Double-gated Si NW FET sensors: Low-frequency noise and photoelectric properties

Journal Article · Sun Aug 14 04:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4960704· OSTI ID:22597704

Gasparyan, F. ^[1]; Khondkaryan, H.; Arakelyan, A. ^[1]; Zadorozhnyi, I.; Pud, S.

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1. Yerevan State University, 1 Alex Manoogian St., 0025 Yerevan (Armenia)

The transport, noise, and photosensitivity properties of an array of silicon nanowire (NW) p{sup +}-p-p{sup +} field-effect transistors (FETs) are investigated. The peculiarities of photosensitivity and detectivity are analyzed over a wide spectrum range. The absorbance of p-Si NW shifts to the short wavelength region compared with bulk Si. The photocurrent and photosensitivity reach increased values in the UV range of the spectrum at 300 K. It is shown that sensitivity values can be tuned by the drain-source voltage and may reach record values of up to 2–4 A/W at a wavelength of 300 nm at room temperature. Low-frequency noise studies allow calculating the photodetectivity values, which increase with decreasing wavelength down to 300 nm. We show that the drain current of Si NW biochemical sensors substantially depends on pH value and the signal-to-noise ratio reaches the high value of 10{sup 5}. Increasing pH sensitivity with gate voltage is revealed for certain source-drain currents of pH-sensors based on Si NW FETs. The noise characteristic index decreases from 1.1 to 0.7 with the growth of the liquid gate voltage. Noise behavior is successfully explained in the framework of the correlated number-mobility unified fluctuation model. pH sensitivity increases as a result of the increase in liquid gate voltage, thus giving the opportunity to measure very low proton concentrations in the electrolyte medium at certain values of the liquid gate voltage.

• OSTI ID: 22597704
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 120; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPARATIVE EVALUATIONS
ELECTRIC POTENTIAL
ELECTROLYTES
FIELD EFFECT TRANSISTORS
LIQUIDS
NANOWIRES
NOISE
PH VALUE
PHOTOCURRENTS
PHOTOSENSITIVITY
SENSORS
SIGNAL-TO-NOISE RATIO
SIGNALS
SILICON
WAVELENGTHS