Synthesis of air-stable 1T-CrS2 thin films and their application in high-performance floating-gate memory

Abstract

Two-dimensional van der Waals materials, with atomic-level thickness and unique electronic structures, have tremendous potential in electronic device applications, making them highly desirable for research in high-performance non-volatile memory. Here, we report a method for the van der Waals epitaxial growth of air-stable and uniformly distributed thin films of a 1T-CrS₂ single crystal, based on a simple chemical vapor deposition technique using a binary metal precursor co-reaction growth mechanism controlled by the evaporation rate of the precursor. The corresponding 1T-CrS₂ electronic devices can maintain their electrical performance without degradation for up to one month in air. Based on this, we have constructed a floating-gate memory device with a full van der Waals heterostructure, exhibiting a large storage window ratio (approximately 79%), a high on/off ratio (10⁷), and stability for over 1000 cycles. The device demonstrates excellent multi-level data storage stability and can be optically programmed with stable operation using 532 nm laser pulses, showcasing outstanding optoelectronic storage performance. The excellent electrical stability of these two-dimensional materials, the non-volatile nature of the devices, and the stable multi-level storage characteristics present enormous potential for the integration of high-performance non-volatile memory.