Low-Frequency Noise in Field-Effect Devices Functionalized With Dendrimer/Carbon- Nanotube Multilayers

• Published in: IEEE sensors journal Vol. 11; no. 1; pp. 142 - 149
• Main Authors: Gasparyan, F V, Poghossian, A, Vitusevich, S A, Petrychuk, M V, Sydoruk, V A, Siqueira, José R, Oliveira, O N, Offenhäusser, Andreas, Schöning, Michael J
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-01-2011; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitance; Carbon nanotube; dendrimer; Dendrimers; Density; Devices; Electrochemical impedance spectroscopy; field-effect sensor; Fluctuations; Insulators; Logic gates; Low-frequency noise; Multilayers; Nanostructure; Noise; Nonhomogeneous media; Single wall carbon nanotubes
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2010.2052355

Low-frequency noise in an electrolyte-insulator-semiconductor (EIS) structure functionalized with multilayers of polyamidoamine (PAMAM) dendrimer and single-walled carbon nanotubes (SWNT) is studied. The noise spectral density exhibits dependence with the power factor of and for the bare and functionalized EIS sensor, respectively. The gate-voltage noise spectral density is practically independent of the pH value of the solution and increases with increasing gate voltage or gate-leakage current. It has been revealed that functionalization of an EIS structure with a PAMAM/SWNTs multilayer leads to an essential reduction of the noise. To interpret the noise behavior in bare and functionalized EIS devices, a gate-current noise model for capacitive EIS structures based on an equivalent flatband-voltage fluctuation concept has been developed.