Defect-tolerant carrier injection in MoS2 enabled by double-sided recessed Ti contacts

Abstract Contact variability remains a major obstacle for scaled two-dimensional transistors, yet whether electrode contact type can control the defect sensitivity of carrier-injection barriers remains unresolved. Here we show that double-sided recessed Ti contacts strongly stabilise MoS 2 carrier-injection barriers against changes in sulfur-vacancy position. By comparing matched MoS 2 model families based on one-sided top Ti contacts and double-sided recessed Ti contacts under the same ordered sulfur-vacancy sequence, first-principles electronic structure and non-equilibrium transport calculations reveal a clear contact-type dependence. For the near-edge vacancy, the Schottky barrier height (SBH) decreases from 0.58 eV for the one-sided top Ti contact to 0.21 eV for the double-sided recessed Ti contact, while the nominal position-dependent SBH variation is reduced by about 85%. Electron transmission calculations further show that this barrier stabilisation results in higher transmission and lower access energies for propagating channel states. The results identify double-sided recessed Ti contacts as a strategy for reducing sulfur-vacancy-induced barrier variability in Ti–MoS 2 electronics.