Metal and Carbon Filaments in Biomemory Devices through Controlling the Al/Apple Pectin Interface

Abstract

Interface control of the filament types and the resistive switching behavior of apple pectin (AP) memory devices were systematically investigated using different sputtering plasmas. Supported by the temperature dependence of resistance and line-scan profiles, it can be observed that the sharp interface between the direct current (DC) Al and AP layer of the DC Al/AP/ITO structure showed semiconducting behavior. In the case of the radio frequency (RF) Al/AP/ITO structure, the transition from the metallic to semiconducting behavior occurred at 333 K. The transformation of filament types was a direct consequence of Al diffusion from the RF Al electrode. The diffused Al atoms from the RF Al electrode contributed to the creation of metallic filamentary channels. Moreover, the metal Al effectively diffused through RF sputtering, leading to the formation of an interfacial oxide layer between the Al electrode and the AP thin film. The role of the interfacial layer in enabling stable resistive switching and high device performance in the Al/AP/ITO resistive memory device was revealed. The AP memory device demonstrated a promising ON/OFF ratio of over 107 with uniform electrical distribution and stable retention. Understanding the underlying switching mechanisms of AP memory devices may pave the way toward smart bioelectronics.