Controlled Growth and Disorder Mitigation of GaAs1– x Sb x /InAs Core–Shell Quantum Wires

We report the growth and transport properties of GaAs1–xSbx/InAs core–shell nanowires. Compared with the well-studied GaAs-InAs system, incorporating Sb substantially reduces the lattice mismatch between the core and shell. Accordingly, both the nanowire crystal quality and device performance improved significantly. Increasing x from 0.15 to 0.35, the density of crystalline defects, such as stacking faults in the InAs shell, decreases by half. Moreover, the field-effect mobility increases from 3850 cm2/(V s) to 4800 cm2/(V s), consistent with the reduction of the lattice mismatch. The incorporation of Sb makes the nanowire easier to pinch off via the gate voltage, enhancing the electric field tunability over the nanowire. Magneto-conductance measurements reveal Aharonov-Bohm-like oscillations, suggesting a phase-coherent tubular InAs shell. Our results identify lattice mismatch as a critical disorder source in core–shell nanowires and provide a practical route toward low-disorder core–shell quantum devices.