Resistive Switching Induced by Electric Pulses in a Single-Component Molecular Mott Insulator

Abstract

Resistive random-access memory (ReRAM) made of organic materials has recently received much attention for application in flexible devices. In the latter, resistive switching is usually obtained thanks to electrochemical effects or charge trapping. This work shows that, under electric pulses, the crystalline molecular Mott insulator [Au(Et-thiazdt)2] exhibits a resistive switching based on an insulator-to-metal transition (IMT). Electric pulses exceeding a threshold electric field of a few kilovolts/centimeter induce a volatile transition, due to an intrinsic, purely electronic effect related to an avalanche phenomenon. Moreover, the application of electric pulses of higher amplitude induces a nonvolatile and reversible resistive switching. Both two-level and multilevel switching between resistances Ron and Roff are observed. At room temperature, a Roff/Ron ratio >100 is obtained, which is very high for this kind of switching mechanism and quite promising for ReRAM applications. [Au(Et-thiazdt)2] appears as the first molecular member of a new class of ReRAM called Mott memories.