Memristors are emerging as a rising star of new computing and information storage techniques. However, the practical applications are severely challenged by their instability toward harsh conditions, including high moisture, high temperatures, fire, ionizing irradiation, and mechanical bending. In this work, for the first time, lead‐free double perovskite Cs2AgBiBr6 is utilized for environmentally robust memristors, enabling highly efficient information storage. The memory performance of the typical indium‐tin‐oxide/Cs2AgBiBr6/Au sandwich‐like memristors is retained after 1000 switching cycles, 105 s of reading, and 104 times of mechanical bending, comparable to other halide perovskite memristors. Most importantly, the memristive behavior remains robust in harsh environments, including humidity up to 80%, temperatures as high as 453 K, an alcohol burner flame for 10 s, and 60Co γ‐ray irradiation for a dosage of 5 × 105 rad (SI), which is not achieved by any other memristors and commercial flash memory techniques. The realization of an environmentally robust memristor from Cs2AgBiBr6 with a high memory performance will inspire further development of robust electronics using lead‐free double perovskites.

Ternary resistive random access memory (RRAM) devices are fabricated from 1D d‐π conjugated coordination polymer chains, which are synthesized via the coordination between Ni(II) salts and benzenetetramine or 3,3′,4,4′‐biphenyltetramine in a solution process. The as‐fabricated devices can retain their memory states for as long as three months at room temperature or work for at least 10 000 s at 150 °C, which is the highest working temperature reported for a ternary RRAM at the time of writing this paper. Thermogravimetric analysis indicates good thermal stability of these two materials because of their good crystallinity and strong intermolecular interaction. The long‐term and high‐temperature stability makes 1D conjugated coordination polymer chains a promising candidate for use as next‐generation material for high‐density data storage via RRAM techniques.

Recently, organic-inorganic hybrid perovskites (OIHP) are studied in memory devices, but ternary resistive memory with three states based on OIHP is not achieved yet. In this work, ternary resistive memory based on hybrid perovskite is achieved with a high device yield (75%), much higher than most organic ternary resistive memories. The pseudohalide-induced 2D (CH NH ) PbI (SCN) perovskite thin film is prepared by using a one-step solution method and fabricated into Al/perovskite film/indium-tin oxide (glass substrate as well as flexible polyethylene terephthalate substrate) random resistive access memory (RRAM) devices. The three states have a conductivity ratio of 1:10 :10 , long retention over 10 000 s, and good endurance properties. The electrode area variation, impedance test, and current-voltage plotting show that the two resistance switches are attributable to the charge trap filling due to the effect of unscreened defect in 2D nanosheets and the formation of conductive filaments, respectively. This work paves way for stable perovskite multilevel RRAMs in ambient atmosphere.

MXenes are a new type of two-dimensional material, and they have attracted extensive attention because of their outstanding conductivity and rich surface functional groups that make surface engineering easy and possible for adapting to diverse applications. However, there are scarce studies on surface engineering of MXene. Herein, we demonstrate for the first time that octylphosphonic acid-modified Ti 3 C 2 T x MXene can be used as an active layer for memory devices and exhibits stable ternary memory behavior. Low threshold voltage, steady retention time, clearly distinguishable resistance states, high ON/OFF rate, OFF/ ON1/ON2 = 1:10 2.7 :10 4.1 , and considerable ternary yield (58%) were obtained. In the proof of the mechanism, in situ conductive atomic force microscopy was conducted and the electrode-area relationship was analyzed to demonstrate that charge trapping and filament conduction are more suitable in the nonvolatile information memory of Ti 3 C 2 T x -OP MXene devices. In addition, a polyethylene-terephthalate-based flexible Ti 3 C 2 T x -OP memory device can maintain its stable ternary memory performance after being bent 5000 times. This work provides an easy method for surface modification of MXene and broadens the field of MXene.

Memristors are a new type of circuit element with a resistance that is tunable to discrete levels by a voltage/current and sustainable after removal of power, allowing for low‐power computation and multilevel information storage. Many organic‐inorganic lead perovskites are reported to demonstrate memristive behavior, but few have been considered for use as a multilevel memory; also, their potential application has been hindered by the toxicity of lead ions. In this article, lead‐free perovskite MASnBr3 was utilized in memristors for quaternary information storage. Indium tin oxide (ITO)/MASnBr3/Au memristors were fabricated and showed reliable memristive switching with well‐separated ON/OFF states of a maxima resistance ratio of 102 to 103. More importantly, four resistive states can be distinguished and repeatedly written/read/erased with a retention time of 104 seconds and an endurance of 104 pulses. By investigating the current‐electrode area relationship, Br distribution in the ON/OFF states by in situ Raman and scanning electron microscopy, and temperature‐dependent current decay, the memristive behavior was explicitly attributed to the forming/breaking of conductive filaments caused by the migration of Br− under an electric field. In addition, poly(ethylene terephthalate)‐ITO/MASnBr3/Au devices were found to retain their multiresistance state behavior after being bent for 1000 times, thus demonstrating good device flexibility. Our results will inspire more lead‐free perovskite work for multilevel information storage, as well as other memristor‐based electronics.image