8.5.4 Fabrication and Characterization of MEMS Based Optical Hydrogen Sensors
- Event
- 14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany - Chapter
- 8.5 Optical absorbance-based Sensors
- Author(s)
- H. Hwang, K. Kim, G. Chung - School of electrical engineering, University of Ulsan (Korea)
- Pages
- 736 - 738
- DOI
- 10.5162/IMCS2012/8.5.4
- ISBN
- 978-3-9813484-2-2
- Price
- free
Abstract
This paper presents the fabrication and characterization of MEMS based optical type hydrogen sensors using transparent 3C-SiC membrane and photovoltaic effect. 3C-SiC membrane was fabricated by anisotropic etching. Gasochromic material of Pd was deposited by sputter on the 3C-SiC membrane for gas sensing layer. Pd and WO3 changes to transparency by exposure to hydrogen and the variations of light intensity generate the photovoltaic of P-N junction between N-type 3C-SiC and P-type Si. Photovoltaic increased with increase of hydrogen concentration. Pd/WO3 shows almost 2 times faster response and recovery toward hydrogen compared with Pd. However, low response factor is shown at Pd/WO3 by low penetration ratio.