Resistive Switching Memory Behavior Research Articles

Ab initio study of ceria films for resistive switching memory applications

The aim of this study is to investigate the charge distribution/relocation activities in relation to resistive switching (RS) memory behavior in the metal/insulator/metal (MIM) structure of Zr/CeO2/Pt hybrid layers. The Zr layer is truly expected to act not only as an oxygen ion extraction layer but also as an ion barrier by forming a ZrO2 interfacial layer. Such behavior of the Zr not only introduces a high concentration of oxygen vacancies to the active CeO2 layer but also enhances the resistance change capability. Such Zr contributions have been explored by determining the work function, charge distribution and electronic properties with the help of density functional theory (DFT) based on the generalized gradient approximation (GGA). In doped CeO2, the dopant (Zr) plays a significant role in the formation of defect states, such as oxygen vacancies, which are necessary for generating conducting filaments. The total density of state (DOS) analyses reveal that the existence of impurity states in the hybrid system considerably upgrade the performance of charge transfer/accumulation, consequently leading to enhanced RS behavior, as noticed in our earlier experimental results on Zr/CeO2/Pt devices. Hence it can be concluded that the present DFT studies can be implemented on CeO2-based RRAM devices, which have skyscraping potential for future nonvolatile memory (NVM) applications.

Hydrogen-peroxide-modified egg albumen for transparent and flexible resistive switching memory

Egg albumen is modified by hydrogen peroxide with concentrations of 5%, 10%, 15% and 30% at room temperature. Compared with devices without modification, a memory cell of Ag/10% H2O2-egg albumen/indium tin oxide exhibits obviously enhanced resistive switching memory behavior with a resistance ratio of 104, self-healing switching endurance for 900 cycles and a prolonged retention time for a 104 s @ 200 mV reading voltage after being bent 103 times. The breakage of massive protein chains occurs followed by the recombination of new protein chain networks due to the oxidation of amidogen and the synthesis of disulfide during the hydrogen peroxide modifying egg albumen. Ions such as Fe3+, Na+, K+, which are surrounded by protein chains, are exposed to the outside of protein chains to generate a series of traps during the egg albumen degeneration process. According to the fitting results of the double logarithm I–V curves and the current-sensing atomic force microscopy (CS-AFM) images of the ON and OFF states, the charge transfer from one trap center to its neighboring trap center is responsible for the resistive switching memory phenomena. The results of our work indicate that hydrogen- peroxide-modified egg albumen could open up a new avenue of biomaterial application in nanoelectronic systems.

Mechanism for an enhanced resistive switching effect of bilayer NiOx/TiO2 for resistive random access memory

Bilayer of NiOx/TiO2 thin film spin-coated and sputtering-deposited on the fluorine doped tin oxide (FTO) substrate is employed to develop a resistive random access memory device. An enhanced resistive switching (RS) behavior, which with appropriate resistance ratio of ∼103, switching cycle endurance for 102 and long retention time for 104 s, is observed in the bilayer NiOx/TiO2 based device. Construction of contact-potential barrier, formation and rupture of a localized conduction filaments and migration of oxygen vacancy existed in the interface near electrodes co-contribute to the enhanced RS memory effects, but the migration of Ag+, Ni2x+ and diffusion of oxygen vacancies are the dominated ones. This work might give an insight into the mechanism of RS memory behaviors of an oxide-stacked structure device.

Mechanism for bipolar resistive switching memory behaviors of a self-assembled three-dimensional MoS2 microsphere composed active layer

A self-assembled three-dimensional (3-D) MoS2 microsphere-based memristor with a favorable ON/OFF resistance ratio of ∼104, endurance, and retention time is demonstrated at room temperature. The formation and rupture of a localized Ag metallic filament, establishment and destruction of a boundary-based hopping path, and charge trapping and detrapping from the space charge region co-contribute to the bipolar resistive switching memory behaviours observed in the device of Ag/MoS2/ITO. This work may give insight into the mechanism of the resistive switching memory behaviours of a device with a 3-D micro-scale.

Effect of electrode material on resistive switching memory behavior of solution-processed resistive switches: Realization of robust multi-level cells

Sol-gel processed ZrO2 was used as the main active channel material for a resistive switching memory device implemented on Indium Tin oxide coated glass substrates. The memory properties of the deposited ZrO2 layers depended on the top electrode material. Inert Au top electrodes did not yield resistive switching memory properties, while Ag top electrodes provided conventional resistive switching memory properties, with sharp on and off switching operation. In contrast, Ti top electrodes provided smooth on and off switching operation, and modifying the pulse widths and voltages allowed good control over the resistivity. The fabricated Au/Ti/ZrO2/ITO systems exhibited four different resistance levels, and good multi level storage characteristics were observed for at least 104cycles without degradation.

Bipolar resistive switching memory behaviors of the micro-size composite particles

Composite particles (CPs) with an average diameter of 100μm, containing the amorphous silicates, but crystal structures are dominated by the NaS2, Al2S3, Al0.55Mo2S4 and MoO3, are synthesized using hydrothermal method. Bipolar resistive switching (RS) memory behaviors with favorable resistance ON/OFF ratio, high retention and voltage cycling endurance performance are observed in the CPs-based device. The RS memory behaviors can be well controlled by stressing visible light at room temperature. The traps/deep traps based physical modes are proposed to interpret the RS memory behaviors for the quasi-bulk silicate-based composites. Different from conventional nano-scale RS memory device, the discovery of the RS memory behavior of micro-scale silicate composites may provide one new insight into the mechanism of resistive switching behavior.

Effect of Cu ions assisted conductive filament on resistive switching memory behaviors in ZnFe2O4-based devices

Resistive random access memory (RRAM) has been developing as a most promising non-volatile memory in the current memory technology. In this work, ZnFe2O4 (ZFO) nano powder were firstly prepared by co-precipitation assisted hydrothermal process. Further, the resistive switching memory devices with Ag/Cu doped ZnFe2O4 (CZFO)/Au/Si and Ag/ZFO/Au/Si structures grown on silicon (Si) substrate were prepared by radio frequency magnetron sputtering, and their memory behaviors were contrastively investigated. It is observed the Cu doping can obviously affect the bipolar resistive switching memory characteristics. Thus a model concerning the formation and rupture of Cu ions assisted conductive filament inside the CZFO layer is suggested to explain the change of memory behaviors. These works provide a foundation for exploring the memory application of multifunctional material and further regulate their nonvolatile memory behaviors.

A larger nonvolatile bipolar resistive switching memory behaviour fabricated using eggshells

Resistive random access memory (RRAM) devices have emerged as promising candidates for near future nonvolatile information storage. Eggshells, a food waste, have not been focused and recycled sustainably today. Eggshell-based devices have shown a large resistive-switching(RS) memory behaviors with favorable resistance ratio of ∼103, larger memory window of ∼3.5 V, and high endurance and retention performance. Redox-based Ag filament models involving the formation and rupture of the metallic conduction filaments between top and bottom electrodes are proposed to interpret the large nonvolatile bipolar RS memory behaviors. This discovery provides for the possibility of an environmentally friendly, low-cost and sustainable material application in the next-generation nonvolatile date storage device.

An optoelectronic resistive switching memory behavior of Ag/α-SnWO4/FTO device

It is known to all of us that the resistive switching memory behavior of metal-oxide-metal structure device is a fascinating candidate for next generation nonvolatile memories. In this work, α-SnWO4 nanoparticles were synthesized by a hydrothermal process. Further, a resistive switching memory device with Ag/α-SnWO4/FTO structure is demonstrated. The device presents an optoelectronic bipolar resistive switching memory behavior at room temperature. This study is useful for exploring multifunctional materials and their applications in optoelectronic nonvolatile memory devices.

Resistance switching characteristics of core–shell γ-Fe2O3/Ni2O3 nanoparticles in HfSiO matrix

Core–shell γ-Fe2O3/Ni2O3 nanoparticles are synthesized by chemical co-precipitation method. Resistive switching memory behaviors, which have resistance ON/OFF ratio of ∼102 and excellent retention property, are observed in the Au/HfSiO/γ-Fe2O3/Ni2O3/HfSiO/Pt structure. Space charge limited current (SCLC) mechanism, which is supported by the fitting current–voltage results, is employed to know the resistive switching memory effects. The transportation of Oxygen vacancy Vo2+, oxygen ion O2−, recombination of oxygen atom and drive of external electric field are responsible for the ON or OFF states observed in device.

Fully Si compatible SiN resistive switching memory with large self-rectification ratio

In this letter, we report unique unipolar resistive switching memory behaviors in the Ni/Si3N4/p-Si structure by controlling the impurity concentration of Si bottom electrode. It is found that we can decrease the reset current drastically by reducing dopant concentration by reducing dopant concentration, which helps low-power operation in the high density resistive switching memory array. Also, the samples with high impurity concentration exhibited ohmic conduction in the low-resistance state (LRS) while those with low dopant concentration below 1018 cm−3 showed a remarkable self-rectifying behavior. The nonlinear metal-insulator-semiconductor (MIS) diode characteristics in the samples with low doping concentration (∼1018 cm−3) are explained by the formation of Schottky barrier at the metal and semiconductor interface. As a result, we demonstrate high rectification ratio (>105) between forward and reverse currents along with the robust nonvolatile properties including endurance cycles and retention from the devices with large self-rectification ratio. The high self-rectifying characteristics of Si3N4-based RRAM cell would be one of the most virtuous merits in the high-density crossbar array.

Preparation of MoSe2 nano-islands array embedded in a TiO2 matrix for photo-regulated resistive switching memory

The electrically driven resistance change of a material, called memristive switching, is a fascinating phenomenon in the development of next generation nonvolatile memory alternatives to flash technology. Herein, the composite of MoSe2 nano-islands array inserted into TiO2 matrix grown on fluorine-doped tin oxide (FTO) substrate was prepared by anodic aluminum oxide (AAO) template assisted radio frequency magnetron sputtering. Further, a photo-controlled resistive switching memory device with Ag/[MoSe2/TiO2]/FTO structure is demonstrated. The device presents stable resistive switching memory behaviors in dark and under illumination respectively. Finally, the mechanism for the photo-controlled memory behaviors is discussed in detail. This implication provides a foundation for exploring the multifunctional composites and their applications in photo-controlled nonvolatile memory devices.

Resistive switching memory of single BiMnO3+δ nanorods

In this work, BiMnO3+δ nanorods were prepared by an improved hydrothermal process. Further, we demonstrate the bipolar resistive switching memory behavior of single BiMnO3+δ nanorods. The physical model of conducting filament formation due to the diffusion of Ag ions along the BiMnO3+δ nanorods under electric field has been suggested to explain the bipolar resistive switching behavior. This study is useful for developing the nonvolatile memory technology in nanoscale.

Photo-electron double regulated resistive switching memory behaviors of Ag/CuWO4/FTO device

In this work, the CuWO4 film based resistive switching memory capacitors were fabricated with hydrothermal and spin-coating approaches. The device exhibits excellent photo-electron double controlled resistive switching memory characteristics with OFF/ON resistance ratio of ~103. It is believed that the interface of CuWO4 and FTO is responsible for such a switching behavior and it can be described by the Schottky-like barriers model. This study is useful for exploring the multifunctional materials and their applications in photo-electron double controlled nonvolatile memory devices.

Resistive switching memory characteristics of single MoSe2 nanorods

Resistive switching memory effect in metal–oxide–metal structures is a fascinating phenomenon toward next generation universal nonvolatile memories. Herein, the MoSe2 nanorods were prepared by hydrothermal method. Further, a resistive switching memory device of single MoSe2 nanorods is demonstrated. The device presents stable resistive switching memory behaviors with on–off ratio (memory window) of ∼50 at room temperature. Moreover, the origin of switching behavior in these devices on the basis of formation and annihilation of conducting filaments is addressed. This study is useful for exploring the multifunctional materials and their applications in nonvolatile memory devices.

Preparation and light-controlled resistive switching memory behavior of CuCr2O4

In this work, CuCr2O4 nanoparticles were successfully prepared by an improved hydrothermal process, and a resistive switching memory behavior with Ag/CuCr2O4/fluorine-doped tin oxide structure is demonstrated. Specially, the resistive switching memory characteristics can be controlled by white-light illumination. The device can maintain superior stability over 100 cycles with an OFF/ON-state resistance ratio of about 103 at room temperature. This study is useful for exploring the promising light-controlled resistive switching memory device in the development of resistive switching random-access memory. We demonstrate a resistive switching device based on Ag/CuCr2O4/FTO structure, and the device shows light-controlled resistive switching memory characteristics.

Space charge polarization-induced symmetrical negative resistive switching in individual p-type GeSe2:Bi superstructure nanobelts for non-volatile memory

Two-terminal devices based on p-type GeSe2:Bi nanobelts show excellent symmetrical nonvolatile negative resistive switching memory behavior, originating from trap-induced space charge polarization effect.

Tuning Resistive Switching Memory Behavior from Non-volatile to Volatile by Phenoxy Linkages in Soluble Polyimides Containing Carbazole-Tethered Triazole Groups

Two soluble functional aromatic polyimides (PIs), 6F-CzTZ PI and 6F-OCzTZ PI, are synthesized for memory device applications. The chemical structures of the 6F-CzTZ PI and 6F-OCzTZ PI are basically identical, with the only difference lying in the incorporation of phenoxy linkages in 6F-OCzTZ PI. However, vastly different memory behaviors are observed. The 6F-CzTZ PI displays a non-volatile write-once read-many times (WORM) memory effect with no polarity, while the 6F-OCzTZ PI exhibits volatile static random access memory (SRAM) characteristics and has polarity. Both the PIs exhibit good long-term operation stability, survive to 108 reading cycles with no current degradation, and show ultrafast switching with a response time less than 20 ns. The charge-transfer mechanisms and the roles of the donor and acceptor components in the PIs associated with the electrical switching effect are elucidated on the basis of the experimental and quantum simulation results.

Nanocrystalline Si pathway induced unipolar resistive switching behavior from annealed Si-rich SiNx/SiNy multilayers

Adding a resistive switching functionality to a silicon microelectronic chip is a new challenge in materials research. Here, we demonstrate that unipolar and electrode-independent resistive switching effects can be realized in the annealed Si-rich SiNx/SiNy multilayers with high on/off ratio of 109. High resolution transmission electron microscopy reveals that for the high resistance state broken pathways composed of discrete nanocrystalline silicon (nc-Si) exist in the Si nitride multilayers. While for the low resistance state the discrete nc-Si regions is connected, forming continuous nc-Si pathways. Based on the analysis of the temperature dependent I-V characteristics and HRTEM photos, we found that the break-and-bridge evolution of nc-Si pathway is the origin of resistive switching memory behavior. Our findings provide insights into the mechanism of the resistive switching behavior in nc-Si films, opening a way for it to be utilized as a material in Si-based memories.

Inorganic–organic hybrid polymer with multiple redox for high-density data storage

A multi-redox polyoxometalate-based hybrid polymer has been demonstrated to show multilevel resistive switching memory behaviors.