Accession Number : ADA547541


Title :   Periodically Porous Top Electrodes on Vertical Nanowire Arrays for Highly Sensitive Gas Detection


Descriptive Note : Journal article


Corporate Author : NATIONAL ACADEMY OF SCIENCES-NATIONAL RESEARCH COUNCIL WASHINGTON DC


Personal Author(s) : In, Hyun J ; Field, Christopher R ; Pehrsson, Pehr E


Full Text : http://www.dtic.mil/dtic/tr/fulltext/u2/a547541.pdf


Report Date : Aug 2011


Pagination or Media Count : 7


Abstract : Nanowires of various materials and configurations have been shown to be highly effective in the detection of chemical and biological species. In this paper, we report a novel, nanosphere-enabled approach to fabricating highly sensitive gas sensors based on ordered arrays of vertically aligned silicon nanowires topped with a periodically porous top electrode. The vertical array configuration helps to greatly increase the sensitivity of the sensor while the pores in the top electrode layer significantly improve sensing response times by allowing analyte gases to pass through freely. Herein, we show highly sensitive detection to both nitrogen dioxide (NO2) and ammonia (NH3) in humidified air. NO2 detection down to 10 parts per billion (ppb) is demonstrated and an order-of-magnitude improvement in sensor response time is shown in the detection of NH3.


Descriptors :   *GAS DETECTORS , AMMONIA , ELECTRODES , NITROGEN DIOXIDE , POROUS MATERIALS , REACTION TIME , SILICON


Subject Categories : Miscellaneous Detection and Detectors
      Chemical, Biological and Radiological Warfare


Distribution Statement : APPROVED FOR PUBLIC RELEASE