Continuously Tuning Electronic Properties of Few-Layer Molybdenum Ditelluride with <i>in Situ</i> Aluminum Modification toward Ultrahigh Gain Complementary Inverters.

Abstract

Semiconducting molybdenum ditelluride (2H-MoTe₂), a two-dimensional (2D) transition metal dichalcogenide, has attracted extensive research attention due to its favorable physical properties for future electronic devices, such as appropriate bandgap, ambipolar transport characteristic, and good chemical stability. The rational tuning of its electronic properties is a key point to achieve MoTe₂-based complementary electronic and optoelectronic devices. Herein, we demonstrate the dynamic and effective control of the electronic properties of few-layer MoTe₂, through the <i>in situ</i> surface modification with aluminum (Al) adatoms, with a view toward high-performance complementary inverter devices. MoTe₂ is found to be significantly electron doped by Al, exhibiting a continuous transport transition from p<i>-</i>dominated ambipolar to n<i>-</i>type unipolar with enhanced electron mobility. Using a spatially controlled Al doping technique, both p<i>-</i> and n<i>-</i>channels are established on a single MoTe₂ nanosheet, which gives complementary inverters with a record-high gain of ∼195, which stands out in the 2D family of materials due to the balanced p<i>-</i> and n<i>-</i>transport in Al-modified MoTe₂. Our studies coupled with the tunable nature of <i>in situ</i> modification enable MoTe₂ to be a promising candidate for high-performance complementary electronics.