Integration of ZnO-BaTiO₃ Nanocomposite Thin Films on Silicon: Structural, Morphological, and Electrical Property Studies

In this communication, we report the results of investigations on the synthesis, characterization, and functional properties of ZnO, BTO and (1-X) ZnO-(X)BaTiO₃ (ZnO-BTO) (X = 0.20–0.50) composite films grown using Pulsed Laser Deposition (PLD) on n-type silicon substrate. Structural analysis using X-ray diffraction (XRD) confirmed the presence of individual ZnO and BTO crystalline phase, indicating successful integration of the composite materials. Atomic force microscopy (AFM) was employed to examine the surface morphology and roughness, revealing a uniform and defect-free layer. Variations in film thickness and elemental compositions were studied using Rutherford Backscattering Spectroscopy (RBS). The non-linear I-V characteristics for all films indicate a semiconducting or insulating nature with possible trap-assisted conduction or space-charge-limited conduction mechanisms. The significant changes observed in the ferroelectric (P-E) loops were attributed to the modifications in surface morphology and the interface between the wurtzite-structured ZnO and the perovskite-structured BaTiO₃, which influence the space charge region. Dielectric measurements performed over a range of frequencies (100 Hz to 1 MHz) and temperatures (room temperature to 150 °C) indicate that, both ZnO and BaTiO₃ exhibit significant variations in dielectric properties with frequency and temperature. The composite thin films exhibited enhanced dielectric properties and reduced leakage current compared to ZnO/Si and BTO/Si films, demonstrating the synergistic effects of the composite structure. The improved performance of composite thin films on silicon substrates suggests their potential for use in advanced electronic devices, such as high-k dielectrics in transistors, sensors, and photovoltaic cells. This work provides a comprehensive understanding of the material properties and underscores the benefits of composite thin films in enhancing the functionality of silicon-based technologies.