Comparative Study of Carbon Monoxide Gas Sensing Mechanism for the LTPS MOS Schottky Diodes With Various Metal Oxides

Author

Juang, Feng-Renn ; Fang, Yean-Kuen ; Chiang, Yen-Ting ; Chou, Tse-Heng ; Lin, Cheng-I ; Lin, Cheng-Wei ; Liou, Yan-Wei

Author_Institution

Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan

Volume

11

Issue

5

fYear

2011

fDate

5/1/2011 12:00:00 AM

Firstpage

1227

Lastpage

1232

Abstract

The carbon monoxide (CO) gas sensing mechanism of the Au/MO/n-LTPS MOS Schottky diodes on a glass substrate has been studied with various metal oxides (MO) including SnO₂, ZnO, and TiO₂ as the sensing element. Because of the deposited SnO₂ has the highest band gap and the largest surface to volume ratio morphology, thus leading the Schottky diode with SnO₂ to gain the highest relative sensitivity ratio of ~546% to 100 ppm CO ambient under condition of 200°C and -3 V bias. These results are better or comparable to the reported CO sensors. We propose a band gap model to interpret the related sensing mechanism in details.

Keywords

Schottky diodes; gas sensors; glass; gold; substrates; tin compounds; titanium compounds; zinc compounds; Au; LTPS MOS Schottky diodes; SnO₂; TiO₂; ZnO; carbon monoxide gas sensing mechanism; glass substrate; metal oxides; surface to volume ratio morphology; temperature 200 degC; voltage -3 V; Gold; Plasmas; Schottky diodes; Sensitivity; Temperature sensors; ${rm SnO} _{2}$; Carbon monoxide (CO) sensor; ELA; Schottky diode; low-temperature poly silicon (LTPS);

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2010.2091404

Filename

5625891