Ferroelectricity in Strategically Synthesized Pb-free LiNbO3-type ZnSnO3 Nanostructure Arrayed Thick Films

Abstract

ABSTRACTWe report the evidence of ferroelectricity from LN-type ZnSnO3 nanostructure arrayed thick films (10 - 20 µm) on Si with remanent polarization value as high as ≈ 30 µC/cm2 in nanowire arrays. A combined pulsed-laser deposition (PLD) technique and a solvothermal synthesis scheme was adopted to effectively synthesize the nanostructured samples assisted by conducting ZnO template-layers. The similar crystal symmetry and comparable lattice parameter between ZnO and LN-type ZnSnO3 facilitated the dense growth of high-quality ZnSnO3 nanostructure arrays in the form of one-dimensional vertical nanowires, nanorods and two-dimensional nanoflakes. The strategic synthesis method allowed controlled tunability of the morphology, crystallinity, and packing density of ZnSnO3 nanostructures, which in turn facilitated the measurement of ferroelectric (FE) properties using a simple sandwich-device geometry. Analyses of the FE properties in relation to the structures are presented and their potential for designing future Pb-free FE devices for non-volatile memory applications is discussed.