Charge Transfer within the F₄TCNQ‐MoS₂ van der Waals Interface: Toward Electrical Properties Tuning and Gas Sensing Application

Abstract

Abstract The development of van der Waals heterostructures in 2D materials systems has attracted considerable interests for exploring new insights of (opto‐) electrical characteristics, device physics, and novel functional applications. Utilizing organic molecular material with strong electron withdrawing ability, charge transfer van der Waals interfaces are formed between 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F 4 TCNQ) and MoS 2 , via which the modulation of the onset voltages and optimization of subthreshold swing values in MoS 2 ‐based field effect transistors are realized. Charge transfer process and its functionality mechanisms are further verified and investigated with first‐principles calculation, scanning Kelvin probe microscope characterization, and temperature‐dependent electrical characterization. With the charge transfer effect between reducing gas molecules and F 4 TCNQ, NH 3 gas sensor is proposed and fabricated with the sensitivity reaching higher than 1000% at 100 ppm, much more outstanding performance than those of any reported MoS 2 ‐based NH 3 gas sensors. The F 4 TCNQ‐MoS 2 hybrid strategy might open up a pathway for tuning and optimizing the electrical properties, in addition to novel functional units designing and fabrications in electric devices based on low‐dimensional semiconducting systems.