We measured the noise in the configuration where two metal electrodes have been fabricated by nanolithography on a single Si NW. A schematic diagram of the Si NW-based device and the corresponding MSM structure are depicted in Figure 1a,b, respectively. For most of the devices, including opto-electronic devices, fabricated on a single Si NW, the basic configuration is the MSM configuration. In such cases, the contact resistance at the Schottky junction plays an important role in carrier transport through the NW. This can also lead to a substantial flicker noise at the junction regions due to the

existence of traps in the depletion region. In this report, we show the noise measurement carried on with an ac excitation (V ac) with a superimposed independent dc bias ((V dc), more than the Schottky barrier height (ϕ) formed at the metal-semiconductor (MS) junction region) which can lead to severe SAR302503 suppression of the noise arising at the junction region by few orders of magnitude. This suppression

of the junction noise enables us to estimate of the noise arising from the single Si NW. In the case of a single Si NW MSM device, such experiments do not exist, and the report here may STA-9090 in vitro provide an independent tool to reduce the junction noise by applying an external dc bias. Figure 1 Entinostat cell line Schematic diagram, MSM structure and SEM image. (a) Schematic diagram of a single Si NW with e-beam-deposited Pt contact electrodes. (b) A representative MSM structure of the NW device, consisting of two Schottky diodes connected back to back with a series resistance R NW. (c) SEM image of the single Si NW device with four electrical leads, and the inset shows a HRTEM image of the wire itself. Methods Synthesis and device fabrication The Si NWs used in this experiment were fabricated by metal-assisted chemical etching [9] technique.

else The method leads to a dense array of single crystalline Si NWs with a diameter ranging from approximately 20 to 100 nm and lengths of more than 10 µm. A high-resolution transmission electron microscope (HRTEM) image shows the probable existence of an oxide layer with a thickness ≤ 2 nm at the surface. The Pt contacts (in the configuration of the MSM device) for the noise measurement were made by using e-beam-assisted local deposition of methylcyclopentadienyl platinum trimethyl precursor at a bias of 15 kV in a dual beam system FEI-HELIOS 600 (FEI Co., Hillsboro, OR, USA). The scanning electron microscopy (SEM) image of a single NW connected with four electrical contacts is shown in Figure 1c. The four electrical contacts allow us four-probe measurements of the resistance of the individual NW and hence its resistivity (ρ). The inner two electrodes were used for current-voltage (I − V) measurements in the MSM device configuration.