Independent Memcapacitive Switching Triggered by Bromide Ion Migration for Quaternary Information Storage

Abstract

Memcapacitors are emerging as an attractive candidate for high‐density information storage due to their multilevel and adjustable capacitances and long‐term retention without a power supply. However, knowledge of their memcapacitive mechanism remains unclear and accounts for the limited implementation of memcapacitors for multilevel memory technologies. Here, repeatable and reproducible quaternary memories fabricated from hybrid perovskite (CH3NH3SnBr3) memcapacitors are reported. The device can be modulated to at least four capacitive states ranging from 0 to 169 pF with retention for 104 s. Impressively, an effective device yield approaching 100% for quaternary memory switching is achieved by a batch of devices; each state has a sufficiently narrow distribution that can be distinguished from the others and is superior to most multilevel memories that have a low device yield as well as an overlapping distribution of states. The memcapacitive switching stems from the modulated p–i–n junction capacitance triggered by Br− migration, as demonstrated by in situ element mapping, X‐ray photoelectron spectra, and frequency‐dependent capacitance measurements; this mechanism is different from the widely reported memristive switching involving filamentary conduction. The results provide a new way to produce high‐density information storage through memcapacitors.

Embedding Azobenzol-Decorated Tetraphenylethylene into the Polymer Matrix to Implement a Ternary Memory Device with High Working Temperature/Humidity

“…Therefore, great efforts have been made to seek new active materials with multilevel memory performances. Up to now, the following types of materials have been utilized as active layers, that is, organic small molecules, − inorganic compounds (e.g., perovskites and WSe 2 /BN), − inorganic/organic hybrids, , and polymers and their composites. ,,− However, some key technical parameters including batch uniformity, ON/OFF ratio, and set/reset voltages are still unsatisfied in these multilevel resistive memories . Overcoming these barriers depends seriously on the discovery of multilevel memristive mechanisms, which are still in their infancy .…”

Structural evolution, optical gap and thermoelectric properties of CH3NH3SnBr3 hybrid perovskite, prepared by mechanochemistry

“…The estimated thermoelectric properties at room temperature also predict that CH 3 NH 3 SnBr 3 may be used in thermoelectric devices 33 . Recently, novel applications such as quaternary memories fabricated from CH 3 NH 3 SnBr 3 memcapacitors are reported 35 , allowing high-density information storage due to their multilevel and adjustable capacitances and long-term retention without a power supply. Despite these interesting antecedents, up to now there are no experimental reports on the transport properties such as the electronic conductivity, Seebeck coefficient or thermal transport.…”

Advances in Halide Perovskite Memristor from Lead-Based to Lead-Free Materials

“…The potential information storage usage of this ability can be taken into account. The first HP memcapacitor with a multilevel information storage capacity was built by the Lu group . Its memristive and memcapacitive I - V characteristics are shown in Figure a,b.…”

“…The pulse voltages are read: 0.0 V; set ON1: 1.1 V; set ON2: 1.7 V; set ON3:5 V; unset: −5 V, pulse width: 30 ms. (f) Capacitance distribution of the four states from a batch of device (sample size: 32). Reprinted with permission from ref , copyright 2019 Wiley-VCH.…”