Design of reversible tuning MoTe2 field effect transistors with gas molecules adsorption and magnesium doping

Molybdenum ditelluride (2H-MoTe₂) has attracted extension research interest for its unconventional features and devices application potentials. Field effect transistors (FETs) based on 2H -MoTe₂ usually exhibit ambipolar electric properties, however, integrating both n-type and p-type FETs is of great significance for the device applications. Here, we found that the electric properties of the MoTe₂ FETs could be reversible tuned with gas molecules adsorption and magnesium (Mg) doping. After the gas molecules adsorption, the MoTe₂ FET is p-type doped and shows hole dominant conduction performance. In the vacuum, the p-type performance of the MoTe₂ FET is effectively weakened after the gas molecules desorption. The similar phenomenon happens at the magnesium (Mg) evaporated on the MoTe₂ FETs. After the Mg atoms surface covering, the MoTe₂ FET is n-type doped and shows electron dominant conduction performance. In the air, the p-type performance of MoTe₂ FET is recovered after the Mg oxidation. These results display an effectively method for reversible controlling the MoTe₂ FETs.