Controllable Growth of GaSb Nanowires Catalyzed by Bi Films for Flexible Near-Infrared Photodetectors

Abstract

With a direct narrow band gap and high hole mobility, the III–V group semiconductors of GaSb nanowire (NW) are considered as promising channel materials for next-generation high-performance nanoelectronics and infrared photodetectors. In this study, the complementary metal oxide semiconductor–compatible metal catalyst of bismuth is utilized in a surfactant-assisted chemical vapor deposition process for the controllable growth of GaSb NWs. The Bi-catalyzed GaSb NWs exhibit a uniform morphology, as well as good crystallinity. As the thickness of the Bi film increases from 10 to 100 nm, the length of the as-grown NWs increases from 8.6 ± 0.9 to 15.1 ± 1.4 μm, along with the diameter increasing from 24.3 ± 5.9 to 34.8 ± 7.5 nm. Furthermore, the as-constructed back-gated GaSb NWs field-effect transistors exhibit a high Ion/Ioff ratio of 104. The peak hole mobility initially increases from 95.4 ± 5.4 to 134.8 ± 15.8 cm2·V–1·s–1 and subsequently decreases to 109.6 ± 8.8 cm2·V–1·s–1 with the increase of diameter, which possibly results from Bi atom doping within NWs. When configured into flexible near-infrared (NIR) photodetectors, robust flexibility and endurance are observed, even after 1200 bending cycles in both parallel and perpendicular directions, demonstrating the great advantage in the coming high-performance flexible NIR photodetection.