Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T15:49:50.339Z Has data issue: false hasContentIssue false

Gas Transport and Response in Porous Silicon Sensors

Published online by Cambridge University Press:  01 February 2011

Serdar Ozdemir
Affiliation:
James L Gole
Affiliation:
[email protected], Georgia Institute of Technology, School of Physics, Atlanta, Georgia, United States
Get access

Abstract

Nanopore covered microporous silicon conductometric gas sensors have been produced via electrochemical etching and standard microfabrication techniques. Reversible and sensitive gas sensors working at room temperature have been fabricated. Sensing of NH3, NOx and PH3 at or below the ppm level have been achieved. The porous silicon (PS) surface has been modified using selective coatings including electroless tin, gold, nickel and copper solutions to increase the response to NOx, NH3, and PH3 respectively. The diffusion of the analyte species has been investigated in the nanopore and micropore regimes by numerical analysis. Comparing the response time of the hybrid porous sensor surface with numerical diffusion calculations on the pores, it has been observed that Knudsen diffusion time scales dominate the sensor response. A transduction model is proposed based on nanopore limited gas diffusion and the experimental response and recovery data.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Canham, L. T. Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers, Appl. Phys. Lett.,57 (1990) 1046–8.Google Scholar
[2] Lehmann, V. Gosele, U. Porous silicon formation: A quantum wire effect, Appl. Phys. Lett., 58 (1991) 856–8.Google Scholar
[3] Ozdemir, S. Gole, J.L. The potential of porous silicon gas sensors, Current Opinion in Solid State and Materials Science (2008), j.cossms. 2008.06.003Google Scholar
[4] Lewis, S. DeBoer, J. R. Gole, J. L. A pulsed system frequency analysis for device characterization and experimental design: application to porous silicon sensors and extension, Sens. Actuators B: Chem, 122 (2007) 2029.Google Scholar
[5] Lewis, S. DeBoer, J. Gole, J.L. Hesketh, P. asSensitive, selective, and analytical improvements to a porous silicon gas sensor, Sens. Actuators B: Chem (2005) 5465.Google Scholar
[6] Malek, K. Coppens, M. Knudsen self- and Fickian diffusion in rough nanoporous media, J. Chem. Phys., 119 (2003), 2801–11.Google Scholar
[7] Roy, S. Raju, R. Chuang, H.F. Cruden, B.A. Meyyappan, M. Modeling gas flow through microchannels and nanopores, J. Appl. Phys., 93 (2003) 4870–9.Google Scholar