Lithium ion trapping mechanism of SiO(2) in LiCoO(2) based memristors.

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.