Intrinsic n- and p-Type MgZnO Nanorods for Deep-UV Detection and Room-Temperature Gas Sensing

VO2(B), VO2(M), and V2O5 are the most famous compounds in the vanadium oxide family. Here, their gas-sensing properties were investigated and compared. VO2(B) nanoflakes were first self-assembled via a hydrothermal method, and then VO2(M) and V2O5 nanoflakes were obtained after a heat-phase transformation in nitrogen and air, respectively. Their microstructures were evaluated using X-ray diffraction and scanning and transmission electron microscopies, respectively. Gas sensing measurements indicated that VO2(M) nanoflakes were gas-insensitive, while both VO2(B) and V2O5 nanoflakes were highly selective to ammonia at room temperature. As ammonia sensors, both VO2(B) and V2O5 nanoflakes showed abnormal p-type sensing characteristics, although vanadium oxides are generally considered as n-type semiconductors. Moreover, V2O5 nanoflakes exhibited superior ammonia sensing performance compared to VO2(B) nanoflakes, with one order of magnitude higher sensitivity, a shorter response time of 14–22 s, and a shorter recovery time of 14–20 s. These characteristics showed the excellent potential of V2O5 nanostructures as ammonia sensors.

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Highly sensitive and selective room-temperature NO2 gas-sensing characteristics of SnOX-based p-type thin-film transistor

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2019.03.046 ◽

2019 ◽

Vol 288 ◽

pp. 625-633 ◽

Cited By ~ 14

Author(s):

Hwan-Seok Jeong ◽

Min-Jae Park ◽

Soo-Hun Kwon ◽

Hyo-Jun Joo ◽

Hyuck-In Kwon

Keyword(s):

Thin Film ◽

Room Temperature ◽

Gas Sensing ◽

Thin Film Transistor ◽

Highly Sensitive ◽

P Type ◽

Sensing Characteristics

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A Room Temperature Gas Sensor Based on Sulfonated SWCNTs for the Detection of NO and NO2

Sensors ◽

10.3390/s19051116 ◽

2019 ◽

Vol 19 (5) ◽

pp. 1116 ◽

Cited By ~ 6

Author(s):

Eusebiu Ionete ◽

Stefan Spiridon ◽

Bogdan Monea ◽

Elena Stratulat

Keyword(s):

Room Temperature ◽

Gas Sensing ◽

Electrical Response ◽

Long Term Stability ◽

Sensing Applications ◽

Specific Configuration ◽

P Type ◽

Walled Carbon Nanotubes ◽

Type Response

The electrical response of sulfonated single-walled carbon nanotubes (SWCNTs) to NO and NO2, for gas sensing applications, at room temperature, is reported in this work. A specific configuration based on SWCNT deposition between double pair configuration gold electrodes, supported on a substrate, was considered for the sensing device; employed characterization technique where FTIR and SEM. The experimental results showed a p-type response of the sulfonated SWCNTs, with decrease in resistance, under exposure to NO gas (40–200 ppb) and NO2 (40–200 ppb). Also, the sensor responses to successive exposures at NO2 800 ppb together with investigation of long term stability, at 485 ppb for NO, are reported. The reaction mechanism in case of NO and NO2 detection with sulfonated SWCNTs is presented.

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N-doped reduced graphene oxide for room-temperature NO gas sensors

Scientific Reports ◽

10.1038/s41598-021-99883-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yu-Sung Chang ◽

Feng-Kuan Chen ◽

Du-Cheng Tsai ◽

Bing-Hau Kuo ◽

Fuh-Sheng Shieu

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Room Temperature ◽

Gas Sensing ◽

Ambient Conditions ◽

Gas Sensitivity ◽

Nitrogen Doped ◽

Low Concentrations ◽

Reduced Graphene ◽

P Type

AbstractIn this study, we use nitrogen-doped to improving the gas-sensing properties of reduced graphene oxide. Graphene oxide was prepared according to a modified Hummers’ method and then nitrogen-doped reduced graphene oxide (N-rGO) was synthesized by a hydrothermal method using graphene oxide and NH4OH as precursors. The rGO is flat and smooth with a sheet-like morphology while the N-rGO exhibits folded morphology. This type of folding of the surface morphology can increase the gas sensitivity. The N-rGO and the rGO sensors showed n-type and p-type semiconducting behaviors in ambient conditions, respectively, and were responsive to low concentrations of NO gases (< 1000 ppb) at room temperature. The gas-sensing results showed that the N-rGO sensors could detect NO gas at concentrations as low as 400 ppb. The sensitivity of the N-rGO sensor to 1000 ppb NO (1.7) is much better than that of the rGO sensor (0.012). Compared with pure rGO, N-rGO exhibited a higher sensitivity and excellent reproducibility.

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Butane Sensing Property of Si-ZnO Nanowires p-n Junction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.364.260 ◽

2011 ◽

Vol 364 ◽

pp. 260-265 ◽

Cited By ~ 3

Author(s):

T.Y. Tiong ◽

Chang Fu Dee ◽

M.M. Salleh ◽

Majlis B. Yeop ◽

M. Yahaya

Keyword(s):

Room Temperature ◽

Gas Sensing ◽

Zno Nanowires ◽

Vapour Transport ◽

Initial State ◽

Resistance Change ◽

Boron Doped ◽

Doped Silicon ◽

Minimum Power Consumption ◽

P Type

The p-n junction has been formed by using p-type boron doped silicon and n-type ZnO nanowires (NWs). It was prepared by using simple vapour-transport deposition method. Gas sensing property has been examined by measuring the resistance change of the junction sample towards 1 % of butane gas at room temperature. Significant improvement of sensing behaviour was observed from the fabricated junction sample when it was compared to sample of non-p-n junction ZnO NWs. The increase in the sensitivity of the p-n junction ZnO NWs and the ability to regain the sensing power by returning back to the initial state at room temperature are useful for future sensing device with minimum power consumption. Keywords: ZnO nanowires, Si-ZnO nanowires p-n junction, room temperature sensing and butane gas

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Получение нанокомпозитов МУНТ/MnO-=SUB=-2-x-=/SUB=-, МУНТ/MnO-=SUB=-2-x-=/SUB=-/CuO и исследования их газочувствительных свойств

Физика твердого тела ◽

10.21883/ftt.2019.11.48435.536 ◽

2019 ◽

Vol 61 (11) ◽

pp. 2240

Author(s):

Ю.А. Стенькин ◽

В.В. Болотов ◽

Д.В. Соколов ◽

В.Е. Росликов ◽

К.Е. Ивлев

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Copper Oxide ◽

Photoelectron Spectroscopy ◽

Room Temperature ◽

Gas Sensing ◽

Multiwalled Carbon ◽

X Ray ◽

P Type ◽

Scanning Electron

Nanocomposites based on multiwalled carbon nanotubes (MWCNT) with manganese dioxide (MnO2-x) and copper oxide (CuO) were obtained and investigated. The morphology and elemental composition of MWCNT-layer and nanocomposites MWCNT/MnO2-х, MWCNT/MnO2-х/CuO were studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The gas sensing response of MWCNT-layer and nanocomposites upon exposure to hydrogen sulfide (H2S) and nitrogen dioxide (NO2) was demonstrated at room temperature. Effect of increasing the conductivity of MWCNT-layer and nanocomposites upon exposure to NO2 indicates these nanomaterials have conductive of p-type. Copper oxide in nanocomposite significantly enhances the gas sensing response to H2S.

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Reversible Room Temperature H2 Gas Sensing Based on Self-Assembled Cobalt Oxysulfide

Sensors ◽

10.3390/s22010303 ◽

2021 ◽

Vol 22 (1) ◽

pp. 303

Author(s):

Hui Zhou ◽

Kai Xu ◽

Nam Ha ◽

Yinfen Cheng ◽

Rui Ou ◽

...

Keyword(s):

Room Temperature ◽

Elevated Temperatures ◽

Gas Sensing ◽

Low Cost ◽

High Sensitivity ◽

Cobalt Sulfide ◽

Bandgap Energy ◽

Gas Molecules ◽

Self Assembled ◽

P Type

Reversible H2 gas sensing at room temperature has been highly desirable given the booming of the Internet of Things (IoT), zero-emission vehicles, and fuel cell technologies. Conventional metal oxide-based semiconducting gas sensors have been considered as suitable candidates given their low-cost, high sensitivity, and long stability. However, the dominant sensing mechanism is based on the chemisorption of gas molecules which requires elevated temperatures to activate the catalytic reaction of target gas molecules with chemisorbed O, leaving the drawbacks of high-power consumption and poor selectivity. In this work, we introduce an alternative candidate of cobalt oxysulfide derived from the calcination of self-assembled cobalt sulfide micro-cages. It is found that the majority of S atoms are replaced by O in cobalt oxysulfide, transforming the crystal structure to tetragonal coordination and slightly expanding the optical bandgap energy. The H2 gas sensing performances of cobalt oxysulfide are fully reversible at room temperature, demonstrating peculiar p-type gas responses with a magnitude of 15% for 1% H2 and a high degree of selectivity over CH4, NO2, and CO2. Such excellent performances are possibly ascribed to the physisorption dominating the gas–matter interaction. This work demonstrates the great potentials of transition metal oxysulfide compounds for room-temperature fully reversible gas sensing.

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Highly sensitive and room temperature detection of ultra-low concentrations of O3 using self-powered sensing elements of Cu2O nanocubes

Nanoscale Advances ◽

10.1039/c9na00043g ◽

2019 ◽

Vol 1 (5) ◽

pp. 2009-2017 ◽

Cited By ~ 2

Author(s):

E. Petromichelaki ◽

E. Gagaoudakis ◽

K. Moschovis ◽

L. Tsetseris ◽

T. D. Anthopoulos ◽

...

Keyword(s):

Metal Oxides ◽

Room Temperature ◽

Gas Sensing ◽

Low Cost ◽

New Class ◽

Temperature Detection ◽

Low Concentrations ◽

Highly Sensitive ◽

Self Powered ◽

P Type

The fundamental development of the design of novel self-powered ozone sensing elements, operating at room temperature, based on p-type metal oxides paves the way to a new class of low cost, highly promising gas sensing devices.

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Room-Temperature H2 Gas Sensing Characterization of Graphene-Doped Porous Silicon via a Facile Solution Dropping Method

10.20944/preprints201710.0106.v1 ◽

2017 ◽

Author(s):

Nu Si A Eom ◽

Hong-Baek Cho ◽

Yoseb Song ◽

Woojin Lee ◽

Tohru Sekino ◽

...

Keyword(s):

Porous Silicon ◽

Gas Sensor ◽

Room Temperature ◽

Gas Sensing ◽

Electrochemical Etching ◽

Sensor Material ◽

Sensing Mechanism ◽

Si Substrates ◽

H2 Sensor ◽

P Type

In this study, a graphene-doped porous silicon (G-doped/p-Si) substrate for low ppm H2 gas detection by an inexpensive synthesis route was proposed as a potential noble graphene-based gas sensor material and to understand the sensing mechanism. The G-doped/p-Si gas sensor was synthesized by a simple capillary force-assisted solution dropping method on p-Si substrates, whose porosity was generated through an electrochemical etching process. G-doped/p-Si was fabricated with various graphene concentrations and exploited as a H2 sensor operated at room temperature. The sensing mechanism of the sensor with/without graphene decoration on p-Si was proposed to elucidate the synergetic gas sensing effect generated from the interface between the graphene and p-type silicon.

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