High sensitivity (1 ppm) hydrogen detection using an unconventional Pd/n-InP Schottky device

Feng, Lei; Mitra, Joy; Dawson, Paul; Hill, G.

doi:10.1088/0953-8984/23/42/422201

Cited by 3 publications

(3 citation statements)

References 16 publications

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“…The exponential interdependence and thereby sensitivity is progressively muted with increasing voltage drop across the junction. The developed model not only enhances our understanding of the high sensitivity reported by Feng et al 31 and Chang et al 58 but crucially helps in optimization of the device parameter space for improved performance. We additionally note that the use of a high-resistance metal electrode in the active device region, inherent in the structure of this type of Schottky device, brings with it the corollary of facilitating better molecular access to the SB region through a very thin, highly porous metal electrode structure.…”

Section: Outlining the Application Potential Of The Alternative Mementioning

confidence: 87%

“…To re-iterate a key finding of that study, the sensitivity of R D to hydrogen concentration, C H , was significant for very low concentrations (C H < 20 ppm), since R D effectively probes the (inverse of) junction conductance, which changes significantly in the near-zero junction bias regime. By contrast, the hydrogen detection sensitivity of Schottky diodes operated in the conventional I-V measurement mode is extremely low for C H < 20 ppm, but increases rapidly in the range of 10 2 < C H < 10 4 before losing sensitivity for very high C H (refer Feng et al 31 and references therein). It is worth mentioning that in addition to the primary effect of interfacial atomic hydrogen altering the SB height, there is also a possible effect on the semiconductor resistance due to hydrogen passivation of the dopants, which may also, in turn, affect the barrier profile.…”

Section: Outlining the Application Potential Of The Alternative Mementioning

confidence: 99%

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An alternative methodology in Schottky diode physics

Mitra

Feng

Penate-Quesada³

et al. 2015

Journal of Applied Physics

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The fabrication and electrical characterization of Schottky junction diodes have been extensively researched for three-quarters of a century since the original work of Schottky in 1938. This study breaks from the highly standardized regime of such research and provides an alternative methodology that prompts novel, more efficient applications of the adroit Schottky junction in areas such as chemical and thermal sensing. The core departure from standard Schottky diode configuration is that the metal electrode is of comparable or higher resistance than the underlying semiconductor. Further, complete electrical characterization is accomplished through recording four-probe resistance-temperature (R D -T) characteristics of the device, where electrical sourcing and sensing is done only via the metal electrode and not directly through the semiconductor. Importantly, this results in probing a nominally unbiased junction while eliminating the need for an Ohmic contact to the semiconductor. The characteristic R D -T plot shows two distinct regions of high (metal) and low (semiconductor) resistances at low and high temperatures, respectively, connected by a crossover region of width, DT, within which there is a large negative temperature coefficient of resistance. The R D -T characteristic is highly sensitive to the Schottky barrier height; consequently, at a fixed temperature, R D responds appreciably to small changes in barrier height such as that induced by absorption of a chemical species (e.g., H 2 ) at the interface. A theoretical model is developed to simulate the R D -T data and applied to Pd/p-Si and Pt/p-Si Schottky diodes with a range of metal electrode resistance. The analysis gives near-perfect fits to the experimental R D -T characteristics, yielding the junction properties as fit parameters. The modelling not only helps elucidate the underlying physics but also helps to comprehend the parameter space essential for the discussed applications. Although the primary regime of application is limited to a relatively narrow range (DT) for a given type of diode, the alternative methodology is of universal applicability to all metalsemiconductor combinations forming Schottky contacts. V C 2015 AIP Publishing LLC.

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Section: Outlining the Application Potential Of The Alternative Mementioning

confidence: 87%

Section: Outlining the Application Potential Of The Alternative Mementioning

confidence: 99%

An alternative methodology in Schottky diode physics

Mitra

Feng

Penate-Quesada³

et al. 2015

Journal of Applied Physics

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“…The procedure could be applied to various semiconductor nanowires/nanopillars [72][73][74] where, moreover, such configurations offer a route to the realisation of high-aspect ratio Schottky diodes with the dual features of an enhanced, plasmonically resonant antenna response 75 and the possibility of using an alternative, simple 2-contact configuration for sensing applications. 76,77…”

Section: Discussionmentioning

confidence: 99%

Origin of enhancement in Raman scattering from Ag-dressed carbon-nanotube antennas: experiment and modelling

Raziman

Dueñas

Milne

et al. 2018

Phys. Chem. Chem. Phys.

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The D- and G-band Raman signals from random arrays of vertically aligned, multi-walled carbon nanotubes are significantly enhanced (up to ∼14×) while the signal from the underlying Si substrate is simultaneously attenuated (up to ∼6×) when the nanotubes are dressed, either capped or coated, with Ag. These Ag-induced counter-changes originate with the difference in geometry of the nanotubes and planar Si substrate and contrast in the Ag depositions on the substrate (essentially thin film) and the nanotube (nano-particulate). The surface integral equation technique is used to perform detailed modelling of the electromagnetic response of the system in a computationally efficient manner. Within the modelling the overall antenna response of the Ag-dressed nanotubes is shown to underpin the main contribution to enhancement of the nanotube Raman signal with hot-spots between the Ag nanoparticles making a subsidiary contribution on account of their relatively weak penetration into the nanotube walls. Although additional hot-spot activity likely accounts for a shortfall in modelling relative to experiment it is nonetheless the case that the significant antenna-driven enhancement stands in marked contrast to the hot-spot dominated enhancement of the Raman spectra from molecules adsorbed on the same Ag-dressed structures. The Ag-dressing procedure for amplifying the nanotube Raman output not only allows for ready characterisation of individual nanotubes, but also evidences a small peak at ∼1150 cm (not visible for the bare, undressed nanotube) which is suggested to be due to the presence of trans-polyacetylene in the structures.

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Study of hydrogen detection response time with Pt-gated diodes fabricated on AlGaN/GaN heterostructure

Liu

Hwang

et al. 2013

Journal of Vacuum Science &Amp; Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phen

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Articles you may be interested inMethane detection using Pt-gated AlGaN/GaN high electron mobility transistor based Schottky diodes J. Vac. Sci. Technol. B 31, 032203 (2013); 10.1116/1.4803743 Effect of humidity on hydrogen sensitivity of Pt-gated AlGaN/GaN high electron mobility transistor based sensors AlGaN/GaN-based metal-oxide-semiconductor diode-based hydrogen gas sensorThe hydrogen detection response time of Pt-gated diode sensors fabricated on AlGaN/GaN heterostructure as a function of the hydrogen concentration was investigated. A new method to extract the response time, taking the derivative of diode current, was proposed and shown to reduce the response time of detecting 1% hydrogen by about 60% as compared to the response time defined as the diode current reaching 90% of its total changes, t 90 . Hydrogen-sensing experiments were conducted at different temperatures, and an Arrhenius plot of the data determined an activation energy of 17.7 kJ/mole for the sensing process.

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High sensitivity (1 ppm) hydrogen detection using an unconventional Pd/n-InP Schottky device

Cited by 3 publications

References 16 publications

An alternative methodology in Schottky diode physics

An alternative methodology in Schottky diode physics

Origin of enhancement in Raman scattering from Ag-dressed carbon-nanotube antennas: experiment and modelling

Study of hydrogen detection response time with Pt-gated diodes fabricated on AlGaN/GaN heterostructure

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