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)xFy, 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)xFy and MoS 2/Ti 2 C(OH)xFy 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)xFy is estimated to be ≈0.23 eV and the electron barrier between the MoS 2 band and Ti 2 C(OH)xFy is ≈0.19 eV, which indicates that the pinning effect occurs at the MoS 2/Ti 2 C(OH)xFy interface but not at the WSe 2/Ti 2 C(OH)xFy 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)xFy with MoS 2 (n‐channel) and WSe 2 (p‐channel) is fabricated, which demonstrates that Ti 2 C(OH)xFy is a promising electrode for future nanoelectronics applications.