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In this research, electronic and optical properties of armchair (7,7), zigzag (7,0), and chiral (4,2) configurations of Single-Walled Carbon Nanotubes (SWCNT) and the effect of spin-orbit coupling (SOC) on their electronic structures were studied with density functional theory (DFT) computing. The armchair, zigzag, and chiral SWCNT structures were built using the CASTEP software. Then, this code was used to calculate the band structures, density of states and optical properties of these systems. Electronic and optical properties of SWCNT material could be influenced by its configuration, such as the bandgap energy, total density of states (TDOS) and partial density of states (PDOS), absorption coefficient, dielectric function, optical conductivity, complex refractive index, and the loss function. In the absence or presence of SOC effect, armchair, zigzag and chiral nanotubes are semiconductors. SOC causes the bandgap energy to increase and the TDOS of "armchair, zigzag, and chiral SWCNTs" to alter. These results provide crucial physical information regarding the control of the electronic properties of SWCNTs using SOC. • Used the CASTEP software to modelled and simulated the SWCNT structures. • Used the CASTEP code to determine the electronic and optical properties of the SWCNT configurations. • Used the CASTEP code to determine the electronic properties of the SWCNT configurations with the effect of SOC. [ABSTRACT FROM AUTHOR] more...

The following article aims to investigate the influence of porphyrin (PP) on the crystallinity, electronic structure, and optical properties of graphene oxide (GO), using the density functional theory (DFT). Theoretical calculation indicates that porphyrin substitution brings about significant distortion in the GO sheet. The substitution of porphyrin on the graphene oxide layer (GO-PP), leads to decrease the bandgap of the GO material. After substitution, the absorption coefficient decreases in the UV domain and increases in the visible range. Thus, the observed redshift in absorption peaks upon porphyrin substitution was attributed to the assembly that consists of J-aggregates. In this work, we explore the substitution effect of PP chain on the GO sheet as a window layer, over the power conversion efficiency of solar cells. The substitution of PP chain on the GO sheet improves the degree of power conversion efficiency of solar cells. Further comparison indicates that calculations are consistent with experimental observation, which indicates that DFT calculation at CASTEP code level gives good results of porphyrin substitution on the graphene oxide layer. [ABSTRACT FROM AUTHOR] more...

This study employs molecular dynamics simulations using the embedded-atom method to investigate the structural and dynamic properties of supercooled liquid silver (Ag) metal under varying external hydrostatic pressures ranging from 0 to 70 GPa. The investigation spans various length scales, analyzing short-to-medium-range order, crystalline order, and fractal dimension to discern patterns that indicate how increased pressure affects atomic arrangements. The results suggest that increased external hydrostatic pressure triggers a shift to more ordered atomic structures characterized by relative atomic positions corresponding to the fcc lattice structure, highlighting the system's heightened sensitivity to pressure conditions. Furthermore, the study reveals pressure-dependent changes in atomic diffusion behavior and shows a reduction in atomic mobility with increasing pressure. In particular, the values of the diffusion coefficient decrease from 3.719 × 10−8 to 1.564 × 10−9 cm2 s−1 for 0 and 70 GPa, respectively, demonstrating the direct influence of pressure on the dynamics of supercooled liquid Ag metal. • Study investigates dynamic behaviors and structural transformations in supercooled silver melts under pressure via MD simulations. • Pressure affects atomic mobility, reducing diffusion coefficients from 3.719 × 10−8 to 1.564 × 10−9 cm2 s−1 at 0 and 70 GPa. • Short-range order (SRO) analysis shows transition to crystal-like clusters, evidenced by bond angle shifts. • Medium-range order (MRO) studies reveal changes in dominant Voronoi polyhedra (VPs) connections. • Fractal dimension analysis indicates enhanced coordination, transitioning to ordered fcc lattice under pressure. [ABSTRACT FROM AUTHOR] more...

• New monolithic solar cell configuration Ag 2 MgSn(S/Se) 4 was studied, • Tandem cell optimization of the top and bottom chalcogenide solar cell, • Current match is not necessary for the optimal performance of 2T tandems, • A great efficiency of 31.84% was obtained, • The work promotes future device optimization and performance enhancement. This research uses the SCAPS-1D simulation tool to present a numerical simulation investigation of unique Ag 2 MgSn(S/Se) 4 chalcogenide materials. In this paper, the impact of the absorbing films width and doping density on the two cells has been tuned and thoroughly examined, the upper cells with broad gaps (1.63 eV) and the lower cells with narrow gaps (1.23 eV). For the devices based on Ag 2 MgSnS 4 and Ag 2 MgSnSe 4 , respectively, simulated power conversion efficiencies of 22.07 % and 17.38 % were attained. This study of two-terminals (2T) monolithic solar cells delivers intriguing PV metrics, including a PCE of 31.84 % and a great fill factor. Our research will encourage scientists to create a device of a similar design. [ABSTRACT FROM AUTHOR] more...

This study investigates the mechanical and structural properties of monoatomic iron metallic glasses under various cooling rates and pressures using a molecular dynamics simulation combined with the Embedded Atom Method potential. By examining the glass transition temperature (T g), radial distribution function, and Voronoi polyhedra analysis, we elucidated the influence of cooling rates (5 × 1012 - 5 × 1013 K/s) and pressures (0–10 GPa) on the formation and stability of the amorphous structure. Our results demonstrate that higher cooling rates and pressures lead to increased T g , enhanced atomic packing density, and more pronounced short-range order. Mechanical tensile tests reveal that ultimate strength decreases with increasing cooling rates, while elastic modulus shows a complex dependency on both cooling rate and pressure. The findings provide insights into optimizing the mechanical properties of bulk metallic glasses through controlled cooling and pressure application. • Molecular dynamics simulations reveal the interplay of cooling rate and pressure in Fe metallic glasses. • Higher cooling rates and pressures elevate the glass transition temperature and atomic packing density. • Voronoi polyhedral analysis identifies key atomic structures governing glass stability. • Mechanical tests show ultimate strength decreases with cooling rate, while elastic modulus varies complexly. • Findings offer insights for optimizing Fe-MG metallic glasses for advanced engineering applications. [ABSTRACT FROM AUTHOR] more...

The aim of this study is to investigate how different pressure levels and annealing times affect the local atomic structure and mechanical properties of pure zirconium metallic glasses. Using molecular dynamics simulations with the embedded atom method, we explored how these changes influence the material's inherent characteristics. Analysis of the radial distribution function, coordination number, and Voronoi tessellation revealed a spectrum of structural arrangements in metallic glass formed across a pressure range of 0–70 GPa. Additionally, the glass transition temperature increased with increasing pressure, accompanied by reduced free volume. The annealing process, ranging from 0 to 5 ns on metallic glass synthesized under 0 GPa pressure, showed the coordination number's significance in achieving a glassy state. Regarding mechanical behavior, both elastic constants and moduli showed a progressive increase with rising pressure, while Young's modulus and hardness displayed enhanced values with longer annealing times. • Increased pressure raises the glass transition temperature and reduces free volume, enhancing structural stability. • Pressure alters the topological structure and environments of zirconium metallic glass. • Rising pressure leads to a progressive increase in elastic constants and moduli. • Longer annealing times result in improved Young's modulus and hardness, indicating enhanced rigidity and resistance to deformation. [ABSTRACT FROM AUTHOR] more...

• Device modeling of CIGS-based solar cell with and without CIGS-P+ has been. • performed by SCAPS-1D. • Comparison of PV performances between ITO/GaSe/CIGS and ITO/GaSe /CIGS/CIGS-P+ is provided. • Improved efficiency of 33.36% for proposed solar cell with CIGS-P+ is achieved. • The work promotes future device optimization and performance enhancement. The aim of this work is to study the photovoltaic performance of a solar cell based on GaSe materials using SCAPS-1D simulator. The novelty of this work consists in the use of GaSe lamellar as a buffer layer, this material has not been used at this part of solar cells before, which makes this new study interesting; we had also used a thin film (CIGS-P+), strongly doped type p as back surface field in order to obtain high performance. The solar cell is made up of two CIGS layers with different acceptors densities, one layer of Gallium selenide GaSe, and ITO anti-reflective layer. The role and impact of the CIGS-P+ layer as a back surface field on the performance of solar cells were investigated. To improve cell performance, the effects of thickness, carrier concentration, operating temperature, and resistors R s and R sh are explored. The carrier concentration as well as the thickness of the GaSe, CIGS absorber layer, and CIGS-P+ were shown to affect the cell's performance. The open circuit voltage of the simulated cell was increased to 309 mV after using CIGS-P+, the current density J sc up to 32.61 mA/cm2, the Fill Factor FF up to 89.39%. After employing CIGS-P+ in a GaSe-based solar cell, an efficiency gains of roughly 10.06 % was recorded. [ABSTRACT FROM AUTHOR] more...

Tandem solar cells have a wider photon absorption range, allowing them to provide better efficiency than single-junction SC. The upper cell absorbs high-energy photons, while the lower cell absorbs low-energy filtered photons. However, in order to obtain affordable, efficient, and long-lasting SC, the absorber layers of the t o p and b o t t o m cells must be integrated with an adequate bandgap. This research suggests tandem perovskite solar cells as upper band active materials in this setting. The Si homojunction solar cell's performance was improved by investigating the thicknesses of the p − t y p e and n − t y p e layers, doping concentrations, and defect densities. The thickness variation of the p e r o v s k i t e solar cell (100 − 400 n m) is then optimized. To precisely replicate the tandem devices, the estimated spectra of the perovskite SC are optically filtered onto the lower cells. Current matching was achieved by adjusting the thickness of the p e r o v s k i t e sub-cell with different bottom layer thicknesses, and the optimized efficiency of 36.26 % for the p e r o v s k i t e / S i tandem device was shown. The discoveries will open the door for the upcoming creation of h i g h − e f f i c i e n c y , low-energy solar cells. • On the basis of SCAPS-1D software, the optical characteristics are investigated in order to correlate the novel eco-friendly tandem solar cell. • Use the results obtained for the elaboration of these samples and to make an optimized solar cell (work in progress). • This paper encourages the fabrication of future flexible solar cells. [ABSTRACT FROM AUTHOR] more...

• Ag 2 BeSnX 4 (S, Se,Te)-based kesterite solar cell modeling: a D F T investigation and S c a p s - 1 d analysis. • The values of the absorption coefficient are remarkably high of the order (104 cm−1) for the 3 structure. • The effects of various variables, such as layer thickness and acceptor concentrations, were studied. • The efficiencies of the three cells are 18.271%, 25.152%, 14.628% for Ag 2 BeSnS 4 , Ag 2 BeSnSe 4 , Ag 2 BeSnTe 4 , respectively. • Intriguing photovoltaic measurements are provided by the study of two-terminal monolithic solar cells Ag 2 BeSnS 4 / Ag 2 BeSnTe 4 , including a η of 19.41% and superb FF. In the present work, computational analysis based on density functional theory is carried out for the optical properties of new kesterite materials Ag 2 BeSnX 4 (S, Se, Te). We used a generalized gradient approximation (GGA) function. On the three structures studied here, the absorption coefficient values are remarkably high of order (104 cm−1). For photovoltaic applications, Ag 2 BeSnX 4 (S, Se, Te) has emerged as a viable choice. The Scaps is used to simulate the Mo / I T O / Ag 2 B e S n X 4 (S , S e , T e) / C d S solar cell. On the Ag 2 BeSnX 4 (S, Se, Te) layer, the effects of various variables, such as layer thickness and acceptor concentrations, were investigated. Simulation results reveal that the optimum thickness and concentration of the absorption layer in Ag 2 B e S n X 4 (S , S e , T e) -based solar cells are 1.25, 1.00, 0.75 µm 1017, 1018, 1018 cm−3, for Ag 2 BeSnS 4 , Ag 2 BeSnSe 4 , Ag 2 BeSnTe 4 respectively. The efficiencies of the three cells equal to 18.271 %, 25.152 %, 14.628 % for Ag 2 BeSnS 4 , Ag 2 BeSnSe 4 , Ag 2 BeSnTe 4 respectively. Intriguing photovoltaic measurements are provided by the investigation of two-terminal monolithic solar cells, including a η of 19.41 % and a superb FF. We hope that our theoretical findings will inspire researchers working on photovoltaic systems to experimentally materialize these materials. [ABSTRACT FROM AUTHOR] more...