Semiconducting direct thermoelectric

Semiconducting direct thermoelectric gas sensors (DTEGs) do not have the disadvantages of resistive or potentiometric gas sensors. The measurand... 

The direct thermoelectric gas sensors introduced in the preceding sections were based on semiconducting oxide materials. However, other materials besides electronic conductors can be employed as materials for DTEGs. Several years ago, it was shown that the thermopower p of an electrochemical cell with Ft electrodes separated by an oxygen ion conductor follows Equation [7.23] (e.g. Ahlgren and Poulsen, 1995) ... 

Rettig, F. and Moos, R. (2010), a-iron oxide An intrinsically semiconducting oxide material for direct thermoelectric oxygen sensors. Sensors and Actuators B Chemical, 145(2), 685-90. 

Rettig F, Moos R (2007b) Direct thermoelectric hydrocarbon gas sensors based on SnO. IEEE Sens J 7 1490-1496 Rettig F, Moos R (2008) Morphology dependence of thermopower and resistance in semiconducting oxides with space charge regions. Solid State Ionics 179 2299-2307... 

Lead Telluride. Lead teUuride [1314-91 -6] PbTe, forms white cubic crystals, mol wt 334.79, sp gr 8.16, and has a hardness of 3 on the Mohs scale. It is very slightly soluble in water, melts at 917°C, and is prepared by melting lead and tellurium together. Lead teUuride has semiconductive and photoconductive properties. It is used in pyrometry, in heat-sensing instmments such as bolometers and infrared spectroscopes (see Infrared technology AND RAMAN SPECTROSCOPY), and in thermoelectric elements to convert heat directly to electricity (33,34,83). Lead teUuride is also used in catalysts for oxygen reduction in fuel ceUs (qv) (84), as cathodes in primary batteries with lithium anodes (85), in electrical contacts for vacuum switches (86), in lead-ion selective electrodes (87), in tunable lasers (qv) (88), and in thermistors (89). 

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