MXenes Contacts for p ‐type 2D Electronics

Abstract

ABSTRACT MXenes, a family of two‐dimensional (2D) transition‐metal carbides and nitrides, offer a compelling combination of metallic conductivity and tunable surface chemistry. However, their potential as electrical contacts for p ‐type 2D semiconductors remains largely untapped. Here, we systematically investigate the role of MXene composition by comparing Ti 3 C 2 T x , Nb 2 CT x , and Mo 2 CT x as contacts for p ‐type 2H‐MoTe 2 transistors. Through a polymer‐assisted transfer process that ensures high‐quality interfaces, we identify Nb 2 CT x as the best‐performing contact material among the MXenes examined in this work, attributed to its superior band alignment, which markedly reduces contact resistance compared to both conventional metals and other MXenes. Consequently, Nb 2 CT x /2H‐MoTe 2 field‐effect transistors achieve a high hole mobility of approximately 17 cm 2 V −1 s −1 and an on/off current ratio exceeding 10 3 . Temperature‐dependent measurements further reveal a near‐ideal interface, with a Schottky barrier height of only a few millielectronvolts under strong gate bias. These findings establish compositional engineering of MXenes as a powerful strategy for designing electrode–semiconductor interfaces and position Nb 2 CT x as a scalable, high‐performance contact material for advancing p ‐type 2D electronics.