Modeling Electrostatic and Quantum Detection of Molecules

Author

Vasudevan, Smitha ; Walczak, Kamil ; Kapur, Neeti ; Neurock, Matt ; Ghosh, Avik W.

Author_Institution

Dept. of Electr. & Comput. Eng., Virginia Univ., Charlottesville, VA

Volume

8

Issue

6

fYear

2008

fDate

6/1/2008 12:00:00 AM

Firstpage

857

Lastpage

862

Abstract

We describe two different modes for electronically detecting an adsorbed molecule using a nanoscale transistor. The attachment of an ionic molecular target shifts the threshold voltage through modulation of the depletion layer electrostatics. A stronger bonding between the molecule and the channel, involving actual overlap of their quantum mechanical wavefunctions, leads to scattering by the molecular traps that creates characteristic fingerprints when scanned with a backgate. We describe a theoretical approach to model these transport characteristics.

Keywords

electrostatics; field effect transistors; gas sensors; molecular electronics; ChemFET; adsorbed molecule; depletion layer electrostatics; ionic molecular target shifts; molecules quantum detection; nanoscale transistor; quantum mechanical wavefunctions; threshold voltage; Bonding; Chemical sensors; Electron traps; Electrostatics; FETs; Particle scattering; Sensor phenomena and characterization; Silicon; Telegraphy; Threshold voltage; Coulomb scattering; field-effect transistor (FET); quantum interference; random telegraph signal (RTS); time-dependent NEGF;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2008.923264

Filename

4529224