New approaches for improving semiconductor gas sensors


Posted May 12, 2016 by industryfans

It is demonstrated that the sensing characteristics of a semiconductor gas sensor using SnO2 can be improved by controlling fundamental factors which affect its receptor and transducer functions.

 
It is demonstrated that the sensing characteristics of a semiconductor gas sensor using SnO2 can be improved by controlling fundamental factors which affect its receptor and transducer functions.

The transducer function is deeply related with the microstructure of the elements, i.e., the grain size of SnO2 (D) and the depth of the surface space-charge layer (L). The sensitivity is drastically promoted when D is made comparable to or less than 2L, either by control of D for pure SnO2 elements or by control of the Debye length for impurity-doped elements.

On the other hand, the receptor function is drastically modified by the introduction of foreign receptors on the surface of SnO2. In the particular cases of Pd and Ag promoters, the oxides (PdO and Ag2O) formed in air interact with the SnO2 surface to produce an electron-deficient space-charge layer, and this contributes much to promoting the gas sensitivity.

For a test gas having a specific reactivity, such specificity can be utilized for exploiting gas-selective receptors, as exemplified by CuO SnO2 and La2O3 SnO2 elements, which detect H2S and ethanol gas respectively very sensitively.
-- END ---
Share Facebook Twitter
Print Friendly and PDF DisclaimerReport Abuse
Contact Email [email protected]
Issued By Sherry
Website Industry sourcing & Wholesale industrial products
Country China
Categories Retail
Tags industry sourcing , infrared co2 sensor , ndir co2 sensor , ndir gas sensor , ndir sensor , semiconductor gas sensor , semiconductor gas sensors , wholesale industrial products
Last Updated May 12, 2016