Sensors semiconducting

Functional polymers may be used for dihierent types of chemical sensors, including acoustic wave sensors (bulk acoustic wave, surface acoustic wave, and flexural plate wave sensors), electronic conductance sensors (semiconducting and capacitance sensors), and calorimetric sensors. ... 

With the increase in needs to monitor a variety of gases in our environment, the solid-state gas sensors based on electrical parameters are widely studied, including silicon-based chemical sensors, semiconducting metal oxide sensors, catalysis. 

Metal oxides fonn the class of materials which has seen the widest application in gas sensors (Park and Akbar 2003 Korotcenkov 2007a, b). As can be seen in Table 2.1 and Fig. 2.1, they can be used in every type of gas sensor. For example, in conductometric sensors, semiconducting metal oxides are typically used as gas-sensing materials that change their electrical resistance upon exposure to oxidizing or reducing gases. 

Several kinds of conduction mechanisms are operative in ceramic thermistors, resistors, varistors, and chemical sensors. Negative temperature coefficient (NTC) thermistors make use of the semiconducting properties of heavily doped transition metal oxides such as n-ty e Ti O andp-ty e... 

Titanium dioxide supported gold catalysts exhibit excellent activity for CO oxidation even at temperatures as low as 90 K [1]. The key is the high dispersion of the nanostructured gold particles over the semiconducting Ti02 support. The potential applications of ambient temperature CO oxidation catalysts include air purifier, gas sensor and fuel cell [2]. This work investigates the effects of ozone pretreatment on the performance of Au/Ti02 for CO oxidation. 

Most probably a commercial utilization of these semiconductive sensors in domestic appliances can be expected for the short term. 

G Yu, J Wang, J McElvain, and AJ Heeger, Large-area, full-color image sensors made with semiconducting polymers, Adv. Mater., 10 1431-1434, 1998. 

Figure 4.2 Schematic diagram of a charge-coupled device (CCD) imaging sensor. It consists of a semiconducting substrate (silicon), topped by a conducting material (doped polysilicon), separated by an insulating layer of silicon dioxide. By applying charge to the polysilicon electrodes, a localized potential well is formed, which traps the charge created by the incident light as it enters the silicon substrate.

N. Barsan, J.R. Stetter, M. Findlay, and W. Gopel. High performance gas sensing of CO Comparative tests for semiconducting (Sn02-based) and for amperometric gas sensors . Analytical Chemistry 71 (1999), 2512-2517. 

E. Comini, G. Faglia, G. Sberveglieri, Z.W. Pan, and Z.L. Wang. Stable and highly sensitive gas sensors based on semiconducting oxide nanobelts . Applied Physics Letters 81 (2002), 1869-1871. 

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