Xps Analysis of the Sapphire Surface as a Function of High Temperature Vacuum Annealing

1989 ◽  
Vol 159 ◽  
Author(s):  
E.D. Richmond
Keyword(s):  
High Temperature ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Vacuum Annealing ◽  
Xps Analysis ◽  
Chemical Changes ◽  
Cleaning Procedure ◽  
Sapphire Surface ◽  
X Ray ◽  
First Time

ABSTRACTFor the first time the (1102) surface of sapphire has been investigated by X-ray photoelectron spectroscopy to ascertain chemical changes resulting from annealing in vacuum at 1300° C and 1450° C. As received substrates had a substantial surface C contaminant. For substrates that were chemically cleaned before inserting them into the MBE system no trace of carbon is detected. A residual flourine contaminant results from the cleaning procedure and is desorbed by the vacuum annealing. Spectra of annealed substrates are compared to the unannealed chemically cleaned substrates. The annealed substrates exhibit 0.4 to 0.5 eV shift to higher binding energy of the Al peak and a 0.3 eV shift to higher binding energy of the O peak. In addition, a 2% depletion of oxygen from the surface occurs.

scholarly journals X-ray Photoelectron Spectroscopy (XPS) Analysis of Undoped ZnO and ZnO:Er Thin Films

2015 ◽  
Vol 16 (1) ◽  
pp. 13
Author(s):  
Iwan Sugihartono ◽  
Esmar Budi ◽  
Agus Setyo Budi
Keyword(s):  
Thin Films ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Zno Thin Films ◽  
Xps Analysis ◽  
X Ray ◽  
Si Substrates ◽  
Ultrasonic Spray ◽  
P Type

Undoped ZnO and ZnO:Er  thin films were deposited on p-type Si substrates by ultrasonic spray pyrolisis (USP). Undoped and ZnO:Er thin films have been analyzed by using X-ray Photoelectron Spectroscopy (XPS). The results show that the XPS spectrum has two Er peak at ∼157 eV and ∼168 eV. The XPS Zn 2p spectrum of undoped ZnO and ZnO:Er thin films have binding energy for Zn 2p3/2 (~ 1021 eV) and Zn 2p1/2 (~1045eV) were found no shift in binding energy after the incorporation of Er. Meanwhile, after Er incorporates into ZnO, the O 1s spectrum is composed two peak of binding energy (BE) at ~530.5eV and the shoulder about 532.5 eV.Keywords: ZnO thin films, ZnO:Er, XPS, binding energy

Nanofunctionalized Phosphor Particles for Advanced Display Applications

2001 ◽  
Author(s):  
Michael Ollinger ◽  
Valentin Craciun ◽  
Rajiv Singh
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Degradation Rate ◽  
Binding Energies ◽  
Xps Analysis ◽  
Surface Chemical ◽  
Chemical Changes ◽  
X Ray ◽  
Two Peaks

Abstract Cathodoluminescence (CL) degradation measurements showed that by applying a nano meter scale indium tin oxide (ITO) coating on micron sized ZnS:Ag particulates the degradation lifetime was dramatically improved. X-ray photoelectron spectroscopy (XPS) analysis showed that the Zn 2p3/2 and S 2p3/2 peaks of the degraded ZnS:Ag were shifted to higher binding energies, which correspond to oxidized elements, with respect to those found for as-received ZnS:Ag. The XPS analysis for the ITO coated ZnS:Ag showed a broadening of the Zn 2p3/2 and S 2p3/2 peaks, which were a convolution of two peaks. In this case, the Zn 2p3/2 and S 2p3/2 peaks corresponding to ZnS were still present together with a small shoulder corresponding to the oxidized elements. This difference in the XPS shows that the ITO coating reduced the degradation rate by slowing the surface chemical changes on the ZnS:Ag.

scholarly journals Determination of chromium valence state in the CaO–SiO2–FeO–MgO–CrOx system by X-ray photoelectron spectroscopy

2020 ◽  
Vol 39 (1) ◽  
pp. 351-356
Author(s):  
Deman Liu ◽  
Jiang Diao ◽  
Yiyu Qiu ◽  
Guang Wang ◽  
Gang Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Binding Energy ◽  
Oxygen Pressure ◽  
Photoelectron Spectroscopy ◽  
Valence State ◽  
Slag Basicity ◽  
X Ray ◽  
Chromium Ions ◽  
Valence States

AbstractThe chromium valence states in the CaO–SiO2–FeO–MgO–CrOx system were investigated by X-ray photoelectron spectroscopy (XPS). The results indicated that the XPS peaks of Cr 2p3/2 and Cr 2p1/2 locate at the binding energy of ∼577 and ∼586 eV, respectively. There are three kinds of chromium ions such as bivalent Cr(ii), trivalent Cr(iii), and hexavalent Cr(vi) in the CaO–SiO2–FeO–MgO–CrOx slag. Cr(iii) is the dominant valence state, and more than 77.99% Cr is trivalent Cr(iii). The fraction of Cr(ii)/Cr is in the range of 11.24–17.22%. The fraction of Cr(vi)/Cr is below 4.80%. The fraction of Cr(ii)/Cr decreases with increasing slag basicity, Cr2O3 content, temperature, or oxygen pressure log(PO2), while the fraction of Cr(iii)/Cr increases with increasing basicity, Cr2O3 content, temperature, or oxygen pressure. The trend of change is opposite. Low log(PO2), high Cr2O3 content, and high temperature are beneficial to reduce the toxic hexavalent Cr(vi). The slag basicity has little influence on the fraction of Cr(vi)/Cr.

Effect of Implantation Dose and Annealing Time on the Formation of Si Nanocrystals Embedded in Thermal Oxide

2007 ◽  
Vol 1020 ◽  
Author(s):  
Cong Qian ◽  
Zheng-xuan Zhang ◽  
Feng Zhang ◽  
Cheng-lu Lin
Keyword(s):  
Annealing Time ◽  
Photoelectron Spectroscopy ◽  
Implantation Dose ◽  
Xps Analysis ◽  
Chemical Changes ◽  
X Ray ◽  
Si Nanocrystals ◽  
Thermal Oxide

AbstractPhotoluminescence (PL) and X-ray Photoelectron Spectroscopy (XPS) are employed to study the Si nanocrystals formed in the thermal oxide by Si+ implantation. PL results estimate the size of nanocrystals and the concentration of Pb centers in the Si-SiO2 nanocrystal-matrix interfaces. It is shown that the size of Si nanocrystals increase with implantation dose. Increasing the dose from 1×1016 to 1×1017 Si+/cm2 shifts the size of nanocrystals from ~2 nm to ~3.5nm, while prolonging the annealing time from 1h to 2h has no effect on the position of PL peak. P and Ar implantations into the SiO2 films are also investigated to suggested that the PL peak is due to implant induced chemical changes rather than implant induced damage. XPS analysis shows that the concentration of Si nanocrystals increases with Si implantation dose. Research on the annealing dependence of the forming of Si nanocrystals suggests that 1000°C annealing produces larger amount of Si nanocrystals than 1100°C annealing.

scholarly journals Near-Infrared Luminescence Investigation of Cr4+ ions Doped Germanate

2021 ◽  
Author(s):  
Fanming Zeng ◽  
Dongmei Wang ◽  
Xiliang Jiang ◽  
Zhuang Leng ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Photoelectron Spectroscopy ◽  
Doping Concentration ◽  
Near Infrared ◽  
Xps Analysis ◽  
X Ray Diffraction ◽  
Broad Application ◽  
X Ray ◽  
Infrared Luminescence ◽  
Luminescence Investigation

Abstract In this paper, the preparation of a series of Li2TiGe1-xCrxO5 phosphors by high-temperature solid-state reaction is reported. The results of X-ray diffraction show that the doping of Cr4+ ions makes the lattice expand to a larger size. X-ray photoelectron spectroscopy (XPS) analysis shows that the chromium ions in the sample are tetravalent, confirmed further by fluorescence spectroscopy. Under the excitation of 980nm laser, the Cr4+ ions 3T2 doped 3A2 radiates transition and emits light at 1300nm. At the same time, the luminescence lifetime decreases with the increase in Cr4+ ions doping concentration. Li2TiGe1-xCrxO5 phosphors have a broad application prospect in near-infrared LEDs.

scholarly journals X-ray Photoelectron Studies of High-temperature Superconductors: Evidence for the Importance of Alkaline Earth Metals

1989 ◽  
Vol 42 (4) ◽  
pp. 409 ◽  
Author(s):  
JF Dobson ◽  
AE Bocquet ◽  
PC Healy ◽  
S Myhra ◽  
AM Stewart ◽  
...  
Keyword(s):  
High Temperature ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Alkaline Earth ◽  
High Temperature Superconductors ◽  
Alkaline Earth Metals ◽  
X Ray ◽  
Binding Energy Peak ◽  
Energy Peak ◽  
Superconducting Ceramics

All high�temperature superconducting ceramics so far studied contain alkaline-earth ions, and in all cases core-level X-ray photoelectron spectroscopy shows an anomalous low-binding energy peak from these ions. We argue that this may point to electron-rich alkaline earth layers. These should be highly polarisable, allowing them to facilitate uperconductivity by screening the repulsion between electrons and/or holes in the CuD layers.

scholarly journals A novel and potentially scalable CVD-based route towards SnO2:Mo thin films as transparent conducting oxides

2021 ◽  
Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conducting Oxides ◽  
Valence States ◽  
3 Omega ◽  
First Time

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract

scholarly journals Reactive Dual Magnetron Sputtering: A Fast Method for Preparing Stoichiometric Microcrystalline ZnWO4 Thin Films

Surfaces ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 106-114
Author(s):  
Yannick Hermans ◽  
Faraz Mehmood ◽  
Kerstin Lakus-Wollny ◽  
Jan P. Hofmann ◽  
Thomas Mayer ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Fast Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Post Annealing ◽  
Rf Signal ◽  
First Time

Thin films of ZnWO4, a promising photocatalytic and scintillator material, were deposited for the first time using a reactive dual magnetron sputtering procedure. A ZnO target was operated using an RF signal, and a W target was operated using a DC signal. The power on the ZnO target was changed so that it would match the sputtering rate of the W target operated at 25 W. The effects of the process parameters were characterized using optical spectroscopy, X-ray diffraction, and scanning electron microscopy, including energy dispersive X-ray spectroscopy as well as X-ray photoelectron spectroscopy. It was found that stoichiometric microcrystalline ZnWO4 thin films could be obtained, by operating the ZnO target during the sputtering procedure at a power of 55 W and by post-annealing the resulting thin films for at least 10 h at 600 °C. As FTO coated glass substrates were used, annealing led as well to the incorporation of Na, resulting in n+ doped ZnWO4 thin films.

Formation of GaN Self-Organized Nanotips by Nanomasking Effect

2001 ◽  
Vol 707 ◽  
Author(s):  
Harumasa Yoshida ◽  
Tatsuhiro Urushido ◽  
Hideto Miyake ◽  
Kazumasa Hiramtsu
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Aspect Ratio ◽  
Formation Mechanism ◽  
High Aspect Ratio ◽  
Photoelectron Spectroscopy ◽  
Nanometer Scale ◽  
Xps Analysis ◽  
X Ray ◽  
Self Organized

ABSTRACTWe have successfully fabricated self-organized GaN nanotips by reactive ion etching using chlorine plasma, and have revealed the formation mechanism. Nanotips with a high density and a high aspect ratio have been formed after the etching. We deduce from X-ray photoelectron spectroscopy (XPS) analysis that the nanotip formation is attributed to nanometer-scale masks of SiO2 on GaN. The structures calculated by Monte Carlo simulation of our formation mechanism are very similar to the experimental nanotip structures.

Comparative Study of Time-Dependent PAES and XPS on a Ni/Pd Surface

2017 ◽  
Vol 373 ◽  
pp. 313-316 ◽  
Author(s):  
Samantha Zimnik ◽  
Christian Piochacz ◽  
Sebastian Vohburger ◽  
Christoph Hugenschmidt
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Structural Changes ◽  
Time Dependent ◽  
Xps Analysis ◽  
Time Constants ◽  
X Ray ◽  
Residual Gas ◽  
Rule Out

We report on time-dependent Positron annihilation induced Auger Electron Spectroscopy (PAES) study on 0.5 monolayers (ML) Ni on polycrystalline Pd accompanied by complementary X-ray induced Photoelectron Spectroscopy (XPS). The normalized PAES spectra showed a significant decrease in the Ni intensity and an increase in the Pd intensity as a function of time. To rule out varying influence on the elements e.g. from surface contaminates due to the residual gas, a time-dependent XPS analysis was performed on pure Ni and Pd as well as to analyze the main contaminants C and O. The O fraction was found to be constant within the measurement time and the time constants for C significantly differ from those of Ni and Pd in the PAES data. Consequently, it was concluded that the PAES data show a superposition of C contamination and structural changes at the surface of Ni/Pd.

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