Optimum Layer Thickness Research Articles

Landau-Levich Scaling for Optimization of Quantum Dot Layer Morphology and Thickness in Quantum-Dot Light-Emitting Diodes.

Quantum dot (QD) light-emitting diodes (QLEDs) are promising candidates for next-generation displays because of their high efficiency, brightness, broad color gamut, and solution-processability. Large-scale solution-processing of electroluminescent QLEDs poses significant challenges, particularly concerning the precise control of the active layer's thickness and uniformity. These obstacles directly impact charge transport, leading to current leakage and reduced overall efficiency. Blade-coating is a prevalent and scalable solution processing technique known for its speed and minimal waste. Additionally, it allows for continuous "roll-to-roll" processing, making it highly adaptable in various applications. In this study, we demonstrate the precise control of blade speed in the Landau-Levich regime to create a uniform QD emission layer, using a commercial CdSe/ZnS QD as a representative example. QDs assemble into different morphologies on glass and the underlying layers of the QLED device due to variations in interaction energy. The QD film thickness can be modified from monolayer to multilayer by adjusting blade speed, which can be predicted by fitting the Landau-Levich-Derjaguin theory. The optimal speed at 7 mm/s results in a QD film with a surface coverage of around 163% and low roughness (1.57 nm mean square height). The QLED external quantum efficiency (EQE) of approximately 1.5% was achieved using commercially available CdSe/ZnS QDs with low photoluminescence quantum yield (PLQY), and an EQE of around 7% has been obtained using lab-made InP/ZnSe/ZnS QDs having a solution PLQY of 74%. All-blade-coated CdSe-QLEDs are further demonstrated by adopting the optimized speed for the QD layer. This method demonstrates significant potential for developing low-cost, reproducible, and scalable QLED technologies with uniform emission characteristics and low-waste production.

Simulation-Based Studies on FAGeI3-Based Lead (Pb2+)-Free Perovskite Solar Cells

In the recent reports, it is clear that lead-free perovskite materials with low band gaps are desirable candidates for photovoltaic cells. In this regard, it was observed that germanium (Ge) is a less toxic lead-free metal that is significant for the preparation of Ge-based perovskite materials. Ge-based perovskite materials, for example, methyl ammonium germanium iodide (MAGeI3), cesium germanium iodide (CsGeI3), and/or formamidinium germanium iodide (FAGeI3) may be the suitable absorber materials and alternatives towards the fabrication of lead-free photovoltaic cells. In the past few years, few attempts were made to develop FAGeI3-based perovskite solar cells, but their photovoltaic performance is still under limitations. This is indicating that some significant and effective strategies should be designed and developed for the construction of Ge-based perovskite solar cells. It is believed that optimization of layer thickness, device structure, and selection of a suitable electron transport layer (ETL) may improve the photovoltaic performance of FAGeI3-based perovskite solar cells. Solar cell capacitance simulation, i.e., SCAPS is one of the promising software programs that can provide significant theoretical findings for the development of FAGeI3-based perovskite solar cells. The simulation studies via SCAPS may benefit researchers to save their energy and high cost for the optimization process in the laboratories. In this research article, SCAPS was adopted as a simulation tool for the theoretical investigations of FAGeI3-based perovskite solar cells. The simulation studies exhibited the excellent efficiency of 15.62% via SCAPS. This study proposed the optimized device structure of FTO/TiO2/FAGeI3/PTAA/Au with enhanced photovoltaic performance.

W/WO3/TiO2 Multilayer Film with Elevated Electrochromic and Capacitive Properties.

Electrochromic capacitors, which are capable of altering their appearances in line with their charged states, are drawing substantial attention from both academia and industry. Tungsten oxide is usually used as an electrochromic layer material for electrochromic devices, or as an active material for high-performance capacitor electrodes. Despite this, acceptable visual aesthetics in electrochromic capacitors have almost never been achieved using tungsten oxide, because, in its pure form, this compound only displays a onefold color modulation from transparent to blue. Herein, we have designed W/WO3/TiO2 multilayer films by a magnetron sputtering device. The impact of TiO2 layer on the optical and electrochemical properties was investigated. The results show that the optimum thickness of the TiO2 layer is 10 nm. The as-prepared film displays a high coloration efficiency (CE) of 74.2 cm2 C-1, a high areal capacitance of 32.0 mF/cm2, an excellent rate performance (with the areal capacitance still retaining 87% of the maximum capacitance at a current density of 1 mA/cm2), and a high cycle life (with a capacity retention of 91% after 1000 cycles).

Theoretical analysis and performance optimization of Cs<sub>2</sub>AgBiI<sub>6</sub> solar cells with dual hole transport layers

Double perovskite materials have received significant attention in the photovoltaic field due to their low cost, environmental friendliness, and lead-free composition, which make them ideal candidates for next-generation solar cell applications. In this work, the photovoltaic performance of solar cells using Cs<sub>2</sub>AgBiI<sub>6</sub> as the light-absorbing layer is systematically investigated through simulations using Silvaco ATLAS software. Based on the previously reported single hole transport layer device architecture, namely ITO/ZnO/Cs<sub>2</sub>AgBiI<sub>6</sub>/HTL/Au, a new dual hole transport layer structure ITO/ZnO/Cs<sub>2</sub>AgBiI<sub>6</sub>/HTL1/HTL2/Au is proposed. Different dual hole transport layer combinations are explored, and their influence on the internal physical mechanism and the device performance are analyzed and optimized in detail. The simulation results show that the devices using Cu<sub>2</sub>O/NiO and NiO/Si respectively as dual hole transport layer significantly improve charge extraction and generate a negative electric field at the interface, thereby reducing recombination losse and accelerating the transport of hole carriers. These two configurations exhibit substantially higher efficiencies than those configurations with a single hole transport layer, confirming the advantages of the dual hole transport layer structure. Additionally, devices using Cu<sub>2</sub>O/CZTS and MoO<sub>3</sub>/CZTS as dual hole transport layer show better performance than the reference structure using Spiro-OMeTAD/CZTS, indicating the potential for further improvement by optimizing material selection and layer properties. Of the various dual hole transport layer combinations tested, the structure utilizing Cu<sub>2</sub>O/CZTS achieves the highest simulated power conversion efficiency (PCE) of 22.85%. By optimizing the thickness of each functional layer, the efficiency can be further increased to 25.62%, and the optimal layer thickness is determined to be 40 nm for ZnO, 850 nm for Cs<sub>2</sub>AgBiI<sub>6</sub>, 140 nm for Cu<sub>2</sub>O, and 150 nm for CZTS. Furthermore, the effects of environmental and material parameters, such as temperature and hole transport layer doping concentration, on device performance are investigated. This study lays a theoretical foundation for the design and enhancement of double perovskite solar cells. By demonstrating the potential that the dual hole transport layer structures can significantly improve device efficiency, their value in advancing environmentally friendly and lead-free photovoltaic technologies becomes very prominent. The insights gained from this research pave the way for developing high-performance double perovskite solar cells with optimized architectures and material properties.

INFLUENCE OF SPIRO-OMETAD FILM THICKNESS ON THE STRUCTURAL AND ELECTRICAL PROPERTIES OF PEROVSKITE SOLAR CELLS

This work investigates the effect of the hole transport layer (HTL) thickness of Spiro-OMeTAD on the electrical transport properties in perovskite solar cells (PSCs).Spiro-OMeTAD films were obtained by the spin-coating method at centrifuge rotation speedsfrom 2000 to 7000 rpm. The thickness and morphology of the Spiro-OMeTAD films were studied by atomic force microscopy (AFM). From the obtained AFM image data, an increase in the surface root mean square (rms) value is observed with decreasing film thickness. A decrease in film thickness leads to an increase in Energy gap (Eg)from 2.97 eV to 3.01 eV. We observe that at a layer thickness of 260 nm, the efficiency of the cells reaches its maximum value; further increasing the layer thickness reduces the efficiency. Analysis of the impedance spectra of PSCs showed that the optimal layer thickness reduces the HTL resistance and increases the recombination resistance at the perovskite/HTL interface, which increases the effective lifetime of charge carriers. Images of the surface and current distribution of Spiro-OMeTAD on the surface of the perovskite layer were studied.A non-uniform current distribution on the surface of the samples was revealed, the observed spots with high conductivity are interpreted as perovskite quantum dots, which have better photovoltaic characteristics.Keywords: Perovskite solar cells, hole transport layer,Spiro-OMeTAD, conductive-AFM, current-voltage characteristics, impedance measurements.1. Introduction In recent years, organic-inorganic perovskite solar cells have attracted much attention from the global scientific community. The unprecedented development of PSCs is driven by their high optical absorption coefficient, tunable bandgap, low cost, ease of fabrication, and great potential to achieve higher efficiency compared to c-Si solar cells [1–3].To increase the efficiency and stability of PSCs, work is being done to search and optimize the composition of all parts of the solar cell, not only the perovskite itself, but also theso-called transport layers. The hole-conducting transport layer plays an important role in the efficiency of charge transfer and extraction of photoexcited perovskite, HTL is important for power conversion efficiency (PCE) and stability in PSCs. Transportlayers typically consist of small organic molecules, polymers, or inorganic materials such as oxides. The energy level of the HTL material must coincide with the maximum

Assessing 3D-printed concrete process parameters through Discrete Element Modeling

Three-dimensional concrete printing (3DCP) has emerged as a promising manufacturing technique in the civil engineering sector, offering myriad advantages over traditional construction methods. Despite its potential, challenges persist in optimizing the manufacturing stage of 3DCP, including determining optimal fresh concrete rheology, layer thickness, print path, and nozzle characteristics. In this study, we incorporate the Discrete Fresh Concrete model (DFC) into our Discrete Element Method (DEM) code to simulate the rheological behavior of fresh printable concrete during printing, aiming to explore a comprehensive range of process parameters and their combinations to enhance understanding and optimization 3DCP process. Through a series of simulations, we systematically vary some of the process variables such as concrete mix design, nozzle specifications, and printing speed to investigate their influence on the printed output quality. By the obtained results, we aim to identify the key parameters that significantly affect the process, offering insights for refining 3DCP technologies and helping guide their development. We believe methodologies of the type as shown here may be an efficient tool for advancing 3DCP technologies.

Enhancing the Efficiency of PM6:Y6 Bulk-Heterojunction Organic Solar Cells through SCAPS Simulation Optimization

Organic solar cell (OSC) is becoming a point of attraction in the solar cell industry due to their benefits, such as light weight, flexibility, low cost, semi-transparency, and easy fabricating methods. By replacing fullerene with non-fullerene acceptors like Y6, ITIC, PCBM, and ICBA, the power conversion efficiency (PCE) of OSCs has surpassed the 15% benchmark. Here, the proposed OSC structure includes an ITO front contact electrode, SnO2 electron transport layer (ETL), PM6:Y6 active layer, Cu2O hole transport layer (HTL), and Ag back contact electrode. Systematic numerical simulation of the above proposed OSC has been performed using a solar cell capacitance simulator (SCAPS)-1D (Version 3.3.09). The device improvement analysis has been carried out in steps by analyzing the ETL-HTL effect, selecting the optimum thickness of the active layer, and the optimum value of defect density. In the first step, a PCE of 24.60% was achieved, followed by an improvement to 27.55% with the optimized defect density value. The best PCE of 27.74% was achieved in the third step with an optimized active layer thickness, leading to high fill factor (80.56%), open-circuit voltage (0.9461 V), and short-circuit current density (36.188 mA/cm2). These simulated results promote an in-depth understanding of the optical and electronic properties of PM6:Y6 blend-based OSC and show the potential of NFA-BHJ OSCs as promising candidates for solar cells in the near future.

Investigating the performance of Tin-based perovskite solar cell with Cadmium Sulphide as etm and graphene as htm using SCAPS-1D

Solar cells based on lead-free perovskite have demonstrated great potential for renewable energy. The SCAPS-1D simulation software was used in this study to perform device modelling of a lead-free perovskite solar cell of the architecture Glass/FTO/CdS/CH3NH3SnI3/Graphene/Pt. For the performance evaluation, an optimization process of the different parameters such as thickness of the ETM, Absorber, Bandgap energy of the hole transport material was conducted. Extensive discussion on its effect on the performance of the solar cell parameters were stated. An optimal ETM and Absorber layer thickness was achieved at 40nm and 950nm. The Bandgap energy gave an optimal performance of device parameters at 0.9eV. Temperature variations were simulated and it was noted that the device had a minimal decrease in PSC parameters performance with increasing temperature. The final optimized device structure achieved a PCE, Voc, Jsc and FF of 25.65%, 0.9606 V, 33.2491(mA/cm2), and 80.32% respectively. Therefore, we expect that our findings will pave the way for the development of lead-free and highly effective perovskite solar cells.

Flip-chip package solder-underfill reliability using finite element analysis

A semiconductor package is responsible to safeguard the die from the external environment that can affect its performance and reliability. A flip-chip package ensures that the assembly, which is capable of high input-output function, maintains its operation and safeguards the interconnection paths particularly the solder ball deformation and fatigue. In this study, a finite element analysis model of the solder-underfill layers of a flip-chip package was developed and validated by statistical comparison of the warpage and stress from experimental data and theoretical calculations of composite deformation and stress. Quarter modeling reduces the computational load while maintaining sufficient detail that allows for efficient use of computational resources. It is then complemented by the design of experiment which systematically varied the parameters to explore the design space and optimize the configuration. Moreover, the method was able to account for nonlinear effects, especially on the impact of solder content on die stress. This provides a more precise control over the thermo-mechanical behavior of the package which would lead to more informed decisions in designing packages. The results have shown desirability of 0.8491 with an optimal layer thickness setting of 0.06 mm and solder content of 18.1% in consideration of the nonlinear factor effect of solder content on the die stress.

Determination of Optimal Layer Thickness by Controlling Feed Rate of Powder in the DED Process

Determination of Optimal Layer Thickness by Controlling Feed Rate of Powder in the DED Process

Exploring the Potential of Various Cyclodextrin-Based Derivatives in Enzyme Supramolecular Engineering.

Enzyme stability and activity are pivotal factors for their implementation in different industrial applications. Enzyme supramolecular engineering relies on the fabrication of a tailor-made enzyme nano-environment to ensure enzyme stability without impairing activity. Cyclodextrins (CDs), cyclic oligomers of glucose, act as protein chaperones and stabilize, upon interaction with hydrophobic amino acid residues exposed at the protein surface, its three-dimensional structure. When used to build an organosilica layer shielding an enzyme, they enhance the protective effect of this layer. In the present study, we systematically assessed the protective effects of three organosilane derivatives based on ɑ-, β- and γ-CDs. A model lipase enzyme was immobilized at the surface of silica nanoparticles and shielded in an organosilica layer containing these organosilanes. Besides layer thickness optimization, the effect of different stressors (i. e., temperature, SDS, urea) was tested. Our results showed that organosilica layers produced with CDs improve enzyme thermal stability. They also support enzyme refolding after denaturation under chaotic conditions. Additionally, we demonstrated that the protective effect of the smallest CD derivative tested, namely ɑ-CD, surpassed the other macrocycles studied for conferring the immobilized enzyme with higher resistance to stress conditions. This protection strategy was also applied to a thermostable β-galactosidase enzyme.

Integrated optimization of ply number, layer thickness, and fiber angle for variable-stiffness composites using dynamic multi-fidelity surrogate model

To fully exploit the efficiency of variable-stiffness composite laminates with spatially varied fiber orientation angles, this paper aims at presenting a novel optimization framework for integrated design of ply number, layer thickness, and fiber angle. The optimization problem is innovatively formulated based on the definition of a ground laminate with redundant layers. The basic optimization idea is to seek both unnecessary and necessary layers in this ground laminate. For unnecessary layers, they can be removed and assigned with small-value ply thicknesses, while necessary layers are retained in the ground laminate and corresponding ply thicknesses and fiber angles are optimally determined using discrete and continuous variables, respectively. Since variable-stiffness composite laminates always require high-fidelity analysis models to accurately capture the spatial characteristics of varying fibers, this results in a time-consuming process. To alleviate this problem, a multi-fidelity surrogate model with an exponent-based comprehensive correction is originally proposed based on Gaussian process regression, generating an approximate problem to replace the original one. The genetic algorithm and sequential quadratic programming method are sequentially employed to solve this approximate problem with mixed design variables. The solution from this procedure is dynamically added to the sampling dataset to update the constructed surrogate model. Numerical benchmark problems and cases studies of a composite plate and a solar wing structure are addressed, demonstrating the efficacy of the newly proposed optimization strategy.

Highly efficient single photon coupling via surface plasmons into single-mode optical fiber

Quanta of light (single photon) play as one of the building blocks of photonic based quantum computations, sensing, and communications. This makes a necessity to develop practical approaches for tuning, guiding, and coupling of single photons in photonic circuits for viable applications. Interaction and coupling efficiency of single photon into optical fibers is a technical bottleneck of quantum optics and should be addressed by novel design and materials. Here, we introduce a fiber-based micro-photonic design to directly coupling of the emitted single-photon to the core of a single mode fiber (SMF). The results of the simulation indicate that the emission of single photon source on a D-shaped SMF coated by a thin plasmonic film, provide remarkable amplifying of the evanescent field by confined surface plasmons into the SMF. The numerical analysis of different types and thicknesses of plasmonic materials by finite element method (FEM) is conducted to study the propagation vectors along the SMF as a function of the emission angle and wavelength of the single photon source. The results revealed that by the optimum thickness of the tantalum layer as novel plasmonic material, the best record of coupling efficiency can be achieved in the fiber optics communication region (λ ∼ 1550 nm). This approach sheds light on novel plasmonic-assisted coupling and promises a functional strategy for single photon manipulation in various fields of quantum optics.

SCAPS numerical modeling of CBTS/WO3 thin film solar cell

The quaternary compound Cu2BaSnS4 (CBTS) has emerged as a suitable and attractive light-harvesting material due to its promising optoelectronic features as well as nontoxic and low-cost constituent elements. Yet efficiency of CBTS-based solar cells did not reach the Shockley-Queisser limit. Here, what we believe to be a novel structure ITO/WO3/CBTS heterojunction solar cell is designed and modeled using a solar cell capacitance simulator in one-dimension (SCAPS-1D). In this work, a what we also believe to be a novel WO3 as a buffer layer is proposed for the first time for the efficiency enhancement of CBTS thin film solar cells. Numerical investigation of the performance of CBTS-based solar cells without and with cuprous oxide (Cu2O) back surface field (BSF) is explored. The impact of thickness, doping density, bulk, and interface defect density of an absorber, buffer and window layer, working temperature, shunt and series resistance, back contact work function, and back surface recombination velocity were analyzed and optimized without and with the BSF layer. In this work, the optimized solar cell achieved an efficiency of 18.8%, fill factor (FF) of 83.79%, short-circuit current density (JSC) of 15.99 mA/cm2, and open circuit voltage (VOC) of 1.4 V without Cu2O BSF layer at optimal CBTS absorber and WO3 buffer layer thickness of 2 µm and 0.04 µm respectively. Furthermore, the efficiency boosted to 21.12% with VOC of 1.43 V, JSC of 16.8 mA/cm2 and FF of 87.77% by inserting 0.1 µm Cu2O BSF layer. Therefore, these results will facilitate the fabrication of an efficient and low-cost CBTS-based solar cell with promising WO3 and Cu2O as buffer and BSF layer, respectively.

Accuracy, Marginal, and Internal Fit of Additively Manufactured Provisional Restorations and Prostheses Printed at Different Orientations.

This systematic review aimed to assess the impact of printing orientation on the accuracy and properties of additively manufactured provisional restorations. A systematic literature search databases (PubMed, Scopus, Web of Science, and Cochrane) were conducted in July 2024 without language restrictions. The included studies were evaluated using the modified CONSORT checklist, and the effect measures and synthetic methods were employed to assess the accuracy of resin provisional restorations printed at various orientations. The web search resulted in 8228 records, and 15 records were ultimately included in the analysis. The printing orientation of provisional restorations has an impact on various factors such as the internal and marginal gap, trueness, precision, and accuracy. To achieve optimal results, it is recommended to utilize printing orientations of 180°, 150°, and 210°, as they showed lower marginal and internal gaps and higher accuracy. Caution should be exercised during the virtual positioning of supporting pillars, as this may also influence the overall accuracy. Horizontally and slightly tilted orientations have demonstrated superior accuracy. To achieve optimal results, factors such as printing layer thickness, printing technology, materials, and supportive pillars should be taken into consideration, besides the printing orientations. The selection of the optimum printing parameters overall printing orientations, layer thickness, and supportive pillar position can generate prosthetic and restorative dental parts with a long survival rate, saving time and effort by avoiding fracture, loss of retention, and consequent clinical complications.

Device optimization of all-perovskite triple-junction solar cells for realistic irradiation conditions

All-perovskite two-terminal tandem solar cells, comprising two or more junctions, offer high power conversion efficiencies (PCEs) that exceed the limits of single-junction photovoltaics. Realizing high-efficiency SCs requires carefully optimizing the photoactive layer, front electrodes, and functional layers. Here, we first aim to determine the optimal device architecture, i.e., the perovskites bandgaps and optimum layer thicknesses, for standard test conditions (STCs). We then optimize the energy yield (EY) under realistic outdoor conditions (ROCs), i.e., the overall electrical energy to be expected in one year at a specific location. In the first step, we reference our simulation with two terminal all-perovskite triple-junction SCs (2T3J-PSCs) to previously experimentally realized PSC with a PCE of 20.1% as a benchmark to derive the underlying diode parameters and use our in-house energy yield code combined with a hybrid particle swarm optimization and gravitational search algorithm (PSOGSA) to find the optimal bandgap combination and perovskite layer thicknesses. The optimized SCs with the optimal bandgap combination offer a PCE of 25.1% with a current density of 10.1 mA/cm2. Furthermore, the effect of the other functional layers, such as transparent conductive oxide (TCO), hole transport layer (HTL), and recombination junctions (RJs), is also investigated to enhance the cell performance further. The SCs with optimized layers exhibit improved parameters: PCE of 27.1%, with a relative improvement of 34.8% in the PCE compared with the fabricated cell, and a high current matching a of 10.8 mA/cm2. The numerical results showed that the reported cell can potentially achieve a PCE of 36% at an eVoc/EG ratio of 0.72. However, the optimal parameters may vary in real-world operating conditions due to variations in temperature, humidity, and light exposure. As a result, the optimal energy yield (EY) parameters may differ. Therefore, the energy yield optimizing process is also carried out by considering ROCs in Phoenix, AZ, USA, to find the best parameters under these conditions. We found that the optimum top layer bandgap under ROCs is lower than under STCs due to a bluer, more shifted spectrum in ROCs. After that, the optimized cell under ROCs is tested in several locations exhibiting different climatic conditions (Seattle, Honolulu, Los Angeles, Miami, and Milwaukee). The numerical results show that the optimized cell under ROCs offers an increase in energy yield in several locations compared to conventional single-junction crystalline Si-SCs (PCE = 23.6%) with a high energy yield of 648.2 kWh/m2 in Phoenix, with an improvement of 39.9% in the EY compared to the Si-SC counterpart. Our results provide design guidelines for fabricating a highly efficient triple-junction perovskite SC in the lab and outdoor applications and improve the efficiency of 2T3J-PSCs beyond the 30% limit.

High performance deep violet InGaN TQW laser diode through multi-layer thickness optimization using particle swarm optimization method

The paper details the optimization of efficiency parameters for a InGaN TQW laser diode using the particle swarm optimization algorithm through SILVACO software. By adjusting layer thickness based on output power, slope efficiency, and threshold current, significant enhancements were achieved. Three optimized laser diodes (LD1, LD2, LD3) were compared with a primary LD, revealing notable improvements in output power and overall performance. Analysis of carrier recombination rates in the active region highlighted increased stimulated recombination and decreased non-radiative recombination, particularly in the n-side well. The study also showed a more uniform radiative recombination in the quantum wells of the optimized LDs, especially in LD3. Investigation of electron and hole concentrations, current densities, and energy levels demonstrated higher electron and hole current density in the optimized LDs, with LD3 exhibiting substantial improvements over the primary LD. Notably, the optimized LDs displayed reduced threshold current and improved slope efficiency compared to the primary LD. The study identified optimal layer thicknesses based on various cost functions, resulting in significant enhancements in output power (0.561 W), slope efficiency (2.515 W/A), and reduced threshold current (less than 0.029 A), indicative of enhanced TQW laser diode performance. Overall, the research showcases the effectiveness of the particle swarm optimization approach in optimizing GaN-based TQW laser diodes, leading to improved efficiency characteristics and demonstrating the potential for enhanced performance in practical applications.

Thin film lithium niobate electro-optic modulator with reduced half-wave voltage length product through design

This paper aims at shortening electrode spacing in a thin film lithium niobate (TFLN) electro-optic modulator (EOM) while avoiding an increase in metal absorption loss, thereby reducing the half-wave voltage length product (V π ⋅L). Through numerical simulations, we find that metal absorption loss reaches its peak values when the optical modes of the metal-clad dielectric waveguide and ridged waveguide hybridize. This negative effect can be mitigated by adjusting the electrode width to modify the optical mode of the metal-clad dielectric waveguide. In addition, we raise the vertical position of the electrodes to further mitigate metal absorption loss and reduce the electrode spacing. By calculating the optimal buffer layer thickness for two crystal axis orientations, our findings reveal a 19% reduction in V π ⋅L at conventional crystal axis orientation (θ=±90∘) and a 16% decrease at unconventional crystal axis orientation (θ=54∘). Notably, V π ⋅L at unconventional crystal axis orientation is 5% lower than at conventional crystal axis orientation. These findings demonstrate the effectiveness of geometric configuration optimization toward enhancing the efficiency and performance of the TFLN EOM.

Design and performance exploration of Pb-free low-cost all-inorganic perovskite-inspired CuAgBi2I8 solar cells: theoretical approach

Abstract Organic–inorganic halide perovskites have demonstrated great potential for photovoltaic applications owing to their unprecedented optoelectronic properties and low manufacturing costs. However, the commercialization of this technology is hindered by its thermal instability and inherent toxicity. In this study, SCAPS-1D simulation software was used to study the performance of solar cell based on CuAgBi2I8, which is a novel inorganic non-toxic lead-free perovskite-inspired material. Different electron transport layers (TiO2, In2S3, ZnO, Zn0.75Mg0.25O,SnO2 and SrTiO3) and hole transport layers (CuI, PEDOT:PSS, CuSCN and Cu2O) were studied, our research indicated that SnO2 and NiO formed the optimal combination. Further analysis revealed that the optimal absorption layer thickness was 900 nm, the absorption layer doping concentration should be less than 1 × 1013 cm−3 and the defect density should be less than 1 × 1014 cm−3. The optimal thickness of SnO2 and NiO was 30 nm, the optimal doping concentration of SnO2 and NiO was 1 × 1020 cm−3, the defect density of absorber layer/SnO2 and absorber layer/NiO interfaces should be less than 1 × 1012 cm−3, C was the optimal back electrode material. Consequently, the optimal device configuration was identified as FTO/SnO2/CuAgBi2I8/NiO/C, the efficiency was improved from original 2.76% to 19.10% after above optimization. These results indicate that solar cell with CuAgBi2I8 as the absorber layer is a potential alternative to organic–inorganic lead halide perovskite solar cells.

Optimized designation of mesoscopic configuration of Zr/Ti layered metal composites for strength-ductility synergy improvement

Zirconium (Zr) and its alloys are highly promising for extreme service environments due to their excellent radiation and corrosion resistance. However, a major challenge in Zr-based materials lies in the strength-ductility trade-off, which limits their broader structural applications. This study aims to address this challenge by fabricating Zr/Ti layered metal composites (LMCs) with different layer thickness ratios (LTRs) and investigating the effects of LTR on the mechanical properties of Zr/Ti LMCs. Zr/Ti LMCs with varying LTRs were fabricated to explore how mesoscopic configurations influence their deformation mechanisms. The results reveal that an optimized layer thickness (∼50 μm for Zr and ∼40 μm for Ti) maximizes the hetero-deformation-induced (HDI) strengthening effect, resulting in a synergy improvement in strength and ductility. Stable and constrained cracks observed in the Zr layers contributed to local stress relief and improved ductility. The anisotropic deformation between the Zr and Ti layers transformed the local stress states into triaxial states. In addition, the localized stress state and inter-layer strain transmission also promote prismatic <a> slip near the interfaces. This study provides key insights into the design of Zr-based composites with improved mechanical performance, offering potential solutions for their application in demanding environments.