Diameter-Controlled and Surface-Modified Sb(2)Se(3) Nanowires and Their Photodetector Performance

Due to its direct and narrow band gap, high chemical stability, and high Seebeck coefficient (1800 μVK(−1)), antimony selenide (Sb(2)Se(3)) has many potential applications, such as in photovoltaic devices, thermoelectric devices, and solar cells. However, research on the Sb(2)Se(3) materials has been limited by its low electrical conductivity in bulk state. To overcome this challenge, we suggest two kinds of nano-structured materials, namely, the diameter-controlled Sb(2)Se(3) nanowires and Ag(2)Se-decorated Sb(2)Se(3) nanowires. The photocurrent response of diameter-controlled Sb(2)Se(3), which depends on electrical conductivity of the material, increases non-linearly with the diameter of the nanowire. The photosensitivity factor (K = I(light)/I(dark)) of the intrinsic Sb(2)Se(3) nanowire with diameter of 80–100 nm is highly improved (K = 75). Additionally, the measurement was conducted using a single nanowire under low source-drain voltage. The dark- and photocurrent of the Ag(2)Se-decorated Sb(2)Se(3) nanowire further increased, as compared to that of the intrinsic Sb(2)Se(3) nanowire, to approximately 50 and 7 times, respectively.