X-ray photoelectron spectroscopy studies of aging effects on the surface of Au – a-Si:H – Sb-Cr Schottky diodes

1989 ◽  
Vol 67 (4) ◽  
pp. 365-369 ◽  
Author(s):  
L. Paquin ◽  
M. R. Wertheimer ◽  
E. Sacher ◽  
N. S. McIntyre
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gold Electrode ◽  
Schottky Diodes ◽  
Thick Layer ◽  
Analytical Techniques ◽  
Ambient Air ◽  
Antireflection Coating ◽  
Aging Effects ◽  
Au Electrode ◽  
X Ray

During investigations of Au – a-Si:H – Cr–Sb photovoltaic Schottky diodes, it was observed that photoconversion parameters (1sc, Voc, η) improved markedly with time for samples stored for several weeks in ambient air. This was always accompanied by apparent color changes in the area under the top (Au) electrode, from gold to deep purple, and by evolution of its surface conductivity (σ) from a highly conducting to an insulating state. Profilometry indicated that the colored area rose about 80 nm above the original surface during these changes. These diodes have been examined using depth-profiling surface analytical techniques, namely secondary-ion mass spectroscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy (XPS), but primarily the latter. The XPS studies of the entire layer thickness on the gold electrode were carried out using erosion by Ar+ ion bombardment. The XPS line positions were used to infer electrical properties of silicon and gold constituents.The results show that Si atoms first diffuse through the gold electrode, where they react with atmospheric constituents to form a thick layer composed mainly of SiO2. This layer is responsible for the observed changes in color, a, and 1sc. The latter change, which leads to a maximum rise in η of about 60%, is felt to result from the fact that the SiO2 layer acts as an antireflection coating. Gold from the electrode layer also diffuses outward, mixed intimately with the silicon oxide. Further aging results in a degradation of the electrical continuity of the Au electrode, which is believed to be responsible for the observed slow drop in η.

Synthesis of Silicon Thin Film by Electrodeposition from Ionic Liquid

2013 ◽  
Vol 650 ◽  
pp. 145-149 ◽  
Author(s):  
Je Sik Park ◽  
Jae Jun Park ◽  
Kyung Jung Kwon ◽  
Han Su Kim ◽  
Churl Kyoung Lee
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Gold Electrode ◽  
Room Temperature ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Elemental Silicon ◽  
Silicon Thin Film ◽  
X Ray ◽  
Reduction Current

The synthesis of a silicon thin film by room-temperature electrodeposition was investigated in the ionic liquids 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide ([EMIM]Tf2N) and 1-butyl-3-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMPy]Tf2N) with SiCl4. Cyclic voltammetry on a gold working electrode showed the possibility of the electrodeposition of elemental silicon. The reduction current of silicon in [EMIM]Tf2N was higher than in [BMPy]Tf2N. The elemental silicon thin film could be synthesized on the gold electrode under potentiostatic conditions, as confirmed by various analytical techniques including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy with energy-dispersive spectroscopy. In the [EMIM]Tf2N electrolyte with dissolved SiCl4, the electrodeposited Si surface was more uniform than in [BMPy]Tf2N and no impurity was detected except trace oxygen caused by contamination during handling for analysis

Interaction of nitric oxide with Ru(II) complexes of deuteroporphyrindimethylester derivatives

2009 ◽  
Vol 13 (01) ◽  
pp. 35-40 ◽  
Author(s):  
Rudy Martin ◽  
Roberto Cao ◽  
Ana M. Esteva ◽  
Franz-Peter Montforts
Keyword(s):  
Nitric Oxide ◽  
Photoelectron Spectroscopy ◽  
Gold Electrode ◽  
Charge Transfer Band ◽  
Bathochromic Shift ◽  
Considerable Change ◽  
Cathodic Peak ◽  
X Ray ◽  
Polycrystalline Gold ◽  
Self Assembled

A new ruthenium(II) porphyrin disulphide derivative, [ Ru ( Pds )( CO )], was obtained from ruthenium(II)(carbonyl)deuteroporphyrin(IX), [ Ru ( DPdc )( CO )] and cystamine. The interaction of this complex with nitric oxide was studied spectrophotometrically and a bathochromic shift of the charge transfer band and considerable change in the α and β bands of the complex were observed. According to the IR spectrum, the product of this interaction is [ Ru ( DmDP )( NO +)( NO 2-)]. [ Ru ( Pds )( CO )] was then self-assembled on polycrystalline gold and characterized by X-ray photoelectron spectroscopy. [ Ru ( Pds )( CO )] was also self-assembled on gold electrode beads and its interaction with nitric oxide in aqueous solution was studied by cyclic voltammetry. A shift in the ruthenium redox process and a new irreversible cathodic peak at -0.59 V were observed, both indicating coordination of NO .

Multiwalled Carbon Nanotubes Covered with Cobalt (II) Phthalocyanine by In Situ Synthesis and its Electrochemical Sensing Performance towards DA and UA

2014 ◽  
Vol 809-810 ◽  
pp. 43-52
Author(s):  
Hua Hua Wang ◽  
Nan Li ◽  
Kai Li ◽  
Yuan Bu ◽  
Wen Le Dai ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Simultaneous Detection ◽  
Thick Layer ◽  
Electrochemical Sensing ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Platinum Particles

Multiwalled carbon nanotubes (MWCNTs) as an excellent supporter covered with a thick layer of cobalt phthalocyanine (CoPc) were prepared by in-situ synthesis. Platinum particles were adopted to enhance the conductivity of CoPc-MWCNTs. The final nanocomposite Pt-CoPc-MWCNTs was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Strong aromatic π-π stacking between MWCNTs and CoPc made CoPc in-situ forming on MWCNTs. With homogeneous thickness of CoPc covered on the MWCNTs and Pt particles equally distributed, the nanocomposite was used as electrocatalyst. The electrochemical properties of the composite got researched by casting the dispersion of Pt-CoPc-MWCNTs on the glassy carbon electrode. Compared with other modified electrodes, Pt-CoPc-MWCNTs/GC electrode exhibited excellent electrochemical activity towards dopamine (DA) and uric acid (UA). Linear responses for DA and UA were obtained in the ranges of 5 to 170 μM and 5 to 100 μM, and limits of detection were 2.6 and 1.4 μM (S/N= 3), respectively. Simultaneous detection of DA and UA in the presence of ascorbic acid (AA) also displayed selective property, with no interference to each other.

Thermally Induced Superlow Friction of DLC Films in Ambient Air

2018 ◽  
Vol 37 (8) ◽  
pp. 725-731 ◽  
Author(s):  
Qunfeng Zeng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ambient Air ◽  
Friction Model ◽  
Repulsive Force ◽  
Hydroxyl Group ◽  
Thermally Induced ◽  
X Ray ◽  
Thermally Activated ◽  
Charged Interface ◽  
Positively Charged

AbstractThermally induced superlow friction (0.008) of diamond-like carbon (DLC) films was achieved in ambient air in the present work. Raman and XPS (X-ray Photoelectron Spectroscopy) measurements and analyses show that superlow friction of the annealed DLC films is involved in the transformation of sp3 to sp2 hybridized carbon during annealing and the tribochemical reactions during sliding. The thermally activated graphitization and oxidation of the annealed DLC films in ambient air is beneficial to form the positively charged interface and achieve the stable superlow friction. A friction model was developed and applied to explain superlow friction, which is attributed to Van de Waals force between graphite layers and the repulsive force between hydroxyl group of graphite oxide and hydrogen terminated DLC films surface.

Magnetic Nanoparticle Supported Ionic Liquid Phase Catalyst for Oxidation of Alcohols

2020 ◽  
Vol 73 (11) ◽  
pp. 1088
Author(s):  
Altafhusen Naikwade ◽  
Megha Jagadale ◽  
Dolly Kale ◽  
Gajanan Rashinkar
Keyword(s):  
Ionic Liquid ◽  
Liquid Phase ◽  
Photoelectron Spectroscopy ◽  
Magnetic Nanoparticle ◽  
Analytical Techniques ◽  
X Ray ◽  
Supported Ionic Liquid ◽  
Transmission Electron ◽  
Oxidation Of Alcohols ◽  
Ft Ir

A new magnetic nanoparticle supported ionic liquid phase (SILP) catalyst containing perruthenate anions was prepared by a multistep procedure. The various analytical techniques such as FT-IR spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, thermogravimetric analysis, energy dispersive X-ray analysis, and vibrating sample magnetometer analysis ascertained the successful formation of catalyst. The performance of a magnetically retrievable SILP catalyst was evaluated in the selective oxidation of alcohols. The split test and leaching studies of the SILP catalyst confirmed its heterogeneous nature. In addition, the reusability potential of SILP catalyst was also investigated which revealed its robust activity up to six consecutive cycles.

Characterization of Ti/TiN Films and SiO2/Ti Interfaces by Use of X-Ray Photoelectron Spectroscopy

1993 ◽  
Vol 318 ◽  
Author(s):  
Joffre Bernard ◽  
Ercan Adem ◽  
Seshadri Ramaswami
Keyword(s):  
Integrated Circuits ◽  
Photoelectron Spectroscopy ◽  
Ambient Air ◽  
Tin Films ◽  
X Ray ◽  
Surface And Interface ◽  
Surface Analysis Techniques ◽  
Contamination Levels ◽  
Reflective Coatings

ABSTRACTThe deposition and processing of thin films, such as barrier metals and anti-reflective coatings, can be enhanced using the information provided by various surface analysis techniques. We will show the application of x-ray photoelectron spectroscopy(XPS) to the production of Ti and TiN films suitable for use in ULSI CMOS integrated circuits. XPS can separate Ti and N photoelectron peaks and detect low (1.0-5.0 atomic%) contamination levels while providing surface and interface chemical state information. In this paper we will show that a) the effect of TiN deposition on subsequent Ti film quality from the same Ti target was determined to be minimal, b) the relation of anneal temperature to the extent of SiO2 reduction by Ti metal was characterized on SiO2/Ti/TiN structures for temperatures from 600°C to 800°C, and c) the absorption of O into TiN films from ambient air was detected and confirmed.

Spectroscopic Characterization of Wilkinson's Catalyst Using X-ray Photoelectron Spectroscopy (ESCA)

1982 ◽  
Vol 36 (3) ◽  
pp. 290-296 ◽  
Author(s):  
Manuel Carvalho ◽  
Larry F. Wieserman ◽  
David M. Hercules
Keyword(s):  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Analytical Techniques ◽  
Spectroscopic Characterization ◽  
Homogeneous Hydrogenation ◽  
X Ray ◽  
Wilkinson’S Catalyst ◽  
Ft Ir ◽  
Wilkinson's Catalyst

Wilkinson's catalyst, RhCl(PPh3)3 is a well known and widely used homogeneous hydrogenation catalyst. This catalyst was analyzed by ESCA which revealed that two rhodium species [Rh(I) and Rh(III)] were present, both for commercial preparations and for catalysts prepared in this laboratory. The ratio of Rh(I) to Rh(III) was 3:2 regardless of the source. A different method of synthesizing RhCl(PPh3)3 was used and produced a compound having only Rh(I) species. Additional analytical techniques such as elemental analysis, FT-IR, liquid chromatography, and 31P NMR were used to determine the origin of the higher binding energy peaks when Wilkinson's procedure was used to prepare RhCl(PPh3)3. Hydrogenation of cyclohexene was also performed to determine the effect of the higher binding energy species on catalytic activity.

Interaction of salicylic acid with zirconium diphosphate and its reactivity toward uranium (VI)

2018 ◽  
Vol 106 (4) ◽  
pp. 291-300
Author(s):  
Nidia García-González ◽  
Eduardo Ordoñez-Regil ◽  
María Guadalupe Almazán-Torres ◽  
Eric Simoni
Keyword(s):  
Salicylic Acid ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Analytical Techniques ◽  
Batch Method ◽  
Sorption Data ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Modified

AbstractThe interaction of salicylic acid with zirconium diphosphate surface and its reactivity toward uranium (VI) was investigated. The interaction of salicylic acid with zirconium diphosphate was firstly studied using several analytical techniques including atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The sorption of uranium (VI) onto surface-modified zirconium diphosphate was evaluated by the classical batch method at room temperature. This study showed that the uranium (VI) sorption onto zirconium diphosphate is influenced by the presence of salicylic acid. A fluorescence spectroscopy study revealed the presence of a uranyl specie onto the modified solid surface. The spectroscopy results were then used to restrain the modeling of experimental sorption data, which are interpreted in terms of a constant capacitance model using the FITEQL code. The results indicated that interaction between the uranium (VI) and the surface of zirconium diphosphate modified with salicylic acid leads to the formation of a ternary surface complex.

Further Development of Iodine Immobilization Technique by Low Temperature Vitrification With BiPbO2I

2009 ◽  
Author(s):  
Atsushi Mukunoki ◽  
Tamotsu Chiba ◽  
Yasuhiro Suzuki ◽  
Kenji Yamaguchi ◽  
Tomofumi Sakuragi ◽  
...  
Keyword(s):  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Structural Information ◽  
Scale Up ◽  
Melting Furnace ◽  
Analytical Techniques ◽  
Nuclear Magnetic Resonance Analysis ◽  
X Ray ◽  
Resonance Analysis ◽  
Chemical Conditions

The authors describe progress in the development of low temperature vitrification with BiPbO2I (BPI) as a promising immobilization technique by which Iodine-129 is recovered by BiPbO2NO3 to form BPI, and then solidified into a lead-boron-zinc glass matrix (PbO-B2O3-ZnO) using a low temperature vitrification process. The microscopic structure of BPI glass was analyzed by various analytical techniques, such as XRD (X-ray diffraction), NMR (nuclear magnetic resonance analysis), and XPS (X-ray photoelectron spectroscopy), using several types of glass samples. The results obtained provide structural information on key elements in BPI glass and can be applied for modeling the structure of the BPI glass, simulated by molecular dynamics. The previous work suggested that the leaching behavior of iodine from BPI glass depended upon the chemical conditions of the solution. Further leaching tests using solutions under varying conditions were carried out in order to predict mechanisms of iodine leaching. Normalized elemental mass loss values of iodine in simulated seawater and bentonite pore water are almost the same as those of boron, showing that iodine dissolves congruently with BPI glass, whereas iodine dissolves incongruently in Ca(OH)2 solutions of pH 9 and 11. To demonstrate the feasibility of the BPI vitrification process, recovery tests of iodine from spent iodine filters were conducted and a prototype melting furnace was developed for scale-up tests of glass sample. It was found that more than 95% of iodine can be recovered from the spent iodine filter and that the prototype furnace can produce approximately 0.5 liters of homogeneous glass.

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