In short-channel two-dimensional (2D) semiconductor field-effect transistors (FETs), the effect of electrode contacts becomes essential due to the dominance of ballistic transport. The pristine MXenes can form strong hybridization with 2D semiconductors. Can the excellent transport properties be achieved by incorporating MXenes as electrodes in 2D semiconductor FETs? To investigate this issue, we constructed FET models based on various types of MXenes and 2D semiconductors to systematically study their electronic structures and transport properties using first-principles calculations. The results suggest that all pristine MXenes exhibit strong hybridization with 2D semiconductors. However, transport properties indicate that FETs utilizing pristine MXenes as electrodes do not achieve significant current enhancement. This is attributed to the hybridization-induced modification of the 2D semiconductor's band structure, which disrupts wavefunction coherence across the vertical interface. The functionalization of MXenes can weaken the hybridization strength, and consequently the current in FETs is enhanced. • All pristine MXenes strongly hybridize with 2D semiconductors, modifying their band structure. • The strong hybridization disrupts the wavefunction coherence across the vertical interface, hindering efficient carrier injection and limiting ballistic current. • Functionalizing MXenes weaken this hybridization strength, thereby restoring better interface transmission and enhancing the FET current. • Properly functionalized MXene electrodes can achieve superior transport properties, offering a promising strategy for low-resistance contacts in 2D semiconductor devices.
Kang et al. (Sun,) studied this question.