Resistive switching behavior in ZnO:Ca thin films deposited by a pulsed laser deposition technique

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2023-03, Vol.129 (3), Article 210
• Main Authors: Mejri, I. H., Omri, K., Ghiloufi, I., Silva, José Pedro Basto, Gomes, M. J. M., El Mir, L.
• Format: Article
• Language: English
• Subjects: Applied physics; Ca thin films; Calcium; Characterization and Evaluation of Materials; Charge transport; Chemical composition; Ciências Físicas; Ciências Naturais; Condensed Matter Physics; Crystallites; Current voltage characteristics; Doping; Electric fields; Electrical properties; Electron microscopy; Machines; Manufacturing; Materials science; Microscopy; Nanoparticles; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Pulsed laser deposition; Pulsed lasers; Resistive switching; Science & Technology; Silicon substrates; Sol-gel processes; Surfaces and Interfaces; Switching; Thin Films; Wurtzite; Zinc oxide; ZnO; ZnO:Ca thin films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-023-06508-1

Calcium-doped ZnO (CZO) nanopowders were synthesized using the sol–gel method. The structural characteristics were investigated by X-ray diffraction (XRD) and the analysis reveals that our samples are crystalized in a wurtzite hexagonal structure. The morphological properties and the chemical composition of the nanoparticles were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The obtained powders are stoichiometric with crystallites in a nanometric scale aggregated in micrometric particles. Then, pulsed laser deposition (PLD) technique was used to grow Ca-doped ZnO thin films with different doping concentrations (1, 3, and 5%), on p-type Si substrates. The Ca doping effect on the electrical properties of the CZO films was investigated by current–voltage characteristics. A resistive switching (RS) effect was observed in the ITO/ZnO:Ca/Au structures. The RS behavior is dependent on the Ca doping concentration. The charge transport mechanisms of the devices were studied. In the positive bias voltage region, the transport is dominated by Ohmic and space-charge limited conduction mechanisms under low and high electric fields, respectively. This work was funded by the National Plan for Sciences, Technology, and innovation (MAARIFAH) – King Abdulaziz City for Sciences and Technology—Kingdom of Saudi Arabia, award number: 13-NAN517-08. This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contract UIDB/04650/2020.