Ag-catalyzed GaSb nanowires for flexible near-infrared photodetectors

High-quality narrow bandgap semiconductors nanowires(NWs)challenge the flexible near-infrared(NIR)photodetectors in next-generation imaging,data communication,environmental monitoring,and bioimaging applications.In this work,complementary metal oxide semiconductor-compatible metal of Ag is deposited on glass as the growth catalyst for the surfactantassisted chemical vapor deposition of GaSb NWs.The uniform morphology,balance stoichiometry,high-quality crystallinity,and phase purity of as-prepared NWs are checked by scanning electron microscopy,energy dispersive X-ray spectroscopy,high-resolution transmission electron microscopy,and X-ray diffraction.The electrical properties of as-prepared NWs are studied by constructing back-gated field-effect-transistors,displaying a high I_(on)/I_(off) ratio of 10^(4) and high peak hole mobility of 400 cm^(2)/(V·s).Benefiting from the excellent electrical and mechanical flexibility properties,the as-fabricated NW flexible NIR photodetector exhibits high sensitivity and excellent photoresponse,with responsivity as high as 618 A/W and detectivity as high as 6.7×10^(10) Jones.Furthermore,there is no obvious decline in NIR photodetection behavior,even after parallel and perpendicular folding with 1200 cycles.

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 cm^2 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 3.86×10^3 A W-1 and 3.15×10^13 Jones for 500 nm light,and 7.22×10^2 A W-1 and 5.90×10^12 Jones for 808 nm light,respectively,which were the highest value compared with those of other reported Ga1-xInxAsySb1-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.

Single-Ga Sb-nanowire-based room temperature photodetectors with broad spectral response

Single-gallium antimonide （GaSb）-nanowire- based photodetectors were fabricated on both rigid SiO2/Si substrate and flexible polyethylene terephthalate （PET） substrates, both of which exhibited high responsivity, fast- response, and long-term stability in photoswitching over a broad spectral range from ultraviolet to near infrared. Besides, the as-fabricated rigid device exhibited high responsivity of 7,350 A/W under illumination of 2 = 350 nm and light intensity P = 0.2 mW/cm^2, while the flexible device displays higher detectivity of 9.67 × 10^9 jones at 700 nm than the rigid one and lower noise equivalent power （NEP, NEP＊700 nm = 2.0 × 10^-12 W/Hz^1/2） for the much lower dark current on PET. The high responsivity, broad spectral detection from ultraviolet to near-infrared and long-term stability make GaSb nanowire one of the most important candidates to construct advanced optical sensors or other optoelectronic devices.