Bottom Contact-Enhanced P-Type Transport Behavior in Plasma Doped MoTe2

ABSTRACT

Two-dimensional (2D) semiconductors, such as molybdenum ditelluride (MoTe2), hold great promise for future electronic devices, but achieving stable and efficient p-type transport remains a challenge. A major issue is the formation of high contact barriers, which significantly hinder hole injection due to poor coordination between contact engineering and doping. Here, we report the enhanced p-type transport in MoTe2 transistors by combining contact engineering and surface oxidation doping in a bottom-contacted configuration. By comparing top-contacted and bottom-contacted devices, we demonstrate that the bottom-contacted design ensures uniform doping across the entire channel, preventing the formation of high barriers caused by unintentional p-n junctions at the contacts. As an application demonstration, an inverter exhibiting a complete logic swing is realized by integrating a p-type MoTe2 transistor with an n-type ReS2 transistor. Moreover, the selective nature of the plasma doping process allows for effective p-doping of MoTe2 without affecting materials with high oxidation resistance. We further demonstrate an anti-ambipolar MoTe2-ReS2 heterostructure and a three-valued logic inverter circuit, verifying the potential of p-type MoTe2 transistors for multi-valued logic applications. Our findings highlight the importance of integrating contact engineering with selective doping and provide an effective strategy for optimizing p-type transport in 2D semiconductors.