Antennas offering wide bandwidth, high gain and efficiency are essential to terahertz (THz) wireless communication systems and has gathered significant attention in antenna research. This paper introduces a compact, high-gain, ultra-wideband (UWB) microstrip patch antenna tailored for THz applications, along with its performance analysis. The proposed antenna has an elliptical patch with a pi shaped slot and is excited by a tapered feedline. An elliptical patch antenna incorporating a pi-shaped slot is introduced for the first time in the terahertz THz spectral region, demonstrating the ability to simultaneously achieve substantial size miniaturization, wideband performance, improved impedance matching, and enhanced gain. The antenna structure was designed and optimized for improved performance using CST Microwave Studio (MWS) version 2018. A Rogers RT/duroid 5880 substrate was used for antenna design, featuring 6 μm thickness, 2.2 relative permittivity, 0.0009 loss tangent, and 120 × 80 μm² planar dimensions. The proposed antenna demonstrates strong performance characteristics with a wide impedance bandwidth of 3.41 THz (5.01–8.42 THz), high gain of 7.906 dB, radiation efficiency of 77.83%, and low return loss of −43.57 dB, with consistent VSWR across the entire frequency range. The surface current distribution as well as the input impedance of the pi-shaped slotted antenna are also favorable. All the simulation results suggest that the proposed small size pi-shaped slotted elliptical patch antenna can be a suitable candidate for high-speed 6G wireless communication applications in the THz band.

ABSTRACT In this work, we present a machine learning–augmented simulation study of a MoTe 2 ‐based solar cell incorporating Sb 2 S 3 (antimony sulfide) as the hole transport layer (HTL). MoTe 2 was selected as the absorber due to its strong optical absorption, low toxicity, and compatibility with low‐cost fabrication methods. Using SCAPS‐1D, we optimised the heterojunction structure (Al/FTO/CdS/MoTe 2 /Sb 2 S 3 /Pt) by varying absorber and HTL thickness, doping concentration, defect density, and temperature. The best simulated device (MoTe 2 thickness 0.5 μm, N A ≈ 10 17 cm −3 ) achieves V oc ≈ 1.05 V, J sc ≈ 40.8 mA/cm 2 , FF ≈ 87.6%, and a power conversion efficiency (PCE) of 40.33%. We clarify that this extremely high efficiency represents a theoretical upper bound under idealised assumptions (e.g., negligible nonradiative losses), rather than an experimentally demonstrated result. For comparison, the baseline cell without Sb 2 S 3 yields V oc ≈ 0.95 V, J sc ≈ 38.15 mA/cm 2 , FF ≈ 81.09%, and η ≈ 29.35%. The Sb 2 S 3 layer significantly suppresses back‐surface recombination and improves carrier extraction, thereby enhancing V oc and FF. To streamline design, we generated a dataset of approximately 6735 SCAPS simulations spanning key input variables (thickness, doping density, defect density, temperature) and trained five regression models for performance prediction. Among these, Random Forest regression achieved the highest accuracy ( R 2 ≈ 0.98), effectively capturing nonlinear dependencies. Feature‐importance analysis confirmed that absorber thickness, defect density, and doping are the dominant performance drivers, consistent with the physics‐based trends. This hybrid SCAPS–ML framework provides a fast, data‐driven tool for optimising next‐generation solar cells. Our study advances previous work by explicitly identifying robust parameter ranges, introducing predictive modelling, and clarifying the theoretical bounds of simulated efficiency.

In the present study, a newly designed polyester substrate-based textile microstrip patch antenna operating in the 3.5 GHz band is proposed for smart clothing in broadband wireless applications. The motivation behind this work stems from the lack of comprehensive studies that address all critical aspects—including off-body performance, fabrication, testing, on-body evaluation, bending analysis, and SAR assessment—while specifically focusing on polyester textile antenna designs for the 3.5 GHz band in next-generation wearable systems. The antenna of small dimension 30×20×0.8 mm³ is designed and simulated in CST, followed by prototype fabrication and subsequent measurements to validate the simulation results. Slotting and partial grounding techniques are employed in the design for improving the radiation performance of the antenna. The effectiveness of the antenna has been assessed under the off-body and on-body conditions. Bending analysis under various bending conditions is performed to assess the antenna’s flexibility and suitability for wearable applications. Experimental results obtained from the fabricated antenna in free space and on-body scenarios show agreement with simulation data. Moreover, the specific absorption rate (SAR) analysis confirming that the antenna complies with IEEE safety standards. The proposed antenna achieves a wide bandwidth of 1.17 GHz (operating range of 3.11-4.27 GHz), a higher radiation efficiency of 94.52%, and a moderate peak gain of 2.59 dB. It covers 5G NR (n77, n78), C-Band (Radar/WiMAX), CBRS, and Extended C-Bands used for wearable broadband applications. Hence, the proposed antenna is robust and well-suited for smart clothing applications in wireless broadband applications as it combines good radiation characteristics and stable performance under bending, while maintaining safe SAR levels and a compact textile-compatible design.

The conventional cadmium sulfide (CdS) window/buffer layer in photovoltaic cells is environmentally hazardous because of the poisoning of cadmium (Cd). Alternatively, ZnS is more environmentally friendly than CdS and has a larger band gap, which makes it a potential candidate for window/buffer layers. In this study, ZnS thin films were deposited on glass substrates by a spin coating process and annealed at three (250 °C, 350 °C, and 450 °C) different temperatures. The XRD patterns confirmed that all the spin coated films had mixed wurtzite and cubic structures with a preferred orientation along the (111) plane of the predominant cubic phase. The highest crystallite size and lowest dislocation density were found at 350 °C annealing temperature due to the narrow, sharp and high intensity diffraction peak compared with those at 250 °C and 450 °C annealing temperatures. The SEM results indicate that the surface of the ZnS film annealed at 350 °C has a better surface coverage area with good uniformity, and is more homogeneous with a minimum amount of pinholes, voids and cracks than the other samples annealed at 250 °C, and 450 °C. The estimated optical band gap was determined to be between 3.957 and 3.991 eV. The calculated electrical resistivity values are on the order of 10^4 Ω cm. All the findings revealed that the film annealed at 350 °C presented good material properties for utilizing as buffer layer in thin film solar cells.

Cadmium telluride (CdTe) absorber layer in solar cells (SCs) is environmentally dangerous for the toxic behavior of cadmium (Cd). Alternatively, zinc telluride (ZnTe) is deliberated as a promising PV material for its adoptable absorption coefficient, better conversion efficiency and low production cost of materials requirements. The main objective of this study is to synthesis and characterization analysis of ZnTe thin films to enhance the performance of ZnS/ZnTe solar cell. The structural, optical, morphological and compositional properties of the ZnTe thin films were investigated by X-ray diffraction, UV-visible spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. The performance of the cell was analyzed by SCAPS-1D. The XRD results showed that all the spin coated ZnTe thin films are in cubic phase. The determining optical band gap values are in the range of 1.77-2.18 eV. The SEM images indicated that the surface of ZnTe thin film annealed at 400 °C has better surface coverage area with homogeneity, good uniformity, and minimum void compared to the other annealed samples. The EDS study exhibits that all the films are Te richness with p-type conductivity. The highest power conversion efficiency (PCE) is found 17.45% with V oc of 1.41 V, J sc of 14.01 mA cm-2 and FF of 88.53% for the 1184 nm optimum thickness of ZnTe and annealed at 400 °C. zinc sulfide (ZnS), indium tin oxide (ITO), platinum (Pt) and aluminum (Al) are indicated as buffer layer, transparent conductive oxide, back metal and front metal respectively of the device. All the findings confirmed that the deposited ZnTe thin films are suitable for usage as an absorber layer in thin film solar cells (TFSCs).

The tandem solar cell (TSC) with top and bottom sub-cells is able to absorb sunlight from visible to near infrared range and is promising for enhancing the photo-conversion efficiency. We have proposed a TSC with a bandgap of 1.8 and 1.29 eV for carbon nitride (C2N) as a top sub-cell and tungsten disulfide (WS2) as a bottom sub-cell absorber layer, respectively. In this research study, 1D solar capacitance simulation software (SCAPS-1D) is used to analyze the open circuit voltage (V-oc), short circuit current (J(sc)), fill factor (FF), and photo-conversion efficiency (eta) of the top and bottom sub-cell for the design of two-terminal (2-T) C2N-WS2 TSC. The current matching condition of J(sc) has been determined at the absorber layer thickness of 450 and 790 nm for the top and bottom sub-cells, respectively. The TSC device parameters such as defect density and doping density have been optimized at 10(15) (C2N), 10(14) (WS2) cm(-3), and 10(17)cm(-3) (C2N and WS2), respectively for achieving better performance of the proposed structure. The determined optimum values of V-oc, J(sc), eta, and FF are 2.38 V, 17.40 mA, 37.60%, and 90.78%, respectively. The present research paves the path for the realization of the high efficiency TSC.

Perovskite solar cells (PSCs) without lead offer broad light absorption, low weight, stability, and environmental safety, making them strong candidates for next-generation photovoltaics (PV). Although the efficiency of PSC has greatly improved, commercialization of the technology on large industrial scale has not been effective, mainly because of the toxicity of the lead-based perovskites, which are damaging to the environment and shorten the operating duration of the cells. Here, a lead-free double absorber PSC is proposed with $\text{Cs}_{2} \text{TiBr}_{6}$ and $\text{CsSnI}_{3}$ as absorber materials. The thicknesses of these absorbers which had different bandgap characteristics were varied systematically in order to get optimal current matching. Here, the AM 1.5 G solar spectrum was used to compute device performance in SCAPS-1D simulations. After careful investigation, the optimized high-performance structure is found $\mathbf{F T O} / \mathbf{T i O}_{\mathbf{2}} / \mathbf{C s}_{\mathbf{2}} \mathbf{T i B r}_{\mathbf{6}} / \mathbf{C s S n I}_{\mathbf{3}} / \mathbf{N i O} / \mathbf{A u}$. The current work also examines the influence of changing in the electron transport layers (ETLs) and absorber-layer thickness on the PV efficacy of the proposed solar cells with two absorbers. The optimized device under normal operating conditions (300 K) had a short-circuit current density $(\mathrm{J}_{\text{sc}})$ of 34.36 $\text{mA} / \text{cm}^{2}$, power conversion efficiency (PCE) of 35.15 percent, open-circuit voltage $(\mathrm{V}_{\text{oc}})$ of 1.1462 V, and fill factor (FF) of 89.25 percent. These findings underscore the high potential of double absorber solar cell (DASC) as effective, stable, and environmentally friendly alternatives to traditional PV technologies.

The nitrogenated holey Graphene (C2N) based solar cell has been modeled and analyzed by using SCAPS-1D. Initially, a reported structure (TCO/IGZO/C2N) has been considered and improved by incorporating Al and Pt as front and back contact, respectively. Then, a novel device structure (Al/TCO/IGZO/C2N/CZT/Pt) has been proposed by inserting a BSF layer with heavily doped p-CZT material. The outcomes of the suggested cell structure have been analyzed numerically by changing different physical parameters. The absorber and BSF layer's thickness has been optimized as 0.6 μm and 0.4 μm, respectively. The cell performance is significantly declined when the bulk defect density in C2N exceeds the value of 1015 cm−3. The rising of device operating temperature shows a negative effect on performance. From this analysis, the structure has been optimized according to device performance. The optimized results have been achieved with the VOC, JSC, FF and efficiency (eta) of 1.40 V, 22.59 mA/cm2, 89.02%, and 28.16%, respectively. This research contributes to enriching the knowledge on the field of C2N materials and its use in optoelectronic applications.

In this study, SCAPS-1D simulator was used to investigate the performance of a solar cell structure based on Molybdenum Telluride (MoTe2) with Sb2S3 (Antimony Sulfide) Hole Transport Layer (HTL). The motivation behind choosing MoTe2 as an absorber layer for its higher optical absorption efficiency, cost-effectiveness, reliable and stable operation. The comparative study of this introduced (Al/FTO/CdS/MoTe2/Sb2S3/Pt) and baseline solar cell (Al/FTO/CdS/MoTe2/Pt) has been implemented. Various photovoltaic parameters like open-circuit voltage, short-circuit current, fill factor, and efficiency have been investigated varying absorber and HTL thickness, doping density, rare surface recombination velocity, defect density, series as well as shunt resistance and temperature. The proposed solar cell performance of η, Voc, Jsc, and FF was found to be 40.33%, 1.13 V, 40.78 mA/cm2, 87.63% optimizing absorber thickness value of 0.5 μm and doping concentration value of cm-3. The determined values of performance parameters Voc, Jsc, FF, and η are 0.95 V, 38.15 mA/cm2, 81.09% and 29.35%, respectively for baseline solar cell. The implantation of Sb2S3 layer contributes to improve the performances by diminishing carrier recombination losses. The present research results indicate the feasible way for obtaining a lower-cost, and higher-efficiency MoTe2-based SC with Sb2S3 HTL layer.

Nano-crystalline Zinc sulfide (ZnS) thin films were deposited on glass substrates by spin coating method using thiol-amine co-solvent through Triton X-100 (TX-100) surfactant. The structural, morphological, and optical properties of the deposited ZnS films for with and without TX-100 surfactant was investigated by X-ray diffraction, scanning electron microscopy, and optical transmission spectroscopy. The X-ray diffraction results showed that hexagonal phase with (008) plane. The highest peak intensity was found from the surfactant-mediated film which originated at 2θ value of 29.30°. The crystalline size increased but the dislocation density and lattice parameters are decreased for with surfactant than without surfactant. The SEM results showed surfactant mediated film offered a smoother and uniform surface with fewer crack than without surfactant film. The optical transmittance was found 62–70

In the photovoltaic (PV) industry, perovskite-based solar cells have garnered a plethora of interest lately as prospective options. However, the predominant use of lead (Pb) in perovskite materials raises toxicity concerns, limiting their potential for commercial applications. This work involves the numerical simulation of a double absorber solar cell (DASC) construction with multilayer transition metal dichalcogenide (TMDC) serving as the bottom absorber and lead-free perovskite materials serving as the top absorber. The Solar Cell Capacitance Simulator-1 Dimension (SCAPS-1D) program is employed to assess the configuration's performance utilizing the AM 1.5G solar spectrum. Here, current matching is accomplished within the architecture through modifying the absorber layers thicknesses having diverse bandgap values. This research investigates the implications of the number of defects and thickness of absorber on the overall effectiveness of the device in further detail. The modeling findings indicate that. $0.7 \ \mu\mathrm{m}$ is the ideal thickness for the MoTe2 absorber layer. Moreover, the analysis indicates that the defect density shouldn't above 1E13 cm-3 to maintain optimal performance. According to the optimized simulation, the proposed device attains a power conversion efficiency (PCE) of 44.49%, with an open-circuit voltage $(\mathrm{V}_{\text{oc}})$ of 1.2930 V, a short-circuit current density $(\mathrm{J}_{\text{sc}})$ of 39.37 mA/cm2, and a fill factor (FF) of 87.40%.

The immense demand for electrical energy motivated us to manipulate solar energy by means of conversion through solar cells (SCs).

Due to the complexity of the fabrication process of tandem solar cells, perovskite materials provide a cost-effective and simpler fabrication solution. In this work, MAPbI(3)/MASnI(3) Perovskite-based Tandem solar cell has been explored numerically by using SCAPS-1D. Methylammonium Lead Iodide (CH3NH3PbI3 or MAPbI(3)) and Methylammonium Tin Iodide (CH3NH3SnI3 or MASnI(3)) have been considered as wide bandgap (WBG) and narrow bandgap (NBG) absorber material for the top cell and bottom cell, respectively. WBG top cell and NBG bottom cell are both investigated through the change in the depth of perovskite materials at the current matching conditions at the illumination of Standard AM 1.5 spectrum. The all-perovskite MAPbI(3)/MASnI(3) tandem solar cell with copper (I) oxide (Cu2O) hole transport layer has achieved excellent performance with a maximum power conversion efficiency (PCE) of 32.74% with V-oc of 1.68 V, J(sc) of 24.6 mA cm(-2), and fill factor (FF) of 79.39%, respectively.

Employing the SCAPS-1D simulator, this research explores the effectiveness of adding an Antimony Sulfide (Sb2S3)Hole Transport Layer (HTL) to a Molybdenum Telluride (MoTe2) solar cell structure. MoTe2 has affordability and stable performance, alongside excellent high optical absorption capabilities. In this study, a new solar cell setup (Al/FTO/CdS/MoTe2/Sb2S3/Pt) with a baseline configuration of (Al/FTO/CdS/MoTe2/Pt) is studied. This investigation has reviewed several aspects, such as the surface recombination velocity, the thickness of the active and HTL, the doping density of the active, the relationship between current and voltage, the defect density, and the series and shunt resistances. The suggested cell impressively demonstrates notable enhancements, obtaining FF = 87.65%, Jsc=40.77 mA/cm2, Voc = 1.12 V, and PCE = 40.29%. By comparison, the standard cell has the following values: FF = 81.13%, Jsc = 38.17 mA/cm2, Voc = 0.96 V, and η = 29.41%. By integrating the Sb2S3 material, effectively reduced carrier recombination losses, leading to the emergence of cost-effective, high-performance MoTe2 PV cells.

Zinc telluride (ZnTe) is considered as a favorable photovoltaic (PV) material for its desirable absorption coefficient, improved conversion efficiency, and consequently inexpensive production material requirements. The principal objective of this research is to improve the performance of newly designed Al/ZnO/CdS/ZnTe/In2Te3/Pt solar cell and to investigate the influence of the Indium telluride (In2Te3) back surface field (BSF) layer on the performance parameters of open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and power conversion efficiency (PCE). This simulation analyses the performance of the baseline structure Al/ZnO/CdS/ZnTe/Pt which is considered as without BSF and the proposed structure Al/ZnO/CdS/ZnTe/In2Te3/Pt with BSF. The thicknesses and doping density have been used are 30, 30, 500, and 100 nm and 1019, 1018, 1019, and 1021 cm−3 for ZnO, CdS, ZnTe, and In2Te3 layer, respectively, with bulk defect density of 1014 cm−3 for each layer of the proposed cell. The PCE has been achieved 18.40 and 20.20

Researchers are currently showing interest in molybdenum disulfide (MoS2)-based solar cells due to their remarkable semiconducting characteristics. The incompatibility of the band structures at the BSF/absorber and absorber/buffer interfaces, as well as carrier recombination at the rear and front metal contacts, prevents the expected result from being achieved. The main purpose of this work is to enhance the performance of the newly proposed Al/ITO/TiO2/MoS2/In2Te3/Ni solar cell and investigate the impacts of the In2Te3 BSF and TiO2 buffer layer on the performance parameters of open-circuit voltage (VOC), short-circuit current density (JSC), fill factor (FF), and power conversion efficiency (PCE). This research has been performed by utilizing SCAPS simulation software. The performance parameters such as variation of thickness, carrier concentration, the bulk defect concentration of each layer, interface defect, operating temperature, capacitance–voltage (C–V), surface recombination velocity, and front as well as rear electrodes have been analyzed to achieve a better performance. This device performs exceptionally well at lower carrier concentrations (1 × 1016 cm–3) in a thin (800 nm) MoS2 absorber layer. The PCE, VOC, JSC, and FF values of the Al/ITO/TiO2/MoS2/Ni reference cell have been estimated to be 22.30%, 0.793 V, 30.89 mA/cm2, and 80.62% respectively, while the PCE, VOC, JSC, and FF values have been determined to be 33.32%, 1.084 V, 37.22 mA/cm2, and 82.58% for the Al/ITO/TiO2/MoS2/In2Te3/Ni proposed solar cell by introducing In2Te3 between the absorber (MoS2) and the rear electrode (Ni). The proposed research may give an insight and a feasible way to realize a cost-effective MoS2-based thin-film solar cell.

Recently, most of the researchers are showing their interest on Iron di-silicide (FeSi2) based solar cell because, it is an excellent and promising light absorbing material for solar cell applications because of its remarkable characteristics. The inappropriateness of device structure, band alignment at the BSF/absorber and absorber/ buffer interface, as well as carrier recombination at the rear and front contact, prevents the expected result from being achieved. The primary goal of this study is to enhance the performance of uniquely designed Al/ITO/CdS/ FeSi2/PEDOT:PSS/Au solar cell and to scope out the influence of the PEDOT:PSS HTL layer on the performance parameters of open circuit voltage (Voc), short circuit current (Jsc), fill factor (FF), and power conversion efficiency (PCE). The photovoltaic (PV) performance of the proposed photovoltaic cell has been simulated utilizing SCAPS-1D software. In this simulation, the defect densities of each layer and interface defect between HTL/ absorber and absorber/buffer have been added. The impact of the variation of thickness, carrier concentration, electron affinity of the HTL layer, shunt and series resistance, operating temperature, and surface recombination velocity (SRV) on the performance parameters have been studied to avail the better performance. The PCE of 39.44 %, Voc of 938 mV, Jsc of 51.58 mA/cm2 and FF of 81.48 % of the proposed SC have been determined with FeSi2 absorber layer thickness and carrier concentration of 300 nm and 1014 cm-3, correspondingly. The results of this research recommend the guidelines for temperature stable, environment friendly, low cost, and high efficiency FeSi2-based SC.

A novel structure of chalcogenide-based antimony selenide (Sb2Se3) which is the most promising absorber materials in the field of thin film solar cells with a tungsten diselenide (WSe2) back surface field (BSF) has been proposed in this paper. Antimony selenide (Sb2Se3) with a BSF has been observed by one-dimensional solar cell capacitance simulator (SCAPS-1D). Its recognizable properties make it one of the most usable for non-toxic solar cell absorbers. This paper demonstrated the planning and modeling of Al/FTO/n-TiO2/p-Sb2Se3/Ni (without BSF) and Al/FTO/n-TiO2/p-Sb2Se3/p(+)-WSe2/Ni (with BSF) structures. The capability of Al/FTO/n-TiO2/p-Sb2Se3/p(+)-WSe2/Ni heterojunction solar cell structure shows the promising performances. We have numerically simulated and observed the performance parameters such as power conversion efficiency (PCE), open circuit voltage (V-OC), short circuit current density (J(SC)) and fill factor (FF) by tuning the different parameters such as thickness, doping concentration, defect density, the interface defect density, surface recombination velocity, series and shunt resistances along with temperature. The PCE of 20.61% with an absorber's thickness of 800 nm for without BSF has been achieved. By inserting the WSe2 BSF with thickness of 100 nm, highly improving efficiency of 32.35% has been demonstrated. Our simulation and numerical analysis also provide valuable and important information that is very effective for further implementation and achieving high efficiency of thin film solar cell.

The demand for compact, lightweight, and high-performance antennas has increased in recent times in the communication industry. Microstrip patch antenna (MPA) becomes a better choice to effectively fulfill these requirements. In this study, hybrid techniques of partial ground plane, slotted patch, and defective ground structure are employed in MPA design to reduce the return loss, good impedance matching, and increased the bandwidth, gain, and efficiency of the antenna. This research demonstrates the impact of altering the feed point position, a crucial phenomenon of antenna design, on the patch antenna and determines the proper feed point location by comparing a minimum return loss (S11) which achieves the highest performance for the designed antenna. High-frequency structure simulator (HFSS) software is used to design and simulate the patch antenna. The operating frequency of the antenna is 6.85 GHz for UWB applications (3.1–10.6 GHz). A FR4 epoxy substrate material with dimensions of 30 mm × 20 mm is used to design the antenna. It has a dielectric constant of 4.4, a thickness of 0.8 mm and a tangent loss of 0.02. Multiple resonant frequencies are observed with different return losses for each feed location. The analysis shows that the finest feeding point is found at the center of the patch (9, 0) with a very low return loss (-28.35 dB), and a high impedance bandwidth (19.7 GHz). The antenna also achieved a gain of 4.46 dB, a directivity of 4.6904 dB, and a radiation efficiency of 95.90%. Hence, the location of the feed point can be considered as an influential factor in the antenna design.