An Atomically Thin and Photosensitive Vanadium Disulfide Memtransistor

Intrinsically ferromagnetic and semiconducting two-dimensional (2D) H-phase vanadium disulfide (VS2) holds tremendous promise for future electronics, optoelectronics, spintronics and valleytronics applications. However, its thermodynamic instability and the formation of intermediate stoichiometric polymorphs during its growth have stymied any progress towards synthesis of high quality 2D VS2 films. In this article, we circumvent these challenges and accomplish large area growth of monolayer VS2 films using atmospheric pressure chemical vapor deposition (APCVD) technique. By incorporating excess sulfur during the growth process which suppresses the formation of intermediate compounds, good quality large-area VS2 film can be synthesized. Furthermore, the electronic and optoelectronic properties of VS2 were explored by fabricating photosensitive memtransistor devices, which reveal an n-type carrier transport along with a high responsivity to red, green, and blue wavelengths of light. In addition the device exhibited multiple non-volatile conductance states through electrical programming. To the best of our knowledge, this is the first comprehensive report on memtransistors built from large area grown H-phase VS2 that integrate compute, sense, and storage functionalities in a single device.