 s on a hot-plate. These spin coating and pyrolyzation processes were repeated four times to obtain the final desired film thickness.…”