Engineered C₁₂₀ Fullertube/MXene Heterostructures for Tunable Schottky–Mott Junctions

Achieving perfect metal–semiconductor (MS) junctions in microelectronics has remained elusive due to Fermi-level pinning and MS interfacial disorder. Here, we report the experimental understanding of the C₁₂₀/Ti₃C₂Tₓ MXene van der Waals junction. Structural and spectroscopic analyses reveal atomically intelligible C₁₂₀/MXene interfaces characterized by seamless lattice continuity and chemically inert van der Waals (vdW) contact formation. Density functional theory calculations reveal strong anisotropic polarizability-controlled band alignment, suppressed metal-induced gap states, and charge redistribution across the 2D heterojunction, validating Schottky–Mott-limited transport with minimal Fermi-level pinning. Temperature-dependent I–V and gate-modulated transport studies further validate the Schottky barrier heights and ideality factors, which vary significantly with the choice of contact metal, thereby validating the restored barrier tunability through metal work-function. This dual functionality highlights C₁₂₀ fullertubes as versatile molecular building blocks for next-generation nanoelectronics and energy devices, proposing a scalable, damage-free integration strategy for high-performance vdW heterojunctions.