title: Single Si nanowire (diameter ≤ 100 nm) based polarization sensitive near-infrared photodetector with ultra-high responsivity.
abstract: We report the fabrication and optical response of boron-doped single silicon nanowire-based metal-semiconductor-metal photodetector. Typical single nanowire devices with diameter of ∼80-100 nm and electrode spacing of ∼1 μm were made using electron-beam lithography from nanowires, grown by a metal-assisted chemical etching process. A high responsivity, of the order of 10(4) A W(-1), was observed even at zero bias in a single nanowire photodetector with peak responsivity in the near-infrared region. The responsivity was found to increase with increasing bias and decreasing nanowire diameter. Finite element based optical simulation was proposed to explain the diameter dependent performance of a single nanowire. The observed photoresponse is sensitive to the polarization of exciting light source, allowing the device to act as a polarization-dependent near-infrared photodetector.
authors.affiliation: Theme Unit of Excellence in Nanodevice Technology, S.N. Bose National Center for Basic Sciences, Sector-III, Salt Lake, Kolkata-700098, India. arup@bose.res.in.
authors.forename: K
authors.initials: K
authors.lastname: Das
authors.forename: S
authors.initials: S
authors.lastname: Mukherjee
authors.forename: S
authors.initials: S
authors.lastname: Manna
authors.forename: S K
authors.initials: SK
authors.lastname: Ray
authors.forename: A K
authors.initials: AK
authors.lastname: Raychaudhuri