The effect of oxygen vacancy on switching mechanism of ZnO resistive switching memory

Abstract

Oxygen vacancy (Vo) is believed to control the switching mechanism of metal oxide resistive switching memory. However, an accurate and quantitative theory to prove this point of view remains absent. In this letter, we propose a model combining the Poole-Frenkel effect, space charge limited current, and the modification of Vo density to simulate the current-voltage curves. The calculated results show reasonable agreements with the experimental data, which indicates that resistive switching between high resistance state and low resistance state in the devices of Al/ZnO/p+-Si is led by the density change of Vo. Furthermore, the essence of this leading effect of Vo density is explained by electrons capture and emission via oxygen vacancies. This research demonstrates the significance of Vo in theory and gives an insight into the switching mechanism.

ZnO and ZnO1−x based thin film memristors: The effects of oxygen deficiency and thickness in resistive switching behavior

“…Table 2. The most dominant conduction mechanism at the high electric field region of all memristor devices was the SE, followed by the P-F, in contrast to findings for ZnO-based devices in the literature [15,18,22,29]. The conduction mechanism most commonly observed in oxides is the Schottky emission [15].…”

Resistive switching and charge transport mechanisms in ITO/ZnO/p-Si devices

“…In the literature, these three states have also been analyzed: (i) the pristine shows trapassisted conduction typical of dielectric materials, like Poole-Frenkel or TAT, in good agreement with our observations. 38,39 On the other hand, (ii) the LRS typically exhibits a high conductance with an Ohmic or SCLC behavior; considering the effective areas reported so far, 12 the current density reaches values compatible with ZnO with a high density of oxygen vacancies, indicating that the CNF formation is due to the out-diffusion of O atoms and/or oxygen deficiency in the film grown by magnetron sputtering. Finally, (iii) the HRS at low voltages presents again conduction typical of dielectric materials assisted by traps, suggesting that the conductive paths are partially re-oxidized, thus inducing the interruption of the CNFs along 9 nm.…”

Recent Progress in Solution‐Based Metal Oxide Resistive Switching Devices

“…Another critical parameter on the synthesis process of resistive switching devices is the metal salt precursors, which are subdivided into three counter anions groups; [ 100 ] oxidants (hydrated nitrates), [ 72,79,80,98,101–121 ] reducers (alkoxides, [ 117,122–125 ] acetates, [ 72,76,78,79,104,105,109,111,113–118,126–153 ] and acetylacetonates [ 81,134,144,154–157 ] ), and neutrals (chlorine‐based). [ 63,71,103,107,110,112,116,119,125,132,158–164 ] Among these, oxidant counter ions are preferable due to the high oxidizing power (negative charge), greater solubility in water or polar organic solvents and low decomposition temperature, which are related to the electronic interactions between the metal and the nitrate group, as shown in Figure 9c.…”

“…It constitutes a substantial portion of the oxide precursor solutions: around 98% and 90% for lower and higher concentrations, respectively. The most common solvents in solution‐based metal oxide RRAMs are 2‐methoxyethanol (2‐ME), [ 63,72,79,80,98,102,104,105,107,109,112,113,115–119,121,127,129,130,133,134,137,139,142,144,150–153,158,159,168–185 ] ethanol, [ 72,77,78,82,103,108,113,114,120,126,132,135,136,138,145,147,157,162–164,168,186–200 ] deionized (DI) water, [ 73,101,116,120,123,148,162,163,190,201 ] acetic acid, [ 103,121,129–131,134,140,142,144,149,150,152,154,173,179,180,183,202 ] and isopropanol [ 23,123,125,128,136,169,181,203 ] among others (ethylene glycol, [ 141,204 ] 2‐butoxyethanol, [ 205 ] acetylacetone, [ 149 ] and acetonitrile […”

“…It constitutes a substantial portion of the oxide precursor solutions: around 98% and 90% for lower and higher concentrations, respectively. The most common solvents in solution-based metal oxide RRAMs are 2-methoxyethanol (2-ME), [63,72,79,80,98,102,104,105,107,109,112,113,[115][116][117][118][119]121,127,129,130,133,134,137,139,142,144,[150][151][152][153]158,159,[168][169][170][171][172][173][174][175][176][177][178][179][180][181][182][183]…”