Lithium ion trapping mechanism of SiO 2 in LiCoO 2 based memristors

Abstract

Pt/LiCoO 2 /SiO 2 /Si stacks with different SiO 2 thicknesses are fabricated and the influence of SiO 2 on memristive behavior is investigated. It is demonstrated that SiO 2 can serve as Li ion trapping layer benefiting device retention, and the thickness of SiO 2 must be controlled to avoid large SET voltage and state instability. Simulation model based on Nernst potential and diffusion potential is postulated for electromotive force in LiCoO 2 based memristors. The simulation results show that SiO 2 trapping layer decreases the total electromotive field of device and thereby prevents Li ions from migrating back to LiCoO 2 . This model shows a good agreement with experimental data and reveals the Li ion trapping mechanism of SiO 2 in LiCoO 2 based memristors.