Ultra-large memory window for non-volatile memory based on ReS2/hBN/Multilayer Graphene heterojunction

Abstract

With the rapid advancement of technology and the exponential growth of big data, the demand for high-performance memory devices intensifies. Non-volatile memories based on van der Waals materials garner significant attention due to their superior data retention and long-term storage capabilities. However, current floating-gate (FG) memories typically exhibit a memory window of less than 60 %, which limits data storage stability and device lifespan. Therefore, developing non-volatile FG memories with larger memory windows is crucial for modern digital technologies. In this work, we fabricate a non-volatile FG memory device based on a rhenium disulfide (ReS₂)/hexagonal boron nitride (hBN)/multilayer graphene (MLG) heterostructure, ReS₂ serves as the channel material, hBN acts as the tunneling dielectric, and multilayer graphene functions as the floating gate. Due to the high carrier mobility of ReS₂ and the excellent charge storage and release capabilities of graphene, the device demonstrates a high on/off ratio (10⁶) and outstanding long-term data retention (>1000 s). It also exhibits low programming current and the potential for multi-level storage applications. Most notably, the device achieves a significant memory window of 85.5 %, enabling enhanced charge storage capacity and improved stability. This performance is attributed to the effective charge injection and retention enabled by Fowler–Nordheim tunneling through the hBN tunneling barrier These exceptional properties support the realization of efficient and stable data storage, which paves the way for developing next-generation memory technologies.