Fig. 3. Fast doping of the MoTe₂ transistor and stability of the doped MoTe₂ device.

(A) p-to-n transition of device B. The device was biased at V_gs = −60 V throughout the measurement. UV light was turned on at ~0.58 s, switching the device from an on-state p-type FET to an off-state n-type FET within approximately 80 ms. (B) Switching process from on-state n-type FET to off-state p-type FET. The transition time is around 600 ms, ~10 times slower compared to the p-to-n transition. Stability tests of the doped n-type (C) and p-type (D) MoTe₂ FETs in ambient air and temperature. Insets are the on-state current and threshold voltage (V_th) of each state as a function of time. The V_ds was 500 mV.