Research on Resistive Switching Mechanism of SnO2/SnS2 Based Heterojunction Memory Devices

Abstract

This study investigates the electrical properties of the SnO₂/SnS₂ heterojunction as the interlayer for resistive random access memory (RRAM). In this work, (NH₄)₄Sn₂S₆ is used as a source for the production of the heterojunction. The results indicate that as the annealing temperature increases, the composition of the SnS₂ based thin film changes while the cycle-to-cycle stability of the device improved. The thin film is examined by X-ray photoelectron spectroscopy (XPS), scanning electronic microscopy (SEM) and atomic force microscopy (AFM), which proves the formation of SnO₂/SnS₂ heterojunction. Devices with SnO₂/SnS₂ heterojunction exhibited lower operating voltages and more uniform resistive switching behavior. The RRAM can be repeatedly and consistently switched between a high-resistance state and a low-resistance state over 1000 cycles, with a long data retention time of > 4 × 10⁴ s at room temperature. Meanwhile, this study explores the relationship between this type of resistive memory and the neuromorphic simulation of the human brain. SnO₂/SnS₂ heterojunction with 224 PJ set power at 0.4 V pulse shows excellent resistive memory characteristics. This study provides a vital reference for high-performance and long-lifespan heterojunction memory devices.