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 Ti2C(OH)(x)F-y, one member of the MXene family, in WSe2 and MoS2 field effect transistors (FETs) are assessed. Kelvin probe force microscopy analysis is performed to determine its work function, which is estimated to be approximate to 4.98 eV. Devices based on WSe2/Ti2C(OH)(x)F-y and MoS2/Ti2C(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 WSe2 and Ti-2 C(OH)(x)F-y is estimated to be approximate to 0.23 eV and the electron barrier between the MoS2 band and Ti2C(OH)(x)F-y is approximate to 0.19 eV, which indicates that the pinning effect occurs at the MoS2/Ti2C(OH)(x)F-y interface but not at the WSe2/Ti2C(OH)(x)F-y interface; this difference arises because of the difference between the band structures of WSe2 and MoS2. A complementary metal-oxide-semiconductor inverter based on these electrode properties of Ti2C(OH)(x)F-y with MoS2 (n-channel) and WSe2 (p-channel) is fabricated, which demonstrates that Ti2C(OH)(x)F-y is a promising electrode for future nanoelectronics applications.