Electric Field Induced Schottky to Ohmic Contact Transition in Fe₃GeTe₂/TMDs Contacts

Although the two-dimensional transition metal dichalcogenides (TMDs) present excellent electrical properties, the contact resistance at the interface of metal/TMDs limits the device performance. Herein, we use 2D metallic Fe₃GeTe₂ (FGT) as an electrode in contact with TMDs semiconductors MX₂ (M = Mo, W; X = S, Se, Te) and investigate the contact properties of FGT/MX₂ based on density functional theory calculations. We demonstrated that FGT/MX₂ presents n-type Schottky contacts, and their n-type Schottky barrier heights are lower than that of the most common bulk metal contacts with MX₂, suggesting that FGT can be used as an efficient metallic electrode for MX₂. The transitions from n-type Schottky contact to p-type Schottky contact and from Schottky contact to Ohmic contact can be achieved in FGT/MX₂ under the electric field. This work not only illustrates an effective method to modulate the contact types and Schottky barrier heights of FGT/MX₂ contacts but also provides a route for designing the nanodevices based on FGT/MX₂ electrical contacts.