Self-catalyzed growth of GaSb nanowires for high performance ultraviolet-visible-near infrared photodetectors

A simple self-catalyzed chemical vapor deposition process was conducted to synthesize single-crystalline GaSb nanowires, where Ga droplets were utilized as the catalysts. The as-grown GaSb nanowires exhibited typical p-type semiconductor behavior with the calculated hole mobility of about 0.042 cm² V⁻¹ s⁻¹ The photoresponse properties of the GaSb nanowires were studied by fabricating nanowire photodetectors on both rigid and flexible substrates. The results revealed that the photodetectors exhibited broad spectral response ranging from ultraviolet, visible, to near infrared region. For the device on rigid substrate, the corresponding responsivity and the detectivity were calculated to be 3.86×10³A W⁻¹ and 3.15×10¹³ Jones for 500 nm light, and 7.22×10²A W⁻¹ and 5.90×10¹² Jones for 808 nm light, respectively, which were the highest value compared with those of other reported Ga_1−xIn_xAs_ySb_1−y structure nanowires. Besides, the flexible photodetectors not only maintained the comparable good photoresponse properties as the rigid one, but also possessed excellent mechanical flexibility and stability. This study could facilitate the understanding on the fundamental characteristics of self-catalyzed grown GaSb nanowires and the design of functional nano-optoelectronic devices based on Gasb nanowires.