CHARACTERIZATION OF THE MULTIFUNCTIONAL PROPERTIES OF ZINC OXIDE BASED MATERIALS BY SCANNING PROBE MICROSCOPY TECHNIQUES

Abstract

ZnO based materials have recently attracted considerable attention due to their multifunctional properties and their potential applications in many fields. The resistive switching (RS) and polarization switching behaviors have been extensively studied. However, the underlying mechanisms remain unclear. In addition, the coexistence of resistive switching and polarization switching phenomena complicates the analysis and understanding of the multifunctional properties. Hence this study has been focused on nano- to micro-scales characterization and understanding of the correlations among the multifunctional properties in the ZnO-based materials. Three types of ZnO-based materials were fabricated and investigated in this work. The undoped ZnO thin films and copper doped ZnO (ZnO:Cu) thin films were deposited by a pulse laser deposition (PLD) technique, and the undoped ZnO nanoplates were deposited by a hydrothermal method. The characterizations were mainly based on various advanced Scanning Probe Microscopy (SPM) techniques, including Piezoresponse Force Microscopy (PFM), conductive Atomic Force Microscopy (c-AFM) and Kelvin Probe Force Microscopy (KPFM).