Semiconductive gas sensors

Figure 1. Change in annual number of patents concerning semiconduct gas sensors.

Yamazoe, N., New approaches for improving semiconductive gas sensors, Sens. Actutators B 1991,5, 7-19... 

Cabot, A. Arbiol, J. Comet, A. Morante, J. R. Chen, F. Liu, M., Mesoporous catalytic filters for semiconducting gas sensors, Thin Solid Films 2003, 436, 64-69... 

Aronova, M. A. Chang, K. S. Takeuchi, I. Jabs, H. Westerheim, D. Gonzalez-Martin, A. Kim, J. Lewis, B., Combinatorial libraries of semiconducting gas sensors as inorganic electronic nose, Appl. Phys. Lett. 2003, 83, 1255-1257... 

Burton K W C and Nickless G 1987 Optimisation via simplex part I. Background, definitions and a simple application Chem. Int. Lab. Syst. 1 135-49 Clifford P K 1983 Homogeneous semiconducting gas sensors a comprehensive model Anal. Chem. Symp. Series 17 (Washington, DC ACS) p 135... 

Naisbitt, S. C., Pratt,K. F. E., WiUiams, D. E. and Parkin, I. P. (2006) A microstmctural model of semiconducting gas sensor response The effects of sintering temperature on the response of chromium titanate (CTO) to carbon monoxide. Sensors and Actuators B-Chemical 114,969-77. 

Construction and Characterization of Semiconductor Sensors. Semiconductor gas sensors are characterized by their simple construction. A schematic overview of the construction principle of a homogeneous semiconducting gas sensor is provided in Figure 2 A [31]. Sensor operation is based on a change in the surface resistance (or conductance) of an oxidic microcrystalline semiconductor in the presence of interacting gases. A time-dependent record reflecting transient expo-... 

Figure 2. A) Schematic drawing of a homogeneous semiconducting gas sensor B) Result of transient exposure of the sensor to a gas that increases the conductance [311 a) Semiconductor b) Ceramic c) Heater d) Contacts (with permission from Elsevier. Amsterdam)...

G. Heiland "Homogeneous Semiconducting Gas Sensors," Sens. Actuators 2 (1982) 343,... 

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. 

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. 

The production of gas sensors. The production records of various types of gas sensors for past five years in Japan are listed in Table I except for the oxygen and humidity sensors. The sensors produced in the largest quantity are of the semiconductive type, followed by the catalytic combustion and thermistor types. These sensors have been mostly applied to domestic uses such as gas leakage alarms or gas control systems for LP gas and town gas which are extensively used for cooking and heating in Japanese houses. This is why these sensors are manufactured on a large scale. Other electrochemical sensors have been developed mainly to monitor other gases. 

The science of gas-sensors based on changes in electronic conductivity of a semiconducting ceramic is a complex matter depending upon a combination of surface chemistry and electron transport in mainly transition metal oxides. As is usual in exploiting electroceramics, the applications technology runs ahead of... 

Sensors The ceria NPs could also be used in biosensors as well as the gas sensors. The redox catalytic activity and the semiconductivity of ceria allow it to be used as gas sensors for the reductive and oxidative gases such as CO, NO2,02, and alcohols by the resistivity or catalumines-cence measurements. The noble metals or metal oxides which could activate the catalytic process of ceria could also help to increase the sensitivity of ceria for gas sensing. 

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