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

Choi, Jungwook; Kim, Jongbaeg

doi:10.1016/j.snb.2008.10.046

Cited by 58 publications

(20 citation statements)

References 35 publications

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“…The microelectrodes are fabricated on a heavily doped silicon-on-insulator (SOI) wafer with 50µm device layer and 1µm buried oxide using single photolithography step, deep reactive ion etching (DRIE) and the following wet etching in hydrofluoric acid. Scanning ion microscope (SIM) image in Fig4 (b) shows the nanowire bridge connecting two microelectrodes with bonded aluminum wire for signal measurement (Choi et al, 2009). The nanowire is synthesized by FIB-CVD on microelectrodes and constant current is applied between the microelectrodes and through the nanowire to monitor the voltage drop when it is exposed to hydrogen gas.…”

Section: Applications Of Metal Oxide Nanostructuresmentioning

confidence: 99%

“…The nanowire is synthesized by FIB-CVD on microelectrodes and constant current is applied between the microelectrodes and through the nanowire to monitor the voltage drop when it is exposed to hydrogen gas. (b) SIM image of microelectrodes and suspended single tungsten nanowire bridge with bonded aluminum wire (Choi et al, 2009). …”

Section: Applications Of Metal Oxide Nanostructuresmentioning

confidence: 99%

See 1 more Smart Citation

Survey of the Application Nanoscale Material in Chemical Sensors

Masrournia¹,

Ahmadabadi²

2012

Advances in Chemical Sensors

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Section: Applications Of Metal Oxide Nanostructuresmentioning

confidence: 99%

Section: Applications Of Metal Oxide Nanostructuresmentioning

confidence: 99%

Survey of the Application Nanoscale Material in Chemical Sensors

Masrournia¹,

Ahmadabadi²

2012

Advances in Chemical Sensors

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“…In metal-oxide semiconductors, n-type semiconductors based on WO 3 have high sensitivity for (0.5 ppm) NO x gas detection (Takafumi et al 2013;Akiyama et al 1991;Tamaki et al 2008). In the past decade, tungsten-oxide nanostructures (NSs) have been considered as a promising functional material for catalysis and gas-sensing application, because of its photocatalytic, electrochromic, gasochromic and field emission properties (Sawicka et al 2005;Meng et al 2012;Choi and Kim 2009;Serrano et al 2011;Li et al 2001;Liao et al 2006;Luo et al 2009). In WO 3 -based NO 2 gas sensors, the adsorption of NO 2 (oxidizing gases) on the n-type WO 3 modifies the potential barrier between the grain boundaries of WO 3 due to the depletion of charge carriers, leading to a change in electrical conductance (Zhao et al 2000;Teoh et al 2003;Zeng et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Ni-catalysed WO3 nanostructures grown by electron beam rapid thermal annealing for NO2 gas sensing

et al. 2015

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Ni-catalysed WO 3 (Ni-WO 3 ) nanowires and nanosheets were grown on Si (100) substrates using electron beam evaporation followed by electron beam-assisted rapid thermal annealing process. Gassensing measurements were performed for various concentrations of NO 2 in dry air at a temperature range of 50-400°C. Nanowires and nanosheets show optimum sensor response of 229 and 197 at operating temperatures of 200 and 250°C, respectively, for 100 ppm of NO 2 exposure. Nanowires demonstrated a rapid response time of 66 s, but a slow recovery time of 204 s owing to poor rate of desorption of the adsorbed NO 2 gas molecules from the internal porous structure of nanowires. In contrast, the recovery time for nanosheet was 126 s due to higher desorption rate of the adhered NO 2 molecules associated with low surface area and less porous structure of nanosheet. The gas-sensing mechanism of WO 3 nanostructure is discussed briefly.

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“…The sensitivity of SMO sensors is typically enhanced by embedding noble metal catalysts such as Pd and Pt. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] In the recent past, several variants of Pd nanostructures have been developed to enhance the sensitivity of H 2 sensors, with room temperature sensing capability for low power applications. Yang et al 8 have used lithographically patterned Pd nanowire electrodeposition (LPNE) to achieve a room temperature sensitivity of about 1% at 50 ppm.…”

Section: Introductionmentioning

confidence: 99%

Suspended core-shell Pt-PtOx nanostructure for ultrasensitive hydrogen gas sensor

Basu

Kallatt

Anumol

et al. 2015

Journal of Applied Physics

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High sensitivity gas sensors are typically realized using metal catalysts and nanostructured materials, utilizing non-conventional synthesis and processing techniques, incompatible with on-chip integration of sensor arrays. In this work, we report a new device architecture, suspended core-shell Pt-PtOx nanostructure that is fully CMOS-compatible. The device consists of a metal gate core, embedded within a partially suspended semiconductor shell with source and drain contacts in the anchored region. The reduced work function in suspended region, coupled with builtin electric field of metal-semiconductor junction, enables the modulation of drain current, due to room temperature Redox reactions on exposure to gas. The device architecture is validated using Pt-PtO 2 suspended nanostructure for sensing H 2 down to 200 ppb under room temperature. By exploiting catalytic activity of PtO 2 , in conjunction with its p-type semiconducting behavior, we demonstrate about two orders of magnitude improvement in sensitivity and limit of detection, compared to the sensors reported in recent literature. Pt thin film, deposited on SiO 2 , is lithographically patterned and converted into suspended Pt-PtO 2 sensor, in a single step isotropic SiO 2 etching. An optimum design space for the sensor is elucidated with the initial Pt film thickness ranging between 10 nm and 30 nm, for low power (<5 lW), room temperature operation. V C 2015 AIP Publishing LLC. [http://dx.

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

Cited by 58 publications

References 35 publications

Survey of the Application Nanoscale Material in Chemical Sensors

Survey of the Application Nanoscale Material in Chemical Sensors

Ni-catalysed WO3 nanostructures grown by electron beam rapid thermal annealing for NO2 gas sensing

Suspended core-shell Pt-PtOx nanostructure for ultrasensitive hydrogen gas sensor

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