Memristive behavior of Al2O3 film with bottom electrode surface modified by Ag nanoparticles

Abstract

The memristive behavior of Al 2 O 3 -based device is significantly improved by introducing Ag nanoparticles (NPs). Inserting Ag NPs can effectively reduce the switching voltages, increase the resistance ratio (about 10 4 ) and enhance the sweep endurance (300 cycles). In particular, the stable switching properties are obtained by inserting an Ag NPs layer with an average diameter of 14 nm on the surface of bottom electrode, and the devices show a long retention time (more than 10 6 s) compared with the devices without Ag NPs. The switching mechanism is related to the oxygen-vacancy-based conducting filaments and the interfacial effect. The local enhancement and nonuniform distribution of electric field have the benefits to promote, induce and modulate the growth of conducting filaments, such as shape, location and orientation, which are responsible for the improvement performance of the devices.

Tuning Resistive, Capacitive, and Synaptic Properties of Forming Free TiO2‐x‐Based RRAM Devices by Embedded Pt and Ta Nanocrystals

“…Concerning the different responses of the two NCs embedded samples, the oxidation of Ta and the consequent decrease of the concentrated electric field effect could justify the lower operating current values. This is in line with the configuration of the energy levels, depicted in Figure , where it is clear that the energy band alignment between the energy levels of oxygen vacancies within TiO 2‐x and Pt NCs favors the electron transfer, taken for granted that NCs act as seeds for CF creation and electrons are the main constituents of the CFs . On the other hand, neither Ta nor TaO x NCs can facilitate electron transfer, since large barriers are created.…”

“…While it seems practically impossible to control their characteristics, we can force them to evolve into specific locations within the device active core . Thus, a variety of optimization procedures have been suggested in order to enhance the memory performance, while NCs incorporation arising as one very promising technique to overcome the switching variations, especially when the issues related with the uniformity of their distribution, in terms of diameter and surface density, will be efficiently harnessed …”

Toward Controlling Filament Size and Location for Resistive Switches via Nanoparticle Exsolution at Oxide Interfaces

“…In order to address the challenge of stochastic filament location, several strategies have been put forward to spatially confine filaments either in the switching or electrode materials. These include 1) switching within a single dislocation in SrTiO 3 [9] and in SiGe, [10] 2) fabricating electrodes into tips, [11][12][13][14][15][16][17][18] 3) integrating nanoporous graphene into the switching material, [19][20][21][22] 4) embedding nanoparticles into the switching material, [23][24][25][26][27][28][29][30][31][32][33] 5) introducing nanoparticles at the metal-oxide interface, [34][35][36][37][38][39][40] and 6) engineering the edges of the devices, which has been shown to be industrially viable. [41] These strategies are analyzed in terms of their opportunities, processing challenges and materials universality in Table 1, and summarized through device [35] sketches in Figure 1a.…”

“…The localizing effect is usually thought to be due to a local field enhancement near the nanoparticles, which can trigger material reduction by attracting oxygen vacancies. [35] In the following section, we highlight the critical aspects of nanoparticle integration including the deposition technique, material, and size/density control, all of which are reviewed in Table 1. The table focuses on oxide switching materials, memory applications and the methods outlined in Figure 1a.…”

Sol–Gel‐Derived Spinel Ag‐Co3O4 Nanocomposite Thin Films for Resistive and Magnetization Switching Applications

“…Compared with the pure Co 3 O 4 device for the same resistance state, the saturation magnetization ( M s ) decreases in the Ag‐Co 3 O 4 nanocomposite film device. Because Ag has a stable lattice structure and the strong electron trap ability, it is harder to be oxidized into Ag ions . A majority of Ag as a metallic state embedded in the Co 3 O 4 matrix, and Ag is diamagnetic, which weakens the saturation magnetization.…”