Investigation of multi-photoconductance state induced by light-sensitive defect in TiO_x -based memristor

A TiOx switching layer with a thickness of ∼83 nm is prepared on a F-doped SnO2 (FTO) substrate by the sol-gel method to fabricate the Ag/TiOx/FTO memristor. The resistive switching memory behavior observed in the developed memristor can be efficiently modulated by the light. After modulating the light-intensity from 2.5 to 12.5 mW/mm2, five discrete photoconductance states can be obtained. The competition and synergy of the oxygen vacancy and Ag atom-based filament are responsible for the resistance switching (RS) memory behavior. The multi-photoconductance states are ascribed to the electron excited by the external light transports along the conduction filament. The programmable multi-photoconductance states provide a realistic RS memory behavior to mimic the function of a visual system.