Abstract
Vertically aligned single-crystal InSb nanowires were synthesized via the electrochemical method at room temperature. The stoichiometry of the deposited InSb nanowire is dependent on the value of KCl concentration, deposition potential, ratios of In3+/Sb3+ and and deposition time. Characteristic field-effect transistor based on InSb nanowires have N-type conductivity. Meanwhile, InSb nanowires have a electron concentration of 3.6 × 1017 cm-3 and a electron mobility of 214.12 cm2 V-1 s-1. Moreover, the mobility was observed to increase as the temperature increases, providing evidence of the ionized impurity scattering as the dominant reason of decreased mobility. In addition, the characteristics of Fourier transform infrared spectrum revealed that in the syntheses of InSb nanowires, energy bandgap shifts towards the short wavelength with the occurrence of an electron accumulation layer. The current-voltage curve, based on the metal-semiconductor-metal model, showed a high electron carrier concentration of 2.0 × 1017 cm−3 and a high electron mobility of 446.42 cm2 V−1 s−1. Additionally, the high carrier concentration of the InSb semiconductor with the surface accumulation layer induced a downward band bending effect that reduces the electron tunneling barrier. Consequently, the InSb nanowires exhibit significant field emission properties with a low turn-on field of 1.84 V m−1 and an estimate threshold field of 3.36 V m−1. Finally, single-crystal InSb nanowire was fabricated into middle-infrared (M-IR) photodetectors based on a metal-semiconductor-metal (M-S-M) structure. The photodetectors exhibit high photoconductive performance, excellent stability, reproducibility, high responsivity (8.4 × 104 A W-1), and quantum efficiency (1.96 × 106). These superior properties are attributed to the single-crystal 1D nanostructure and high electron mobility of photodetectors that significantly reduce the scattering and the transit time between the electrodes during the transport process. Furthermore, the M-S-M structure can effectively enhance space charge effect by the formation of the Schottky contacts, which significantly assists with the electron injection and photocurrent gain.