Design of defect-chemical properties and device performance in memristive systems

Abstract

Future development of the modern nanoelectronics and its flagships internet of things, artificial intelligence, and neuromorphic computing is largely associated with memristive elements, offering a spectrum of inevitable functionalities, atomic level scalability, and low-power operation. However, their development is limited by significant variability and still phenomenologically orientated materials’ design strategy. Here, we highlight the vital importance of materials’ purity, demonstrating that even parts-per-million foreign elements substantially change performance. Appropriate choice of chemistry and amount of doping element selectively enhances the desired functionality. Dopant/impurity-dependent structure and charge/potential distribution in the space-charge layers and cell capacitance determine the device kinetics and functions. The relation between chemical composition/purity and switching/neuromorphic performance is experimentally evidenced, providing directions for a rational design of future memristive devices.

Filament‐Free Bulk Resistive Memory Enables Deterministic Analogue Switching

“…[ 4 ] Neuromorphic computing architectures for fully connected [ 5–7 ] and convolutional [ 8,9 ] neural networks have been developed. Despite significant research into memory technologies such as conductive‐bridge random access memory, [ 10–12 ] ferroelectric memory, [ 13 ] phase‐change memory, [ 14–16 ] among others, the search for a CMOS compatible analogue non‐volatile memory element, or artificial synapse, with accurate and efficient switching has been elusive.…”

“…We hypothesize that bulk storage also makes these devices less sensitive to impurities and variations in oxide thickness, and not require extensive process control as in filamentary memristors. [ 11 ] Our ability to achieve deterministic switching is not specific to the properties of the materials used here and is generalizable to many mixed‐conducting transition metal oxides, [ 38 ] opening up new opportunities for materials research.…”

Robust Polyethylenimine Electrolyte for High Performance and Thermally Stable Atomic Switch Memristors

“…Avoiding moisture is often not possible in the process of manufacturing devices. [ 21,31 ] Valov et al. pointed out that water molecules are easily absorbed in a thin film with a nonporous structure.…”

“…Avoiding moisture is often not possible in the process of manufacturing devices. [21,31] Valov et al pointed out that water molecules are easily absorbed in a thin film with a nonporous structure. [32] Here, the I-V curves in Figures 2b and 3e show different polarization behaviors at two temperatures.…”

Impact of Oxygen Non‐Stoichiometry on Near‐Ambient Temperature Ionic Mobility in Polaronic Mixed‐Ionic‐Electronic Conducting Thin Films

“…[29] Nevertheless, due to the much lower mobilities associated with ionic rather than electronic carriers, such MIEC materials tend to be predominately electronically conductive in their behavior at near ambient conditions, making it difficult to isolate and characterize the ionic conductivity component and specifically, ionic mobility, which plays a critical role in controlling nanoionic device response times. [43] The oxygen ion migration properties of metal oxides have primarily been studied at elevated temperatures. Owing to their thermally activated character, high temperatures are necessary to achieve sufficient conductivity to be readily and accurately measured, for example, by impedance spectroscopy.…”