Screening functionalized MXene electrodes for monolayer GeC: achieving Schottky transistors with ideal contacts.

Electrode screening is a pivotal issue for advancing the performance of two-dimensional Schottky barrier field effect transistors (SBFETs). We present a systematic first-principles screening of functionalized MXene electrodes for ML GeC and rigorously evaluate their full-device performance using ab initio quantum transport simulations. Starting from 256 candidate functionalized MXene structures, we identify 33 thermodynamically stable ML metallic MXenes; among these, three n-type and three p-type candidates are selected as promising electrodes for ML GeC. Crucially, device performance exhibits pronounced sensitivity to electrode identity, even among configurations yielding nominally ohmic contacts. The optimal n-type and p-type electrodes are Nb2C(OH)2 and Ti2CS2, respectively, exhibiting excellent and symmetric performances that exceed the IRDS low-power and high-performance targets for the next decade. Beyond identifying ideal contact materials for ML GeC SBFETs, this study establishes a generalizable, physics-informed electrode screening framework applicable to arbitrary 2D channel systems.