Few layer chemical vapor deposited two dimensional WS2 for low voltage resistive switching application

Abstract

Optimizing the fabrication method gives rise to control over the deposition of WS₂ sheets in a CVD chamber. The deposition was executed on Pt-coated silicon substrate so that electrical behavior of the WS₂ domains could be observed. Utilizing two types of electrode material helped in understanding the role of metal diffusion mediated switching failure. The Au/WS₂/Pt/Ti/SiO₂/Si device exhibited resistive switching characteristics at very low operating voltages. A high on/off ratio (>10⁴), high retention time (10⁴ s), and a long endurance (1500 cycles) were respectively recorded to establish the non-volatile memory characteristics in a device with thin layer of WS₂. The switching mechanism was established by performing conducting atomic force microscopy. This work also explained the mechanism of resistance switching in CVD grown tungsten disulfide in two steps and pave the way for the development of large-scale devices.