MXene Electrode for the Integration of WSe₂ and MoS₂ Field Effect Transistors

Abstract

Recently, MXenes, which are 2D early transition metal carbides and carbonitrides, have attracted wide attention because of their excellent conductivities. Here, the electrode applications of Ti 2 C(OH) x F y , one member of the MXene family, in WSe 2 and MoS 2 field effect transistors (FETs) are assessed. Kelvin probe force microscopy analysis is performed to determine its work function, which is estimated to be ≈4.98 eV. Devices based on WSe 2 /Ti 2 C(OH) x F y and MoS 2 /Ti 2 C(OH) x F y heterostructures are fabricated with the mechanical transfer method and their electronic performances evaluated. The temperature‐dependent current–voltage transfer characteristics of the devices are determined to extract their Schottky barrier heights. The hole barrier between WSe 2 and Ti 2 C(OH) x F y is estimated to be ≈0.23 eV and the electron barrier between the MoS 2 band and Ti 2 C(OH) x F y is ≈0.19 eV, which indicates that the pinning effect occurs at the MoS 2 /Ti 2 C(OH) x F y interface but not at the WSe 2 /Ti 2 C(OH) x F y interface; this difference arises because of the difference between the band structures of WSe 2 and MoS 2 . A complementary metal–oxide–semiconductor inverter based on these electrode properties of Ti 2 C(OH) x F y with MoS 2 (n‐channel) and WSe 2 (p‐channel) is fabricated, which demonstrates that Ti 2 C(OH) x F y is a promising electrode for future nanoelectronics applications.