- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Treatment of disorder effects in X-ray absorption spectra beyond the conventional approach
摘要： The contribution of static and thermal disorder is one of the largest challenges for the accurate determination of the atomic structure from the extended X-ray absorption fine structure (EXAFS). Although there are a number of generally accepted approaches to solve this problem, which are widely used in the EXAFS data analysis, they often provide less accurate results when applied to outer coordination shells around the absorbing atom. In this case, the advanced techniques based on the molecular dynamics and reverse Monte Carlo simulations are known to be more appropriate: their strengths and weaknesses are reviewed here.
关键词： Reverse Monte Carlo,Extended X-ray absorption fine structure (EXAFS),Molecular dynamics,Static and thermal disorder,X-ray absorption spectroscopy
更新于2025-09-23 15:23:52
-
Systematic investigations on the effect of prolong UV illumination on optoelectronic properties of ZnO honeycomb nanostructures
摘要： Herein, the effect of prolong UV illumination over ZnO optoelectronic characteristics has been investigated. The photoluminescence analysis has shown significant enhancement in deep level emission (DLE) after sample being exposed to UV radiations. The formation of photo-induced oxygen vacancies (VO) over the ZnO surface was found to be responsible for such noteworthy enhancement in DLE. The observed phenomenon was further utilized for controlled incorporation of VO in ZnO via UV illumination, towards obtaining optimal device performance. The UV treated photo-detector has shown significantly high photo-responsivity and photo-sensitivity in the deep UV region.
关键词： Zinc oxide,Honeycomb structure,Deep UV photodetector,XRD,Lattice defects
更新于2025-09-23 15:23:52
-
Optoelectronic Properties of Zinc Oxide: A First-Principles Investigation Using the Tran-Blaha Modified Becke-Johnson Potential
摘要： In this work, density functional theory (DFT) is used to investigate the influence of semi-local exchange and correlation effects on the electronic and optical properties of zinc oxide. It is found that the inclusion of such effects using the Tran–Blaha modified Becke–Johnson potential yields an excellent description of the electronic structure of this material giving an energy band gap which is systematically larger than the one obtained with standard local functionals such as the generalized gradient approximation. The discrepancy between the experimental and theoretical band gaps is then significantly reduced. We also calculated the dielectric functions of ZnO and find a violet shift to the absorption edge which is in good agreement with experimental results.
关键词： zinc oxide,electronic structure,optical properties
更新于2025-09-23 15:23:52
-
Spin Rectification dc Voltage Spectra via Sweeping Frequency
摘要： A new measurement method of a spin rectification dc voltage spectrum through fixing the magnetic field and sweeping the frequency has been proposed, which is compared to the common method to acquire a typical spectrum via sweeping an external magnetic field. Based on the shortened microstrip fixture, the measurements of rectified dc voltage as a function of frequency have been performed. From the analysis of results of the permalloy (Py) film with various thicknesses, the magnetic parameters are presented. This method can be used in samples with magnetic domains varied with respect to the external magnetic field, such as, stripe domain structures.
关键词： stripe domain structure,monolayer Py films,frequency-swept,spin rectification effect (SRE)
更新于2025-09-23 15:23:52
-
Study on Band-Gap Behaviors of 2D Hierarchical Re-Entrant Lattice Structures
摘要： An investigation of Poisson’s ratios and band gap behaviors of 2D hierarchical re-entrant lattice structures is conducted using finite element method (FEM). The structure with a hierarchy order n (n≥1) is constructed by replacing each outmost vertex of the re-entrant octagons of a hierarchical structure of hierarchy order n?1 with a smaller self-similar re-entrant octagon. The dispersion relation and transmission spectrum of the proposed hierarchical structures are analyzed based on the Bloch’s theorem. The effects of geometrical parameters, order of rotational symmetry and orientation angle of some types of re-entrant polygon cores on the lattice Poisson’s ratio and band gap structures are also investigated. Results show that the re-entrant structures with first order hierarchy exhibit a wider band gap and a stronger attenuation effect compared with structures without structural hierarchy. The first order 2D hierarchical re-entrant structure with a negative Poisson’s ratio of ?0.032 exhibits the widest band gap, 17.8% wider than that of the zeroth order 2D re-entrant structure. The order of rotational symmetry and the orientation angle of the re-entrant polygon cores of the lattice have a strong impact on the lattice Poisson’s ratio and band structures.
关键词： re-entrant,negative Poisson’s ratio,band gap,hierarchical structure,transmission spectrum
更新于2025-09-23 15:23:52
-
24.4: High Performance Top-gate Self-aligned Coplanar a-IGZO TFTs with Light Shielding Metal Design
摘要： The TG-SA a-IGZO TFTs with different light shielding metal (SM) layers design were demonstrated and compared in this paper. Their electrical characteristics have been measured in order to systematically analyze the effect that the SMs ever made on. The relationship between device instability and different SMs design have been systematically analyzed. Then the prototype 14” OLED display with an excellent performance using TG-SA a-IGZO TFTs backplane have been made successfully, which indicates an excellent mass-production prospect.
关键词： reliability,light shielding metal,top-gate self-aligned coplanar structure,a-IGZO TFTs
更新于2025-09-23 15:23:52
-
Fast-Growing Field of Interfacial Solar Steam Generation: Evolutional Materials, Engineered Architectures, and Synergistic Applications
摘要： The lack of fresh water resources is attracting concern worldwide. Recently, to address this global issue, researchers proposed the heat localization concept for interfacial solar seawater desalination in 2014. Since then, interfacial solar steam generation (ISSG) devices have attracted much attention, due to their potential for achieving highly enhanced optical-thermal conversion through a single interface as compared with traditional solar seawater desalination. To date, the promising prospect of ISSG systems in seawater desalination has stimulated the rapid development of solar desalination technology based on heat localization. To comprehensively recognize ISSG devices and acquire more insights into their design associated with biological relevance, efficiency improvement, and applications, this review summarizes the progresses and prospects of ISSG devices in relation to the evolution of advanced materials, the engineering architecture, the collaborative application, and the current challenges.
关键词： biological relevance,interfacial solar steam generation devices,structure design,applications
更新于2025-09-23 15:23:52
-
Structure, growth and characterization of a new naphthalene family crystal for fluorescence and third order nonlinear optical applications
摘要： In the present work we have investigated the fluorescence and nonlinear optical property of a new naphthalene family crystal, Decyl 6-(decyloxy)naphthalene-2-carboxylate (D6DN2C). This crystal was grown for the first time by slow evaporation solution technique (SEST). Single crystal X-ray diffraction analysis reveals that D6DN2C belongs to triclinic crystal system with centrosymmetric space group of Pī. The determined lattice parameters are a = 8.669(3) ?, b = 9.495(3) ?, c = 19.757(6) ?, α =82.697(1)°, β =77.726(1)°, γ = 65.465(1)°and volume = 1444.17(8)?3. Functional groups present in D6DN2C were identified by FT-IR studies. Transparency of the title crystal in UV–Visible region was analyzed and the optical band gap energy was found to be 3.51eV. Fluorescence spectra were recorded for the excitation wavelength of 300 nm. The negative third order nonlinear optical parameters like refractive index (n2), absorption coefficient (β) and susceptibility (χ(3)) were estimated by Z-scan studies.
关键词： Crystal structure,Characterization,Growth from solutions,Nonlinear optic materials,Organic compounds
更新于2025-09-23 15:23:52
-
Performance improvement in photosensitive organic field effect transistor by using multi-layer structure
摘要： In this study, a new approach was introduced for Photo-OFETs as a multi-layer structure. Poly(3-hexylthiophene-2,5-diyl) regioregular (P3HT) and Copper(II) phthalocyanine (CuPc) thin films were used as two different active photo-absorber layers in the same device structure. Poly(methyl methacrylate) (PMMA) was used as a dielectric layer and all devices were fabricated with a top-gate bottom-contact configuration. In order to investigate the effect of the location of each layer on the Photoresponsive organic field-effect transistors (Photo-OFET) performance, five different devices in various structures were produced and analyzed. Surface properties of active layers have been investigated via Atomic Force Microscopy (AFM) and effects of surface roughness on device performance have been discussed. P3HT/CuPc/P3HT multi-layered structure exhibited the best performance in terms of photoresposivity(as 45 mA/W) and photosensitivity (~ 2x103). Photo-OFET based on a multi-layer structure demonstrated superior performance with wider absorbance spectrum region compared to conventional single component devices of P3HT or CuPc. The proposed multi-layer structure can be a model to improve the realization of high performance Photo-OFETs.
关键词： Photoresponsive organic field-effect transistors,Organic field effect transistors,Multilayer structure,Poly(3-hexylthiophene),Photosensitivity,Poly(methyl methacrylate)
更新于2025-09-23 15:23:52
-
Atomic Structures and Electronic Properties of Large-Sized GeN Clusters (N?=?45, 50, 55, 60, 65, 70) by First-Principles Global Search
摘要： A two-step unbiased global search was performed to explore the lowest-energy structures of large GeN clusters with N = 45–70 atoms. It has been revealed that the most stable structures for these large-sized Ge clusters are stuffed cages. Based on the lowest-energy structures, the theoretical results for the size-dependent structural transition, binding energy and ionization potential compare well with the available experimental data. Overall speaking, the structural characteristics and electronic properties of GeN clusters in the considered size range gradually approach the bulk limits, but still with certain deviations.
关键词： Global search,Germanium cluster,Structure
更新于2025-09-23 15:23:52