Field ionization gas sensors

Using SiNWs fabricated by various methods, resistive gas sensors (Gao et al. 2010 Field et al. 2011), FET (McAlpine et al. 2007 Paska et al. 2011), Schottky type gas sensors (Skucha et al. 2010), and field-ionized gas sensors (Sadeghian and Islam 2011) have been designed. Examples of such devices... 

Fig. 19.5 Effects of environmental factors on the operating characteristics of carbon MWNT-based field ionization gas sensors (a) temperature and (b) relative humidity (Reprinted with permission from Hui et al. (2006). Copyright 2006 TOP)...

Gas sensors based on field ionization from multiwall carbon nanotube arrays grown on PSi templates have been developed (Nikfaijam et al., 2010). Such sensors showed good sensitivity, selectivity and short response times, as well as higher discharge current and good mechanical stability in comparison with those which were fabricated on polished silicon substrates. Validation of the compatibility between PSi-based gas sensor technology and standard microelectronic processes has been demonstrated (Barillaro etal.,2010). 

Liao L, Lu HB, Shuai M, Li JC, liu YL, Liu C, Shen ZX, Yu T (2008) A novel gas sensor based on field ionization from ZnO nanowires moderate working voltage and high stability. Nanotechnology 19 175501... 

The following section reviews the field emission process and various field emission applications in which CNTs have found particular recognition, including displays, microwave and X-ray sources, parallel electron beam lithography systems, gas ionization sensors, and interstellar propulsion. 

Sharp morphologies increase the local electric field. Though often related expressly to high vacuum field emission, such an effect can also be used for gas and pressure detection. The typical structure of a gas ionization sensor is depicted in Figure 5.28(a,b). Here, an MWCNT thin film forms the sensing element and the current... 

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