Directed Assembly of Nanoparticle Threshold‐Selector Arrays

Abstract

The directed assembly of ordered arrays of cubic silver nanoparticles featuring distinct electrical threshold‐switching characteristics is reported. Threshold selectors are key elements for nonvolatile resistive random‐access‐memory architectures, as they suppress sneak path currents in crosspoint arrays. Nanocubes are site‐selectively immobilized on a TiO2‐coated silicon surface via a complementary molecular surface functionalization of nanoparticles and substrate based on a Cu(I)‐catalyzed alkyne‐azide cycloaddition without any physical template. Electrical characterization of individual silver nanocubes by conductive‐probe atomic force microscopy reveals pronounced and reproducible threshold‐switching behavior, featuring ultralow OFF currents below 1 pA, steep turn‐on slopes of <50 mV dec−1 and ON‐OFF ratios in excess of 103. Numerical simulation of Ag‐ion migration dynamics in the TiO2 electrolyte using a kinetic Monte Carlo model supports a switching mechanism based on conductive filament formation from Ag nanoclusters, and their reversible rupture in the low‐voltage regime. Assembled Ag nanocube threshold selectors are proposed for applications in memristive memory architectures, in particular for future highly integrated 3D circuitry.

Nonvolatile Memristive Switching in Self-assembled Nanoparticle Dimers

“…In this context, an extension of the electronic circuitry, beyond common cross-point geometries, into the third dimension appears to be the first indispensable approach. , To construct a scalable, interconnected network of memristive junctions, a controlled bottom-up self-assembly process of nanoparticles is a potentially viable approach. Large-scale colloidal assemblies of nanoparticles have been demonstrated, − and also memristive functions have been observed for various assemblies of nanoparticles, even including neuromorphic functions. − Recently, we have demonstrated memristive (threshold) switching for individual Ag nanoparticles, which were assembled in a directed manner on dedicated sites on the surface …”

Flexible Threshold Switching Based on CsCu2I3 with Low Threshold Voltage and High Air Stability

“…Similarly, the I–V curves, corresponding to the HRS and LRS, and the V th and V hold distributions of ten different devices are shown in Figure S5, reflecting the decent uniformity and repeatability of different devices. Furthermore, a comparison of the SS and V th of our device to the reported values is summarized in Figure i. − The Ag/PMMA/CsCu 2 I 3 /ITO device exhibits a comparable SS of ∼6.2 mV decade –1 and a V th as low as 0.54 V, indicating the possibility of CsCu 2 I 3 -based TSDs for low-power applications with steep SSs.…”