Band Thickness Research Articles

Performance Analysis of Hydrogenated Cs2AgBiBr6 Perovskite Solar Cells under White LED Illumination

The emergence of lead-free double perovskites has sparked considerable concern due to their decreased toxicity and enhanced stability. Among these, Cs2AgBiBr6 perovskite has garnered attention as promising contenders for photovoltaic (PV) applications. Herein, we introduce the design and simulation of all-inorganic lead-free Cs2AgBiBr6-based perovskite solar cells (PSCs) under the influence of white light emitting diode (WLED) lighting conditions. The preliminary calibrated cell is centered on experimental findings wherein the Cs2AgBiBr6 layer is treated with hydrogenation. Through the application of such a technique, the bandgap of Cs2AgBiBr6 films can be engineered. We investigate three different bandgap values (2.18, 1.91, and 1.64eV) and assess the performance of the constituted PSCs under the effect of WLED illumination for various color temperatures. Key parameters significantly impacting cell performance are identified and comprehensively analyzed to boost the power conversion efficiency (PCE). Key technological parameters, including conduction band offsets, thickness and defects, are adjusted in order to optimize cell performance. For Eg = 1.64eV, which shows the maximum efficiency among the other cases, the efficiency increases from 15.61% for the initial designed cell to about 41% after optimization at a color temperature of 2900K and 200lx. All simulation endeavors are performed employing the device simulator, SCAPS, ensuring accurate and reliable predictions. The present study unveils the potential of Cs2AgBiBr6 double PSCs to be used in indoor applications.

Physical Vapor Deposition of High-Mobility P-Type Tellurium and Its Applications for Gate-Tunable van der Waals PN Photodiodes.

Recently, tellurium has attracted resurgent interest due to its outstanding p-type characteristics and ambient environmental stability. Here, we present a substrate engineering-based physical vapor deposition method to synthesize high-quality Te nanoflakes and achieved a field-effect hole mobility of 1450 cm2/(V s), which is, to the best of our knowledge, the highest among existing synthesized two-dimensional p-type semiconductors. The high mobility of Te enables the fabrication of Te/MoS2 PN diodes with highly gate-tunable characteristics. The Te/MoS2 heterostructure is demonstrated to be used as visible-light photodetectors with a current responsivity up to 630 A/W, which is about 1 order of magnitude higher than one achieved using p-type Si-MoS2 PN photodiodes. The photoresponse of Te/MoS2 heterojunctions also exhibits strong gate tunability due to their ultrathin thickness and unique band alignment. The successful synthesis of high-mobility Te and its integration into Te/MoS2 photodiodes show promise for the development of highly tunable and multifunctional photodetectors.

Low-Dimensional Snse – Ti3C2 Mxene Composite As Binder-Free Anode for Energy Storage Applications

Two-dimensional (2D) materials exhibit unique structural and electronic properties such as reduced thickness, high conductivity, packing density and tuneable band gap.[1] These properties present compelling opportunities for their applications in sustainable battery technologies.[1] Sodium-ion batteries (SIBs) are attracting great interest as an alternative to lithium-ion batteries due to their material abundance, lower cost, and environmental sustainability. However, the quest for a high-performance anode for SIBs remains challenging owing to the severe volume expansion caused by the intercalation of the large Na-ion.Tin (II) selenide (SnSe), a layered 2D material, demonstrates very high theoretical capacity as an anode for sodium and lithium-ion batteries. Nevertheless, its instability primarily, attributed to the substantial pulverization of active materials during cycling, poses a challenge.[2] To address this, we investigated a novel 2D composite material comprising SnSe nanoparticles and MXene (Ti3C2Tx) nanosheets (Figure 1) to be used as an anode in batteries. Due to the exceptional conductivity and viscosity of MXene [3], it can act as a conductive binder in this composite eliminating the need for traditional non-conductive binders like PVDF and CMC. This reduces the dead volume in the electrode and enhances its specific capacity. Additionally, the MXene layers with terminating fluorine functionals promote the growth of stable solid-electrolyte interfaces (SEI) improving the overall Coulombic efficiency of the battery.[4] Further optimization studies were done with VC and FEC electrolyte additives. Characterization techniques, including XPS, SEM, EDX, XRD, and AFM were performed on the composite nanomaterial to study its morphology, as well as compositional and structural changes upon processing. The electrode material showed a high initial discharge capacity of 700 mAh/g and 98% Coulombic efficiency for 100 cycles in lithium-ion batteries. This shows promise in overcoming the instability issues of SnSe, thereby improving the performance and longevity of SIBs for sustainable energy storage solutions.

Study of the Photovoltaic Parameters of Inorganic Solar Cells Based on Cu<i>2</i>O and CuO

A theoretical study of the photovoltaic parameters of inorganic solar cells based on ZnO/Cu2O and ZnO/CuO heterojunctions was carried out to improve the energy conversion efficiency. The influence of the thickness, charge carrier concentration and band gap of Cu2O and CuO films, as well as ZnO, on the photovoltaic parameters of solar cells has been studied. The simulation results showed that the efficiency of solar cells is significantly affected by the contact potential difference, the diffusion length of minority charge carriers, the amount of generated photocurrent and the recombination rate. The maximum efficiency of a solar cell based on ZnO/Cu2O was obtained equal to 10,63%, which is achieved with a band gap, thickness and charge carrier concentration in Cu2O equal to 1.9 eV, 5 μm and 1015 cm–3 and band gap, thickness and the concentration of charge carriers in ZnO is equal to 3,4 eV, 20 nm and 1019 cm–3, as well as the displacement of the edges of the conduction bands is 0.8 eV. For a solar cell based on ZnO/CuO, a maximum efficiency of 18.27% was obtained with a band gap, thickness and charge carrier concentration in CuO equal to 1.4 eV, 3 μm and 1017 cm–3, as well as a displacement of the conduction band edges of 0.03 eV. The obtained results of modeling solar cells can be used in the design and manufacture of inexpensive and efficient photovoltaic structures.

Screening of Sugarcane Commercial GMP Varieties Tolerant to Drought Stress Based on Molecular Detection of P5CS Gene

Sugarcane (Saccharum officinarum L.) requires sufficient a water supply to produce optimal productivity. The selection of the superior varieties of sugarcane that are tolerant to drought can be done by molecular detection of the presence of the pyrroline-5-carboxylate synthetase (P5CS) gene. The research is aimed at molecular detection of P5CS gene in a commercial varieties at PT Gunung Madu Plantations (GMP), Indonesia that are potentially drought resistant. Similar research has never been conducted at PT GMP, as evidenced by the absence of official publications. The varieties used are GMP 3, GMP 5, RGM 06-654, PS 864, RGM 08-1026, PSJT 941, RGM 01-1834, GP11, RGM 07-099, and RGM 02-108. The research phases include DNA isolation, quantitative and qualitative DNA amplification, and PCR product visualization. Molecular data analysis is based on DNA band scoring results in the form of binary data which is then used to calculate the level of polimorphism information content (PIC) on the primary data used. The results of the study showed that nine out of ten varieties had P5CS-specific band sizes of ±167 bp, namely GMP 3, GMP 5, RGM 06-654, PS 864, PSJT 941, RGM 01-1834, GP 11, RGM 07-099, and RGM 02-108. A total of four of the nine varieties showed P5CS gene band thicknesses of RGM06-654, PSJT 941, PS864, and RGM 01-1834 which indicates the selected varieties most resistant to drought. The result of the PIC calculation has a value of > 0.25 which indicates the primary P5CS used is quite informative. The molecular detection was continued on one selected variety is PSJT 941, which showed that the relationship analysis of P5CS gene shows close affinity with the isolates from China and Bogor.

Light attenuation parameterization in a highly turbid mega estuary and its impact on the coastal planktonic ecosystem

Light is essential for phytoplankton photosynthesis and many other biogeochemical processes in the aquatic system. However, light regimes vary greatly in the estuaries and coasts due to the optical complexity of the Case-2 waters. In this study, observed vertical profiles of photosynthetically active radiation (PAR; 400-700 nm) in a highly turbid mega estuary, the Changjiang (Yangtze River) Estuary, are used to quantify the effects of sedimentary and biogeochemical components on PAR attenuation in the water column and associated ecological impacts. The in-situ data suggest suspended sediment plays the most crucial role in light diffuse attenuation coefficient (Kd) distribution, followed by salinity (i.e., an index for colored dissolved organic matter) and phytoplankton chlorophyll-a. A new parameterization of Kd, based on suspended sediment, chlorophyll-a concentration, and salinity, is fitted using multiple linear regression. The previous and new Kd parameterizations are further applied to a coupled hydrodynamics-sediment-ecosystem model to simulate spring phytoplankton blooms. Comparative model runs reveal that the new Kd parameterization resulted in a better representation of the spring bloom patterns in magnitude, horizontal distribution, and vertical thickness of the high chlorophyll-a band offshore the turbidity maximum zone during the spring bloom. In summary, accurate representations of underwater light fields in the optically complex Case-2 water are critical in understanding biophysical processes that control planktonic ecosystem dynamics in the estuaries and coastal seas.

Multiscale evaluation of sand-geomaterial interface shear response in terms of material geometry effects

This study evaluates the effects of particle and surface geometric features on the interface shear behavior of sand-geomaterial. Particle shape and size were adjusted for the sand, and surface roughness form and height were set for the geomaterial part. 3D printing technology was used to produce geomaterials in the desired form. A custom-made transparent interface shear box was developed to perform digital image processing. For macroscale response, peak and residual strengths and dilation angle were measured. Sliding percentage and shear band thickness were determined from digital image correlation analyses for the mesoscale response. The experimental results showed that the macroscale response parameters increased as the overall regularity of the sand particles decreased. The increase in mean particle size and roughness height led to an increase in macroscale parameters. Digital image correlation analyses showed that the sliding percentage had an inverse correlation with the shear band thickness in terms of the particle shape and the roughness height effects. The roughness form controlled the trend of mean particle size effects on the sliding percentage. Overall, the mesoscale parameters revealed the traces of interlocking response, particle kinematics, and the failure mechanism in the interface region. Thus, a bridge was established between meso- and macro-scale responses.

Oxidation resistance mechanism of copper wire regulated by nano-palladium coating

The microstructure characteristics of palladium coating are the key to the oxidation resistance of palladium-coated copper wire. In this paper, the microstructure characteristics of palladium coating thickness, nanocrystalline size and amorphous band width were controlled by adjusting the process parameters of micro-area coating. The relationship between microstructure characteristics of palladium coating and oxidation resistance was studied. The results show that the wire has good oxidation resistance when the deposition temperature is 400℃ and the copper wire/mold clearances are 2.5 μm. The surface of the copper wire has a palladium coating with a thickness of 74 nm, and the palladium particles are composed of amorphous encapsulated nanocrystals. The relationship between the thickness of palladium coating and the copper wire/mould clearances is y=0.012x+44, and the increase of palladium coating thickness can inhibit the migration of copper ions. The increase in the size of the nanocrystalline and the width of the amorphous band has a certain inhibitory effect on the lattice or grain boundary diffusion of copper to the palladium coating. The multi-stage distorted nanotwins in the amorphous palladium coating can reduce the strain difference at the palladium-copper bonding interface, reduce the diffusion driving force of copper outward, and thus improve the oxidation resistance of palladium-coated copper wires.

Role of Trans perineal Ultrasound in Inflammatory Bowel Disease

Abstract Background Inflammatory Bowel Disease (IBD) is a medical terminology for a group of diseases that cause chronic intestinal inflammation. It is categorized into two subtypes: Ulcerative colitis and Crohn’s disease. Fistulae are frequently seen manifestations of perianal IBD, and their clinical course these consists of flare-ups with bouts of active drainage, followed by intervals of clinical remission. Improved prognosis, treatment, and assessments of perianal disease activity may all contribute to a better patient quality of life. Aim of the Work to explore the role of trans perineal ultrasound in assessment of disease activity and/or complications in patients with inflammatory bowel disease. Patients and Methods The Diagnostic Radiology Unit; Radiology Department, Ain Shams University Hospitals. For 6 months. We studied the relevance of 23 different ultrasound parameters and 6 indices in conjunction with clinical, endoscopic based scores. Sample size of at least 30 patients with IBD with affection of anal or perianal area were sufficient to achieve study objective. Results Rectal wall thickness and submucosal band thickness could be used as indicators for presence of disease in ulcerative colitis patients. TPUS could be used to assess the internal sphincter thickness, external sphincter integrity in Crohn’s disease. Partial Mayo clinical score showed significant correlation with Mayo endoscopic score; however, it couldn’t predict degree of severity. Internal sphincter thickening increased anal canal vascularity and perianal fistula is more common in Crohn’s disease than ulcerative colitis. Conclusion Trans perineal ultrasound is considered as a good tool that is noninvasive, cost effective and convenient and shows a potential in the assessment of disease activity and complications in inflammatory bowel disease.

An extended lumped damage mechanics IGABEM formulation for quasi-brittle material failure

This study proposes a new formulation for the mechanical modeling of quasi-brittle materials. The material degradation due to cracking is addressed through the Extended Lumped Damage Mechanics (XLDM) approach. The model is inserted into an IGABEM formulation, where Non-Uniform Rational B-Splines (NURBS) are the basis functions. A novel nonlinear solution technique has been developed for the numerical implementation. Crack propagation is captured using the initial stress field approach, widely utilized by the BEM community to account for nonlinear material behavior. The XLDM is coupled into an IGABEM formulation by discretizing part of the domain into cells, placed only where damage is expected to grow. Classical benchmark problems are presented to demonstrate the method’s capability and effectiveness. The results show excellent agreement with both experimental and numerical findings from the literature. Damage evolution is assessed through the band thickness opening, leading to material degradation. This method offers a new way of addressing damage mechanics problems within the BEM framework. It could benefit the BEM community, as traditional damage analysis within this numerical method often leads to significant time-consuming and elevated computational costs, which are mitigated by the formulation proposed herein.

Effect of Sclerosis Bands in Femoral Head Necrosis on Non-Vascularized Fibular Grafting-A Finite Element Study.

Femoral head necrosis is a challenging condition in orthopaedics, and the occurrence of collapse is an important factor affecting the prognosis of femoral head necrosis. Sclerosis bands are known to influence the collapse of the femoral head, yet there is a lack of research on the biomechanical role of sclerosis bands in non-vascularized fibular grafting surgery. This study aims to evaluate the biomechanical impact of sclerosis bands in femoral head necrosis and their role in non-vascularized fibular grafting surgery (NVFG) using finite element analysis. We constructed 11 finite element models based on CT scan data of a normal hip joint, simulating different sclerosis band thicknesses and defect scenarios. The models were analyzed for changes in femoral head displacement and von Mises stress. We constructed a hip joint model based on CT data from a normal hip joint, and after reconstruction, assembly, and optimization using 3-matic. We created five groups consisting of 11 finite element analysis models of the hip joint. Mesh partitioning and mechanical parameter settings were performed in ANSYS. The changes and differences in femoral head displacement and von Mises stress of these models were analyzed. Increasing sclerosis band thickness led to reduced peak displacement of the femoral head by 28.6%, 42.9%, and 47.6%, and increased surface von Mises stress by 28.3%, 13.8%, and 13.0%, respectively. Post-surgery, peak displacement decreased in all groups compared to pre-surgery levels. Increasing sclerosis band thickness post-surgery resulted in decreased maximum von Mises stress of the femoral head by 13.9%, 3.0%, and 8.1%. Defect volume in the defect groups correlated with increased peak displacement of the femoral head by 10.0%, 30.0%, and 100.0%, and increased surface maximum von Mises stress of the femoral head by 9.3%, 14.0%, and 15.1%. Sclerosis band formation exacerbates von Mises stress concentration on the femoral head surface. However, thicker sclerosis bands improve post-NVFG stability and mechanical performance. Larger anterior lateral sclerosis band defects significantly compromise postoperative stability, increasing the risk of collapse. Protecting the anterior lateral sclerosis band during NVFG surgery is crucial.

Deriving Flow Velocity and Initial Concentration From Liesegang‐Like Patterns

AbstractZebra rocks, characterized by their striking reddish‐brown stripes, rods, and spots of hematite (Fe‐oxide), showcase complex self‐organized patterns formed under far‐from‐equilibrium conditions. Despite their ease of recognition, the underlying mechanisms of pattern‐forming processes remain elusive. We introduce a novel advection‐dominated phase‐field model that effectively replicates the Liesegang‐like patterns observed in Zebra rocks. This numerical model leverages the concept of phase separation, a well‐established principle governing Liesegang phenomena in a two‐dimensional setting. Our findings reveal that initial solute concentration and fluid flow velocity are critical determinants in pattern morphologies. We quantitatively explain the spacing and width of a specific Liesegang‐like pattern category. Furthermore, the model demonstrates that vanishingly low initial concentrations promote the formation of oblique patterns, with inclination angles influenced by rock heterogeneity. Additionally, we establish a quantitative relationship between band thickness and geological parameters for orthogonal bands. This enables the characterization of critical geological parameters based solely on static patterns observed in Zebra rocks, providing valuable insights into their formation environments. The diverse patterns in Zebra rocks share similarities with morphologies observed on early Earth and Mars, such as banded iron formations and hematite spherules. Our model, therefore, offers a plausible explanation for the formation mechanisms of these patterns and presents a powerful tool for deciphering the geochemical environments of their origin.

A Preliminary Study Using High‐Frequency Ultrasound to Evaluate Vulvar Skin With Lichenoid Vulvar Dermatoses

ABSTRACTBackgroundLichenoid vulvar dermatoses (LVD) are inflammatory diseases primarily affecting the vulva and anus. This study aims to evaluate the skin changes in patients with LVD using high‐frequency ultrasound.MethodsForty‐five patients with LVD, who attended Henan Provincial People's Hospital from November 2021 to March 2024, were selected. According to the pathological conclusions, patients were divided into two groups: the vulvar lichen sclerosus (VLS) group (n = 24) and the vulvar lichen simplex chronicus (VLSC) group (n = 21). Thirty age‐ and BMI‐matched healthy women were selected as the control group. We assessed the epidermal thickness, subepidermal low echogenic band (SLEB) thickness, dermal thickness, and vascular index (VI) among the three groups. Receiver operating characteristic curve (ROC) analysis was performed to determine the diagnostic efficacy of these ultrasound parameters for LVD. Binary logistic regression was used to investigate risk factors influencing LVD pathology in VLS patients.ResultsEpidermal thickness, SLEB thickness, dermal thickness, and VI were increased in the VLS and VLSC groups compared to the control group (p < 0.05). There were no statistically significant differences in ultrasound parameters between the VLS and VLSC groups (p > 0.05). The ROC curves showed that the area under the curve (AUC) value for the dermis (AUC = 0.882) was the largest for VLS, and VI (AUC = 0.917), it was the largest for VLSC. Binary logistic regression indicated that having an allergic disease was a risk factor for VLS between VLS and VLSC groups (OR = 6.797, p = 0.028).ConclusionHigh‐frequency ultrasound can detect thickening of the skin and increasing VI in patients with LVD, which can be helpful in the evaluation and management of LVD.

Exploring eco-friendly novel charge transport materials for enhanced performance of tin based perovskite solar cell

This pioneering simulation study explores the potential of perovskite materials, particularly the non-toxic methyl ammonium tin iodide (MASnI3), in solar cell technology. The investigation focuses on eco-friendly, solution-processed compounds—specifically, WO3 and In2S3 as Electron Transport Layers (ETL) and MoO3 and WSe2 as Hole Transport Layer (HTL)—to develop planar n-i-p MASnI3 perovskite solar cell (PSC) devices. WO3 is chosen for its solution processing and high electron mobility, while In2S3 offers n-type properties, superior carrier mobility, non-toxicity, and thermal durability. MoO3 and WSe2 are selected as HTLs for their efficient charge transport capabilities. Utilizing the solar cell capacitance simulator (SCAPS-1D) software, the study systematically evaluates alternative charge-selective materials, considering various parameters such as thickness (0.1 µm to 1.5 µm for absorber and 0.1 µm to 0.35 µm for CTLs), doping concentration (3.2E10 to 3.2E16 for absorber and E16 to E20 for CTLs), defect density, and energy band offset for MASnI3 PSCs. Four distinct n-i-p device structures are optimized, yielding impressive PCE improvements ranging from 14.63 % to 25.34 %, a significant 3 % enhancement compared to initial results. Notably, the WO3/MASnI3/WSe2 configuration exhibits limitations in electrical performance, while the other optimized structures demonstrate substantial efficiency gains. Further analysis investigates the impact of reflecting coatings (10 % to 90 %), varying contact work functions (5.2–5.8 eV), and temperature (300–400 K) on photovoltaic parameters. Critical factors including energy band offset, recombination current profile, and built-in potential, are meticulously examined, laying the groundwork for advanced PSC implementation. The study culminates in the In2S3/MASnI3/MoO3 device configuration, which achieves a peak efficiency of 25.34 %, showcasing superior thermal stability and an enhanced fill factor, thus propelling all-inorganic PSCs towards practical implementation.

Topographic Measurement of the Subretinal Pigment Epithelium Space in Normal Aging and Age-Related Macular Degeneration Using High-Resolution OCT.

A micrometer scale hyporeflective band within the retinal pigment epithelium basal lamina - Bruch's membrane complex (RPE-BL-BrM) was topographically measured in aging and age-related macular degeneration (AMD). In a prospective cross-sectional study, 90 normal eyes from 76 subjects (range = 23-90 years) and 53 dry AMD eyes from 47 subjects (range = 62-91 years) were enrolled. Isotropic volume raster scans over 6mm × 6mm (500 × 500 A-scans) were acquired using a high-resolution (2.7 µm axial resolution) spectral-domain optical coherence tomography (SD-OCT) prototype instrument. Six consecutive optical coherence tomography (OCT) volumes were computationally motion-corrected and fused to improve feature visibility. A boundary regression neural network was developed to measure hyporeflective band thickness. Topographic dependence was evaluated over a 6-mm-diameter Early Treatment Diabetic Retinopathy Study (ETDRS) grid. The hyporeflective band thickness map (median of 4.3 µm and 7.8 µm in normal and AMD eyes, respectively) is thicker below and radially symmetric around the fovea. In normal eyes, age-associated differences occur within 0.7 to 2.3mm from the foveal center (P < 0.05). In AMD eyes, the hyporeflective band is hypothesized to be basal laminar deposits (BLamDs) and is thicker within the 3-mm ETDRS circle (P < 0.0002) compared with normal eyes. The inner ring is the most sensitive location to detect age versus AMD-associated changes within the RPE-BL-BrM. AMD eyes with subretinal drusenoid deposits (SDDs) have a significantly thicker hyporeflective band (P < 0.001) than those without SDDs. The hyporeflective band is a quantifiable biomarker which differentiates AMD from aging. Longitudinal studies are warranted. The hyporeflective band may be a useful biomarker for risk stratification and disease progression.

Synergetic Triple Absorber Based High‐Efficiency Solar Cell Design

AbstractComputational analysis of triple absorber‐based solar cell structure is undertaken. This solar cell device configuration allows better utilization of the incident solar spectrum. Three different absorbers with a band gap in the range 1–1.5 eV are sandwiched between high‐doped p+ and n+ regions in descending order of electron affinity to form an energy‐matched multiple absorber device. A comprehensive analysis of key device parameters influencing performance, including band gap, conduction band alignment, interfacial defects, and thickness, is presented. The optimized triple absorber device shows beyond Shockley–Queisser limit (SQ limit) performance under the constraint of passivated interfaces with defect density below 1013 cm−2. Wide spectrum coverage leads to high short circuit current and an efficiency of 40.3%, which is higher than the SQ limit for single band gap solar cell.

The relationship between the cutting-edge, tool wear, and chip formation during Inconel 718 dry cutting

This study comprehensively addresses the machining of nickel alloys, focusing its attention on crucial aspects related to chip formation and tool wear. Detailed characterization of the morphology and the chip formation process was performed by analyzing parameters such as chip segmentation ratio and variables such as shear band thickness and strain rate. Additionally, a numerical model was used to quantify stresses and temperatures at the tool/chip interface and to evaluate damage, thus contributing to the understanding of the development of chip formation. A transition in chip shapes as the toothing increases is highlighted, evidenced by segmentation ratio values below 0.5, indicative of the presence of discontinuous chips. The increase in cutting-edge radius is associated with a gradual increase in the compression ratio, indicating a higher plastic energy requirement in chip formation. Numerical simulations support this theory of failure. A significant correlation of 80% was identified between flank wear and the increase in shear force oscillation amplitude, indicating that flank wear contributes to system vibration. It is also noted that the adiabatic shear bands (ASB) are narrow, revealing a marked plastic deformation in the primary shear zone. Consequently, the remarkable incidence of wear with cutting parameters on chip formation is demonstrated, affecting the cutting force amplitude and, hence, the workpiece topography.

Numerical Optimization of Thickness and Optical Band Gap of Absorber and Buffer Layers in Earth-Abundant Cu2ZnSnS4 Thin-Film Solar Cells

Numerical Optimization of Thickness and Optical Band Gap of Absorber and Buffer Layers in Earth-Abundant Cu2ZnSnS4 Thin-Film Solar Cells

Shear failure analysis of slip zone soil with different coarse particle shapes: Visualized shear test and PIV technology

Coarse particle shape in slip zone soil influences the mesoscopic structure of the soil, which in turn affects soil shear strength and failure behavior. In order to investigate the effect of particle shape on the shear characteristics of coarse–fine-grained mixed slip zone soil, three types of coarse particles (spheroidal, rounded, and angular) were selected for mixing and matching, and a total of 10 sets of medium-scale shear tests were designed for this paper. To quantify the shear deformation and failure process of slip zone soils, particle image velocimetry (PIV) technology and the hanging hammer method were used to obtain mesoscopic data of the soil (displacement vector data of soil particles and elevation data of the shear failure surface), which were used to calculate shear band thickness, shear dilatation, and roughness coefficient of the shear failure surface. The results indicate that coarse particle shape can considerably affect the macroscopic mechanical properties (internal friction angle and shear strength) and mesoscopic deformation characteristics (shear band thickness, shear dilatation, and shear surface morphology) of soils. Angular coarse particles have higher interlocking strength than spheroidal and rounded coarse particles, allowing angular coarse-grained slip zone soils to develop large shear band thickness and rough shear failure surfaces. In addition, mesoscopic damage analysis suggests that the damage rate of slip zone soils decreases with increasing coarse particle shape complexity. These findings enhance comprehension of the failure characteristics of soil-rock mixture slopes and serve as a good reference for the stability analysis of similar slopes.

Replacing the electron-hole transport layer with doping: SCAPS simulation of lead-free germanium-based perovskite solar cells based on CsGeI3

In recent years, scientists have shown increasing interest in perovskite solar cells because of their remarkable light absorption capabilities and promising prospects, among which germanium-based perovskite solar cells have been praised for non-toxicity. However, the defects between the charge transport layers affect its performance, and the charge transport layer materials also bring environmental hazards due to some organic properties. In this work, we propose to replace the charge transport layer with a solar cell based entirely on the germanium-based perovskite absorption layer by varying the CsGeI3 doping concentration. We created n-CsGeI3 and p-CsGeI3 layers conducive to electron hole transport, thus effectively reducing the defects between the interface transport layers, improving the electron hole transport environment, and improving the transmission efficiency. We employed SCAPS software for designing and optimizing the cell structure, enabling us to model and fine-tune parameters such as band gap, thickness, doping concentration, and defect density. These optimizations led to the calculation of optimal values, resulting in an impressive 34.57 % efficiency. The cell structure developed in this work validates the feasibility of germanium-based perovskite solar cells without electron hole transport layer, reducing environmental risks and optimizing performance parameters to some extent. This provides a valuable reference for future research on such solar cells.