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XPS depth profile spectra of A) the O1s peak of bulk PS, B) the O1s peak of surface PS, and C) the C1s peak of surface PS. The spectra are normalized in order to visualize all peaks. 

XPS depth profile spectra of A) the O1s peak of bulk PS, B) the O1s peak of surface PS, and C) the C1s peak of surface PS. The spectra are normalized in order to visualize all peaks. 

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Efficient anti-reflection coatings (ARC) improve the light collection and thereby increase the current output of solar cells. By simple electrochemical etching of the Si wafer, porous silicon (PS) layers with excellent broadband anti-reflection properties can be fabricated. In this work, ageing of graded PS has been studied using Spectroscopic Elli...

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Context 1
... peak located at 99.7 eV has a 0.3 eV higher binding energy than elemental Si, which means that it is probably due to Si 3 SiH. XPS spectra of the O1s peak for surface and bulk PS is presented in Figure 4 together with the surface PS spec- tra of the C1s peak. The O1s spectrum of both surface and bulk PS have two clear peaks. ...
Context 2
... smaller peak at higher bind- ing energy may therefore be due to C-OH and/or C-O-C. Bulk PS after 42 days shows an additional peak at 531.7 eV, which may be due to C=O. Figure 4 also shows the C1s peak of surface PS. The spectra can be fitted with two peaks located at a binding energy of 284.5 eV and 286.5 eV. ...

Citations

... (e,f) Nyquist plots for the silicane-based electrodes in different cycles.higher energies, such as Si(III) (102.5 eV) and Si(IV) (103.5 eV), may originate from the partial or complete oxidation of silicon.45 However, the intense signals of Si(III) and Si(IV) do not indicate that the samples are mostly oxidized because XPS is only sensitive to the surface of silicane, which is inevitably oxidized when exposed to air or water. ...
... The first peak is related to metal oxygen bonds, in this case Ti -O [57]. The second peak falls in the region of C-O or C--O bonds [ [51,55,58,59]). Since we did not observe C--O bonds in C1s spectrum in case of HC Butox, it is more likely that the 532.0 eV peak is related to C -O. The third peak is related to C-OH, and the 536.7 eV corresponds to region where adsorbed oxygen or water exist [55,58,59]. ...
... Since we did not observe C--O bonds in C1s spectrum in case of HC Butox, it is more likely that the 532.0 eV peak is related to C -O. The third peak is related to C-OH, and the 536.7 eV corresponds to region where adsorbed oxygen or water exist [55,58,59]. The O1s spectrum of HC Butox W was deconvoluted into three peaks. ...
... The first one at 530.4 eV corresponds to both Ti-O and W-O [ [57,60]). The second peak appearing at 531.8 eV is related to C--O bond [51,59]. The third peak appears at the region of C-O and C-OH at 533.3 eV [51,55,59], and based on C1s spectrum we do not want to rule out the presence of either of the two. ...
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Hydrothermal carbonization was used to develop novel carbon-based hybrids for the removal of diclofenac and amoxicillin from water. These non-crystalline and partly graphitic materials can be regenerated by photocatalysis. The synthesized materials have beneficial oxygen containing surface functional groups, of which CO were observed only for tungsten-containing hybrid. An interaction between W, C and TiO2 was observed, which could influence the photocatalytic performance. The best performance was observed for W-containing hybrid (HC butox W) at pH 3 (diclofenac photocatalytic degradation of 80% and removal of 93% after 60 min). Significant part of the removal appeared due to precipitation of diclofenac on the hybrid material surface. Removal efficiency was fully recovered after regeneration at pH 7 under uv-B irradiation. With the same hybrid, 10% removal of amoxicillin after 30 min with 42% photocatalytic degradation at non-adjusted pH was reached. In general, tungsten improved the photocatalytic activity of material, while specific surface area played only a minor role.
... A similar peak at 103.6 eV has previously been assigned to the Si 4+ of SiO 2 . 50 The formation of SiO 2 in our data is furthermore supported by the loss of signal from the previously added Si, as seen by the strong attenuation of the Si2 signal. Comparing the Si 2p core levels from inside and outside the growth regions, the new SiO 2 feature does not appear in Region II but rather a small tail of intermediate oxide states (Si x O y ). ...
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The large-scale formation of patterned, quasi-freestanding graphene structures supported on a dielectric has so far been limited by the need to transfer the graphene onto a suitable substrate and contamination from the associated processing steps. We report μm scale, few-layer graphene structures formed at moderate temperatures (600–700 °C) and supported directly on an interfacial dielectric formed by oxidizing Si layers at the graphene/substrate interface. We show that the thickness of this underlying dielectric support can be tailored further by an additional Si intercalation of the graphene prior to oxidation. This produces quasi-freestanding, patterned graphene on dielectric SiO2 with a tunable thickness on demand, thus facilitating a new pathway to integrated graphene microelectronics.
... In our analysis, all the spectra were referenced to the most intense PS peak present at 284.8 eV where the prominent contribution of saturated C 1s emission is typically identifiable in hydrocarbons. [16,54,55] The shake-up peak, corresponding to the p-p* transition of the aromatic ring in PS with a binding energy between 291.0 and 293.0 eV, is also clearly discernible especially for the layer of PS560k. The quantitative analysis performed on the spectra of the C 1s band is suggesting increased adsorption onto silicon surface with different PS molecular weights. ...
Article
Hypothesis: Solid-state polymer adsorption offers a distinct approach for surface modification. These ultrathin, so-called Guiselin layers can easily be obtained by placing a polymer melt in contact with an interface, followed by a removal of the non-adsorbed layer with a good solvent. While the mechanism of formation has been well established for Guiselin layers, their stability, crucial from the perspective of materials applications, is not. The stability is a trade-off in the entropic penalty between cooperative detachment of the number of segments directly adsorbed on the substrate and consecutively pinned monomers. Experiments: Experimental model systems of Guiselin layers of polystyrene (PS) on silicon wafers with native oxide layer on top were employed. The stability of the adsorbed layers was studied as a function of PS molecular weight and polydispersibility by various microscopic and spectroscopic tools as well as dynamic contact angle measurements. Findings: Adsorbed layers from low molecular weight PS were disrupted with typical spinodal decomposition patterns whereas high molecular weight (>500 kDa) PS resulted in stable, continuous layers. Moreover, we show that Guiselin layers offer an enticing way to modify a surface, as demonstrated by adsorbed PS that imparts a hydrophobic character to initially hydrophilic silicon wafers.
... The peak shift of 1.3 eV from 102.2 to 103.5 eV is attributed to oxidation from Si 3+ to Si 4+ . [34] Si 3+ and Si 4+ correspond to Si 2 O 3 and SiO 2 , respectively, with their binding energies of 102.2 and 103.5 eV and FWHM of 1.7-1.9 eV and 1.7-2.0 ...
... eV. [34] These oxides serve as fillers in the epoxy. Fig. 7(h) presents atomic concentration of each components deconvoluted from O 1 s as a function of plasma power and compares with the untreated surface. ...
... Analysis from ToF-SIMS is focused on identifying major compounds [diglycidyl ether of bisphenol A (DGEBA), curing agent, carbon black, and SiO 2 ] and LMWOM available in epoxy. One of the positive ions is cycling hydrocarbon C 22 H 16 (m/z = 280) derived from DGEBA and ocresol novolac [34][35] that were detected on the epoxy (Table 1S) and the raw data of 400-W plasma-treated surface is shown in Fig. 1S. This is an indication of intact polymer chains of epoxy available in the material. ...
Article
Strong adhesion between epoxy and silicone is essential for optoelectronic packaging. The adhesion of epoxy can be enhanced by microwave plasma treatment in oxygen flow. However, the plasma effect is time dependent. The shear strength of un-aged and aged epoxy for up to two months was systematically investigated as a function of plasma power (200 – 600 W) with different surface analysis tools. The shear strength between epoxy and silicone assembly was correlated with surface wettability, chemical, and structural properties. 300-W plasma-treated epoxy revealed the highest shear strength and the factors contributing to the improved strength were identified. The phenomenon of hydrophobic recovery was recorded after ageing, which had minimal effect on the reduction of shear strength. By keeping the plasma-treated surface for up to two months, a significant increment of shear strength was demonstrated below one week of ageing. Beyond that, a slight deterioration of the strength was observed but the reduction was still higher than the un-aged surface. The reasons behind of these observations have been elucidated and justified.
... The Si 2p XPS spectra showed an intense peak centred at 103.7 eV and a small feature at the low binding energy side (~ 102 eV) as indicated by an arrow. The main peak is assigned to Si 4+ while low binding energy is indicative of Si in the low-oxidation state (3+) [33]. The O 1s spectra also displayed two main features where a high binding energy component is consistent with Si-oxide [33], while low binding energy component is representative of Mn-oxide [34]. ...
... The main peak is assigned to Si 4+ while low binding energy is indicative of Si in the low-oxidation state (3+) [33]. The O 1s spectra also displayed two main features where a high binding energy component is consistent with Si-oxide [33], while low binding energy component is representative of Mn-oxide [34]. The observed binding energies of Al 2p and Ge 2p core-level spectra identify the presence of Al2O3 [35] and GeO2 [36]. ...
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The oxidation kinetics and mechanisms of higher manganese silicides (HMS) MnSi1.75, MnSi (1.75-x)Gex, MnSi(1.75-x)Alx (with x = 0.005 and 0.01)were studied and the effects of densification methods and dopant concentration discussed. Oxidation experiments were conducted using thermogravimetry (TGA), while post characterization with X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscope (SEM) showed that spark plasma sintering (SPS) is a better densification method than hot pressing (HP). Except for undoped HMS, HMS doped with 0.5at% Ge had the lowest oxidation rate. Stable formation of a SiO2 protective layer was the main reason for improved oxidation resistance in air in the temperature range 200 °C-500 °C.
... As shown in Figure S7, the fitted Si 2P spectra of the Si@graphene samples had three peaks located at ∼99.0, ∼101, and ∼103 eV, corresponding to Si 0 , Si 2+ , and Si 4+ , respectively. 40,41 Both Si 2+ (101 eV) and Si 4+ (103 eV) belonged to SiO x, which preserved the Si NPs and prevented direct contact with the electrolyte, which improved the stability of the LIB electrochemical perform-ACS Sustainable Chemistry & Engineering pubs.acs.org/journal/ascecg Research Article ance. ...
... These significant characteristic peaks confirm the presence of a polyhydroxyethyl methacrylate (PHEMA) coating layer atop the control membrane. It is also worth noting that the O1s spectrum of control membrane is only dominated by two main peaks at 532.3 eV and 533.3 eV which belong to C-O-C and S=O bonds, respectively [35,36]. Figure 6 compares the water contact angle of AA-and HEMA-modified membranes at various plasma deposition times. ...
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In this work, several ultrafiltration (UF) membranes with enhanced antifouling properties were fabricated using a rapid and green surface modification method that was based on the plasma-enhanced chemical vapor deposition (PECVD). Two types of hydrophilic monomers-acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) were, respectively, deposited on the surface of a commercial UF membrane and the effects of plasma deposition time (i.e., 15 s, 30 s, 60 s, and 90 s) on the surface properties of the membrane were investigated. The modified membranes were then subjected to filtration using 2000 mg/L pepsin and bovine serum albumin (BSA) solutions as feed. Microscopic and spectroscopic analyses confirmed the successful deposition of AA and HEMA on the membrane surface and the decrease in water contact angle with increasing plasma deposition time strongly indicated the increase in surface hydrophilicity due to the considerable enrichment of the hydrophilic segment of AA and HEMA on the membrane surface. However, a prolonged plasma deposition time (>15 s) should be avoided as it led to the formation of a thicker coating layer that significantly reduced the membrane pure water flux with no significant change in the solute rejection rate. Upon 15-s plasma deposition, the AA-modified membrane recorded the pepsin and BSA rejections of 83.9% and 97.5%, respectively, while the HEMA-modified membrane rejected at least 98.5% for both pepsin and BSA. Compared to the control membrane, the AA-modified and HEMA-modified membranes also showed a lower degree of flux decline and better flux recovery rate (>90%), suggesting that the membrane antifouling properties were improved and most of the fouling was reversible and could be removed via simple water cleaning process. We demonstrated in this work that the PECVD technique is a promising surface modification method that could be employed to rapidly improve membrane surface hydrophilicity (15 s) for the enhanced protein purification process without using any organic solvent during the plasma modification process.
... Although the above-mentioned arrangement and order repeat themselves here, slope and steepness differ over wavelength. Figs. 3 and 4 confirm the robustness and stable optical response of porous structures (S2 1…3) to post-production annealing as opposed to the high variation in particulate structure (S1 1…3), which is aligned with previous work [13,14]. Originally, a reduced reflection intensity in the as-deposited (S11, S21) sample of group1 relative to its counterpart in group2 is attributed to a bulky amorphous structure and less SiO2 content [12]. ...
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In this study, selective optical properties of Si/SiO2 thin films and their dependence on heat treatment were investigated. Samples were synthesized by pulsed-laser ablation deposition of c-Si on glass substrates and annealed at different temperatures (400 °C, 1000 °C). Nanofabrication parameters were chosen to produce significantly different nanostructures ranging from agglomerated particles to nanofibers. Morphology, crystalline, and elemental characterization techniques were employed to explore the variations in visible range reflection measurements. The adverse effect of annealing temperatures on Vis-range reflection spectra to increase and decrease the intensity was confirmed. These improvements are attributed to crystalline and amorphous lattice structures and elemental composition supported by the X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method results.
... The corresponding Si 2p signals were also deconvoluted into seven Gaussian profiles (considering spin-orbit spiriting with two decomposed peaks corresponding to the Si 2p 3/2 and 2p 1/2 core-levels) with the positions of 2p 3/2 at 99. 25 [8,[70][71][72][73][74]. The Si 4+ peak which corresponds to SiO 2 shows a shift to higher binding energies with depth. ...
... Also, there are few works considering Si 3 SiH or Si 2 SiH 2 in the deconvolution of the Si 2p. Since we observed Si-H x bonds in our Raman data (Fig. 3(e) and (f)), a separate peak for these compounds was adapted similar to the model used Rein et al. [69] and Thøgersen et al. [70]. ...
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Temperature-induced evolution of Si-doped hydrogenated amorphous carbon films on Silicon was monitored using Raman, x-ray photoelectron spectroscopy (XPS) with depth profiling, and electron microscopy. XPS showed that carbon on the surface of as-deposited films is present as sp2>SiC>SiCxOy>sp3>C-O>C=O>COOR. sp2 and sp3 carbon decrease with depth and are stable until 600°C when they evaporate. Carbon rich SiOxCy is higher deeper in the sample and is stable up to 450°C, after which SiO2 and intermediate oxidation states of Si start to form. SiC is present evenly throughout the film and is stable until 600°C. After 600°C nearly all carbon in the film evaporates from the surface to a depth of 63nm. The ratio of sp2 to sp3 is lower on the surface and is constant with temperature until 600°C. Other carbon oxygen species form as the temperature is increased to 400°C, above which they evaporate. Carbon atoms leave the surface by gasification between 600-750°C. Raman data strongly supports the XPS conclusions. Optical and electron microscopy shows that at 750°C the surface of the film is optically different and cracked. The fact that the films were stable up to 600°C demonstrates the great potential of Si-doped coatings for high-temperature applications.