检索结果-内蒙古大学图书馆

Infrared optical functions of Water Retrieved Using Attenuated Total Reflection Spectroscopy

APPLIED SPECTROSCOPY 2023年第2期77卷 178-186页

作者： Vieira, Luis G. Univ Minho Ctr Fis Univ Minho & Porto CF UM UP Lab Fis Mat & Tecnol Emergentes LaPMET Braga Portugal Univ Minho Dept Fis Campus Gualtar P-4710057 Braga Portugal

Comprehensive modeling of non-polarized infrared attenuated total reflection spectrum based on Fresnel equations and wavenumber-dependent dielectric function models of isotropic materials is shown to be a suitable and easy methodology to retrieve optical functions. The scheme is completely general and can be used even for strong dispersion and absorption resonances. Attenuated total reflection spectra in liquid water, measured in the spectral region 100-4400 cm(-1) with diamond and germanium as internal reflection elements, were used to illustrate and evaluate the method. The refractive index of water computed from the dispersion analysis is critically compared with literature data.

关键词： Infrared spectroscopy attenuated total reflection ATR spectrum modelling optical functions water

来源：评论

学校读者我要写书评

暂无评论

Synthesis and optical functions distribution of CdSe nanorods/poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] nanocomposites

引用

optical AND QUANTUM ELECTRONICS 2021年第7期53卷 393-393页

作者： Farag, M. A. El-Menyawy, E. M. El-Nahass, M. M. Abdallah, T. Youssef, G. M. Ain Shams Univ Dept Phys Fac Sci Cairo Egypt Natl Res Ctr Phys Res Div Dept Solid State Phys Solid State Elect Lab 33 El Bohouth St Giza 12622 Egypt Ain Shams Univ Dept Phys Fac Educ Cairo Egypt

CdSe nanorods (NRs) are assembled using hydrothermal method using polyethylene glycol as a surfactant. The diameter and the length of the rods are found to be in the ranges of 10-30 and 80-210 nm, respectively. Besides, the CdSe NRs exhibit hexagonal structure with a crystallite size of 9.61 nm. Different concentration of CdSe NRs are mixed with poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). The structural features of the nanocomposites in the form of thin films prepared by spin-coating technique are studied by using of X-ray diffraction, field emission scanning microscope and atomic force microscope. The surface roughness of the MEH-PPV is calculated as 5.4 nm, which is significantly increased by the addition of CdSe NRs. Besides, the transmittance and the reflectance of the nanocomposite films are measured at the normal incidence of the light over wavelength range 200-2500 nm. The optical functions such as absorption coefficient and refractive index of the films are calculated and analyzed. The optical band gap of MEH-PPV is determined as 1.95 eV and is decreased with increasing CdSe NRs content. In addition, the single oscillator model is used to evaluate the optical oscillator parameters. Finally, the ratio of the free carriers to their effective mass is found to increase by increasing CdSe content.

关键词： CdSe nanorods Structural properties Nanocomposites optical functions

来源：评论

学校读者我要写书评

暂无评论

Diphenylsiloxane-dimethylsiloxane copolymer: optical functions from 191 to 1688 nm (0.735-6.491 eV) by spectroscopic ellipsometry

引用

SURFACE SCIENCE SPECTRA 2020年第2期27卷

作者： Patel, Dhananjay, I Shah, Dhruv Roychowdhury, Tuhin Wheeler, Joshua, I Ess, Daniel H. Hilfiker, James N. Linford, Matthew R. Brigham Young Univ Dept Chem & Biochem C100 BNSN Provo UT 84602 USA JA Woollam Co Inc 645 M StSuite 102 Lincoln NE 68508 USA

We report the optical functions of diphenylsiloxane-dimethylsiloxane (DPS-DMS) copolymer as determined from reflection spectroscopic ellipsometry (SE) and transmission ultraviolet-visible data, which were generated over 191-1688 nm from a commercial sample of DPS-DMS. This material is a random, linear copolymer terminated with silanol groups that is a liquid at room temperature and pressure. Both reflection and transmission measurements required special experimental considerations. The reflection SE measurements utilized the "rough-surface" method, wherein the liquid was poured onto a roughened (frosted) glass slide, which scatters the reflected light leaving only the reflection from the liquid surface. That is, there is effectively no substrate or material beneath the liquid that affects the ellipsometry measurements or that needs to be modeled. Transmission measurements were obtained via a dual cuvette approach to eliminate the effects of the cuvettes. The reflection data provided the refractive index across the entire spectral range as well as the extinction coefficient at ultraviolet wavelengths. The transmission measurements provided input for the extinction coefficients at visible and near infrared wavelengths, where the liquid is transparent or semitransparent. The reflected SE data were modeled using a Sellmeier dispersion model and six Gaussian oscillators plus a surface roughness layer. This produced a good fit with a mean squared error (MSE) of 2.41. For example, we obtained the following n(lambda) values, where lambda is the wavelength in nanometers: n(300) = 1.534, n(500) = 1.477, and n(1000) = 1.458. As expected, the refractive index of DPS-DMS is higher than that of liquid polydimethylsiloxane.

关键词： Phenyl PDMS DPS-DMS spectroscopic ellipsometry optical function Sellmeier Gaussian BEMA layer optical functions transmission

来源：评论

学校读者我要写书评

暂无评论

Bistable optical functions of Polyethylene Glycol 2

Bistable Optical Functions of Polyethylene Glycol

引用

2nd IEEE International Conference on Dielectrics (ICD)

作者： Saito, Mitsunori Tsuji, Kanami Ryukoku Univ Dept Elect & Informat Otsu Shiga 5202194 Japan

ISBN: (纸本)9781538663899

Polyethylene glycol takes both transparent and translucent phases during the phase transition process at around room temperature. This bistability seems useful to create optical devices including 3D displays and tunable random lasers. These devices, however, require a spot-heating technique that controls the phase of each microelement. Self-heating of microelements is achievable if the electric conductivity of the polyethylene glycol is enhanced by the dissolution of alkaline halide salts.

关键词： polyethylene glycol optical functions ionic conduction phase transition bistability

来源：评论

学校读者我要写书评

暂无评论

Spectroscopic Ellipsometry and Optimized B-Spline Coefficients of Non-hydrogenated Amorphous Silicon for Amorphous Silicon-Based Semiconductors

引用

JOURNAL OF ELECTRONIC MATERIALS 2025年 1-14页

作者： Ebdah, M. A. Kordesch, M. E. Jadwisienczak, W. M. Ibdah, A. Alcorn State Univ Coll Arts & Sci Dept Chem & Phys Lorman MS 39096 USA Ohio Univ Coll Sci Dept Phys & Astron Athens OH 45701 USA Ohio Univ Sch Elect Engn & Comp Sci Athens OH 45701 USA Univ Toledo Dept Phys & Astron Ctr Photovolta Innovat & Commercializat Toledo OH 43606 USA

Amorphous silicon plays a crucial role in renewable energy and energy storage devices. Here, we report on the application of the Kramers-Kronig consistent B-spline parametric model to the complex dielectric function of non-hydrogenated amorphous silicon (a-Si). a-Si thin films were deposited onto quartz and thermal SiO2/c-Si(100) substrates using radio-frequency magnetron sputtering at a relatively low temperature of 195 K (-78 degrees C). Room-temperature ex situ spectroscopic ellipsometry was employed post-growth with high resolution, and the energy-slicing B-spline parametric model was implemented within a multilayered structure using 14 non-vanishing optimized B-spline series expansion coefficients, {c(i)}, which resulted in accurate determination of the complex dielectric function, optical bandgap, and film thickness simultaneously. The correlation matrix of the fitting parameters was further obtained and analyzed in detail. The obtained B-spline parameterization represents an accurate basis reference for a-Si over the wide ultraviolet-visible-near-infrared (UV-Vis-NIR) spectral range of 270-1240 nm corresponding to 1.0-4.6 eV. It was successfully applied to two amorphous silicon-based semiconductors until accurate fittings were achieved, which are the non-hydrogenated phase a-Si deposited under different growth conditions and the hydrogenated phase a-SixH1-x with various atomic percentages of alloyed hydrogen.

关键词： Spectroscopic ellipsometry amorphous silicon B-spline optical functions correlation

来源：评论

学校读者我要写书评

暂无评论

TlBX3 (B = Ge, Sn;X = Cl, Br, I): Promising non-toxic metal halide perovskites for scalable and affordable optoelectronics

引用

JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T 2024年 29卷 897-909页

作者： Rony, Jahid Kabir Islam, Minhajul Saiduzzaman, Md Hossain, Khandaker Monower Alam, Safin Biswas, Arpon Mia, M. H. Ahmad, Sohail Mitro, S. K. Khulna Univ Engn & Technol KUET Dept Mat Sci & Engn Khulna 9203 Bangladesh Bangladesh Atom Energy Regulatory Author BAERA E12-A Agargaon Dhaka 1207 Bangladesh Univ Rajshahi Dept Mat Sci & Engn Rajshahi 6205 Bangladesh Univ Rajshahi Dept Phys Rajshahi 6205 Bangladesh King Khalid Univ Coll Sci Dept Phys POB 9004 Abha Saudi Arabia Bangamata Sheikh Fojilatunnesa Mujib Sci & Technol Jamalpur 2012 Bangladesh

Inorganic, non-toxic metal halide perovskites are the benchmark for optoelectronic device commercialization. Due to their significant importance, the density functional theory -based ab initio method was engaged to study the fundamental physical properties of metal halide perovskites TlBX3 (B = Ge, Sn;X = Cl, Br, I). The studied lattice constants and volume are different from the chosen systems, and the crystal stability is also justified in particular. Among six studied compounds, Sn-based compounds show lower band gaps than Ge-based compounds, where I at site X shows the lowest band gaps. The illustration of the density of states and the specific projection of the electronic contribution of atomic orbitals were added to verify the actual semiconducting electronic behavior. The presence of dual chemical bonds is confirmed by bond length statistics and charge density distribution. The optical properties vary among the compounds, and there is an opposite behavior between low and high-energy regions. TlGeX3 has a higher Young modulus, bulk modulus, and shear modulus than TlSnX3, whereas the hardness and anisotropic behavior are lower than TlSnX3. In this investigation, threedimensional diagrams of elastic moduli have been depicted using the ELATE tool, which facilitates the easy identification of anisotropic elastic properties. Furthermore, this study will shed light on how to fabricate leadfree inorganic perovskites for use in optoelectronics.

关键词： Lead-free inorganic perovskites Electronic band structure optical functions Mechanical properties

来源：评论

学校读者我要写书评

暂无评论

DFT based computational investigations of the physical properties of perovskites-structure SrXO3 (X = Si, Tb, Th) for optoelectronic and thermo-mechanical applications

引用

MATERIALS TODAY COMMUNICATIONS 2024年 38卷

作者： Jamila, Nusrat Farah, Israt Jahan Modak, Jibon Krishna Hasan, Wakil Rahman, Md. Atikur Hossain, Md. Mukter Rasheduzzaman, Md. Choudhury, M. S. H. Chowdhury, Swapnil Rahaman, Rajabur Hasan, Md. Zahid Int Islamic Univ Chittagong Dept Elect & Elect Engn Kumira 4318 Chittagong Bangladesh Int Islamic Univ Chittagong Dept Elect & Elect Engn Mat Res & Simulat Lab Kumira 4318 Chittagong Bangladesh Bangabandhu Sheikh Mujibur Rahman Sci & Technol Un Dept Phys Gopalgonj 8100 Bangladesh Pabna Univ Sci & Technol Dept Phys Pabna 6600 Bangladesh Chittagong Univ Engn & Technol CUET Dept Phys Chattogram 4349 Bangladesh

Density Functional Theory (DFT) method is employed for investigating the structural, elastic, electronic, optical, and thermal properties of Perovskite structure SrXO3 (X = Si, Tb, and Th). The studied lattice parameters show good agreement with the previous theoretical and experimental results. The elastic stiffness constants, (Cij) of SrSiO3, SrTbO3, and SrThO3 satisfied the born stability criteria which confirm the mechanical stability of these phases. It is observed that when Tb or Th is replaced with Si, the brittleness behaviours of SrTbO3 or SrThO3 change to ductility, which improves its machinability for industrial applications. The investigation of anisotropic factors of SrSiO3, SrTbO3, and SrThO3 ensured that SrSiO3 is more anisotropic than SrTbO3 and SrThO3. By evaluating the electronic properties, it can be advantageous for applying the topological insulators (TI), solar cells, or PV (Photovoltaic) cell fabrication. Furthermore, the optical properties are studied and detail discussed with SrXO3 (X = Si, Tb, and Th). The reason of low Debye temperature (Theta D) and low minimum thermal con-ductivity (Kmin) has been perfectly explicated through the consideration of the mean atomic weight (M/n) of the compounds. Temperature-dependent of heat capacities (Cv, Cp) and linear thermal expansion coefficient (alpha) are also estimated using the quasi-harmonic Debye model and discussed. The SrTbO3 and SrThO3 compounds can be employed as potential thermal barrier coating (TBC) materials for high-temperature applications, according to the low values of Kmin, Theta D and alpha.

关键词： Perovskite material Elastic properties Elastic anisotropic Electronic properties optical functions

来源：评论

学校读者我要写书评

暂无评论

Study on low hydrostatic pressure-dependent optoelectronic, mechanical, and anisotropic properties of heavy thallium perovskites TlPbX3 (X = Cl, Br)

引用

JOURNAL OF MATERIALS RESEARCH 2023年第7期38卷 2007-2017页

作者： Mitro, S. K. Saiduzzaman, Md Hossain, Khandaker Monower Rony, Jahid Kabir Ahmad, Sohail Bangamata Sheikh Fojilatunnesa Mujib Sci & Technol Jamalpur 2012 Bangladesh Khulna Univ Engn & Technol KUET Dept Mat Sci & Engn Khulna 9203 Bangladesh Univ Rajshahi Dept Mat Sci & Engn Rajshahi 6205 Bangladesh King Khalid Univ Coll Sci Dept Phys POB 9004 Abha Saudi Arabia

The fundamental physical properties of perovskite materials are crucial for technological applications in a variety of disciplines. Therefore, this study explores the pressure effects on various physical properties of perovskite halides TlPbX3 (X = Cl, Br) via density functional theory and investigate the compounds' optoelectronic performance. The lattice parameters are reduced for enhancing interaction among the constituent atoms upon pressure. The semiconducting nature of both compounds is revealed by band structure and density of states. The band gap is also reduced under pressure, which improves the optical functions. Moreover, the bonding between Tl-Cl(Br) and Pb-Cl(Br) becomes stronger as pressure is applied than that observed at zero pressure systems. All the optical functions become favorable for using both compounds in several interesting optoelectronic applications under pressure. The mechanical properties are also significantly affected by induced pressure. The applied pressure significantly enhances the ductility, machinability, and anisotropic nature of the studied compounds.

关键词： Halide perovskite DFT calculations Electronic band structure optical functions Mechanical properties

来源：评论

学校读者我要写书评

暂无评论

Ab initio studies of the gas adsorption on the surface CdSe1-xSx ultra-thin films

引用

APPLIED NANOSCIENCE 2023年第10期13卷 6749-6759页

作者： Kashuba, A. I. Semkiv, I. V. Andriyevsky, B. Ilchuk, H. A. Kashuba, N. Yu. Lviv Polytech Natl Univ Dept Gen Phys 12 S Bandera St UA-79013 Lvov Ukraine Koszalin Univ Technol Fac Elect & Comp Sci 2 Sniadeckich St PL-75453 Koszalin Poland

In this study, we report for the first time the results of ab initio calculations of the electron band energy structure and optical properties for thin films of solid-state solution CdSe1-xSx (x = 0, 0.25, 0.50, 0.75 and 1.00) with the interaction of their surface with H-2 and NO2 molecules. It is practically important concerning the problem of developing new gas sensors and for the photocatalytic hydrogen (H-2) evolution. Concentration dependences of the energy gaps, the position of an energy level of the valence band, and the conduction band are studied. Interaction of the thin films with H-2 creates a tendency to decrease the band gap and transform its concentration dependence to a quasi-linear one. The concentration dependences of optical properties are mainly studied on the example of refractive index at the light wavelength 500 nm. Moreover, we elucidate the influence of adsorption of the H-2 and NO2 gas occurring on the surface of CdSe1-xSx thin films on their optical functions.

关键词： Ultra-thin films First-principles calculations Band gap optical functions Refractive index Gas sensors

来源：评论

学校读者我要写书评

暂无评论

Electron-Plasmon Interaction in Bi2Te3-Sb2Te3 Crystals

引用

JOURNAL OF SURFACE INVESTIGATION 2024年第2期18卷 419-423页

作者： Stepanov, N. P. Zabaikalsky State Univ Chita 672039 Russia

Upon studying the optical properties of solid solutions of p-type Bi2Te3-Sb2Te3 in the infrared range, it is found that in the single crystal Bi0.6Sb1.4Te3, deformation of the reflection-coefficient spectra is observed in the frequency range of observation of the plasma resonance of free charge carriers. Deformation of the plasma edge increases with a decrease in temperature. Using the Kramers-Kronig dispersion relations from experimental reflection spectra, the spectral dependences of the real epsilon(1) and imaginary parts epsilon(2) of the permittivity function, as well as the energy-loss function characterizing the rate of energy dissipation, are calculated. Splitting of the peak of the energy loss function is found, which indicates the effect on the plasma resonance from another process occurring in the electronic system. It is established that such a process is the transition of electrons between nonequivalent extrema of the valence band. Convergence of the collective and single-particle energies of the electronic system leads to amplification of the electron-plasmon interaction, which is the most probable cause of the observed deformation of the plasma edge.

关键词： plasma of free charge carriers electron-plasmon interaction optical functions electronic transitions

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：