Laser terahertz emission system to investigate hydrogen gas sensors

Abstract

A laser terahertz emission system is proposed to investigate the catalytic metal/semiconductor interfaces of hydrogen sensors. Samples were fabricated by depositing a catalytic metal thin film on a semi-insulating silicon substrate. A femtosecond laser was used to radiate terahertz waves from the sample in a gas cell filled with a hydrogen and nitrogen gas mixture. The peak amplitude of the terahertz waves decreased with increasing hydrogen concentration. We also fabricated a metal-oxide-semiconductor field effect transistor hydrogen sensor, and compared its properties with the terahertz radiation properties. These results suggest that the laser terahertz emission system is a potential tool to investigate catalytic metal/semiconductor interfaces.

Imaging of Chemical Reactions Using a Terahertz Chemical Microscope

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A terahertz technology for label-free immune assay

“…In our group, a THz chemical microscopy (TCM) has been proposed and developed in order to detect chemical reactions in the water solutions [8][9][10][11]. Recently, we have applied TCM to detect analyze with small molecules, which is generally difficult to detect using conventional SPR methods.…”

Highly sensitive hydrogen sensor based on suspended, functionalized single tungsten nanowire bridge

“…Among them, hydrogen gas sensors were extensively studied for their great potential needs in industrial applications [1][2][3]. To enhance sensitivity or to verify the sensing capability, various types of nanostructures have been adopted as hydrogen sensing structures including agglomerated WO 3 nanoparticles [4], single-walled carbon nanotubes with palladium nanoparticles [5], electrodeposited palladium nanowires [6,7], SnO 2 nanobelts dispersed on Si/SiO 2 substrate [8] and functionalized silicon nanowires [9].…”