Grain boundary effect on the resistive switching characteristics of SrTi1-xFexO3 directly patterned via photochemical organic-metal deposition

Abstract

Ionic memristors are a promising candidate for use in next-generation non-volatile memory and neuromorphic computing systems. To ensure that ionic memristors exhibit appropriate resistive switching characteristics, the precise control of oxygen vacancies is required. The ABO3 structure can accommodate various ions of different sizes in the A and B sites, and this flexibility allows for the accurate design of materials and for the oxygen defects to be controlled. This study systematically investigated the effect of Fe doping on the resistive switching characteristics of SrTi1-xFexO3 (x = 0, 0.05, 0.10, and 0.15) films fabricated using photochemical organic–metal deposition. The Fe dopant created oxygen vacancies via Schottky defects, especially at grain boundaries, with the space charge at the grain boundaries inhibiting grain growth and increased the number of defective grain boundaries. Since the defective grain boundary acts as a conducting path filament, an increase in the Fe content reduced the initial resistance of the films, and SrTi1-xFexO3 film optimized Fe content exhibited complementary resistive switching behavior without the need for a forming process. The Fe doping effects on the crystal and electronic structure were also analyzed using X-ray diffraction, valence band, O 1s X-ray absorption, and Raman spectra.