A Study on the Transition of Copper Oxide by the Incorporation of Nitrogen

In the present study, the effects of nitrogen incorporation on the transition of a p-type copper oxide semiconductor are investigated. The properties of sputtered copper oxide and nitrogen-incorporated copper oxide are evaluated and compared at various nitrogen gas flow rates. The results indicate that the addition of nitrogen results in an increased optical bandgap, accompanied by significantly reduced tail states compared to pristine copper oxide. In addition, X-ray diffraction and X-ray photoelectron spectroscopy reveal that the incorporation of nitrogen stimulates the transition from copper (II) oxide to copper (I) oxide.

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Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽

10.3390/coatings11080937 ◽

2021 ◽

Vol 11 (8) ◽

pp. 937

Author(s):

Yingying Hu ◽

Md Rasadujjaman ◽

Yanrong Wang ◽

Jing Zhang ◽

Jiang Yan ◽

...

Keyword(s):

Crystal Structure ◽

Optical Properties ◽

Photoelectron Spectroscopy ◽

Crystal Size ◽

Silicon Substrates ◽

X Ray Diffraction ◽

Dc Magnetron Sputtering ◽

Flow Rates ◽

X Ray ◽

N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

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Gold nanoclusters reductively deposited on porous silicon: morphology and electronic structures

Canadian Journal of Chemistry ◽

10.1139/v98-146 ◽

1998 ◽

Vol 76 (11) ◽

pp. 1707-1716 ◽

Cited By ~ 30

Author(s):

I Coulthard ◽

S Degen ◽

Y -J Zhu ◽

T K Sham

Keyword(s):

Gold Nanoparticles ◽

Porous Silicon ◽

Photoelectron Spectroscopy ◽

Gold Nanoclusters ◽

Gold Complex ◽

X Ray Diffraction ◽

Complex Ions ◽

X Ray ◽

Preparation Conditions ◽

P Type

Utilizing porous silicon as a reducing agent and a substrate, gold complex ions [AuCl4]- were reduced from aqueous solution to produce nanoparticles of gold upon the surface of porous silicon. Scanning electron microscopy (SEM) was utilized to study the morphology of the porous silicon layers and the deposits of gold nanoparticles. It is found that preparation conditions have a profound effect on the morphology of the deposits, especially on porous silicon prepared from a p-type wafer. The gold nanoparticles, varying from micrometric aggregates of clusters of the order of 10 nm, to a distribution of nearly spherical clusters of the order of 10 nm, to strings of ~10 nm were observed and compared to bulk gold metal using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). These techniques confirm and complement the SEM findings. The potential for this reductive deposition technique is noted.Key words: gold nanostructures, reductive deposition, porous silicon, morphology, X-ray spectroscopy.

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Nitrogen-Doping Induced Optical Bandgap Widening of P-Type Cu2O Flms

MRS Proceedings ◽

10.1557/proc-1217-y03-38 ◽

2009 ◽

Vol 1217 ◽

Author(s):

Yoshitaka Nakano ◽

Shu Saeki ◽

Takeshi Morikawa

Keyword(s):

Photoelectron Spectroscopy ◽

Structural Changes ◽

Optical Bandgap ◽

Bandgap Energy ◽

X Ray Diffraction ◽

X Ray ◽

N Doping ◽

Hall Effect Measurements ◽

Optical Bandgap Energy ◽

P Type

AbstractWe have investigated the effect of N doping into Cu2O films deposited by reactive magnetron sputtering. With increasing N-doping concentration up to 3 at.%, the optical bandgap energy is enlarged from ˜2.1 to ˜2.5 eV with retaining p-type conductivity as determined by optical absorption and Hall-effect measurements. Additionally, photoelectron spectroscopy in air measurements shows an increase in the valence and conduction band shifts with N doping. These experimental results demonstrate possible optical bandgap widening of p-type N-doped Cu2O films, which is a phenomenon that is probably associated with significant structural changes induced by N doping, as suggested from x-ray diffraction measurements.

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Effect of Duty Cycle on Pulse Electrodeposited Tin Seleno Telluride Semiconductor Thin Film

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1107.643 ◽

2015 ◽

Vol 1107 ◽

pp. 643-648

Author(s):

Chew Ping Chia ◽

Zulkarnain Zainal ◽

Yusran Sulaiman ◽

Sook Keng Chang

Keyword(s):

Thin Film ◽

Duty Cycle ◽

Dendritic Structure ◽

X Ray Diffraction ◽

Direct Transition ◽

Nitrogen Gas ◽

Xrd Pattern ◽

X Ray ◽

Structure Morphology ◽

P Type

Tin seleno telluride thin film was deposited by pulse electrodeposition onto fluorine doped tin oxide coated glass from aqueous solution containing Sn-EDTA, Na2SeO3 and TeO2. The sample was deposited at a potential of-0.40 V vs Ag/AgCl with various duty cycle between 10% to 90% followed by annealing under nitrogen gas at 250°C for 30 minutes. The crystalline structure, morphology and photoresponse of the thin film was analyzed using X-ray diffraction (XRD), scanning electron microscopy and linear sweep photovoltammetry techniques. The XRD pattern shows polycrystalline cubic structure of SnSe0.4Te0.6 for film deposited at 50% duty cycle. The domain peak at 2θ=28.82o shows a high intensity and a better photoresponse due to the small crystalline size. The tin seleno telluride thin film reflects the loose short rod type aggregates at 10%-50% duty cycle and dendritic structure was formed at deposition of 75% and above. The deposited tin seleno telluride is a p-type semicoductor and the band gap was found to be 1.60 eV with direct transition.

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Synthesis of Silicon Nitride Ceramic Fibers and the Effect of Nitrogen Atmosphere on their Morphology

Materials Science Forum ◽

10.4028/www.scientific.net/msf.922.92 ◽

2018 ◽

Vol 922 ◽

pp. 92-97 ◽

Cited By ~ 1

Author(s):

Sotaro Baba ◽

Tomoyo Goto ◽

Sung Hun Cho ◽

Tohru Sekino

Keyword(s):

Silicon Nitride ◽

Gas Flow ◽

Sol Gel ◽

Heat Treating ◽

Treatment Method ◽

Nitrogen Atmosphere ◽

Ceramic Fibers ◽

Nitrogen Gas ◽

Flow Rates ◽

X Ray

The effect of nitrogen gas flow rate on the morphology of silicon nitride fibers obtained via carbothermal nitridation heat treatment method was investigated. A precursor containing silicon, oxygen and carbon was obtained by a sol-gel method from a mixture of tetraethyl orthosilicate, polyvinyl alcohol, H2O and ethanol. A white wool-like product was obtained by heat treating the precursor placed in an alumina crucible under a 0.5 MPa nitrogen gas pressure at 1500oC with different nitrogen gas flow rates. The mass-based production rates of the samples obtained from the precursor powder were 20-30% for the different nitrogen gas flow rates. X-ray diffraction analysis revealed that the samples contained α-Si3N4 as the major phase along with β-Si3N4, Si2N2O and a small amount of amorphous product as minor phases. Unique twisted fibers with diameters of several hundreds of nanometers were found among the straight fibers by SEM observation. Elemental analysis using energy dispersive X-ray spectroscopy indicated that silicon and nitrogen were contained in the twisted fibers along with approximately 68 at.% of oxygen and several at.% of aluminum, which might have come from the crucible material. The SiAlON-like structures might have been formed by the partial dissolution of Al and O in the Si3N4 fibers. It was considered that the twisted morphology of some fibers might be formed by co-existing of β-SiAlON and/or amorphous phase regions in the Si3N4 fiber and resultant distortion of the fibers.

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Morphological and structural evolutions of nonequilibrium titanium-nitride alloy powders produced by reactive ball milling

Journal of Materials Research ◽

10.1557/jmr.1992.0888 ◽

1992 ◽

Vol 7 (4) ◽

pp. 888-893 ◽

Cited By ~ 57

Author(s):

M. Sherif El-Eskandarany ◽

K. Sumiyama ◽

K. Aoki ◽

K. Suzuki

Keyword(s):

Electron Microscopy ◽

Titanium Nitride ◽

Gas Flow ◽

Lattice Parameter ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Nitrogen Gas ◽

X Ray ◽

Grain Sizes ◽

Transmission Electron

Nonequilibrium titanium-nitride alloy powders have been fabricated by a high energetic ball mill under nitrogen gas flow at room temperature and characterized by means of x-ray diffraction, scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry. Initial hcp titanium is completely transformed to nonequilibrium-fcc Ti–N after 720 ks of the milling time. The fcc Ti–N phase is stable at relatively low temperature and transforms at 855 K to Ti2N and δ phases. At the final stage of milling, the particle- and grain-sizes of alloy powders are 1 mm and 5 nm, respectively, and the lattice parameter is 0.419 nm.

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Oxidation Stabilization of ZrFe Alloys in Nitrogen Gas Atmosphere

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2021.59.10.754 ◽

2021 ◽

Vol 59 (10) ◽

pp. 754-760

Author(s):

Kwangbae Kim ◽

Saera Jin ◽

Yesol Lim ◽

Hyunjun Lee ◽

Seonghoon Kim ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Elevated Temperatures ◽

Nitrogen Atmosphere ◽

Metallic Silver ◽

X Ray Diffraction ◽

Alloy Specimen ◽

Surface Color ◽

Nitrogen Gas ◽

X Ray ◽

Gas Atmosphere

A porous ZrFe alloy specimen was prepared as a 6 × 3 mm (diameter × thickness) disk. The reaction of the ZrFe alloy was confirmed while the whole system was maintained at a target temperature, which was increased from 150 oC to 950 oC in a 99.999% low purity nitrogen atmosphere, consisting of 10 ppm of impurity gas. Surface color, pore size, stabilized layer, and phase change were confirmed with optical microscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Micro-Raman, according to temperature. The surface color of the ZrFe alloy changed from metallic silver to dark gray as the temperature increased. In the EDS and XPS results, nitrogen component was not observed, and oxygen content increased on each surface at the elevated temperatures. In this way, the ZrFe alloy was stabilized in a low purity nitrogen atmosphere, preventing rapid nitride reactions.

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Defect Passivation and Carrier Reduction Mechanisms in Hydrogen-Doped In-Ga-Zn-O (IGZO:H) Films upon Low-Temperature Annealing for Flexible Device Applications

Materials ◽

10.3390/ma15010334 ◽

2022 ◽

Vol 15 (1) ◽

pp. 334

Author(s):

Rostislav Velichko ◽

Yusaku Magari ◽

Mamoru Furuta

Keyword(s):

Low Temperature ◽

Photoelectron Spectroscopy ◽

Oxygen Diffusion ◽

Gas Flow ◽

Hydrogen Gas ◽

Oxide Semiconductor ◽

Activation Temperature ◽

X Ray ◽

Gas Flow Ratio ◽

Temperature Activation

Low-temperature activation of oxide semiconductor materials such as In-Ga-Zn-O (IGZO) is a key approach for their utilization in flexible devices. We previously reported that the activation temperature can be reduced to 150 °C by hydrogen-doped IGZO (IGZO:H), demonstrating a strong potential of this approach. In this paper, we investigated the mechanism for reducing the activation temperature of the IGZO:H films. In situ Hall measurements revealed that oxygen diffusion from annealing ambient into the conventional Ar/O2-sputtered IGZO film was observed at >240 °C. Moreover, the temperature at which the oxygen diffusion starts into the film significantly decreased to 100 °C for the IGZO:H film deposited at hydrogen gas flow ratio (R[H2]) of 8%. Hard X-ray photoelectron spectroscopy indicated that the near Fermi level (EF) defects in the IGZO:H film after the 150 °C annealing decreased in comparison to that in the conventional IGZO film after 300 °C annealing. The oxygen diffusion into the film during annealing plays an important role for reducing oxygen vacancies and subgap states especially for near EF. X-ray reflectometry analysis revealed that the film density of the IGZO:H decreased with an increase in R[H2] which would be the possible cause for facilitating the O diffusion at low temperature.

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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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H2S Sensing Properties of Added Copper Oxide in WO3

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.543.145 ◽

2013 ◽

Vol 543 ◽

pp. 145-149 ◽

Cited By ~ 1

Author(s):

Rasoul Nowrouzi ◽

Fatemeh Razi Astaraei ◽

Shima Kashani ◽

Azam Iraji Zad

Keyword(s):

Copper Oxide ◽

Photoelectron Spectroscopy ◽

Recovery Time ◽

Gas Detection ◽

X Ray Diffraction ◽

Pure Tungsten ◽

Hydrogen Atoms ◽

X Ray ◽

Structure Morphology ◽

Scanning Electron

We study Hydrogen sulfide gas detection properties of pure and 1% copper oxide added WO3 thin films. The spin coated deposits on alumina substrates were annealed at 500 C for 1 hour in order to improve the crystallinity of the films. The sensitivity of pure tungsten oxide is poor even at temperatures of about 100 C but the doped samples exhibit good response to H2S gas. Our data show sensitivity of about 1500 in 10 ppm diluted gas in air at 100 C. The films are sensitive to the gas even at 250 ppb (sensitivity about 2) H2S concentration at 100 C but with rather long recovery time. Crystal structure, morphology and chemical composition of samples were studied by X-Ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses. We suggest that Cu2O dopants dissociate H2S molecules and spillover of the hydrogen atoms onto the cracked WO3 surface. The reaction of dissociated H2S with adsorbed oxygen is the main reason for reduction of resistivity.

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