High sensitivity of middle-wavelength infrared photodetectors based on an individual InSb nanowire
Department of Materials Science & Engineering, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd, Hsinchu 30013, Taiwan
Nanoscale Research Letters 2013, 8:327 doi:10.1186/1556-276X-8-327Published: 18 July 2013
Single-crystal indium antimony (InSb) nanowire was fabricated into middle-infrared photodetectors based on a metal–semiconductor-metal (M-S-M) structure. The InSb nanowires were synthesized using an electrochemical method at room temperature. The characteristics of the FET reveal an electron concentration of 3.6 × 1017 cm−3 and an electron mobility of 215.25 cm2 V−1 s−1. The photodetectors exhibit good photoconductive performance, excellent stability, reproducibility, superior responsivity (8.4 × 104 A W−1), and quantum efficiency (1.96 × 106%). These superior properties are attributed to the high surface-to-volume ratio and single-crystal 1D nanostructure of photodetectors that significantly reduce the scattering, trapping, and the transit time between the electrodes during the transport process. Furthermore, the M-S-M structure can effectively enhance space charge effect by the formation of the Schottky contacts, which significantly assists with the electron injection and photocurrent gain.