Facile p‑Doping of Few-Layer MoTe2 by Controllable Surface Oxidation toward High-Performance Complementary Devices

High-performance field-effect transistors based on two-dimensional (2D) semiconductors have been realized, but they often exhibit inherent transport property. Local p- and n-doping on same the semiconductor is essential for realizing the basic components of integrated circuits, such as diodes and logic inverters. However, existing doping technologies on 2D semiconductors are complex or expensive. Here, a simple and low-cost method for p-doping of few-layer MoTe2 transistor is demonstrated. Air heating at a low temperature of 100 °C induces a continuous and efficient modulation of carrier polarity from n- to p-type, and the doping effect can be controlled by adjusting the heating time. The hole mobility of MoTe2 is significantly enhanced from 0.3 to 25.8 cm2 V–1 s–1 by 2 orders of magnitude. The doping effect originates from the surface oxidation of few-layer MoTe2. Based on the method, MoTe2-based logic devices were fabricated, realizing p–n diode with an ideality factor of 1.3 and rectification ratio of ∼3 × 103 and complementary inverters with a high gain of ∼108. The facile method shows great potential for developing high-performance electronic devices with 2D semiconductors.