Pulsed laser deposition of mesoporous niobium oxide thin films and application as chemical sensors

✍ Scribed by Mary E Gimon-Kinsel; Kenneth J Balkus Jr.

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 412 KB
• Volume: 28
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(98)00291-1

✦ Synopsis

The pulsed laser deposition (PLD) of a mesoporous niobium oxide, Nb-TMS1, and post-hydrothermal treatment result in mesoporous thin films (90 nm-3 mm thick) having what appears to be a three-dimensional disordered hexagonal or 'wormhole' structure. These films were characterized by FT-IR spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The mesoporous Nb-TMS1 thin films were employed as the dielectric phase in capacitive-type chemical sensors. These sensors produce a capacitance change upon the reversible absorption of volatile compounds into the molecular sieve pores. The molecular sieve based sensors were exposed to a variety of analytes, including N 2 , CO 2 , H 2 O, NH 3 , methanol and acetone. The mesoporous niobium oxide based sensors were found to be particularly good humidity sensors, exhibiting capacitance changes at least 10 times greater than that for N 2 , ammonia, methanol and acetone. The Nb-TMS1 based sensors also showed responses to H 2 O that were 1000 times greater than for dense Nb 2 O 5 based sensors prepared by PLD.