High energy density and reliable BaZrxTi1−xO3 thin film capacitors from novel aqueous chemical solution deposition

High energy density capacitors are essential in portable energy-autonomous devices for the Internet of Things (IoT). Capacitors based on perovskite ferroelectric thin films, where substitution breaks down ferroelectricity to the local scale, are interesting due to their improved energy density, efficiency and breakdown strength. For this work, Mn-substituted (1.5 %) Barium Zirconate Titanate (BaZr x Ti 1-x O 3 , BZT) thin films were prepared on Pt/Si substrates via a novel aqueous chemical solution deposition (CSD) process using entirely environmentally friendly chemicals. The thin films were investigated with Grazing incidence X-ray Diffraction (GI-XRD), Raman Spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and dielectric/ferroelectric characterization under application-relevant conditions. All thin films exhibit a highly crystalline and dense microstructure with a smooth surface. All compositions offer high energy density and efficiency, whereby the best results were obtained at 15 % Zr content, with a high recoverable energy density (11 Jcm −3 at 1.8 MVcm −1 ), high fatigue resistance, high frequency and temperature stability with deviations from the reference state (lowest value) of less than 3 % (10 6 cycles), 5 % (0.1–100 kHz) and 16 % (20–200°C), respectively. These thin films are highly suitable as capacitors for IoT devices, and moreover, they are prepared using a green process. • Structural and electrical characterization of high-quality BZT thin films from environmentally friendly aqueous CSD. • Onset of relaxor-like behavior at ∼10 % Zr content. • High efficiency, fatigue resistance and temperature stability. • 15 % Zr substitution yielded superior energy storage properties.