Electroforming free resistive switching memory in two-dimensional VOx nanosheets

Abstract

We report two-dimensional VOx nanosheets containing multi-oxidation states (V5+, V4+, and V3+), prepared by a hydrothermal process for potential applications in resistive switching devices. The experimental results demonstrate a highly reproducible, electroforming-free, low SET bias bipolar resistive switching memory performance with endurance for more than 100 cycles maintaining OFF/ON ratio of ∼60 times. These devices show better memory performance as compared to previously reported VOx thin film based devices. The memory mechanism in VOx is proposed to be originated from the migration of oxygen vacancies/ions, an influence of the bottom electrode and existence of multi-oxidation states.

In Situ Nanostructural Analysis of Volatile Threshold Switching and Non‐Volatile Bipolar Resistive Switching in Mixed‐Phased a‐VOx Asymmetric Crossbars

“…However, this behavior has been reported previously for V 2 O 5 oxidation phase of a-VO x , [4,6] which is also present in our films as reported previously in Figure 1. However, this behavior has been reported previously for V 2 O 5 oxidation phase of a-VO x , [4,6] which is also present in our films as reported previously in Figure 1.…”

“…This kind of behavior has been reported before to occur in V 2 O 5 , [4,6] which is also present in our mixed phased a-VO x film. This kind of behavior has been reported before to occur in V 2 O 5 , [4,6] which is also present in our mixed phased a-VO x film.…”

“…[1] The major disadvantage of 3D crossbars currently is the high-leakage or sneak-path current. [3] Depending on the stoichiometry, crystal structure, and device structure it has demonstrated bipolar resistive switching (BRS) [4][5][6][7][8][9][10] as well as apolar threshold switching (TS). [3] Depending on the stoichiometry, crystal structure, and device structure it has demonstrated bipolar resistive switching (BRS) [4][5][6][7][8][9][10] as well as apolar threshold switching (TS).…”

Multistate Resistive Switching Memory for Synaptic Memory Applications

“…This type of conduction might be from the Poole-Frenkel (PF) conduction process. [31][32] The current conduction dominated by the PF conduction process strongly indicates the existence of a defective interfacial layer in between top electrode and the oxide layer. [33] The existence of this defective interfacial layer, is also proved in the SIMS study (see ("III" and "IV"), the slope in the current-voltage fitting become more then 2, which signifies trap controlled space charge limited conduction process (TC-SCLC).…”

“…After the forming process, when the negative bias was applied to the top electrode, the oxygen vacancies ( an interfacial layer (as also confirmed from the conduction mechanism mentioned above) near the bottom electrode along with rest of the 2 O − ions. [32] These interfacial layer offers an internal resistance which helps in the controlling of the CC process, as this types of internal resistance layer leads to self-complince effect in the resistive swithcing memory devices. [42] The reaction process of shown in Figure 5d.…”