Atomically engineered, high-speed non-volatile flash memory device exhibiting multibit data storage operations

Non-volatile memory devices, which offer large capacity and mechanical dependability as a mainstream technology, have played a key role in fostering innovation in modern electronics. Despite the advantages of non-volatile memory devices, their low ON/OFF ratio and slow operational speed have limited their performance compared to their volatile counterparts. In this study, we present a non-volatile floating-gate memory device based on van der Waals heterostructures, which exhibits ultrahigh-speed memory operations in the range of a hundred nanoseconds with an extinction ratio of up to 10⁶. The device consists of atomically sharp interfaces between different functional elements, including atomically thin sheet of multilayer Graphene (MGr) as a floating gate, hexagonal boron nitride (h-BN) as a tunnel barrier, and two-dimensional (2D) semiconductor tin di-selenide (SnSe₂) as a channel material. The memory device exhibits excellent endurance performance with stable and dependable behavior across numerous program/erase cycles, comparable to commercial volatile dynamic random access memory technology. In addition, we demonstrate the ability of the device to store multiple bits per memory cell, which offers promising potential for ultrahigh-density information storage. Our findings provide important implications for memory storage, data processing, and electronic device development, and offer new opportunities in the field of emerging 2D materials with optimal device engineering.