Resistance Rs Research Articles

Estimation of photovoltaic model parameters using the Rao-1 optimization algorithm

Predicting the performance of photovoltaic (PV) systems in industrial applications has become increasingly important due to the complex and non-linear behavior of PV modules. Accurate performance prediction is essential for optimizing energy production and ensuring system reliability. However, a significant challenge arises from the lack of critical information in manufacturer datasheets, which often do not include all the necessary details for precise PV module modeling. This limitation can hinder accurate analysis and system performance evaluation. Optimization methods are recommended to accurately determine the electrical and physical characteristics of PV cells and modules to address this issue. These methods enable detailed and precise analysis of current-voltage (I-V) and power-voltage (P-V) characteristics across various PV models, improving the overall modeling accuracy. Among these methods, the Rao-1 optimization technique has been selected and evaluated in this paper to solve this issue. It is specifically used to extract the unknown parameters of photovoltaic models, including the photo-generated current (Iph), diode ideality factor (n), series resistance (Rs), reverse saturation current (I0), and shunt resistance (Rsh). The effectiveness of the Rao-1 optimization method has been demonstrated through its successful application in estimating PV parameters across a wide range of datasets, ensuring its reliability and adaptability for various industrial scenarios.

Effect of differently shaped spiral inductors on micro power integrated circuit

Abstract This paper investigates the impact of parasitic effects on the performance of on-chip planar spiral inductors for DC-DC converter applications, focusing on three geometries: square, hexagonal, and octagonal. Detailed electromagnetic simulations in MATLAB are employed to analyze the frequency-dependent behavior of key parasitic components, including ohmic resistance (Rs), substrate resistance (Rsub), oxide capacitance (Cox), and substrate capacitance (Csub) across a frequency range of 1 GHz to 10 GHz. The study reveals that the octagonal spiral inductor outperforms the others, demonstrating a 29% reduction in ohmic resistance at 1.5 GHz compared to the square geometry and achieving the highest substrate resistance, which helps reduce current leakage. Additionally, the octagonal inductor exhibits the lowest parasitic capacitance and a high-quality factor, peaking at 30 at 4.2 GHz. These results underscore the significant impact of inductor geometry on minimizing energy dissipation and electromagnetic interference, positioning the octagonal spiral inductor as a compelling choice for enhancing efficiency and miniaturization in DCDC converter designs.

Computational simulation of alternating current (AC) impedance of hardened cement mortar

The present study proposes a novel methodology for simulating the AC impedance of hardened cement mortar, through the technology of micro computed tomography based finite element analysis (μCT-based FEA). Three-dimensional (3D) physical meso-scale structure of hardened cement mortar is first segmented into multicomponent phases of air void, cement paste, sand aggregate, and interfacial transition zone (ITZ) considered with different thicknesses. Then, the real structure of mortar after discretization is subjected to current harmonic perturbations to acquire its AC impedance spectra. Compared to traditional impedance measurement, the proposed simulation approach avoids the influence of external electrode and hence improves the characterization of cementitious electrochemical system in its true state. The simulated complex impedance presents a depressed high-frequency loop and varies with the increasing ITZ thickness in the range of 26.6 to 106.4 μm. The numerical impedance plots are fitted to a theoretical equivalent circuit model of Rs(RctQ) consisting of bulk ionic resistance (Rs), charge transfer resistance (Rct) at the solid/liquid interface, and non-Debye capacitance (Q). The changes in mesostructure of cement mortar with the thickened ITZs can be captured by a linear reduction of Rs, a non-linear decrease of Q, and a limited increase of Rct. Based on the electrochemical impedance modelling, the study establishes the mathematical relationship between the defect's volume (air voids plus ITZ) and the model's parameters (Rs or Rct) for prediction of material deterioration.

Trichosanthes Cucumerina Derived Activated Carbon: The Potential Electrode material for High Energy Symmetric Supercapacitor

AbstractHigh surface area porous activated carbons obtained from sustainable biomass are excellent functional materials for energy storage applications. This is the first report on snake gourd (Trichosanthes cucumerina) pericarp as a raw material of activated carbon and supercapacitor electrode material. Herein, a simple KOH activation and carbonisation method is used. The obtained SGC900 sample has a surface area of 1841 m2/g and an average pore volume of 0.52 cm3/g. SGC900 based supercapacitor exhibits good electrochemical storage capacity in 1 M H2SO4 with a specific capacitance of 206 F/g at 1 A/g. The symmetric device delivered an energy density of 11 Wh/kg at a power density of 1.6 kW/kg. It provides a series resistance (Rs) of 1.2 Ω and a charge transfer resistance Rct of 1.9 Ω. Furthermore, the device retains 95 % of capacitance over 5000 cycles. This work presents an easy and feasible approach for producing value‐added activated carbon from sustainable biomass, potentially used in high‐performance energy storage.

Frequency and voltage dependent of electrical and dielectric properties of Ag/GO doped NiO/p-Si/Al MOS structures under darkness and light

At studying, we searched the frequency and voltage dependency of the electrical and dielectric traits of a nano-made NiO-contributed GO thin film enlarged on a p-type silicon substrate using sol-gel technique. The electrical and dielectric features of Ag/GO-NiO/p-Si were investigated by capacitance–voltage (C–V) and conductance–voltage (G/ ω–V) indications in the frequency interval of 10 kHz–1000 kHz below dark and illumination at ambient temperature. While the capacitance and series resistance (Rs) values decrease with increment of frequency and increment trend in conductance was observed with the increasement of frequency. These decrement/increment trend observed at greater frequencies are attributed to existence of interface state densities. After, the frequency dependence of dielectric constant (εʼ), dielectric loss (εʼʼ), loss tangent (tanδ), ac electrical conductivity (σac) and complex impedance (Z∗) of Ag/GO-NiO/p-Si structures were investigated in the frequency by means of the capacitance–voltage (C–V) and conductance-voltage (G/w-V) indications. The experimental findings showed that εʼ, εʼʼ and σac were strongly frequency dependent.

Self-assembly monolayer impact on Schottky diode electrical properties

This study examines the electrical and charge transport properties of p-Si/TiO2/self-assembly monolayer (SAM)/Al type Schottky diodes. The diodes were fabricated by applying the SAM molecule 4′-[(3-methylphenyl)(phenyl)amino]biphenyl-4-carboxylic acid (CT21) onto titanium dioxide (TiO2) synthesized via the sol-gel method. The key parameters, including the ideality factor (n), series resistance (Rs), and barrier height (∅b), were used to assess the impact of CT21 on diode performance. Experimental results revealed that using CT21 at the TiO2/Al interface significantly enhances diode performance. The n decreased from 3.8 in the control diode to 1.9 with CT21. Rs was substantially reduced, and the ∅b increased. The rectification ratio improved from 1x104 in the control diode to 1.1x105 in the CT21-modified diode. These enhancements, due to the CT21 molecule's ability to reduce interface states (Nss) and improve surface properties, underscore the potential of SAM coatings to open a new window in nanoelectronics with better performance and reliability.

The trifunctional electrocatalytic activity of hierarchically structured porous carbon derived from environmentally malignant Prosopis juliflora

Finding an efficient and affordable multifunctional electrocatalyst with long-term durability has received paramount interest in the recent scenario. The present work attempted to facilitate ecologically threatful invasive biomass – P. juliflora- derived porous carbon as an effectual Pt support for trifunctional electrocatalytic applications. The preparation of Pt decorated P. juliflora -derived porous carbon (Pt/J-600, Pt/J-700, and Pt/J-800) involves simple hydrothermal carbonization, pyrolysis at various temperatures of 600, 700 & 800⁰C and polyol mediated reduction. The obtained XRD results reveal the turbostratic nature of the prepared porous carbon favoring to anchor the Pt NPs. Significantly, the estimated ID/IG ratios of Raman profile substantiates the highly defective structure of Pt/J-800. The TEM images disclose the agglomeration-free dispersion of Pt NPs in the Pt/J-800 electrocatalyst. The EIS analysis demonstrates the relatively low solution and charge transfer resistances (Rs = 0.646 Ω & Rct = 0.312 Ω). The desirable 4e- transfer with an improved limiting current density of -4.44 mA cm-2 signpost better oxygen reduction reaction (ORR) performance of Pt/J-800 than the other prepared electrocatalysts. Additionally, the high electrochemical surface area (652.72 m2 g-1) and good mass activity (49.09 mA mgpt-1) prove the excellent methanol oxidation reaction (MOR) activity. Moreover, a minimal overpotential of 31 mV @ 10 mA/cm2, and a lower Tafel slope of 32 mV/dec with 24 hr stable performance proved the efficient hydrogen evolution reaction (HER) performance of Pt/J-800. The remarkable electrochemical performance of Pt/J-800 is attributed to the enhanced surface area created by hierarchically porous carbon support and the uniform dispersion of Pt nanoparticles with optimum loading.

Electrical properties of acetone imprinted hematite nanomaterials doped with Pd & Ag for gas sensing and simulation of their wireless devices

This article presents a novel technique for wireless hydrothermally improved gas sensor devices enhanced by molecular imprinting technique (MIT) for hematite nanomaterials with the existence of acetone using different ratios (10 %, 15 %, and 25 %) as well as doping with palladium/ silver to detect the imprinted gas. α-Fe2O3 are characterized utilizing field emission scanning electron microscope (FESEM), photoluminescence, Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photo-spectroscopy (XPS), and High-Resolution Transmission Electron Microscopy (HRTEM), Thermogravimetric Analysis (TGA) and utilizes Brunauer-Emmett-Teller (BET) to ascertain their shape, optical properties, and values for surface area and thermal characteristics, respectively. Depending on the preparation conditions, non-regular cubes and rods have typical particle sizes ranging from 25 to 120 nm, acetone imprinted and doped with palladium sample (Ap) offers smaller particles than acetone imprinted sample (A15) making adsorption easier. Where XRD showed all diffraction peaks for α-Fe2O3 as well as XPS authorized the oxidation state, also FTIR showed the characteristic peaks of the stretching mode Fe-O which indicates the formation of α-Fe2O3. Lower defects for (Ap) as it has the highest intensity of 176.15 a.u. in the photoluminescent spectrum, for TGA analysis results explain that pure sample has more thermal stability and lower weight loss. Six hematite films are fabricated using the spin coating technique where acetone molecules are presented during the synthesis process of the nanomaterials to imprint their shapes on the surface of hematite. By measuring the response of the gas sensors and their electrical properties, the I-V curve for Ap showed a rectifying behavior and its shunt resistance (Rsh) is higher than series resistance (Rs) which ensures a high response of (115 %). To develop a wireless gas sensor COMSOL Multiphysics software 5.3(a) software is used for the simulation of three devices model by depositing a layer by specified dimensions of hematites (A15, As, and Ap) with their different electrical conductivities on the surface of rectangular patch antenna by showing geometry, the microstrip patch antenna bandwidth, resonant frequency, scattering parameters, and radiation patterns in the E-plane and 3-D far-field pattern and directivity is calculated also, Sp gives improved reflection coefficient, gain quality factor and directivity due to its high electrical conductivity.

Amplifying energy storage and production efficiency: Utilizing BaS3: Ni2S3: Sb2S3 synthesized from dithiocarbamate precursors for enhanced and sustainable energy solutions

During this period of increasing energy use, the scientific community and energy stakeholders have been closely monitoring electrochemical energy storage. In an attempt to enhance the functionality of charge storage devices, diethyldithiocarbamate ligand is employed as a chelating agent during the production of the novel BaS3: Ni2S3: Sb2S3. The semiconductor BaS3: Ni2S3: Sb2S3, which was made in an environmentally friendly manner, showed good photoactivity due to its 2.97 eV energy band gap and light absorption. The resultant chalcogenide had an average crystallite size of 19.69 nm and displayed outstanding crystallinity with mixed crystallographic phases. Furthermore, infrared spectroscopy was used to investigate metallic sulfide connections, and the findings indicated that they varied between 500 and 875 cm−1. This chalcogenide featured varied sites for electrochemical reactions due to its morphology. The electrochemical performance of BaS3: Ni2S3: Sb2S3 was assessed using a conventional three-electrode setup. With a specific capacitance of up to 1019.4 F g−1 and a power density of 11931.26 W kg−1, BaS3: Ni2S3: Sb2S3 has proven to be an excellent electrode material for energy storage. This remarkable electrochemical performance was further reinforced by the comparable series resistance (Rs) of 0.57 Ω. During electrocatalysis, the electrode produced an OER overpotential with a Tafel slope of 348 mV and 119 mV dec−1. In contrast, the overpotential and Tafel slope in terms of the HER activity and were 211 mV and 100 mV/dec, respectively.

Beneficial effects of AMP Scy-hepc on the gut microbiota contribute to the potential growth of Larimichthys crocea

BackgroundIn light of the global ban on antibiotics in animal feed, antimicrobial peptides (AMPs) have emerged as a compelling substitute, garnering considerable interest for their potential as feed additives. Our previous study revealed that the extended (one-year) daily administration of the AMP Scy-hepc substantially boosted the growth of Larimichthys crocea. However, the exact influence of dietary supplementation with AMPs on the gut microbiota and the potential beneficial mechanisms remain unclear. Inspired by this, the present study endeavors to examine the alterations in gut microbiota at various gut sites in L. crocea following a 60-day Scy-hepc feeding regimen, building upon our prior research efforts.ResultsUtilizing 16S rRNA sequencing, we found that dietary supplementation with Scy-hepc significantly promoted the growth of L. crocea, which may be caused by the remarkable changes in the microbial communities within the foregut and midgut. Notable changes were observed in Tenericutes, Firmicutes, Proteobacteria, Cyanobacteria and Spirochaetes. The bacterial load trends in both the foregut and midgut demonstrated a notable increase following a 60-day Scy-hepc feeding, as determined by absolute quantitative PCR analysis. Moreover, Scy-hepc supplementation increased the abundance of potential probiotics (Rhodobiaceae and Planococcaceae) and reduced the abundance of opportunistic pathogens (Flavobacteriia and Mollicutes). This led to a more intricate microbial network with enhanced metabolism-related functions, especially in lipid transport and metabolism, signal transduction mechanisms, and coenzyme transport and metabolism. And the microbial resistance (Rs) exhibits no significant change between the Scy-hepc and control groups, indicating a minimal level of toxicity to the gut microbiota of L. crocea.ConclusionsIn summary, this study provides compelling evidences supporting the beneficial alteration of gut microbiota in the foregut and midgut as an underlying mechanism by which Scy-hepc feeding promotes host growth. These findings offer a novel perspective for investigating the advantageous effects of AMPs on fish health and the advancement of aquaculture.

LG = 50 nm T-gated and Fe-doped double quantum well GaN‒HEMT on SiC wafer with graded AlGaN barrier for future power electronics applications

High-performance LG = 50 nm graded double-channel (GDC)-HEMT featuring AlN top barrier, recessed T-gate and graded-AlGaN bottom barrier is designed and investigated. Two quantum wells are formed in the AlN-GaN-graded AlGaN-GaN multilayer structure developed on a SiC substrate and the clear double hump feature of the transconductance (GM), cut-off frequency (fT), and capacitance plots clearly illustrates the double-channel (DC) behavior. The investigations carried out to explore the impact of barrier thickness (both AlN & graded-AlGaN) revealed superior performance with the GM showing two peaks at 181.5 & 488.1 mS/mm, the peak-drive-current (ID_peak) with VGS biased at 3 V is 1.81 A/mm, maximum saturation drain current of 3.08 A/mm (VGS = 3V), and the fT derived from the left- and right-hump are 263.7 GHz & 354.2 GHz, respectively, when both barriers are 6 nm thin, attributable to enhanced 2DEG density due to the coordination of channels because of proximity and lower leakage. It has been noticed that when the bottom barrier is thick, the DC behaviour is less obvious due to insufficient gate access to the lower channel. We investigated the impact of varying the Al % in AlGaN top barrier on the DC/RF performance of GDC-HEMTs, demonstrating enhanced performance with increased Al content, particularly for Al0.35Ga0.65N. By using various metals, this study also investigates how gate engineering affects the electrical characteristics of the GDC-HEMT. The lower ϕm (work function) of the Al-gate led to better DC/RF performance. When the Schottky barrier rises as a result of the conduction band edge being elevated, the performance reduces, and the threshold voltage (Vth) increases. Since it is essential to comprehend the role that source resistance (Rs) & drain resistance (Rd) play in RF design, we have also conducted simulations by varying the source-gate gap (LGS) & drain-gate gap (LGD). Due to low Rs & Rd, it was determined that the GDC-HEMT performed better at the smallest LGS & LGD. The extraordinary performance strongly highlights the immense potential and applicability of the GDC-HEMTs for future broadband power amplifiers.

Investigation of the Electrical Properties of Cu-doped CoOx/n-Si Structures Fabricated by the Sol-Gel Method

The sol-gel spin coating technique was employed for the deposition of thin films comprising CoOx, Cu-doped CoOx, and CuOx onto n-Si substrates. Subsequently, an exhaustive examination of the electrical properties of the resultant heterojunction structures was conducted. The outcomes unequivocally indicate that the incorporation of Cu through doping exerts a pronounced influence on the electrical attributes of the CoOx/n-Si diode. Notably, all diodes exhibit rectifying behavior, a discernible feature in their dark current-voltage (I-V) characteristics. The I-V data was further utilized to ascertain pivotal junction parameters, encompassing series resistance (Rs), rectification ratio (RR), ideality factor (n), and barrier height (ΦB). The values of the ideality factor for CoOx/n-Si, Cu doped CoOx/n-Si and CuOx/n-Si are obtained to be 3.19, 1.99 and 2.19 eV, respectively. Furthermore, the capacitance-voltage (C-V) characteristics of diodes were performed within the frequency range of 10 kHz to 1 MHz. These findings underscore that judicious manipulation of the copper doping concentration can serve as an effective means to modulate the electrical properties of CoOx/n-Si diodes.

Ag-doped MgCo2O4/MXene composite: Tailoring the electrochemical properties via 2D layered material for next generation supercapacitor study

The major concern of the modern era is to conserve and store energy for future use because of the continuous depletion of natural resources. Spinel cobaltites have attracted a lot of attention to be studied in the energy storage and conversion arena because of their prospective applications and excellent electrochemical performance. Achieving excellent chemo-mechanically robust electrode materials requires creative structural design and effective multicomponent strategy implementation. Herein, MgCo2O4 (MC) and Ag-MgCo2O4 (AMC) were fabricated by hydrothermal treatment. Further, Ag-MgCo2O4 (AMC) coupling with MXene sheets was accomplished by ultrasonication treatment. After structural, morphological, functional, and compositional analyses, prepared materials were studied for supercapacitor measurements. AMC/MXene exhibited remarkable outcomes because of Ag ions insertion into the spinel oxide structure, providing electron transport paths by creating voids and interfacial contact between the electrolyte and available active sites, and 2D MXene layers boosting the transportation of ions during the charging and discharging stages. The specific capacitance at 1 Ag−1 was found to be 1722 Fg−1 for AMC/MXene. The bulk (solution) resistance Rs was found to be the lowest 0.63 Ω for AMC/MXene among other fabricated materials in this study. Hence, developing AMC/MXene offers an advanced method to build high-performance 2D electrode materials with hybrid structures for energy storage applications.

Unveiling the origin of metal contact failures in TOPCon solar cells through accelerated damp-heat testing

Tunnel oxide passivated contact (TOPCon) solar cells are expected to dominate the global photovoltaic market in the coming decade thanks to rapid advancements in power conversion efficiency (PCE). However, there are concerns about the reliability of TOPCon modules, particularly in hot and humid conditions. The current module-level fundamental analysis strategies for TOPCon solar cells provide too slow feedback for rapid process development. This study explores the degradation of metal contacts in TOPCon solar cells under accelerated testing conditions of 85 °C and 85 % relative humidity (DH85). The degradation was induced by two commonly used sodium-related salts, sodium bicarbonate (NaHCO3) and sodium chloride (NaCl), in the testing of the solar cells. When applied to the front side, NaHCO3 caused a ∼5%relPCE reduction after 100-h DH85 exposure, while NaCl leads to a more significant ∼92%relPCE reduction. The primary cause of degradation is a considerable increase in series resistance (Rs), likely due to electrochemical reactions within the Ag/Al paste. When the salts are applied to the rear of the TOPCon solar cell, the degradation becomes more complex. NaHCO3 increases recombination and results in a deterioration of the contact, resulting in a ∼16%relPCE reduction after 100-h DH85 testing. Conversely, NaCl primarily causes a decline in open-circuit voltage (Voc) and a ∼4%relPCE loss. This manuscript primarily investigates degradation mechanisms related on the rear side, with a focus on significant oxidation occurring at the interface between Ag and Si. These findings highlight the susceptibility of TOPCon solar cells to contact corrosion, emphasizing the electrochemical reactivity of metallisation as a potential risk for long-term TOPCon module operation. This study provides crucial insights into TOPCon cell degradation mechanisms, which are essential for optimising performance and enhancing the long-term reliability of TOPCon modules.

Optical properties of transition metals complex films derived from hydrazone oxime for optoelectronic devices

Hydrazone incorporating oxime nucleus and its Ni2+, Mn2+, Zn2+ and UO22+ metallic chelates have been prepared and completely characterized by different spectral, theoretical, and analytical techniques including NMR, FT-IR, mass, and EAS spectroscopy. The finding denoted that the Hydrazone ligand bonded as a dibasic tridentate chelator via deprotonated oximato nitrogen, enol carbonyl oxygen and hydrazono azomethine nitrogen atoms resultant in octahedral geometry for Ni2+, Mn2+, Zn2+ and UO22+. Theoretical studies by DFT/B3LYP/LANLDZ together with dipole moment, geometrical optimization, energetic parameters, and energy gap (HOMO–LUMO) were employed to support the geometrical structure of the synthetics. Additionally, these complexes were prepared in the form of thin film onto cleaned glass substrate by spin-coating technique. The values of the optical band gap (Eg) and film index of refraction (n) have been determined by many different methods. It was found that the hydrazone-oxime (OBBH2) film has the highest value of Eg (eV) where the UOBB complex film has the smallest value of Eg (2.56 eV). The latter is very close to the Eg value of ZnSe (2.58 eV). The refractive index changes with wavelengths show normal dispersion which is well discussed in terms of Sellmeier's dispersion model. Also, the nonlinear optical parameters viz. the first (χ(1)) and third (χ(3)) orders of nonlinear optical susceptibilities and the non-linear index of refraction (n2) have been studied. The complex dielectric constant (ε⌣=εr+iεi)), conductivity (σ⌣=σr+iσi), sheet resistance (Rs), and thermal have been investigated over the whole spectral range. According to the results of χ(1), χ(3) and n2 the complex films under study are candidates to be used in optical switching gadgets, optical modulators, and optical signal processing.

Investigation of Interface States, Series Resistance and Barrier Height Variation with Frequency in Al/WO3/p-Si (MOS) Capacitors

In the study, Tungsten oxide (WO3) was synthesized via the sol-gel method on P-type 〈100〉 silicon wafer. Electrical characterization of the Al/WO3/p-Si (MOS) capacitor was performed through capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements at different frequencies (from 50 kHz to 1 MHz). As the applied voltage frequency increased, the maximum values of the measured C-V and G/ω-V characteristics decreased. This phenomenon was attributed to interface state trap (Dit) charges following low-frequency AC voltage signals. The variation of series resistance (Rs) and barrier height (ΦB) with frequency was examined. It was shown that Rs significantly affects the device behaviour. The ΦB also decreased with increasing frequency. This situation is suggested to indirectly affect the mobility of charge carriers directly through the Vo value. Ultimately, although WO3 material exhibits variable results in terms of dielectric properties, the study's finding of a high dielectric constant (e.g., 3688.75) is consistent with similar results in the literature. This high dielectric property underscores the material's importance for future applications.

Study of electrochemical behavior of rGO and Metal-Organic Framework nanocomposite electrodes for supercapacitive applications

Abstract This research studied the electrochemical performance of reduced Graphene Oxide (rGO) and a nanocomposite comprising rGO and Metal-Organic Framework-5 (MOF-5) for supercapacitor applications. The nanocomposite, synthesized through a solvothermal method, aimed to capitalize on the synergistic effects of combining rGO with MOF-5 under normal laboratory conditions without utilizing autoclave. By adjusting the concentration of the oxidizing agent, the oxidation degree of rGO was effectively regulated, thereby influencing its structural properties. Utilizing the optimized rGO, electrodes were fabricated for both rGO and MOF5-rGO configurations. Electrochemical studies were carried out using a three-electrode (3E) system with a 6M KOH electrolyte. The MOF-5, reduced graphene oxide (rGO), and MOF5-rGO nanocomposite samples were characterized using X-ray powder diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to determine their chemical composition and structural information. The Electrochemical Impedance Spectroscopy (EIS) spectra show low internal resistance (Rs) and charge transfer resistance (Rct), indicating higher conductivity of rGO and nanocomposite. The rGO electrode in the 3E system showed a specific capacitance of 65 Fg-1 whereas MOF5-rGO displayed 73 Fg-1 at a current density of 1.2 Ag-1. MOF5-rGO nanocomposite demonstrates better capacitor retention (96%) compared to rGO (90%) at 5A/g. These results indicate that the MOF5-rGO sample is a promising electrode for supercapacitor application.

Exploring low temperature-sputtered indium tin oxide (ITO) as an anti-reflection layer for silicon solar cells

Abstract This paper tackles challenges in silicon (Si) solar cells, specifically the use of hazardous Phosphorus Oxychloride (POCl3) for emitter formation and silane/ammonia for the Anti-Reflective Coating (ARC) layer, accompanied by high-temperature metallization. The study proposes an eco-friendly ARC layer process, replacing toxic materials. Indium Tin Oxide (ITO) with a refractive index of ∼2.0 is suggested as a non-toxic substitute for SiN x in the ARC layer. ITO enables fine-tuning of optical parameters and, with its electrical properties, supports low-resistivity contacts through efficient, low-temperature metallization processes. ITO-passivated solar cells with Ag polymer paste as a front contact exhibit promising characteristics: a commendable photocurrent density (J sc) of 20 mA cm−2 at 850 °C, low series resistance (R s) of 1.9 Ω, and high shunt resistance (R shunt) of 28.9 Ω, as demonstrated by illuminated I–V measurements. Implementing ITO as the ARC on a less toxic emitter junction enhances Si solar cells’ current density gain, minimizing current leakage during high-temperature processing. In conclusion, adopting less toxic materials and employing low-temperature processing in passive silicon solar cell fabrication presents an attractive alternative for cost reduction and contributes to environmentally sustainable practices in green manufacturing.

Comprehensive analysis of the performance of a microfluidic photoelectrochemical solar cell with heat exchanger

A dye-sensitized solar cell (DSSC) is a type of photoelectrochemical cell that converts sunlight directly into electricity using a photoanode with a dye-sensitized, nonporous semiconductor layer. This study investigates the impact of integrating microfluidic capabilities into DSSCs, resulting in a flow-cell configuration that introduces new electrical characteristics without compromising its performance. The primary goal of the work was to define and determine the values of heat, mass, and charge transport resistances, and to explore their relationships with the cell’s current–voltage characteristics, temperature, light intensity, and spectra. We employed both experimental methods and computational fluid dynamics using the Lattice-Boltzmann solver to analyze the cell’s dynamics. A novel multilayered microfluidic DSSC (µDSSC) was designed, featuring an innovative “gapless” configuration with a photoactive surface area exceeding 7 cm2, integrated directly with a microfluidic heat exchanger. This configuration allowed the µDSSC to achieve a power conversion efficiency (PCE) of at least 6 % under standard test conditions, with a fill factor reaching up to 68 %. By gradually covering the cell surface, the impact of series resistance (Rs) on PCE was minimized, enabling a maximum PCE of 19–22 %. A new integral definition of the fill factor (IFF) was proposed, which accurately describes the performance of cells constrained by ion mass transport resistance. For the gapless µDSSC, the IFF ranged from 58 % to 88 %. Additionally, we introduced a maximum cell efficiency (MCE) parameter to represent the cell’s efficiency at the theoretical limit of Rs = 0, determined to be 20.7 % for the gapless µDSSC. This MCE value is specific to the cell and is independent of the illuminated surface area and incident light intensity. The thermal efficiency of µDSSC cells is generally limited by heat conduction through the multilayer structure, but at practical cell surface temperatures of 50–80 °C, this limitation is 3 to 6 times less significant than the limitation imposed by the maximum solar energy flux reaching the cell surface. The integration of microchannels into the cell led to a 58 % reduction in hydraulic resistance along the main flow direction. While electrolyte flow typically reduces efficiency in wide-gap DSSCs, the gapless configuration minimizes mass transport resistance, ensuring that fluid flow does not adversely affect the performance of gapless µDSSCs.

Comparative Analysis of 50 MeV Li3+ and 100 MeV O7+ Ion Beam Induced Electrical Modifications in Silicon Photodetectors

This article investigates the impact of 100 MeV O7+ and 50 MeV Li3+ ions on Silicon Photodetectors, focusing on their electrical characteristics with similar Sn/Se ratios. Elevated ion fluences led to a significant rise in the ideality factor “n”, indicating the presence of Generation-Recombination (G-R) current due to introduced defects, especially those with deep energy levels in the forbidden gap acting as G-R centers. While Ideality factor (n) values decreased for oxygen ions at maximum fluence, they increased for lithium ions, reflecting consistent patterns in series resistance (Rs) and reverse leakage current (IR), attributed to ion-induced defects. Oxygen ions showed a monotonic variation in Rs, whereas lithium ions exhibited a slight reduction at maximum fluence, possibly due to defect annihilation. Despite differing Se values, 50 MeV Li3+ ions demonstrated improved device characteristics, suggesting potential defect annihilation. The ratio of Sn to Se indicated comparable damage contributions from nuclear and electronic energy. Additionally, TRIM computations revealed non-uniform damage distributions, with ions penetrating deep into the substrate, away from the n+/p junction.