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Optical properties of ZnO thin films deposed by RF magnetron
摘要： We have grown ZnO thin films on glass substrate by RF magnetron sputtering using metallic zinc target. The influences of some parameters on thin film optical properties were assessed. They exhibited extremely high resistivity of 1012 ?.cm, an energy gap of 3.3 eV at room temperature. It was found that a RF power of 50 W, a target to substrate distance of 70 mm, very low gas pressures of 3.35 x 10-3 Torr of argon and oxygen mixed gas atmosphere gave ZnO thin films with a good homogeneity and a high crystallinity. All the films are transparent in the visible region (400 to 800 nm) with average transmittance above 80%. The optical transmittance and refractive index, calculated from the spectra of optical absorbance, show a significant dependence on the growth parameters. As for the sample grown at 100°C, the average transmittance is about 80% in the visible wavelength range and the refractive index is estimated to be 1.97.
关键词： X-ray diffraction,RF sputtering magnetron,refractive index,ZnO,transmittance
更新于2025-09-23 15:19:57
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Studies on structural, surface morphology and optical properties of Zinc sulphide (ZnS) thin films prepared by chemical bath deposition
摘要： Zinc sulphide (ZnS) thin films have been prepared by chemical bath deposition method. X-ray diffraction (XRD) is used to analyze the structure and crystallite size and scanning electron microscopy is used to study the particle size and morphology of ZnS thin film. Optical studies have been carried out using UV-Visible-NIR absorbance spectrum. The band gap value of the film is calculated and it is found to be 3.45 eV. The dielectric properties of ZnS thin films have been studied in the different frequency at different temperatures.
关键词： scanning electron microscopy (SEM),Zinc sulphide (ZnS) thin films,dielectric studies,X-ray diffraction (XRD)
更新于2025-09-23 15:19:57
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Substitution Effect on Near Infrared Absorbance Based Selective Fluoride Sensing of Indole Functionalized Thiourea Molecules
摘要： A series of six new symmetrically functionalized thiourea based indole conjugated ligands (S1–S6) are synthesized in good yields and their anion recognition/sensing ability in the solution as well as in solid state is explored. Chemosensors S1–S6 show selective colorimetric sensing of fluoride by stable NIR signatures at 942 nm, 956 nm, 825 nm, 890 nm, 948 nm, and 1160 nm with corresponding spectral shifts (Δλ) of 592 nm, 588 nm, 603 nm, 485 nm, 610 nm, and 800 nm by virtue of position, conjugation and electronic effect of different functional groups attached to indole unit. To the best of our knowledge the peak shift of a chemosensor by magnitude of 800 nm (from UV to NIR region) in the presence of fluoride represents the highest of its kind. The changes in absorption spectra in the presence of various anions follow the Hofmeister series of anions. All the chemosensors show a bathochromic shift in the absorption spectra of the ligands in the presence of acetate, benzoate, di-hydrogen phosphate and hydrogen pyrophosphate due to hydrogen bonding interactions with the indole and thiourea-NH groups. The single-crystal X-ray structures evidence in favour of planar structures of the free sensors (S1, S4, and S5) and strong hydrogen bonding interactions between phosphate anion and indole–thiourea NH groups.
关键词： X-ray diffraction,NMR titration,Fluorides,UV/Vis titration,Sensing
更新于2025-09-23 15:19:57
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Comparative study of radiation defect dynamics in 3C-SiC by X-ray diffraction, Raman scattering, and ion channeling
摘要： At moderately elevated temperatures, radiation defects in SiC exhibit pronounced dynamic annealing, which remains poorly understood. Here, we study 3C-SiC bombarded at 100°C with pulsed beams of 500 keV Ar ions. Radiation damage is monitored by a combination of X-ray diffraction, Raman scattering, and ion channeling. Similar damage buildup behavior but with different defect relaxation time constants, ranging from ～1 to ～6 ms, is observed for the different types of lattice defects probed by these techniques. A correlation between relaxation times and the nature of the defects is proposed. These results reveal additional complexity of radiation defect dynamics in SiC and demonstrate that results of different defect characterization techniques are needed for a better understanding of dynamic annealing processes in solids.
关键词： X-ray diffraction,Ion channeling,Raman scattering,Dynamic annealing,Radiation defects,3C-SiC
更新于2025-09-23 15:19:57
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Hydration of Ti3C2Tx MXene: an interstratification process with major implications on physical properties
摘要： The MXenes, among which Ti3C2Tx is the most studied, are a large family of 2D materials with proven potential in a variety of application fields (e.g., energy storage and conversion, water purification, electromagnetic interference shielding, humidity sensor, etc). For most of these applications, MXenes properties depend, at least partly, on their water sorption ability and on the induced structural swelling, which is commonly considered a stepwise process, like in clay-like materials. In the present study, we rather evidence the systematic coexistence of different hydrates in MXene interstratified crystals. Hydration heterogeneity and related structure disorder are described from the quantitative analysis of X-ray diffraction data. This specific methodological approach allows disentangling the complex interstratification and rationalizing the prediction of MXene electrical properties. The widespread use of this approach paves the way for a systematic and thorough determination of MXene structure, including order-disorder, and thus for grasping the influence of structural disorder (hydration heterogeneity) on a large number of MXene physical properties (e. g. optical transparency, capacitance). Deciphering this complex structural disorder is also essential in the design of new MXene-based materials for a variety of applications (supercapacitors, batteries, water treatment…).
关键词： MXenes,Ti3C2Tx,electrical properties,X-ray diffraction,hydration,interstratification
更新于2025-09-23 15:19:57
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Investigation of Dimethylammonium Solubility in MAPbBr <sub/>3</sub> Hybrid Perovskite: Synthesis, Crystal Structure, and Optical Properties
摘要： The possible existence of mixed methylammonium (MA)/dimethylammonium (DMA) lead bromide hybrid perovskites of general formula MA1?xDMAxPbBr3 (0 ≤ x ≤ 1) was investigated. A combined X-ray di?raction and solid-state nuclear magnetic resonance approach indicates that DMA can be incorporated up to about x = 0.30 while retaining the cubic lattice of MAPbBr3. By increasing the DMA content (x), the absorption shows a progressive blue shift and the band gap moves from about 2.17 eV (x = 0) to about 2.23 (x = 0.30) with a concomitant slightly faster recombination in the mixed cation powders.
关键词： X-ray diffraction,hybrid perovskites,optical properties,mixed methylammonium,solid-state nuclear magnetic resonance,lead bromide,dimethylammonium
更新于2025-09-23 15:19:57
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Investigation of Statistical Broadening in InGaN Alloys
摘要： Optical and structural properties of thick InGaN layers grown by MOCVD and MBE were studied by photoluminescence, optical transmission and Raman spectroscopies and X-ray diffraction analysis. Optical bandgap, Urbach energy, and full widths at half maximum (FWHM) of photoluminescence and Raman spectra depending on the InGaN alloy composition were determined experimentally. Minimal theoretical linewidth of photoluminescence spectra resulted from random distribution of In and Ga atoms in cation sublattice was calculated.
关键词： optical bandgap,photoluminescence,Urbach energy,X-ray diffraction,InGaN,Raman spectroscopy
更新于2025-09-23 15:19:57
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Studying the influence of deposition temperature and nitrogen contents on the structural, optical, and electrical properties of N-doped SnO2 films prepared by direct current magnetron sputtering
摘要： This report focuses on studying and investigating in detail the structural, electrical, and optical properties of p-type N-doped SnO2 (NTO) versus the deposition temperature and nitrogen content. P-type transparent conductive NTO films were deposited on quartz glass substrates using a direct current (DC) magnetron sputtering method. The substitution of oxygen by nitrogen in the SnO2 host lattice was verified using measurements such as X-ray photoelectron spectroscopy. The position of the N3? defect state in the band gap was determined using photoluminescence and ultra-violet-visible spectroscopy measurements. The data for the (110) to (101) rutile lattice planes changed, and the rutile (plane (101)) to cubic (plane (111)) SnO2 phase transition indicated the substitution of oxygen by nitrogen in the SnO2 host lattice. The best p-type conductive properties achieved were 8 × 10?2 Ω cm, 1.36 × 1019 cm?3, and 6.75 cm2 V?1 s?1 for the resistivity, hole concentration, and hole mobility, respectively, for film deposited at the optimum substrate temperature of 300 °C in a gas mixture of Ar and 50% N2.
关键词： deposition temperature,nitrogen content,p-type N-doped SnO2 thin film,X-ray photoelectron spectroscopy,DC magnetron sputtering,X-ray diffraction
更新于2025-09-19 17:15:36
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Investigation on growth, physico-chemical properties, density functional theory and anti-microbial studies of a new organic acentric NLO crystal: Bis (2-aminobenzimidazolium) phthalate
摘要： Highly transparent NLO crystal bis (2-aminobenzimidazolium) phthalate (B2ABP) was successfully grown by solvent evaporation method. The lattice parameters and crystalline nature were confirmed by X-ray diffraction studies. The FT-IR and Raman spectrum were used to assert the various functional groups present in title compound. NMR studies evidently portray the molecular structure of the grown crystals. A UV study shows the high transmittance range of B2ABP crystal. Photoluminescence study shows sharp emission peak. The mechanical stability of the grown crystal was investigated by Vickers microhardness test. Etching studies were carried for the grown crystal. The dielectric studies have been carried out as a function of frequency at different temperatures. SHG efficiency was found to be 1.9 times greater than that of standard KDP. Laser damage threshold value for B2ABP was found to be 2.2 GW/cm2. Melting point of B2ABP was studied by means of TG-DTA studies. HOMO-LUMO energy gap and first order hyperpolarizability value was theoretically predicted. The anti-microbial activity of B2ABP was determined.
关键词： SHG,Anti-microbial activity,TG-DTA,2-Aminobenzimidazole,Dielectric,X-ray diffraction
更新于2025-09-19 17:15:36
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Growth, Thermal and Spectroscopic Studies of Bis-thiourea Nickel Barium Chloride Single Crystals
摘要： Bis-thiourea nickel barium chloride was synthesized and crystals were grown by slow aqueous solvent evaporation technique. The powder XRD analysis of grown crystal was suggested to have orthorhombic crystal structure. The unit cell parameters of grown crystal as: a = 9.70 ?, b = 10.68 ? and c = 17.95 ?. The contents of nickel and barium in the grown crystals was analyzed using EDAX. The presence of various functional groups was confirmed by FTIR spectroscopy studies. From the UV-visible spectrum, the material has about 90 % optical transparency in the entire visible region. From the thermogravimetric analysis, it was found that the crystals remained stable up to 170 oC. The endothermic reactions were identified from the differential thermal analysis.
关键词： Crystal growth,Slow evaporation technique,Bis-thiourea nickel barium chloride,Powder X-ray diffraction
更新于2025-09-19 17:15:36