- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Structural and optical studies on PVA capped SnS films grown by chemical bath deposition for solar cell application
摘要： Tin monosulphide (SnS) thin films capped by PVA have been successfully deposited on glass substrates for cost effective photovoltaic device applications by a simple and low-cost wet chemical process, chemical bath deposition (CBD) at different bath temperatures varying in the range, 50–80 °C. X–ray diffraction analysis showed that the deposited films were polycrystalline in nature, showing orthorhombic structure with an intense peak corresponding to (040) plane of SnS. These observations were further confirmed by Raman analysis. FTIR spectra showed the absorption bands which corresponds to PVA in addition to SnS. The scanning electron microscopy and atomic force microscopy studies revealed that the deposited SnS films were uniform and nanostructured with an average particle size of 4.9 to 7.6 nm. The optical investigations showed that the layers were highly absorbing with the optical absorption coefficient ~105 cm–1. A decrease in optical band gap from 1.92 to 1.55 eV with an increase of bath temperature was observed. The observed band gap values were higher than the bulk value of 1.3 eV, which might be due to quantum confinement effect. The optical band gap values were also used to calculate particle size and the results are discussed.
关键词： structural properties,optical properties,SnS thin films,polyvinyl alcohol,capping agent,chemical bath deposition
更新于2025-11-21 11:18:25
-
An investigation of 60Co gamma radiation-induced effects on the properties of nanostructured α-MoO3 for the application in optoelectronic and photonic devices
摘要： Gamma ray has sufficient energy to ionize and displace of atoms when interacts with optoelectronic and photonic devices that are placed at γ-radiation exposure environment, can be exposed to gamma radiation, resulting the alteration of the physical properties and hence the performances of devices. A comprehensive investigation of physical properties of the semiconductor materials under the influence of gamma radiation is essential for the effective design of devices for the application in the radiation exposure environment. In this article, a potential candidate for optoelectronic and photonic devices, orthorhombic MoO3 nanoparticles with average crystallite size of 135.31 nm successfully synthesized by hydrothermal method. Then, the properties of nanoparticles exposed to low (10 kGy) and high (120 kGy) absorbed dose of γ-rays from 60Co source were characterized by XRD, FESEM, FTIR and UV–Vis–NIR spectrophotometer and effects of absorbed doses was investigated for the first time. A significant change is observed in different physical properties of α-MoO3 nanoparticles after gamma exposure. The XRD patterns reveal the average crystallite size, intensity and the degree of crystallinity decrease for low dose (10 kGy) and increases for high dose (120 kGy). The calculated average crystallite size exposed to low and high doses are 127.79 nm and 136 nm, respectively. The lattice strain and dislocation density, however, shows the opposite trend of crystallite size with absorbed doses. This result is good evidence for the deterioration of crystallinity for low dose and improvement for high dose. The FESEM results reveal the significant effects of gamma doses on the micrographs of layered structure and on grain size. The optical studies disclose that band gap increases gradually from 2.78 to 2.90 eV, this behavior is associated with the reduction of electronic localized states. These results suggest that α-MoO3 nanoparticles could tolerate high doses of gamma radiation, making it a promising candidate for optoelectronic and photonic devices for γ-ray exposure environment applications.
关键词： Optoelectronic and photonic devices,α-MoO3 nanoparticles,Co-60 gamma radiation,Optical bandgap,Structural properties
更新于2025-10-22 19:40:53
-
Synthesis of Bi <sub/>2</sub> O <sub/>3</sub> films, studying their optical, structural, and surface roughness properties
摘要： Reactive pulse laser deposition system was used to prepare Bi2O3 thin films at different laser fluence. It effect on the physical properties of thin films was investigated. A Polymorphous structure was obtaining from XRD results. While the obtained microscopic results from AFM show that grain size is varied between 33.48nm and 131.6 nm. The estimated band gap value from the optical transmission found to range from 1.7-2.9 eV.
关键词： Pulsed laser deposition,morphological properties,Optical properties,Bismuth trioxide,structural properties
更新于2025-09-23 15:23:52
-
Effect of Na doping on structural and optical properties in Cu2ZnSnS4 thin films synthesized by thermal evaporation method
摘要： Quaternary chalcogenide Cu2ZnSnS4 (CZTS) compound, a potential material for application as absorber layer in thin film solar cells, is synthesized by direct melting of the constituent elements taken in stoichiometry compositions. Alkali element Na was incorporated into CZTS thin films synthesized by thermal evaporation method, in order to further improve the structural and optical properties. X-Ray diffraction (XRD), Raman spectroscopy, Energy dispersive spectrometry and optical spectrophotometry were used to characterise the phase purity and optical properties. It showed that the diffusion of Na ions is uniform in the films after annealing. XRD analysis showed that CZTS films possess polycrystalline structure with [221] preferred orientation. Na ions incorporation in CZTS thin films could improve the cristallinity, the graine size and the absorption coefficient. For CZTS: Na 5%, optical results revealed higher absorption coefficient (>105 cm-1) and direct optical band gap of 1.56 eV with p-type conductivity.
关键词： Semiconductors,Sodium doping,Structural properties,Optical properties,Copper zinc tin sulfide,Thin films,Thermal evaporation
更新于2025-09-23 15:23:52
-
Structural and Optical Properties of CeO2 Nanoparticles Synthesized by Modified Polymer Complex Method
摘要： Ceria nanoparticles (Ceria-NPs) were synthesized using a modified polymer complex method and their structural and optical properties were evaluated. The solids were heated at 550 °C and characterized using Raman, UV–Vis absorption, diffuse reflectance, X-ray photoelectron and photoluminescence spectroscopies, X-ray diffraction (XRD) and scanning and transmission electron microscopy. The primary particles obtained presented a size of ~ 10 nm. The XRD indicated that CeO2 was the only crystalline phase. From the UV–Vis and diffuse reflectance spectra, energy values of 3.8 eV and 3.4 eV were obtained, values that can be associated with band—band electronic transitions and/or with those that involve ionized states located within the gap caused by defects and isolated atoms of Ce3+. Photoluminescence spectra reiterated the existence of localized states in the gap. Raman spectra revealed the existence of peroxide (O2^2-) and superoxide (O2^-) over the surface of the ceria-NPs. The XPS results indicated that the concentrations of Ce3+ and Ce4+ were ～ 20.5% and ～79.5% respectively, and that the stoichiometry of oxygen was 1.9 per atom of Ce. The results obtained from the characterization of CeO2-NPs synthesized make it as promising material for environmental remediation, biomedicine, gas sensing and optoelectronic applications.
关键词： Modified polymer complex,Structural properties,Ceria-NPs,Optical properties,Synthesis
更新于2025-09-23 15:23:52
-
A comparative ab initio study of the structural, mechanical, electronic and optical behaviors of ZnO:Ni thin films with nanometer scale
摘要： The electronic and optical properties of undoped and Ni–doped ZnO thin films with nanometer scale have been studied in the wurtzite phase, by first–principle approach. Density functional theory has been employed to calculate the fundamental properties of the films using full–potential linearized augmented plane–wave method. Ni doping was found to reduce the bandgap value of the material. Additionally, DOS effective mass of the electrons was evaluated. It was revealed that the effective mass of the electrons at the bottom of conduction band increased with Ni doping. Decrease of reflectance for thin films with nanometer scale in the UV–vis region was observed. The substitution by Ni decreased the intensity of the peaks, and a red shift was observed in the absorption peak. Moreover, the static dielectric constant, and static refractive index decreased with Ni content. Energy loss function of the modeled compounds was also evaluated. All calculated parameters were compared with the available experimental and other theoretical results.
关键词： DFT,band structure,structural properties,electronic behaviors,optical properties,ZnO:Ni thin film
更新于2025-09-23 15:23:52
-
Catalytic Growth of 1D ZnO Nanoneedles on Glass Substrates Through Vapor Transport
摘要： In this study, one-dimensional (1D) zinc oxide (ZnO) nanoneedles are successfully fabricated on a Ag catalyst-coated glass substrate through simple physical vapor deposition via thermal evaporation of zinc (Zn) powder in the presence of oxygen (O2) gas at a low growth temperature of 450°C. The growth rate and diameter of ZnO nanoneedles increase as a function of varying silver (Ag) film thicknesses and argon (Ar) flow rates. Detailed structural investigations confirm that the synthesized nanoneedles have high crystallinity with a hexagonal wurtzite structure, and they preferentially grow along the c-axis orientation. This approach provides a simple and cost-effective method for the synthesis and controlled growth of 1D nanostructures, which can be useful in solid-state devices and various optoelectronic applications.
关键词： 1D ZnO,x-ray diffraction,UV emission enhancement,structural properties
更新于2025-09-23 15:23:52
-
Ab-initio study of electronic, optical, thermal, and transport properties of Cr <sub/>4</sub> AlB <sub/>6</sub>
摘要： Theoretical investigation of different physical parameters of Cr4AlB6 have been done within the framework of density functional theory. Cr4AlB6 is a no band gap material. Its Cr-3d states contributes the most at the Fermi level. Thermal properties are investigated using quasi-harmonic Debye model as implemented in Gibbs code for different values of pressure and temperature. Study of transport property suggests that its electrical conductivity increases nonlinearly with increase in temperature but the relative change in its value is very low whereas its thermal conductivity increases linearly with the increase in temperature and relative increase in thermal conductivity is very high. The behavior of Cr4AlB6 is anisotropic and property is ceramic. It has potential applications in making ceramic capacitors. Its reflectivity is high in low energy region. It suggests that material can be used as coating material for far-infrared radiation. Study of the transport property suggests that because of very high value of thermal conductivity, it can be used for heat sink applications.
关键词： optical properties,first principles,electronic properties,thermal properties,thermoelectric transport properties,structural properties
更新于2025-09-23 15:22:29
-
Disorder Control in Crystalline GeSb <sub/>2</sub> Te <sub/>4</sub> and its Impact on Characteristic Length Scales
摘要： Crystalline GeSb2Te4 (GST) is a remarkable material, as it allows to continuously tune the electrical resistance by orders of magnitude without involving a structural phase transition or stoichiometric changes. While well-ordered specimen are metallic, increasing amounts of disorder eventually lead to an insulating state with vanishing conductivity in the 0 K limit, but a similar number of charge carriers. Hence, GST provides ideal grounds to explore the impact of disorder on transport properties. Here, a sputter-deposition process is employed that enables growing biaxially textured GST films with large grain sizes on mica substrates. The resulting films exhibit a systematic variation between metallic and truly insulating specimen upon varying deposition temperature. Transport measurements reveal that their electron mean free path can be altered by a factor of 20, while always remaining more than an order of magnitude smaller than the lateral grain size. This proves unequivocally that grain boundaries play a negligible role for electron scattering, while intra-grain scattering, presumably by disordered vacancies, dominates. These findings underline that the insulating state and the system’s evolution toward metallic conductivity are intrinsic properties of the material.
关键词： metal–insulator transition,electrical properties,phase-change materials,disorder,structural properties
更新于2025-09-23 15:22:29
-
The Effect of Precursor Composition on the Structural Properties of Nanocrystalline Diamond Films
摘要： Nanocrystalline diamond (NCD) films were grown by hot filament CVD and the precursor composition dependence of the structural properties was examined. Films grown at 1 and 2 CH4 Vol% were found to be NCD layers with grain sizes of ～23–25 nm while films grown at 3–5 Vol% were identified as the mixtures of microcrystalline diamond and graphitic phase. The sp2/sp3 bonded carbon ratio in the grown films increased as the CH4 content increased up to 3 Vol% and then decreased beyond 4 Vol%. Microstructure and deposition rate were also found to be affected by the precursor composition and the NCD film grown at 1 CH4 Vol% showed a very dense microstructure and the highest deposition rate of ～3 nm/min.
关键词： Precursor Composition,Structural Properties,Nanocrystalline Diamond
更新于2025-09-23 15:22:29