Ga/GaSb nanostructures: Solution-phase growth for high-performance infrared photodetection

Gallium antimonide (GaSb)-based nanostructures have been reported via various vapor-phase synthetic routes while there is not a report on the growth of GaSb nanostructures via a complete one-step solution-phase synthetic strategy. Herein we report the design and synthesis of tadpole-like Ga/GaSb nanostructures by a one-step solution-phase synthetic route typically from the precursors of commercial triphenyl antimony (Sb(Ph)₃) and trimethylaminogallium (Ga(NMe₂)₃) at 260 °C in 1-octadecene. The GaSb nanocrystals are grown based on a solution–liquid–solid (SLS) mechanism with zinc blende phase, and their size and shape can be controlled in the procedures via manipulating the reaction conditions. Meanwhile, the tadpole-like Ga/GaSb nanostructures can be applied for the fabrication of a GaSb/Si nanostructured heterojunction-like photodetector over silicon wafer, which demonstrates excellent photoresponse and detection performances from wavelength of 405 to 1,064 nm with high photoresponding rate. Typically, the photodetector exhibits a high responsivity of 18.9 A·W⁻¹, a superior detectivity of 1.1 × 10¹³ Jones, and an ultrafast response speed of 44 ns. The present work provides a new strategy to group III–V antimonide-based semiconducting nanostructures that are capable for the fabrication of photodetector with broadband, high-detectivity, and high-speed photodetecting performances.