A titanium dioxide-based MOS hydrogen sensor

Yadava, Lallan; Dwivedi, R.; Srivastava, S.K.

doi:10.1016/0038-1101(90)90025-a

Cited by 17 publications

(15 citation statements)

References 21 publications

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“…The maximum sensitivity was found $88% at lower frequency (25 kHz) at 4000 ppm H 2 . However, gridded Pt/SiO 2 /Si MOS structure shows better sensitivity to H 2 as reported, [12][13][14] while keeping the SiO 2 film thickness same. The high sensitivity of gridded Pt/SiO 2 /Si MOS structure to H 2 is attributed to the side diffusion of H 2 molecules, increase in surface area of Pt film due to large porosity found in the film, high polarizability of SiO 2 , spill-over mechanism, and increase in fixed surface state density with H 2 concentration.…”

Section: Discussionmentioning

confidence: 76%

“…During this process, some carriers may get trapped inside SiO 2 resulting in an increase in fixed surface state density. 12 The increase fixed surface state density effects the depletion layer, upon exposure to H 2 , appears to be responsible for a better H 2 response of the device based on SiO 2 . 12 Therefore, the change in fixed surface state density is attributed to high diffusibility and high polarizability of H 2 in SiO 2.…”

Section: Resultsmentioning

confidence: 97%

“…[18][19][20] In spite of this, the gridded Pt gate MOS sensor has shown better sensitivity as reported by earlier methods. [12][13][14] The high response is attributed to the following reasons: 16 (i) the porous and gridded gate structure increase the diffusibility of H 2 , so that more number of H 2 atoms will reach at Pt-SiO 2 interface which forms the strong dipole layer at the interface results in decrease in Pt work function causes decrease in flat band voltage and linear increase in fixed surface state density, refer Figure 7, 21,22 (ii) better chemical absorption of H 2 in air ambient atmosphere in gridded Pt/SiO 2 /Si MOS sensor. In ambient air, anions on Pt surface will be (like O À 2 , O À , and O 2À ) more.…”

Section: Resultsmentioning

confidence: 97%

“…24 The effect of H 2 on flat band voltage of MOS structure can be described by the following model. 12 The change in flat band voltage of Pt gate MOS sensor upon exposure to H 2 is partially due to a change in the metal work function has been described by several researchers. Another effects which are responsible for shift in flat band voltage are H 2 induced drift (HID) and the formation of interface state.…”

Section: Resultsmentioning

confidence: 98%

“…In such gridded metal gate structures, the sensitivity of device is incredibly enhanced towards several H 2 containing gases like H 2 S, NH 3 , etc. 11 Yadava et al 12 have observed $47% sensitivity towards H 2 in Pd/TiO 2 /Si MOS structure in N 2 ambient atmosphere.…”

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confidence: 97%

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Influence of gridded gate structure on gas sensing behavior of hydrogen

Kumar

Sunny

Dwivedi

et al. 2014

Journal of Applied Physics

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A gridded Pt/SiO2/Si MOS sensor for hydrogen detection has been fabricated on p-type ⟨100⟩ Si wafer having resistivity (1–6 Ω cm). The SiO2 and Platinum (Pt) gate thickness were kept about 10 nm and 35 nm. The performance of Pt gate MOS sensor was evaluated through C-V characteristics (capacitance vs voltage) upon exposure to H2 (250 ppm–4000ppm) at different frequencies (25 kHz and 50 kHz) in a closed chamber at air ambient atmosphere. The capacitance of the sensor decreases with increase in frequency as well as H2 gas concentration. The flat band voltage characteristics have been evaluated at different frequencies and concentrations. It decreases as the frequency and concentration of gas both increases. The maximum flat band voltage change was observed −0.6 V at 25 kHz. The sensor exhibits better sensitivity (∼88%) at low frequency (25 kHz). The high response of sensor is attributed to the side wall diffusion, increase in surface area caused by inner side wall and increase in porosity, increase in fixed surface state density, spill-over mechanism and change in interface state density on exposure of gas along with the formation of dipole layer.

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Section: Discussionmentioning

confidence: 76%

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 98%

mentioning

confidence: 97%

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Influence of gridded gate structure on gas sensing behavior of hydrogen

Kumar

Sunny

Dwivedi

et al. 2014

Journal of Applied Physics

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Work Function‐Based Metal–Oxide–Semiconductor Hydrogen Sensor and Its Functionality: A Review

Sahoo

Kale

2021

Adv Materials Inter

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Solar PV and wind energy conversion systems convert input energy directly to electricity, are techno-economically viable, and have already achieved grid parity. [3,4] Though renewables fulfill most modern energysource criteria, they still possess low energy density, are challenging to transport, less efficient, costly, and are intrinsically intermittent, thus requiring a storage media.Hydrogen, a less popular renewable, can be used as a fuel as apart from being abundant gas, possesses high energy density, [5] exhibits better combustion characteristics, [5] owes a nonpolluting nature, [6] and has several other favorable properties, listed in Table 1. Hydrogen is a promising alternative energy source [6,7] that overcomes most of the challenges faced by classical renewables.Figure 2 describes hydrogen energy transformation from primary energy sources to the end-users in an integrated way. The hydrogen production, storage, transportation and delivery, application, awareness and capacity building, safety codes and standards are all interrelated to form the hydrogen energy system. The two prime methods of producing hydrogen are i) from the conventional process, and ii) using renewable energy sources (such as biomass, solar, wind, and hydro). Hydrogen possesses significantly higher gravimetric energy density than other storage techniques (such as batteries, pumped hydropower, supercapacitors, Flywheels, pressurized air). The use of abundant renewable energy when available, hydrogen production, and storage is an optimal choice. Hydrogen can be stored as pressurized gas or as a cryogenic liquid or solid fuel. [27] Storage of hydrogen as a gas typically requires high-pressure tanks (350-700 bar tank pressure). Due to the low boiling point (−252.8 °C at atmospheric pressure), liquid hydrogen storage requires cryogenic temperature.The conventional conversion of fossil fuel feedstock to hydrogen includes steam-methane reforming, thermal cracking of natural gas, thermal decomposition (partial oxidation) of heavy oil, catalytic decomposition of natural gas, coal gasification, and steam-iron coal gasification. [20][21][22][23][24][25] When released into the atmosphere, the conventional methods generate CO 2 as a by-product, assisting global warming. The generation of renewable hydrogen makes it more economical and environmentally benign. Electrolysis uses electrical power supplied from renewables to produce hydrogen and oxygen. Biomass routes Hydrogen, a nonpolluting gas, is emerging as an ideal, suitable, and economical energy carrier. The current global non-carbon hydrogen production is 105.8 MW in 2020 and is expected to reach 218 MW in 2021. Hydrogen possesses low ignition energy of 0.017 mJ and reacts exothermically with air, posing severe safety challenges. Humanly undetectable gas needs accurate and sensitive sensors to prevent accidents. Amongst different hydrogen sensors currently developed, work function-based sensors are sensitive, selective, costeffective, smaller in size, less susceptible to environmental change, an...

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Thick-film hydrogen sensor

Mishra

Agarwal

1994

Sensors and Actuators B: Chemical

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A titanium dioxide-based MOS hydrogen sensor

Cited by 17 publications

References 21 publications

Influence of gridded gate structure on gas sensing behavior of hydrogen

Influence of gridded gate structure on gas sensing behavior of hydrogen

Work Function‐Based Metal–Oxide–Semiconductor Hydrogen Sensor and Its Functionality: A Review

Thick-film hydrogen sensor

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