Lead-free perovskite MASnBr3-based memristor for quaternary information storage

Abstract

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. (Figure presented.).