scholarly journals Effect of Nitrogen Doping on the Photoluminescence of Amorphous Silicon Oxycarbide Films

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 649 ◽  
Author(s):  
Jie Song ◽  
Rui Huang ◽  
Yi Zhang ◽  
Zewen Lin ◽  
Wenxing Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Nitrogen Doping ◽  
Silicon Oxycarbide ◽  
Chemical Bonds ◽  
X Ray ◽  
Nitrogen Doped ◽  
Orange Yellow ◽  
Luminescent Films ◽  
Decay Dynamic ◽  
Luminescent Centers

The effect of nitrogen doping on the photoluminescence (PL) of amorphous SiCxOy films was investigated. An increase in the content of nitrogen in the films from 1.07% to 25.6% resulted in red, orange-yellow, white, and blue switching PL. Luminescence decay measurements showed an ultrafast decay dynamic with a lifetime of ~1 ns for all the nitrogen-doped SiCxOy films. Nitrogen doping could also widen the bandgap of SiCxOy films. The microstructure and the elemental compositions of the films were studied by obtaining their Raman spectra and their X-ray photoelectron spectroscopy, respectively. The PL characteristics combined with an analysis of the chemical bonds configurations present in the films suggested that the switching PL was attributed to the change in defect luminescent centers resulting from the chemical bond reconstruction as a function of nitrogen doping. Nitrogen doping provides an alternative route for designing and fabricating tunable and efficient SiCxOy-based luminescent films for the development of Si-based optoelectronic devices.

29Si NMR and XPS Investigation of the Structure of Silicon Oxycarbide Glasses Derived from Polysiloxane Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
R.J.P. Corriu ◽  
D. Leclercq ◽  
P.H. Mutin ◽  
A. Vioux
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
Random Distribution ◽  
Silicon Oxycarbide ◽  
29Si Nmr ◽  
Xps Spectra ◽  
Excess Carbon ◽  
X Ray ◽  
Silicon Oxycarbide Glasses

ABSTRACTTwo silicon oxycarbide glasses with different compositions (O/Si ratio 1.2 and 1.8) were prepared by pyrolysis at moderate temperature (900 °C) of polysiloxane precursors. Their structure was investigated using quantitative 29Si solid-state NMR and X-ray photoelectron spectroscopy (XPS). The environment of the silicon atoms in the oxycarbide phase corresponded to a purely random distribution of Si-O and Si-C bonds depending on the O/Si ratio of the glass only and not on the structure of the precursors. At the light of the NMR results, the Si2p XPS spectra of the glasses may be interpreted using the contribution of the five possible SiOxC4-x tetrahedra. The Cls spectra of these glasses indicated the presence of oxycarbide carbon in CSi4 tetrahedra, similar to carbide carbon, and graphitic-like excess carbon.

Oxidation of silicon carbide and the formation of silica polymorphs

2006 ◽  
Vol 21 (10) ◽  
pp. 2550-2563 ◽  
Author(s):  
Maxime J-F. Guinel ◽  
M. Grant Norton
Keyword(s):  
Silicon Carbide ◽  
Photoelectron Spectroscopy ◽  
Polycrystalline Silicon ◽  
Ambient Pressure ◽  
Silicon Oxycarbide ◽  
Oxide Scales ◽  
X Ray ◽  
Transmission Electron ◽  
Polycrystalline Silicon Carbide ◽  
Crystalline Films

The oxidation of both single crystal and relatively pure polycrystalline silicon carbide, between 973 and 2053 K, resulted in the formation of cristobalite, quartz, or tridymite, which are the stable crystalline polymorphs of silica (SiO2) at ambient pressure. The oxide scales were found to be pure SiO2 with no contamination resulting from the oxidizing environment. The only variable affecting the occurrence of a specific polymorph was the oxidation temperature. Cristobalite was formed at temperatures ≥1673 K, tridymite between 1073 and 1573 K, and quartz formed at 973 K. The polymorphs were determined using electron diffraction in a transmission electron microscope. These results were further confirmed using infrared and Raman spectroscopies. Cristobalite was observed to grow in a spherulitic fashion from amorphous silica. This was not the case for tridymite and quartz, which appeared to grow as oriented crystalline films. The presence of a thin silicon oxycarbide interlayer was detected at the interface between the SiC substrate and the crystalline silica using x-ray photoelectron spectroscopy.

Field emission properties of nitrogen-doped diamond-like carbon films deposited by direct metal ion beam deposition

2001 ◽  
Vol 697 ◽  
Author(s):  
Kie Moon Song ◽  
Namwoong Paik ◽  
Steven Kim ◽  
Daeil Kim ◽  
Seongjin Kim ◽  
...  
Keyword(s):  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Nitrogen Doping ◽  
Ion Beam ◽  
Diamond Like Carbon ◽  
Emission Data ◽  
Nitrogen Doped ◽  
Ion Beam Deposition ◽  
Beam Deposition

AbstractNitrogen-doped diamond-like carbon (DLC) films were deposited on a silicon substrate by direct metal ion beam deposition (DMIBD). Partial pressures of nitrogen gas were changed to get different compositions of nitrogen in the DLC films. The composition and surface morphology of the films were examined using X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). Effect of nitrogen doping on field emission property was studied. The field emission data indicated that the nitrogen doping lowered the turn-on field and increase the current density. It was believed that doping of nitrogen into the DLC film plays an important role in enhancement of the field emission. This enhancement of field emission could be explained by the improvement of electron transport through nitrogen-dope DLC layer.

Hydrogenation and dehydrogenation of nitrogen-doped graphene investigated by X-ray photoelectron spectroscopy

2015 ◽  
Vol 634 ◽  
pp. 89-94 ◽  
Author(s):  
F. Späth ◽  
W. Zhao ◽  
C. Gleichweit ◽  
K. Gotterbarm ◽  
U. Bauer ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

scholarly journals Hydrothermal Activation of Porous Nitrogen-Doped Carbon Materials for Electrochemical Capacitors and Sodium-Ion Batteries

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2163 ◽  
Author(s):  
Yuliya V. Fedoseeva ◽  
Egor V. Lobiak ◽  
Elena V. Shlyakhova ◽  
Konstantin A. Kovalenko ◽  
Viktoriia R. Kuznetsova ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nanomaterials ◽  
Carbon Materials ◽  
Sodium Ion ◽  
Carbon Surface ◽  
Energy Storage And Conversion ◽  
Sodium Ion Batteries ◽  
X Ray ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Highly porous nitrogen-doped carbon nanomaterials have distinct advantages in energy storage and conversion technologies. In the present work, hydrothermal treatments in water or ammonia solution were used for modification of mesoporous nitrogen-doped graphitic carbon, synthesized by deposition of acetonitrile vapors on the pyrolysis products of calcium tartrate. Morphology, composition, and textural characteristics of the original and activated materials were studied by transmission electron microscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, infrared spectroscopy, and nitrogen gas adsorption method. Both treatments resulted in a slight increase in specific surface area and volume of micropores and small mesopores due to the etching of carbon surface. Compared to the solely aqueous medium, activation with ammonia led to stronger destruction of the graphitic shells, the formation of larger micropores (1.4 nm vs. 0.6 nm), a higher concentration of carbonyl groups, and the addition of nitrogen-containing groups. The tests of nitrogen-doped carbon materials as electrodes in 1M H2SO4 electrolyte and sodium-ion batteries showed improvement of electrochemical performance after hydrothermal treatments especially when ammonia was used. The activation method developed in this work is hopeful to open up a new route of designing porous nitrogen-doped carbon materials for electrochemical applications.

Interaction between Graphene Oxide and the Mycelia of Morchella sextelata

NANO ◽  
2020 ◽  
Vol 15 (03) ◽  
pp. 2050035
Author(s):  
Renhao Tan ◽  
Jiwei Li ◽  
Li Zhou ◽  
Lu Zhou ◽  
Jia Lei ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Growth Process ◽  
Culture Media ◽  
Xps Analysis ◽  
Potential Harm ◽  
X Ray ◽  
Nitrogen Doped ◽  
Mda Content ◽  
High Level

Graphene oxide (GO) is expected to be harmful to the environment due to the toxicity. Accordingly, this work aimed to assess the potential harm of GO to the environment by investigating the toxicity of GO to the M. sextelata, and the effects of M. sextelata to GO. The dry weights, IR spectra, morphology, ultra-structures of mycelia, pH, conductivities of culture media, the activity of superoxide dismutase (SOD) and malondialdehyde (MDA) contents were measured to display the potential hazards of GO to M. sextelata. Then the Raman spectroscopy, dispersibility, and X-ray photoelectron spectroscopy (XPS) of GO were measured to show the effect of M. sextelata on GO. The results indicated that the lower GO concentrations promoted the growth of M. sextelata while the high level of GO inhibited the growth process of M. sextelata. After 7 d of culture, the effect was suppressive, with the biomass significantly reduced by 10.10%, the MDA content of G200 increased by 69.06%. GO nanosheets covered the surface of mycelia which caused change of the mycelial microstructures. Correspondingly, M. sextelata induces more defects in GO, accompanied by poor dispersion of GO in ethanol. Based on the XPS analysis, in the G10, G50 and G200 treatments, their atomic percentage of nitrogen in GO increased by 3.03%, 4.28% and 2.2%, respectively, and the atomic percentage of oxygen in GO reduced by 8.61%, 9.42% and 4.09%, respectively. The effect of mycelia on GO is mainly in deoxygenated and nitrogen-doped. We expected that the above results would provide a reference for the environmental hazard of GO.

Fabrication of Nickel Sulfide/Nitrogen-Doped Reduced Graphene Oxide Nanocomposite as Anode Material for Lithium-Ion Batteries and Its Electrochemical Performance

2020 ◽  
Vol 20 (11) ◽  
pp. 6782-6787
Author(s):  
Yeon-Ju Lee ◽  
Tae-Hyun Ha ◽  
Gyu-Bong Cho ◽  
Ki-Won Kim ◽  
Jou-Hyeon Ahn ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Lithium Ion ◽  
Treatment Method ◽  
Retention Capacity ◽  
Graphene Nanocomposites ◽  
X Ray ◽  
Nitrogen Doped ◽  
Reduced Graphene

In this study, NiS/graphene nanocomposites were synthesized by simple heat treatment method of three graphene materials (graphene oxide (GO), reduced graphene oxide (rGO) and nitrogen-doped graphene oxide (N-rGO)) and NiS precursor. The morphology and crystal structure of NiS/graphene nanocomposites were characterized using field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Electrochemical properties were also investigated. NiS/graphene nanocomposites homogeneously wrapped by graphene materials have been successfully manufactured. Among the three nanocomposites, NiS/N-rGO nanocomposite exhibited the highest initial and retention capacity in discharge, respectively, of 1240 mAh/g and 467 mAh/g up to 100 cycles at 0.5 C.

Surface Structure of Sulfur Coated GaAs

1989 ◽  
Vol 163 ◽  
Author(s):  
Yoshihisa Fujisaki ◽  
Shigeo Goto
Keyword(s):  
Electron Beam ◽  
Surface Structure ◽  
Chemical Bond ◽  
Photoelectron Spectroscopy ◽  
Strong Dependence ◽  
High Energy ◽  
Chemical Bonds ◽  
High Energy Electron ◽  
X Ray ◽  
Beam Diffraction

AbstractSurface structure of (NH4)2S treated GaAs. is investigated using PL (PhotoLuminescence), XPS (X-ray Photoelectron Spectroscopy) and RHEED (Reflection of High Energy Electron beam Diffraction). The data taken with these techniques show the strong dependence upon the crystal orientations coming from the stabilities of chemical bonds of Ga-S and As-S on GaAs crystals. The greater enhancement of PL intensity, the clearer RHEED patterns and the smaller amount of oxides on (111)A than (111)B implies the realization of a more stable structure composed mainly of the Ga-S chemical bond.

Preparation of N-doped TiO2 by oxidizing TiN and its application on phenol degradation

2013 ◽  
Vol 68 (4) ◽  
pp. 934-939 ◽  
Author(s):  
Ji-Guo Huang ◽  
Xiao-Guang Zhao ◽  
Meng-Yang Zheng ◽  
Sen Li ◽  
Yu Wang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Phenol Degradation ◽  
Light Sources ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Doped Tio2 ◽  
X Ray ◽  
Nitrogen Doped ◽  
Different Temperatures

Incomplete oxidation of titanium nitride (TiN) to prepare nitrogen-doped TiO2 was verified by calcining TiN at different temperatures in air for 30 min. The as-prepared samples were characterized by X-ray diffraction, UV-Vis diffuse reflectance spectra and X-ray photoelectron spectroscopy. The results confirmed that oxidizing TiN incompletely is an effective and simple method to prepare nitrogen-doped TiO2. Photocatalytic degradation of phenol was conducted to evaluate the photocatalytic activity of as-prepared samples. The results showed that phenol can be degraded efficiently by the as-prepared samples under visible light; low phenol concentration was conducive to degradation; the optimum calcination temperature and photocatalyst dosage are 650 °C and 0.5 g/L, respectively. The effects of different light sources on phenol degradation were compared. The reusability of nitrogen-doped TiO2 was tested and the results indicated a relatively good reusability under laboratory conditions.

Preparation and Characterization of N Doped TiO2/ Sepiolite Composite Materials

2011 ◽  
Vol 284-286 ◽  
pp. 597-600
Author(s):  
Dai Mei Chen ◽  
Hai Peng Ji ◽  
Jian Xin Wang ◽  
Jian Chen ◽  
Xin Long Luan ◽  
...  
Keyword(s):  
Composite Materials ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrogen Doped ◽  
Nitrogen Contents ◽  
Scanning Electron ◽  
Oxygen Atoms

Nitrogen doped TiO2/sepiolite composite materials (N-TiO2/sep) with different nitrogen contents were prepared by a sol-gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), respectively. XRD and SEM results showed that anatase-TiO2nanoparticles were distributed homogenously on the surface of sepiolite. XPS revealed that N atoms could incorporate into the lattice of anatase TiO2substituting the oxygen atoms sites of oxygen atoms.

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