Tin oxide slanted nanorod array-based optoelectronic memristor with enhanced resistive switching performance

One-dimensional (1D) metal oxide-based photonic memristors, combining information storage and optical response, have shown great potential for the design and development of high-density and high-efficient computing systems beyond the era of von-Neumann architecture and Moore’s law. Here, the functional memristive devices based on SnO_x slanted nanorod arrays are demonstrated; wherein both the optical and electrical stimuli can be used to modulate the switching characteristics. These exhibit excellent device parameters, including low operating voltages, currents, and longer retention in the dark. Under illumination, ranging from ultraviolet (254 and 365 nm) to visible light (400-700 nm), the unusual negative photo response with an enlarged ON/OFF ratio > 10⁶ is observed. The optoelectronic resistive memory behaviour is attributed to the electric field-induced formation of oxygen vacancies and light-stimulated dissolution of oxygen vacancies. The results suggest that the optical illumination reduces the oxygen ion migration barrier, leading to the dissolution of conductive filaments and thereby locally increasing the OFF state resistance. In addition, the well-aligned tin oxide nanorod arrays eliminate the branching or overgrowth of the conductive filaments and significantly reduce stochasticity in the resistive switching device parameters. These results demonstrate the potential applications of metal oxide-based 1D nanostructures for optoelectronic memory applications. Such memristors, with the combination of optical and electrical stimuli, have scope in the applications of artificial visual memory and other optoelectronic systems for integrated photonic circuits.