Enhancement of CO sensitivity of indium oxide-based semiconductor gas sensor through ultra-thin cobalt adsorption

Citation
Hj. Lee et al., Enhancement of CO sensitivity of indium oxide-based semiconductor gas sensor through ultra-thin cobalt adsorption, SENS ACTU-B, 79(2-3), 2001, pp. 200-205
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
SENSORS AND ACTUATORS B-CHEMICAL
ISSN journal
0925-4005 → ACNP
Volume
79
Issue
2-3
Year of publication
2001
Pages
200 - 205
Database
ISI
SICI code
0925-4005(20011015)79:2-3<200:EOCSOI>2.0.ZU;2-L
Abstract
An In2O3-based thin film sensor was fabricated on alumina substrate for det ecting CO gas and ultra-thin transition metal Co was adsorbed by sputtering and annealed as a surface activator as thick as 0.7-2.4 nm to enhance its sensitivity (S). As the thickness W of Co catalyst layer increased, the sen sitivity of Co-In2O3 Sensor for show the highest sensitivity of S = 7.5 at t = 2.1 run at 350 degreesC. For the comparison, C3H8 was used as a test ga s of hydrocarbon contained gas and the maximum sensitivity for 1000 PPM C3H 8 was S = 13.5 at t = 1.4 mn at 400 degreesC. In consequence, it was found the possibility that CO and C3H8 can be detected without cross-talking by u sing hybrid type Co-In2O3 sensor. From X-ray photoelectron spectroscopy, ad sorbed Co layer was oxidized Coo after 500 degreesC annealing in air and to be covered with Co3O4. Such a formation of Coo (p-type)-In2O3 (n-type) jun ction was suggested as a main sensing mechanism to explain the enhanced sen sitivity of Co-In-In2O3 sensor. (C) 2001 Elsevier Science B.V. All rights r eserved.