Ultra-fast photodetectors based on high-mobility indium gallium antimonide nanowires

Because of tunable bandgap and high carrier mobility, ternary III-V nanowires (NWs) have demonstrated enormous potential for advanced applications. However, the synthesis of large-scale and highly-crystalline In _x Ga _1−x Sb NWs is still a challenge. Here, we achieve high-density and crystalline stoichiometric In _x Ga _1−x Sb (0.09 < x < 0.28) NWs on amorphous substrates with the uniform phase-purity and <110 >-orientation via chemical vapor deposition. The as-prepared NWs show excellent electrical and optoelectronic characteristics, including the high hole mobility (i.e. 463 cm ² V ⁻¹ s ⁻¹ for In _0.09 Ga _0.91 Sb NWs) as well as broadband and ultrafast photoresponse over the visible and infrared optical communication region (1550 nm). Specifically, the In _0.28 Ga _0.72 Sb NW device yields efficient rise and decay times down to 38 and 53 μs, respectively, along with the responsivity of 6000 A W ⁻¹ and external quantum efficiency of 4.8 × 10 ⁶ % towards 1550 nm regime. High-performance NW parallel-arrayed devices can also be fabricated to illustrate their large-scale device integrability for next-generation, ultrafast, high-responsivity and broadband photodetectors.