One-dimensional Structure Research Articles

GLAD Fabricated Self-Powered Photodetector Based on WO3 with SiO2 as Interfacial Layer

Photodetectors based on one-dimensional structures have recently attracted great interest due to their high surface-to-volume ratio and light-trapping efficiency. In this study, a self-powered photodetector based on vertically aligned WO3 nanorod with SiO2 as an interfacial layer has been fabricated using glancing angle deposition. Scanning electron microscope (SEM) analysis confirms the successful growth of WO3 nanorod and SiO2 thin film with a thickness of ~125 nm and ~70 nm, respectively. The device’s optical properties were also analysed using UV-visible spectroscopy, which revealed a wide bandgap and an intense absorption peak in the ultraviolet region. The electrical analysis showed a nonlinear rectifying current-voltage behaviour with high photosensitivity. Additionally, the photodetector exhibits a fast response of 0.31 s rise time and 0.32 s fall time at 0 V. Moreover, the devices possess a high detectivity and a responsivity of 0.68 mA/W. Thus, the obtained finding reveals a potential candidate for self-powered photodetector application.

Periodic and quasi-periodic one-dimensional extrinsically magnetized photonic crystals with robust photonic bandgaps.

The study of light wave transmission spectra for a one-dimensional extrinsic multilayered photonic structure is investigated by using the transfer matrix method. The photonic transmission properties of the proposed structure are analyzed for the different values of the external magnetic field, incident angles in terms of standard and oblique, and the electron concentrations of the electromagnetic wave propagation through the extrinsic quasi-periodic and periodic photonic structures. Robust and wider PBGs have appeared for several kinds of quasi-sequences. The increase in electron concentration strengthens the PBG, though it is highly affected by the collision frequency. Furthermore, various PBGs in the terahertz frequency ranges are significantly influenced by the physical entities. The terahertz region's optical bandpass filters can be fabricated using the proposed framework. We also demonstrate that this proposed quasi-periodic multilayered architecture can be supplely controllable photonic crystals with positionable versions of the aforementioned features.

Intercultural adaptation and influencing factors analysis of the Chinese version of the anxiety scale for the older adults in a long-term care population.

The purpose of this study was to translate the Geriatric Anxiety Scale-Long-Term Care into Chinese and to assess its reliability and validity in a long-term care population, as well as to explore factors contributing to anxiety in older adults requiring long-term care. The study recruited 399 older adults residents requiring long-term care and used the Brislin double translation-back-translation method to create the initial Chinese version of the Geriatric Anxiety Scale-Long-Term Care. The study used internal consistency and split-half reliability to assess the reliability of the scale, as well as exploratory factor analysis, validation factor analysis, and content validity to assess the validity of the scale. Linear regression was used to analyze the relationship between the independent variables and anxiety levels in the long-term care population. The Cronbach's coefficient value of the Chinese version of the Geriatric Anxiety Scale-Long-Term Care was 0.81, and the split-half reliability was 0.80. The results of exploratory factor analysis showed support for a one-dimensional factor structure. The results of the validation factor analysis indicated a good fit for the one-factor model. Gender (β = 0.190, 95% CI:0.540 ~ 1.546, p < 0.001), self-rated health (β = 0.220, 95% CI:0.379 ~ 0.953, p < 0.001), life satisfaction (β = -0.315, 95% CI: -1.355 ~ -0.734, p < 0.001) and participation in activities (β = -0.106, 95% CI: -1.122 ~ -0.084, p < 0.05) were significant predictors of anxiety levels in the long-term care population. The Chinese version of the Geriatric Anxiety Scale-Long-Term Care has good reliability and validity in the long-term care population. The Geriatric Anxiety Scale-Long-Term Care is effective in assessing the anxiety level of the Chinese long-term care older adults population and provides an opportunity to detect and observe anxiety disorders in the long-term care population.

Co and Cu crystalline frameworks built with nitrogen heterocycle polycarboxylic acids and their catalytic property towards the reduction of p-nitrophenol

Nitrogen heterocyclic polycarboxylic acid is a type of ligands with excellent coordination ability and rich conformations. Two metal complexes, ([Co2(L1)2(CH3COO)(H2O)3]‧(CH3COO)‧H2O (1) (HL1 = 4-[2,6-bis(pyrazin-2-yl) pyrid-4-yl]benzoic acid)) and (Cu2(L2)(H2O) (2) (H4L2 = 5-[6-(3,5-dicarboxy phenylamino)pyrid-2-ylamino]benzene-1,3-dicarboxylic acid)) were synthesized with transition metal salts and nitrogen heterocycle polycarboxylic acid ligands by solvothermal method. Both complexes were characterized by infrared and ultraviolet spectroscopy, powder X-ray diffraction analysis, and thermogravimetric analysis. The X-ray single crystal structural analysis shows that complex 1 is a one-dimensional double-chain supramolecular structure built by intermolecular hydrogen bonds. While complex 2 is a three-dimensional framework with multiple channels, where the two independent Cu(II) metals are five-coordinated to form a square pyramidal coordination geometry. In addition, in order to investigate the functional properties of the two complexes, catalytic reduction experiments towards p-nitrophenol were carried out preliminarily. The reduction efficiency above 96 % demonstrates their potential as catalysts.

Enhanced stability of Pt@S-1 with the aid of potassium ions for n-hexane and n-heptane aromatization

As a typical high-efficient alkane aromatization catalyst, Pt/KL is prone to deactivation due to the sintering growth of Pt on the outer surface of KL and the channel blockage caused by carbon deposition, which is further exacerbated by the one-dimensional channel structure of KL. Therefore, a series of encapsulated catalysts combining the three-dimensional channel structure advantages of S-1 with the role of potassium are prepared and evaluated. It is shown that the encapsulated catalyst KPt@S-1-02 modified by moderate potassium exhibits extremely superior stability and no significant deactivation is observable after n-heptane aromatization for 180 h under harsh conditions. On the one hand, encapsulation structure enables a strong anti-agglomeration ability of Pt and the topological structure of S-1 endows the encapsulation catalysts less susceptible to channel blockage, which has been demonstrated by HAADF-STEM and N2-adsorption. On the other hand, characterizations involving NH3-TPD, CO-DRIFT and HAADF-STEM verify that the modification by an appropriate amount of K can inhibit acid sites of catalysts and improve Pt dispersion and electron density, thus enhance the stability of catalysts. However, excessive K can serve as weak acid sites, poison of active sites and inhibitor of H2 adsorption on Pt surface, leading to deactivation of the catalyst.

Four orotate-based lanthanide coordination polymers with rhomboid [Ln4(μ3-OH)2]-based 1D chainlike structure exhibiting luminescence and large magnetocaloric effect

Four isostructural lanthanide coordination polymers with orotic acid (H3OA) as building ligand, {[Ln(HOA)(μ3-OH)(H2O)2]·H2O}n (Ln = Eu (1); Gd (2); Tb (3); Dy (4)), were synthesized under hydrothermal conditions. Single-crystal X-ray diffraction analyses demonstrate that complexes 1–4 have an one-dimensional (1D) chainlike structure consisting of rhomboid [Ln4(μ3-OH)2] unit and HOA2- linker. Magnetic studies indicate that 2 displays a large magnetocaloric effect with magnetic entropy value of 37.11 J kg−1 K−1 at 2.0 K for ΔH = 7.0 T. This is a considerable value among the reported molecular magnetic coolants, and has a great application potential in the field of ultra-low temperature refrigeration. In addition, the solid-state photophysical properties of 1 and 3 exhibit obvious characteristic Eu(III) and Tb(III) photoluminescence emission in the visible region, suggesting that Eu- and Tb-based luminescence were sensitized effectively by the energy transfer from the ligand to the metal centers.

A novel efficient method for transient heat analysis of cylindrical periodic structure based on the physical features and group theory

In this paper, a novel efficient and accurate numerical method is developed for analyzing the transient temperature responses of cylindrical periodic structures. By exploiting the structure’s circumferential cyclic periodic property and leveraging group theory, a circumferential decomposition strategy is presented to transform the temperature response analysis of the cylindrical periodic structure into the analyses of a series of one-dimensional periodic structures. Then, based on the physical nature of the transient heat conduction, an axial decomposition strategy is developed to convert the computations of the temperatures of these one-dimensional periodic structures into the calculations of the temperatures of a series of small-scale structures. The computational cost of these small-scale structures is further reduced by using the group theory. Several numerical examples demonstrate that the proposed method has higher accuracy and computational efficiency in comparison with the Crank-Nicolson method. When the Crank-Nicolson method attains the acceptable results, the proposed method is about 10 and 20 times faster than the Crank-Nicolson method with direct and preconditioning conjugate gradient solvers, respectively.

The transmittance properties of the one-dimensional gyroidal superconductor photonic crystals

Abstract In this study, the transfer matrix method is used to analyze the optical properties of a layered structure, {Air(SrTiO3/BSCCO)20Substrate}, consisting of air, SrTiO3, BSCCO (bismuth strontium calcium copper oxide) bilayers, and a substrate. This paper aims to investigate the transmittance spectra of two proposed one-dimensional (1D) structures, including a conventional superconductor photonic crystal (PC) and a gyroidal superconductor PC at infrared (IR) wavelengths. A comprehensive analysis has been carried out to provide useful insights into the optical properties and the behavior of the proposed structure, highlighting the impact of many parameters, such as refractive index, filling fraction, and layer thickness. The numerical findings showed that the permittivity of the BSCCO superconductor of a gyroidal geometry takes a different response compared to the conventional one. Notably, the filling fraction and refractive index of the host material have a significant control on both real and imaginary parts of the gyroidal BSCCO permittivity through the considered wavelengths. Thus, the proposed design provides high transmittivity outside the obtained photonic band gap compared to the conventional one. We believe that the designed one-dimensional gyroidal BSCCO photonic crystals could act as an efficient reflector through near IR for optoelectronics and energy applications.

Two forms of transfer matrix for one-dimensional optical structures

Two forms of the transfer matrix applied for treatment of light propagation through one-dimensional optical structures are discussed. A detailed comparison between those forms is presented. A case of structures with absorption (gain) is included. The relation between the transfer matrix method and the Floquet-Bloch theory is highlighted for the case of a periodic structure.

Dimension-Dependent Phase Transitions, Ferroelasticity, and Photoluminescence in Hybrid Organic-Inorganic Materials.

[(CH3)3P(CH2)2OH]2Cd3(SCN)8 (1) and [(CH3)3P(CH2)2OH]Cd(SCN)3 (2) were obtained with completely different structures and properties under the same synthesis conditions. Compound 1, showing green fluorescence, has a rare three-dimensional 4,6-connected fsh topology having (43.63)2(46.66.83) Schläfli notation, while compound 2 with blue-violet phosphorescence displays a one-dimensional perovskite structure with an infinite {[Cd(SCN)3]-}∞ chain and exhibits both ferroelastic and dielectric switching characteristics.

Collective oscillations of systems of Xe atoms in a groove between two carbon nanotubes

The collective oscillations of systems of Xe atoms adsorbed in a groove between two carbon nanotubes have been studied by the method of molecular dynamics. The one-dimensional and three-chain structures of atoms that appear in such grooves are considered depending on the number of particles, temperature, and external potentials. It is shown that the infinite one-dimensional structures of Xe atoms are stable at finite temperatures only in the presence of such potentials acting in the direction normal to the axis of the structure. The oscillation spectrum is found, which is in accordance with theoretical calculations of the dispersion laws of collective modes. Collective oscillations of three-chain structures have been studied. The theoretical calculation of the laws of dispersion of modes, carried out by the method of equations of motion for small displacements of atoms from the equilibrium position, showed that the collective modes of the system show a great similarity with the corresponding dispersion laws of a one-dimensional chain of atoms. At the same time, it was found that a torsion mode arises, which is characteristic of a three-chain structure. The calculation agrees well with the spectrum of oscillations obtained by the molecular dynamics method. Using the established mode dispersion, the heat capacity of Xe chains is calculated within the framework of the Einstein model. The calculation results are in good agreement with the experimental data in the temperature range of up to 35–40 K, which can be explained if we assume the presence of both one-dimensional and three-chain structures of Xe atoms adsorbed in the grooves between carbon nanotubes. The effect of temperature on the stability of Xe atomic structures on nanotubes has been studied, and it has been shown that one-dimensional structures start to defragment at temperatures higher than 60 K, whereas three-chain structures defragment at temperatures higher than 90 K.

A Review on Silicon Nanowires and their use in the Development of Nano Piezoresistive Pressure Sensors

Abstract: Silicon has been the most trusted and used material in the fabrication of microelectronics components and systems. Recently, silicon nanowires have gained a lot of importance in the development of devices/components in many applications. SiNWs have unique attributes that are not found in bulk silicon. Their one-dimensional electronic structure provides interesting properties. Unique properties and small dimension (nm) of silicon nanowires have made them to be used as sensing elements in the development of nanosensors and devices. Silicon nanowires are now being extensively used in the development of biosensors, FETs, lithium-ion batteries, transistors, microelectronic chips, and sensors. SiNWs are used in the development of solar cells and photovoltaic batteries, because of their charge-trapping capabilities. The fabrication of silicon nanowires follows chemical etching, chemical vapor deposition (CVD), electron beam lithography, etc. The dimensions of silicon nanowires are highly compatible with the dimensions of biological and chemical species, hence making them more efficient to be used as sensing elements in bio and chemical domains. SiNWs exhibit excellent piezoresistive properties and hence are used as piezoresistors in piezoresistive sensing applications. This article presents a review of SiNWs in the development of sensors. An emphasis is given to the piezoresistive property of SiNWs. The use of SiNWs as a piezoresistor in the development of piezoresistive pressure sensors is also extensively reviewed in this article, along with the unique properties of SiNWs. Typical dimensions and applications of SiNWs are also reviewed. Moreover, this article also explores the fabrication, characterization aspects, and capabilities of SiNWs in the design and development of nanoscale devices/sensors.

Study transmission characteristics of graded photonic crystal as low pass filter

Here, we investigate propagation characteristics of graded thickness one-dimensional photonic crystal structure made of silicon and air. The optical transmission is obtained by transfer matrix method (TMM) and studied impact of graded index and refractive index variation on the transmission spectra. The optical transmission of suggested structure drops as frequency increases and falls to zero more rapidly as graded index increases. The graded index variable can be used to tune the suggested structure’s cut off frequency, which corresponds to half of the transmission value. So, such device has useful application as tunable optical low-pass filter.

The Psychometric Properties of the Adlerian Courage Scale in a Sample of Turkish Adolescents

Courage has received considerable attention in recent years. However, courage research has been limited due to a lack of appropriate measurement tools for adolescents. In this field, there is a measurement tool for courage from an Adlerian perspective for adults, but it is lacking for adolescents. Therefore, the present study aimed to examine the psychometric properties of the Adlerian Courage Scale – Adolescents Form within an adolescent sample in Türkiye. The scale was administered to 618 Turkish adolescents aged between 14-18. The confirmatory factor analysis results indicated that the scale's one-dimensional structure was confirmed with high factor loadings for the items. Additionally, the internal reliability coefficient (α = .93) and test-retest reliability score (.95) illustrated that the items of the scale were reliable. Overall, considering reliability and validity results, the findings suggested that Adlerian Courage Scale – Adolescent Form is a valid and reliable measure to investigate the concept of courage in the context of positive psychology within the Turkish adolescent context.

An Unsymmetrical 5,15-Disubstituted Tetrabenzoporphyrin: Effect of Molecular Symmetry on the Packing Structure and Charge Transporting Property.

Molecular design strategy to control the crystal structure of two-dimensional (2D) π-extended organic semiconductors has not been intensively explored. We synthesized an unsymmetric tetrabenzoporphyrin derivative (TIPS-Ph-BP) to demonstrate the effect of molecular symmetry on crystal packing. TIPS-Ph-BP formed an antiparallel slipped π-stacking and 2D herringbone-like structure. An unsymmetric structure would make 2D π-stacking more stable than a one-dimensional (1D) columnar structure to counteract steric and electronic imbalance in the crystal. As a result, TIPS-Ph-BP achieved the high hole mobility of 0.71 cm2 V-1 s-1.

Polyaniline nanosheets templated from aniline‒acid precipitates and their electrochemical performance for flexible supercapacitor

The simple synthesis of two-dimensional (2D) polyaniline (PANI) structures remains a big challenge owing to the intrinsic growth of PANI chains into one-dimensional structures and the curling of the PANI chains into spherical particles. In this contribution, we report on the simple synthesis of PANI nanosheets by oxidizing aniline–acid precipitates with ammonium persulfate (APS) through a chemical oxidation polymerization method. The tested acids include methylene disulfonic acid, sulfuric acid, benzoic acid, oxalic acid, p-toluenesulfonic acid, hydrochloric acid, and acetic acid. The aniline–acid precipitates serve as separation-free templates for producing PANI nanosheets. The yield, oxidation level, electronic conductivity, conjugation length, and thickness of the PANI nanosheets can be tuned by controlling the molar ratio of aniline/APS. The electrochemical performance of PANI nanosheets-based symmetric supercapacitors was examined at the temperature ranging from room temperature to –60 °C. The PANI nanosheets with relatively high specific surface area rather than the oxidation level manifest superior electrochemical performance.

Pore-scale melting behaviors in composite phase change material with porosity gradients

Latent heat storage is a promising thermal energy storage solution to tackle the time–space conflict in energy demand. However, the low thermal conductivity of pure phase change material may limit the thermal energy storage performance of latent heat storage systems. In this work, porous support with gradient porosity and high thermal conductivity is incorporated into the phase change material to minimize the total melting time. A pore-scale lattice Boltzmann model for simulating the melting process of composite phase change material is established to investigate the effect of gradient porosity on the dynamic melting process. The results show that the two-dimensional gradient porosity structure can significantly improve the melting rate of composite phase change material. Compared with a uniform porosity structure, the melting time can be reduced by up to 8.58% in this work. By considering the changes in dominant heat transfer mechanisms during the melting process and the asymmetric evolution of the upper and lower parts of the melting front, the two-dimensional gradient porosity structure combines the advantages of horizontal and vertical one-dimensional gradient porosity structure. It is also found that the gradient porosity structures slow down the melting process of composite phase change material when the porosity is too small in the lower right corner of the square cavity or when the two-dimensional gradient porosity is divided too finely. The solid phase change material in this area mainly relies on thermal convection for melting, and it can significantly delay the melting time when the flow velocity is low, with a maximum extension of 26.58% of the melting time as compared to a uniform porosity structure.

Direct CVD-growth and optoelectronic characterizations of monolayer ribbon-like MoS2 flakes

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) materials provide a perspective development for optoelectronic, catalytic and quantum devices. However, relative approach to modify corresponding physical performance via explicit synthetic control of edge structure and dimensionality is still an enormous challenge. Here, we elucidate the successful fabrication of high-yield monolayer ribbon-like MoS2 crystals via a catalyst-free chemical vapor deposition (CVD) strategy. These ribbon-like MoS2 flakes exhibit a monolayer feature with tunable width in the range of 0.6–4.2 µm and a changed optical/electronic performance depending on the flake width. Furthermore, the proposed growth mechanism of such unique structures is analyzed at the basis of the change of Mo/S atom ratio. Our result emphasizes the potential to enable the successful preparation of special quasi one-dimensional (1D) TMDC structures for next-generation micro-nano optoelectronic devices.

Preparation, Structure, Characterization and Properties of a Novel [Y(HIA)3(H2O)2]n · nYCl3 (HIA = Isonicotinic Acid)

A novel yttrium complex [Y(HIA)3(H2O)2]n·nYCl3 (HIA = isonicotinic acid) has been synthesized via a hydrothermal reaction and characterized by single crystal X-ray diffraction technique. The title complex features a one-dimensional (1-D) chain-like structure. A solid state photoluminescence measurement revealed that there is one strong emission peak at 487 nm. These peak can be assigned to the characteristic electronic transition and stacking effect inside the ligand. The title complex shows CIE (Commission Internationale de I’ Éclairage) chromaticity coordinates in the blue region (0.1049, 0.1221). At the same time, the title complex has a wide band gap of 2.03 eV, which was revealed by a solid-state UV/Vis diffuse reflection experiment.

Towards high photoresponse of perovskite nanowire/copper phthalocyanine heterostructured photodetector

One-dimensional nanowire structures composed of perovskite are widely recognized for their exceptional optoelectronic performance and mechanical properties, making them a popular area of investigation in photodetection research. In this work, a perovskite nanowire/copper phthalocyanine heterojunction-based photodetector was fabricated, which exhibits high photoresponse in the visible-near-infrared region. The incorporation of a heterojunction significantly enhanced the photoelectric performance. Specifically, the photoresponsivity and external quantum efficiency of the nanowire-based device were elevated from 58.5 A W−1 and 1.35 × 104% to 84.5 A W−1 and 1.97 × 104% at 532 nm, respectively. The enhanced photoresponse of the heterojunction device can be attributed to the unique microstructure of nanowire arrays. The wrapping of the nanowires by copper phthalocyanine forms heterojunctions with a larger dissociation area, which facilitated exciton dissociation and enhanced device performance. This work provides a promising example for optimizing the performance of nanowire devices.