
48 Semiconductor Device-Based Sensors for Gas, Chemical, and Biomedical Applications
© 2011 by Taylor & Francis Group, LLC
absorbed by the gas whose concentration is to be determined while ltering out the unwanted wave-
lengths. The IR detector produces an electrical signal that represents the intensity of the radiation
impinging upon it. It is generally considered that the NDIR technology is limited by power con-
sumption and size.
In recent years, monomers or polymers containing amino-groups, such as tetrakis(hydroxyethyl)
ethylenediamine, tetraethylene-pentamine, and polyethyleneimine (PEI), have been used for CO
2
sensors to overcome the pow ...