Calculation of the electronic and optical properties of indium tin oxide by density functional theory

Density functional theory (DFT) was used to calculate the bulk electronic and optical properties of indium tin oxide (ITO). The ITO model was constructed replacing indium atoms with tin atoms in the cubic unit cell of indium oxide. To allow more possibilities for tin atom substitution than afforded by the forty-atom primitive cell of indium oxide all eighty atoms of the unit cell were included in the stoichiometry (In_32−xSn_xO₄₈) using periodic boundary conditions. A number of properties of ITO were calculated including the optical band gap, charge carrier density and plasma frequency. The dependence of the electronic and optical properties of ITO on a variety of parameters such as the tin content, cubic lattice parameter and the distance between adjacent tin atoms was investigated. The electronic and optical properties agreed well with experimental data and allowed insight into the origin of the electronic and optical properties of ITO.     

CdSe的电子结构和光学性质研究

CdSe是Ⅱ-Ⅵ族半导体材料中一种重要的半导体材料,它有闪锌矿和纤锌矿两种不同的结构,带隙较窄,具有优良的电光特性和广泛的应用前景,得到了人们的广泛关注[1-3].     

Evolution of Structural, Electronic and Optical Properties of Monoclinic ZrO2 under High Pressure： A First Principles Study

The structural, electronic and optical properties of the monoclinic ZrO2 were studied by ab initio calculations based on the density functional theory and pseudopotential method. The calculated lattice parameters and band gap are in agreement with the experimental and other theoretical values. The evolution of lattice parameters and electronic properties were illustrated under high pressure. Meanwhile, the optical properties, such as adsorption coefficients, imaginary part of dielectric function, and energy loss function, were investigated under both ambient and high pressures.     

C60异噁唑环衍生物的结构、电子光谱和非线性光学性质的研究

The AM1 semiempirical calculation method was employed to study the structures and electronic properties of a series of isoxazolo fullerene derivatives. Based on the AM1 geometry optimization, the electronic spectra of molecules were studied by using ZINDO/CIS methods. The results indicated the HOMO LUMO energy gaps of those isoxazolo fullerenes were lower than that of C60. There existed the intramolecular electron transfer from the additional section to C60 moiety. The electronic spectrum data showed that the exception of the absorption was beyond 400 nm.The results were in good accordance with the experiment results. Nonlinear optical susceptibilities α, β and γ of molecules were calculated according to Finite Field(FF)/AM1, and the influence of molecular structures on nonlinear optical properties was examined.     

14族杂环戊二烯分子(硅、锗、锡)的电子结构与光谱性质

14族杂原子取代的杂环戊二烯分子具有独特的光谱性质, 成为发光材料的明星分子. 为了更深层次地理解硅、锗、锡杂环戊二烯分子的光谱性质, 本文从理论上计算了它们的电子结构及其吸收和发射光谱. 分别采用密度泛函理论(DFT)和含时密度泛函理论(TD-DFT), 优化了硅、锗、锡杂环戊二烯分子基态和第一激发态的平衡构型, 计算了电子结构和振动性质. 在此基础上, 运用振动关联函数公式计算了吸收光谱和发射光谱. 得到的吸收光谱和发射光谱, 特别是发射光谱的半峰宽与现有的实验值吻合很好. 通过分析结构和光谱性质的关系, 指出光谱的性质主要取决于苯环转动对应的低频振动模式和中心环C—C键的伸缩振动对应的高频振动模式.     

Organic Polymeric and Non-Polymeric Materials with Large Optical Nonlinearities

Nonlinear optical properties are a sensitive probe of the electronic and solid-state structure of organic compounds and as a consequence find various applications in many areas of optoelectronics including optical communications, laser scanning and control functions, and integrated optics technology. Because of their strongly delocalized π electronic systems, polymeric and non-polymeric aromatic compounds show highly nonlinear optical effects. Nowadays, polymer chemists are able to tailor specific materials properties for various applications. Some organic substances with π electronic systems exhibit the largest known nonlinear coefficients, often considerably larger than those of the more conventional inorganic dielectrics and semiconductors, and thus show promise for thin-film fabrication, allowing the enormous function and cost advantages of integrated electronic circuitry. The electronic origins of nonlinear optical effects in organic π electronic systems are reviewed, with special emphasis being given to second-order nonlinear optical effects. Methods for measuring nonlinear optical responses are outlined, and the critical relationships of the propagation characteristics of light to observed nonlinear optical effects and to solid-state structure are discussed. Finally, the synthesis and characterization of organic crystals and polymer films with large second-order optical nonlinearities are summarized.     

C~6~0-TTF及其衍生物的二阶非线性光学性质的理 论研究

采用ZINDO系列方法优化了环状桥联的C~6~0-TTF分子及其6个衍生物的几何构型,研究了各分子的稳定构型并以稳定构型为基础,计算了这些分子的电子光谱,二阶非线性光学系数β~μ,β~0,及激发态电荷转移,考察了取代基变化对β~μ的影响,并对上述结果在微观上给予了解释。     

Peptide-Based Optical/Electronic Materials: Assembly and Recent Applications in Biomedicine,Sensing, and Energy Storage

The unique optical and electronic properties of living systems are impressive. Peptide-based supramolecular self-assembly systems attempt to mimic these properties by preparation optical/electronic function materials with specific structure through simple building blocks, rational molecular design, and specific kinetic stimulation. From the perspective of building blocks and assembly strategies, the unique optical and electronic properties of peptide-based nanostructures, including peptides self-assembly and peptides regulate the assembly of external function subunits, are systematically reviewed. Additionally, their applications in biomedicine, sensing, and energy storage are also highlighted. This bioinspired peptide-based function material is one of the hot candidates for the new generation of green intellect materials, with many advantages such as biocompatibility, environmental friendliness, and adjustable morphology.     

Electronic interactions in a branched chromophore investigated by nonlinear optical and time-resolved spectroscopy

The third order nonlinear optical properties of a trimer branched chromophore system and its linear molecule analog are investigated. Two-photon absorption and degenerate four wave mixing measurements were carried out on both systems. An enhancement in the nonlinear optical effect is observed for the branched trimer molecule in comparison to the linear chromophore system. Ultrafast time-resolved measurements were carried out to probe the excited state dynamics in the branched structures. The time-resolved measurements suggest that the two important processes affecting the nonlinear optical properties in the trimer system, charge transfer stabilization and initial electronic delocalization, occur on two different time scales.     

Structural,electronic, and optical properties of some new dithienosilole derivatives

Structural Chemistry - Structural, electronic, and optical properties of a series of organic semiconductors based on dithienosilole (DTS) and its derivatives were theoretically studied using...     

Spectral properties and solubility of the lanthanide complexes with substituted and annelated porphyrazines

An analysis of the electronic optical properties and solubility in chloroform and DMF of the erbium and ytterbium complexes with porphyrazine and its octaphenyl- and octa(p-alkylsulfamoylphenyl)-substituted derivatives and tetrapyrazinoporphyrazine and its octaethyl-, tetra(tert-butyl)-, and octaphenyl-substituted derivatives is presented. The dependence of the electronic optical properties and solubility on the composition of the macrocycle of the studied complexes, namely, on the nature of the extraligand and peripheral environment of the porphyrazine macrocycle, is shown.     

Electronic properties of oxides: Chemical and theoretical approaches

An original analysis of the electronic and chemical properties of oxides is proposed based on the electronegativity χ and the chemical hardness η. This model which has been applied to various oxide based metals, degenerate semiconductors and optical properties of transition metal oxides allows explaining their electronic behaviors: Strong electronegativity and weak chemical hardness characterize oxides of transition elements with high oxidation state. Strong electronegativity and strong chemical hardness feature insulators with a large optical gap. Weak electronegativity and moderate chemical hardness describe alkali and alkaline earth oxides and weak electronegativity and strong chemical hardness are for ionic oxides with a relatively large optical gap. For a few illustrative case studies, ab intio electronic band structure calculations within the density functional theory framework are used.     

稀土无机发光材料:电子结构、光学性能和生物应用

目前,稀土无机发光材料在激光、光通讯、平板显示、荧光生物标记和纳米光电子器件等领域具有广泛的应用前景.稀土离子(从Ce到Yb)是一类性能优异的结构和光谱探针,其在不同介质材料中的光学性能主要取决于其局域态的电子结构和激发态动力学.对稀土发光材料开展深入的光学和光电子学基础研究有助于发现新颖的光学性能或开辟新的应用领域.依托研制的低温高分辨激光光谱和上转换量子产率等仪器,本课题组致力于稀土无机发光材料电子结构与性能研究,近年来在发光材料的控制合成、电子结构、光学性能及生物应用等方面取得了系列重要结果.这些研究有望加快实现稀土无机发光材料在生物应用的突破,实现稀土资源的高值利用.     

Theoretical investigation of the structural,elastic, electronic and optical properties of the ternary indium sulfide layered structures AInS2 (A = K,Rb and Cs)

Ab initio calculations were performed to investigate the structural, elastic, electronic and optical properties of the ternary layered systems AInS₂ (A = K, Rb and Cs). The calculated structural parameters are in good agreement with the existing experimental data. Analysis of the electronic band structure shows that the three studied materials are direct band-gap semiconductors. Density of states, charge transfers and charge density distribution maps were computed and analyzed. Numerical estimations of the elastic moduli and their related properties for single-crystal and polycrystalline aggregates were predicted. The optical properties were calculated for incident radiation polarized along the [100], [010] and [001] crystallographic directions. The studied materials exhibit a noticeable anisotropic behaviour in the elastic and optical properties, which is expected due to the symmetry and the layered nature of these compounds.     

Toward an understanding of intermediate- and short-range defects in ZnO single crystals. A combined experimental and theoretical study

A joint use of experimental and theoretical techniques allows us to understand the key role of intermediate- and short-range defects in the structural and electronic properties of ZnO single crystals obtained by means of both conventional hydrothermal and microwave-hydrothermal synthesis methods. X-ray diffraction, Raman spectra, photoluminescence, scanning electronic and transmission electron microscopies were used to characterize the thermal properties, crystalline and optical features of the obtained nano and microwires ZnO structures. In addition, these properties were further investigated by means of two periodic models, crystalline and disordered ZnO wurtzite structure, and first principles calculations based on density functional theory at the B3LYP level. The theoretical results indicate that the key factor controlling the electronic behavior can be associated with a symmetry breaking process, creating localized electronic levels above the valence band.     

由螺旋原子连接的系列立体交叉型分子的光谱与二阶非线性光学性质

用AM1和ZINDO系列方法研究了以螺原子连接的立体交叉型分子的几何构型,研 究了各分子的稳定构型并以稳定构型为基础,计算了这些分子的电子光谱,二阶非 线性光学系数β_μ, β_0,考察了取代基变化对β_μ的影响。计算结果表明所设 计分子兼具较大的二阶非线性光学系数和较高的透过率,有希望成为一类新型的二 阶非线性光学材料。     

A theoretical study of the structural,thermoelectric, and spin-orbit coupling influenced optoelectronic properties of CsTmCl3 halide perovskite

This first principles study explores the structural, electronic, optical, and thermoelectric properties of the CsTmCl₃ halide perovskite using density functional theory. The structural and thermoelectric properties are calculated without considering the spin-orbit coupling (SOC), while both the electronic and optical properties are calculated with and without the SOC effect. A comparison of the results obtained with and without SOC reveals that inclusion of the SOC effect reduces the band gap from 1.18 to 0.99 eV due to shifting of the Tm-d states toward the Fermi level. However, direct nature of the band gap remains the same in both the cases. The effect of SOC on the optical properties is, however, only visible in shifting of the third characteristic peak to lower energies. Strong optical absorption in the visible and ultraviolet regions shows effectiveness of CsTmCl₃ in the optical devices working in these regions. Moreover, the calculated transport properties reveal CsTmCl₃ as a useful thermoelectric material at room temperature.     

新型非线性光学材料的分子设计: 系列螺旋共轭化合物的结构、光谱及二 阶非 线性光学性质的理论研究

采用AM1和ZINDO系列方法研究了螺旋共轭分子2,2'-螺二茚-1,1',3,3'-四酮及其腈基衍生物的几何构型,研究了各分子的稳定构型,并以稳定为基础,计算了这些分子的电子光谱,二阶非线性光学系数βμ,β0,及电荷转移,考察了取代基变化对βμ的影响,计算结果表明所设计分子兼具较大的二阶非线性光学系数和较高的透过率,有希望成为一类新型的二阶非线性光学材料。     

Theoretical investigation of substitution and end-group effects on poly(p-phenylene vinylene)s

Semi-empirical AM1 and ZINDO/S, as well as density function theory (DFT) method B3LYP/6-31G(d) quantum chemical calculations were carried out to study the electronic structures and optical properties of poly(p-phenylene vinylene) derivatives (PPVs) with 10 and 11 phenylene rings in the backbone. The calculations suggest that the assembly of alternate incorporation of CN and alkoxy substituted phenylene rings in the PPV backbone could be a good way to construct organic semiconductors with low HOMO/LUMO energy band-gaps. The effect of the end-group on the electronic structures and optical properties of the conjugated polymer was investigated by the calculated UV-Vis and UPS spectra. It was demonstrated that the aldehyde and phosphate end-groups have limited effects on the photophysical properties in the UV-visible range.     

新型双重电荷转移分子的二阶非线性光学性质的 理论研究

以INDO/SCI方法为基础,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β~i~j~k和β~μ的程序。研究了1,2-二氨基-4,5-二硝基苯1和其异构体1,3-二氨基-4,6-二硝基苯2的电子光谱和二阶非线性光学性质。计算表明分子1具有与分子2几乎相等的二阶非线性极化率。但由于分子1的偶极矩明显大于分子2的,故分子1的μβ值比分子2的μβ值大的多。在此基础上,研究了2,3-二(β-苯乙烯基)-5,6-二氰基吡嗪和2,3-二(β-噻吩乙烯基)-5,6-二氰基吡嗪和2,3-二(β-噻吩乙烯基)-5,6二氰基吡嗪衍生物的电子光谱和二阶非线性光学性质。结果表明,这些化合物均具有两个相距很近的强吸收峰,它们对β值的呈加和模式。由于这类化合物特征吸收峰均位于413nm以下且具有大的μβ值,所以,它们是一类很有前途的二阶非线性光学候选材料。