Enhance the Properties of BiI3‐Based Resistive Switching Devices via Mixing Ag and Au Electrodes

Abstract

Abstract The correlation between the electrodes and the properties of the BiI3 device is systematically investigated. The X‐ray and UV photoemission spectroscopies are carried out to study the chemical state and electronic structure of the metal/BiI3 interfaces formed by the in‐situ deposition of BiI3 on the metal. This revealed the upward diffusion of Ag and the self‐formation of a conductive filament; the latter is further confirmed via tunneling electron microscopy. By coating the Au substrate with Ag layers of various thicknesses as a buffer layer, the morphology, surface roughness, chemical states, and quantity of the filament in the BiI3 layer can be manipulated. The device with the structure of Au/10 nm Ag/BiI3/Au demonstrated an ultrahigh on/off ratio of 109, good retention of 104 s, and multistate data storage. This study provides not only a fundamental insight into the interaction of BiI3 with metal, which will be helpful to design resistive switching devices and optoelectronics based on BiI3 material, but also a facile method to control the quantity of conductive filament in the BiI3 layer.

Keywords

• bismuth iodide
• metal substrates
• multistate data‐storage
• resistive random‐access memory