First principles study of electron transport through diarythylene-transition metal dichalcogenide molecular switch

Computational methods are fast becoming an integral part of nanoelectronics design process. With increasing computational power, electron transport simulation methods such as Non-equilibrium Green’s function (NEGF) methods now become of great interest in studying and designing new electronic materials. In this research, we study and design a single molecule switch based on a transition metal dichalcogenide (TMD) electrode (molybdenum disulfide MoS₂ and a photo-chromic molecule. The chosen molecule, Diarylethene, is one of the only few thermally irreversible photochromes. The 1T phase of TMD monolayer has metallic properties and can therefore act as a conducting electrode for these molecular switches. In this study, we compare and contrast different chemistry and spacer groups with respect to their response as a molecular switch, focusing on the ON/OFF transmission ratio at the Fermi level. We identify promising chemistries for further experimentation. If experimentally realized, these switches are expected to become integral part of various applications including molecular memories, photon detectors and logic devices.