Accepted Manuscript Title: Atmospheric pressure fabrication of SnO 2 -nanowires for highly sensitive CO and CH 4 detection Authors: Anton K ¨ ock, Alexandra Tischner, Thomas Maier, Michael Kast, Christian Edtmaier, Christian Gspan, Gerald Kothleitner PII: S0925-4005(09)00172-5 DOI: doi:10.1016/j.snb.2009.02.055 Reference: SNB 11361 To appear in: Sensors and Actuators B Received date: 22-10-2008 Revised date: 17-12-2008 Accepted date: 20-2-2009 Please cite this article as: A. K ¨ ock, A. Tischner, T. Maier, M. Kast, C. Edtmaier, C. Gspan, G. Kothleitner, Atmospheric pressure fabrication of SnO 2 -nanowires for highly sensitive CO and CH 4 detection, Sensors and Actuators B: Chemical (2008), doi:10.1016/j.snb.2009.02.055 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. 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Page 1 of 40 Accepted Manuscript hot plate Si wafer air atomizing nozzle carrier gas N 2 solution shutter wafer carrier siphon height solution Fig. 1 Page 2 of 40 Accepted Manuscript Figure 2 Page 3 of 40 Accepted Manuscript Figure 3 Page 4 of 40 Accepted Manuscript Fig. 4 Page 5 of 40 Accepted Manuscript Figure 5 Page 6 of 40 Accepted Manuscript Figure 6 Page 7 of 40 Accepted Manuscript Fig. 7 new as pdf Page 8 of 40 Accepted Manuscript Fig. 7 new as ppt Page 9 of 40 Accepted Manuscript 2.2E+06 2.3E+06 2.4E+06 2.5E+06 2.6E+06 2.7E+06 2.8E+06 2.9E+06 0 10 20 30 40 50 60 70 80 90 100 300 600 900 1200 1500 1800 2100 2400 Sensor Resistance [Ω] Humidity [%] Time [s] rH meas (%) Sensor R [Ω] Fig. 8 color [...]... intermediate metal films, and are strongly branched and interconnected Additional nanowire growth experiments will be carried out in order to fully understand the growth mechanism and to clarify whether it is a VLS dominated mechanism or not 3.2 Tin oxide nanowire sensors 8 Page 24 of 40 The fabrication of the SnO2-nanowire sensors requires no sophisticated e-beam-lithography processing and is as follows:... Williams, Tin dioxide gas sensors: Part 1: Aspects of the M surface chemistry revealed by electrical conductance variations, J Chem Soc., Faraday Trans 1 83 d (1987) 1323–1346 ce p Actuators B 26-27 (1995) 1–12 te [6] W Göpel, K D Schierbaum, SnO2 sensors: current status and future prospects, Sensors and [7] J Kappler, A Tomescu, N Barsan, U Weimar, CO consumption of Pd doped SnO2 based sensors, Thin Solid... of gas sensors the SnO2-nanowires have been transferred to another SiO2-coated Sisubstrate; final evaporation of Ti/Au contact pads on both ends of single SnO2-nanowires has enabled Ac their direct use as sensing elements The nanowire sensors are very sensitive and are able to detect concentrations of CO and CH4 in the low ppm-regime Experiments for better understanding of the growth mechanism, and for... ip t As SnO2 has been the most prominent sensing material in conventional gas sensors, the major focus has been put on the fabrication and implementation of SnO2 nanobelts and nanowires as sensing probes cr Nanosensors based on SnO2-belts with high sensitivity for CO, NO2 and Ethanol have been reported [26] Detection of CO and O2 has been achieved with template grown SnO2 nanowires, while enhanced us... sensitive CO and CH4 detection Gspan3, and Gerald Kothleitner3 cr Anton Köck*1, Alexandra Tischner1, Thomas Maier1, Michael Kast1, Christian Edtmaier2, Christian Division Nano-System-Technologies, Austrian Research Centers GmbH – ARC, 1220 Vienna, Austria 2 Institute of Chemical Technologies and Analytics, Vienna University of Technology, 1040 Vienna, an us 1 Austria Institute for Electron Microscopy and Fine... resistance and thermal stability Gas sensing has been successfully achieved with a variety of metal oxide nanowires, such as 3 Page 19 of 40 In2O3 nanowires [27, 32] or WO3 nanowire networks [33] Also ZnO nanorods and nanowires have been employed for sensing applications [34, 35], a field effect transistor configuration has been used for NO2 and NH3 sensing [36] Arrays of individual nano- and mesowire sensors. .. of nanostructured sensors based on tin oxide d synthesized with different methods, Materials Science and Engineering B 140 (2007) 73–80 te [16] C Moon, H.-R Kim, G Auchterlonie, J Drennan, J.-H Lee, Highly sensitive and fast ce p responding CO sensor using SnO2 nanosheets, Sens Act B 131 (2008) 556–564 [17] Y Cui, Q Wei, H Park, C Lieber, Nanowire nanosensors for highly sensitive and selective detection... detection of biological and chemical species, Science 293 (2001) 1289–1292 Ac [18] F Patolsky, G Zheng, O Hayden, M Lakadamyali, X Zhuang, C Lieber, Electrical detection of single viruses, PNAS 101 (2004) 14017–14022 [19] F Patolsky, C M Lieber, Nanowire nanosensors, Materials Today 8 (2005) 20–28 [20] U Yogeswaran, S.-M Chen, A review on the electrochemical sensors and biosensors composed of nanowires... applications based on a combined spray pyrolysis and annealing an process The SnO2-nanowires have been grown on SiO2-coated Si-substrates with diameters 30 - 400 nm and lengths up to several 100 µm The SnO2-nanowire fabrication procedure is performed at M atmospheric pressure and requires no vacuum The experimental results suggest a competing evaporation and condensation process, which converts the nanocrystalline... nanoribbons and nanowires have been developed for the detection of H2S [40]; CO and humidity have been detected with M single SnO2 nanowires [41] In this paper we report on atmospheric pressure synthesis of single crystalline SnO2-nanowires directly d on the Si-chip by spray pyrolysis and subsequent annealing Our two-step SnO2-nanowire fabrication te procedure is very simple, requires no vacuum, and allows