Influence of substrates on resistive switching behaviors of V-doped SrTiO3 thin films

Abstract

V-doped SrTiO3 (V:STO) thin films on Si and Pt/Ti/SiO2/Si substrates are synthesized by sol–gel method to form metal–insulator–metal (MIM) structures. Bipolar resistive switching (RS) characteristics were investigated in Pt/V:STO/Si and Pt/V:STO/Pt structures respectively. The enhancement of resistive switching behavior in Pt/V:STO/Pt/Ti/SiO2/Si structures were demonstrated in terms of the maximum operation voltage reduced from 20 to 2 V and the improved ROFF/RON ratio increased from 102 to 103. The electrochemical migration of oxygen vacancies resulted from the metal–oxide interfaces was applied to explain the resistive switching behaviors. On the basis of current–voltage characteristics, the switching mechanisms for the low resistance state (LRS) and high resistance state (HRS) currents of V:STO films are considered as Ohmic and trap-controlled space charge-limited current (SCLC) behavior, respectively.