Controllable Growth and Electrical Properties of Homogeneous Ternary In_xGa_1-xAs Nanowires

Ternary In_xGa_1-xAs nanowires, with their continuously tunable bandgaps spanning the near- to mid-infrared range, have emerged as ideal candidate materials for developing novel optoelectronic devices. However, achieving controlled growth of high-quality ternary In_xGa_1-xAs nanowires with widely tunable compositions remains a key challenge in this field. Particularly for ternary In_xGa_1-xAs nanowires grown via the self-catalytic method, common issues include low indium incorporation efficiency, severe compositional segregation, and the spontaneous formation of core-shell structures. In this work, we demonstrate the controlled growth of ternary In_xGa_1-xAs nanowires with widely tunable and uniform composition on Si (111) substrates by molecular-beam epitaxy. It was found that simply increasing the indium flux cannot effectively raise the indium content (x < 0.05), while lowering the growth temperature, although it increases indium incorporation, induces severe axial and radial compositional inhomogeneity, leading to the formation of multilayered In_xGa_1-xAs core-shell structures with varying indium contents. By synergistically regulating the growth temperature and the V/III flux ratio, we successfully suppressed indium segregation and obtained ternary In_xGa_1-xAs nanowires with uniform composition and homogeneous distribution. The indium composition x in the nanowires could be tuned up to 0.85. Microstructural characterization and energy-dispersive spectroscopy confirmed the absence of spontaneous core-shell structures. Electrical measurements revealed an electron mobility at low temperatures around 4600 cm²/V·s. This study provides a material foundation for the development of high-performance ternary In_xGa_1-xAs nanowire-based optoelectronic devices.