Ru-Al codoping to mediate resistive switching of NiO:SnO2 nanocomposite films

The Ru-Al codoped NiO:SnO2 nanocomposite films are revealed to exhibit bipolar resistive switching. The switching mechanism is well explained by the formation/rupture of filamentary paths due to the field-induced migration of oxygen vacancies and oxygen ions. Compared with that of the undoped NiO:SnO2 film, the ON/OFF ratio of Ru-Al codoped samples is largely improved. This is ascribed to the increased content of oxygen vacancies and trapped states between the equilibrium Fermi level and conduction band induced by the interstitial defects of Ru and Al.