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- 摘要
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- 实验方案
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Application of Nanostructured Tungsten Fabricated by Helium Plasma Irradiation for Photoinduced Decolorization of Methylene Blue
摘要: The dendritic nanostructure was fabricated on a surface of tungsten plate by helium plasma irradiation. The nanostructure consisting of W metal was partially oxidized to form WO3 on exposure to air, and the resulting surface exhibited a broad photoabsorption in the range from 1 to 5 eV. We examined photoinduced reaction of methylene blue (MB) on the material. It was found that the partially and fully oxidized surface nanostructures were able to promote a decolorization of MB under photoirradiation even with the near-infrared light (< 1:55 eV), whose energy is lower than the band gap of WO3. The reaction rate was varied with the fraction of W and WO3 on the surface layers, that is, the partially oxidized sample promoted the reaction at a higher rate than the fully oxidized one. It is also found that the reaction rate decreased with time, which would be caused by the products accumulation on the surface and the surface oxidation.
关键词: Scanning electron microscopy (SEM),Tungsten oxide,Surface photochemistry,Plasma processing,Nano-wires, quantum wires, and nanotubes,Visible/ultraviolet absorption spectroscopy, X-ray photoelectron spectroscopy
更新于2025-09-23 15:21:01
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Enhancement in the performance of nanostructured CuOa??ZnO solar cells by band alignment
摘要: In this study, we investigated the effect of cobalt doping on band alignment and the performance of nanostructured ZnO/CuO heterojunction solar cells. ZnO nanorods and CuO nanostructures were fabricated by a low-temperature and cost-effective chemical bath deposition technique. The band offsets between Zn1?xCoxO (x = 0, 0.05, 0.10, 0.15, and 0.20) and CuO nanostructures were estimated using X-ray photoelectron spectroscopy and it was observed that the reduction of the conduction band offset with CuO. This also results in an enhancement in the open-circuit voltage. It was demonstrated that an optimal amount of cobalt doping could effectively passivate the ZnO related defects, resulting in a suitable conduction band offset, suppressing interface recombination, and enhancing conductivity and mobility. The capacitance–voltage analysis demonstrated the effectiveness of cobalt doping on enhancing the depletion width and built-in potential. Through impedance spectroscopy analysis, it was shown that recombination resistance increased up to 10% cobalt doping, thus decreased charge recombination at the interface. Further, it was demonstrated that the insertion of a thin layer of molybdenum oxide (MoO3) between the active layer (CuO) and the gold electrode hinders the formation of a Schottky junction and improved charge extraction at the interface. The ZnO/CuO solar cells with 10% cobalt doped ZnO and 20 nm thick MoO3 buffer layer achieved the best power conversion efficiency of 2.11%. Our results demonstrate the crucial role of the band alignment on the performance of the ZnO/CuO heterojunction solar cells and could pave the way for further progress on improving conversion efficiency in oxide-based heterojunction solar cells.
关键词: nanostructured,solar cells,X-ray photoelectron spectroscopy,power conversion efficiency,molybdenum oxide,chemical bath deposition,band alignment,CuO–ZnO,cobalt doping
更新于2025-09-23 15:21:01
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Low temperature platinum chemical vapor deposition on functionalized self-assembled monolayers
摘要: The reaction pathways of Pt CVD using (COD)PtMe2 – xClx (x = 0, 1, 2) have been investigated on functionalized self-assembled monolayers (SAMs) as models for organic substrates. Residual gas analysis for (COD)PtMe2 and (COD)PtMeCl is consistent with the loss of methyl radicals as the initial step in deposition, while for (COD)PtCl2, the first step is the loss of a chlorine radical. It is further shown using x-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry that the deposition process leads to chemical damage of the SAM layer and little Pt deposition. Using this understanding, it is demonstrated that the Pt CVD rate can be controlled using a radical trap. In the presence of 1,4-cyclohexadiene, a well-known alkyl radical trap, Pt deposition was increased by 5× to 10×, creating a room-temperature effective Pt CVD process.
关键词: time-of-flight secondary ion mass spectrometry,x-ray photoelectron spectroscopy,Pt CVD,chemical vapor deposition,self-assembled monolayers,radical trap
更新于2025-09-23 15:21:01
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Influence of Focused Pulsed Laser Radiation on the Properties of Amorphous FeSi6B16 Metal Alloy
摘要: The effect of focused pulsed laser radiation (number of pulses and power density) on an amorphous FeSi6B16 metal film is studied. The states of the alloy before and after laser irradiation are analyzed using methods of atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and microhardness measurements. Focused laser radiation in any exposure mode is established to cause high-temperature heating of the surface of an amorphous alloy in the irradiation zone. The result of such heating is melting of the material surface and propagation of the heat wave front from the strongly heated surface to its inner layers, which induces the redistribution of elements in the Fe–Si–B system, a change in the structure, and an increase in the microhardness.
关键词: microhardness,nonequilibrium state,X-ray photoelectron spectroscopy,atomic-force microscopy,surface,laser radiation,amorphous alloys
更新于2025-09-23 15:21:01
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Thermal degradation behavior of self-assembled monolayer surfactant on silicon substrate
摘要: In nanoimprint lithography, a release agent on the mold surface is usually necessary for easy demolding between the mold and the imprinted (thermal) resist. In this work, the thermal stability of 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) monolayers is studied using x-ray photoelectron spectroscopy. The FDTS monolayers are deposited on Si (100) substrates via vapor phase reactions. Significant fluorine desorption of the monolayers is observed for samples annealed at 250 and 300 °C in air. The fluorine coverage decreases as a function of annealing time at a given annealing temperature. The desorption is proposed to be dependent on the monolayer packing details and may be influenced by the intermolecular heat transfer. Removal of the CF3 groups is found to be faster than that of the CF2 group as evidenced by the CF2/CF3 peak area ratios that increase with the annealing time. Sessile drop water contact angle and fluorine coverage evolution results show that the estimated useful coating lifetime is 180 min when the samples are annealed at 300 °C and ~560 min when annealed at 250 °C. The peak position of the binding energy of the F 1s spectral line is related to the monolayer fluorine coverage and it may be a result of the interactions between the molecular chain and the negatively charged silicon substrate. Furthermore, nearly no chain desorption is detected for samples annealed in an inert environment, which may be attributed to the elimination of reactive oxygen and moisture molecules. The thermal degradation behaviors in ambient and inert atmosphere provide useful information for designing a nanoimprint process for the commercial manufacturing of polymeric microstructure and nanostructure.
关键词: fluorine desorption,x-ray photoelectron spectroscopy,thermal stability,FDTS monolayers,nanoimprint lithography
更新于2025-09-23 15:21:01
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Ultrathin films of L1 <sub/>0</sub> -MnAl on GaAs (001): A hard magnetic MnAl layer onto a soft Mn-Ga-As-Al interface
摘要: Ferromagnetic MnAl (L10-MnAl phase) ultrathin films with thickness varying from 1 to 5 nm have been epitaxially grown on a GaAs (001) substrate. A coercivity above 8 kOe has been obtained with no need of a buffer layer by tuning the sample preparation and the growth parameters. Surface and interface analysis carried out by in situ characterization techniques (x-ray photoelectron spectroscopy and low energy electron diffraction), available in the molecular beam epitaxy chamber, has shown the formation of a ferromagnetic interface consisting of Mn-Ga-As-Al, which contribution competes with the MnAl alloyed film. The appearance of this interface provides important information to understand the growth mechanism of MnAl-based films reported in the literature.
关键词: x-ray photoelectron spectroscopy,ferromagnetic,GaAs,molecular beam epitaxy,low energy electron diffraction,ultrathin films,L10-MnAl
更新于2025-09-23 15:21:01
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Physicala??Chemical Properties of Self-Assembled Structures in Solution of Zinc Phthalocyanine and Bis-3-pentyl-PTCDI Derivative
摘要: For the first time, in this work, we succeed in synthesizing in solution a novel supramolecular self-assembled zinc phthalocyanine (ZnPc) and N,N′-bis(3-pentyl)-perylene-3,4,9,10-bis(dicarboximide) (bis-3-pentyl-PTCDI) system with improved light absorption and phosphorescence lifetime of the charge separated states up to 2.5 ms. Moreover, the structural and optical properties of undoped and doped with iodine ZnPc thin films were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman analysis, and UV?vis spectroscopy. Analysis of ZnPc:I2:bis-3-pentyl-PTCDI blend in a 2:1 ratio shows that sandwich complexes between them result in improved bulk properties as compared to those of the single-component systems.
关键词: light absorption,Fourier transform infrared spectroscopy,UV?vis spectroscopy,bis-3-pentyl-PTCDI,X-ray diffraction,supramolecular self-assembly,X-ray photoelectron spectroscopy,zinc phthalocyanine,phosphorescence lifetime,Raman analysis
更新于2025-09-23 15:19:57
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Spectral analysis of Miracle Moringa tree leaves using X-ray photoelectron, laser induced breakdown and inductively coupled plasma -optical emission spectroscopic techniques
摘要: The antioxidant Moringa oleifera (a medicinal plant) leaves (MOLs) containing diverse nutrients are highly beneficial for the human health. The MOLs upon consumption can lower the blood sugar, cure the heart diseases, and reduce the inflammation. In this perception, the “primary nutrients contents” in the dry MOLs (pellet samples) were evaluated for the first time using the XPS, LIBS and ICP-OES techniques. The XPS analysis of the MOLs showed the presence of vital elements like calcium (Ca), magnesium (Mg), manganese (Mn), copper (Cu), phosphorous (P), sulfur (S) and zinc (Zn). The LIBS analyses of the MOLs revealed the atomic and ionic spectral lines corresponding to the essential nutrients such as the Ca, Na, K, Fe, Mg, Mn, Cu, P, S and Zn. The calibration free LIBS algorithm (CF-LIBSA) was developed to quantify the content of each element in the dry MOLs. In addition, the LIBS results were validated by the analysis using ICP-OES standard analytical technique. The elemental contents in the MOLs obtained from the CF-LIBS analyses were counter verified by the ICP-OES results. Present results are highly valuable for the development of a traditional herbal medicine using the miracle MOLs.
关键词: Calibration free LIBS algorithm,Laser induced breakdown spectroscopy,Moringa oleifera leaves,X-ray photoelectron spectroscopy,Inductively coupled plasma atomic emission spectroscopy
更新于2025-09-23 15:19:57
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Detailed investigation of photoluminescence, structural, and elemental properties of ZnO thin films under various annealing ambient
摘要: Zinc oxide (ZnO) has extensively exploited the material in the field of optoelectronics due to its inherent wide bandgap and high electron mobility. Properties of ZnO is very sensitive to its deposition methods and conditions. We report the effect of annealing ambient (i.e. argon, nitrogen, oxygen, or vacuum) on the optical, structural and elemental properties of the RF-sputtered ZnO thin films. In this work, we have performed compressive study on the effects of annealing ambient on a donor-bound exciton peak, exciton-exciton and electron-exciton scattering using low temperature (18 K) photoluminescence measurement which is not yet well understood. We have reported dominant on the donor-bound exciton peak with the lowest full width half maximum value (~4.48 nm) for annealing in an oxygen ambient. The annealing ambient strongly influenced the elemental properties of the film and we have reported the reduction in oxygen vacancy with annealing in an oxygen ambient. This work showed that the influence of ex-situ annealing ambient on exciton emission of ZnO thin films and thus providing a tool for enhancing the optical and elemental properties of the film.
关键词: ZnO thin films,Radio-frequency sputtering,X-ray photoelectron spectroscopy,Rapid thermal processing,Photoluminescence
更新于2025-09-23 15:19:57
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Scanning atmospheric-pressure plasma jet treatment of nickel oxide with peak temperature of a??500 ?°C for fabricating pa??ia??n structure perovskite solar cells
摘要: Scanning atmospheric-pressure plasma jet (APPJ) treatment of nickel oxide with a peak temperature of 500 °C was performed for fabricating p–i–n structure perovskite solar cells (PSCs). APPJ post-treatment leading to enhanced light scattering in PSCs that in turn increases the haze of NiO on FTO glass, improves the cell efficiency. APPJ treatment on NiO also improves the wettability to facilitate the follow-up deposition of CH3NH3PbI3. This also leads to better PSC performance. X-ray photoelectron spectroscopy indicates that APPJ treatment results in fewer C–N bonds and reduced NiAc2 content, suggesting more complete conversion of the liquid precursor into NiO. With three APPJ scans, the average PCE improves from 11.91% to 13.47%, with the best-performing PSC achieving an efficiency of 15.67%.
关键词: X-ray photoelectron spectroscopy,light scattering,Scanning atmospheric-pressure plasma jet,perovskite solar cells,wettability,nickel oxide
更新于2025-09-23 15:19:57