AP3.1 - Silicon Nanowire Arrays for the Preconcentration and Joule Heating-Based Desorption of Trace Vapors

Event
17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
Chapter
Applications 3 - Indoor Gas Sensing
Author(s)
P. Pehrsson, B. Giordano, D. Ratchford, K. Johnson - Chemistry Division, Naval Research Laboratory, Washington, D.C. (USA)
Pages
380 - 381
DOI
10.5162/IMCS2018/AP3.1
ISBN
978-3-9816876-9-9
Price
free

Abstract

We preconcentrated trace nitroaromatic vapors onto silicon nanowire (SiNW) arrays and desorbed them by Joule heating the array. The ordered arrays were fabricated by nanosphere lithography (NSL) combined with metal-assisted chemical etching (MACE). The nanowires had diameters of ~350 nm, lengths of ~5 μm, and center-to-center spacing of 500 nm. Each SiNW array chip was approximately 108 individual wires. The nanowires were Joule heated by passing a current along their lengths, and the nanowire temperature was measured using the shift of the Si Raman single phonon line. The adsorption and selective desorption of 2,4-dinitrotoluene (2,4-DNT) and similar trace vapors was evaluated by coupling the array to a mass spectrometer.

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