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.