Short-circuit Research Articles

Coordinated optimization method of renewable energy sources and energy storage devices based on synergistic capacity short circuit ratio

The traditional short circuit ratio index does not consider the impact of energy storage devices (ESDs) and cannot be used for the collaborative optimization of ESDs and renewable energy sources (RESs). Therefore, this paper proposes a novel synergistic capacity short circuit ratio (SCSCR) index, which can reflect the interaction between multiple RESs and ESDs on each bus under different capacities. Based on the proposed SCSCR, a coordinated optimization method of RESs and ESDs is proposed. It ensures system strength while determining the optimal location and capacity proportion of RESs and ESDs. Firstly, the location and capacity proportion of RESs are obtained through optimization method because the system strength is mainly determined by RESs connection points. Secondly, the optimal location and capacity proportion of the ESDs are found under the optimal configuration of the RESs. The proposed optimization method ensures the system strength while obtaining the optimal location and optimal capacity proportion of RESs and ESDs. Finally, the simulation results verify the effectiveness of this method on the IEEE 9 bus and 39 bus systems, providing reference for the site selection and efficient operation of RESs and ESDs.

Heat transfer performance analysis of medium - deep coaxial borehole heat exchanger (CBHE): combination of heat extraction operation test and numerical simulation

Abstract Geothermal energy is a clean and renewable energy source that can effectively reduce carbon emissions. Coaxial borehole heat exchanger (CBHE) is a crucial component of the geothermal mining system. To understand the heat transfer mechanism of a CBHE and to design its construction, this paper analyzes the geotechnical thermal response characteristics of CBHE under constant power conditions. COMSOL was used to simulate the performance of the heat exchanger during intermittent operation in both summer and winter. The results indicate that the inlet water temperature and the thermal conductivity of the grouting material have a weak impact on the energy efficiency coefficient of the heat exchanger. The energy efficiency coefficient can increase by about 22% when the inner pipe's thermal conductivity is lower. The temperature difference between the medium flowing into the inner pipe at the bottom of a shallow cased buried pipe and the medium flowing out of the inner pipe defines the thermal short circuit value. The influence on the thermal short circuit value is on the order of the inner pipe thermal conductivity, grouting material thermal conductivity, and the inlet water temperature. The fluctuation of soil temperature in the summer is greater than that in the winter, the soil temperature of shallow-buried pipes is easier to recover in the winter. The characteristic law obtained in this paper provides a valuable reference for the scientific design of CBHE.

A Fault Diagnosis Method for Pumped Storage Unit Stator Based on Improved STFT-SVDD Hybrid Algorithm

Stator faults are one of the common issues in pumped storage generators, significantly impacting their performance and safety. To ensure the safe and stable operation of pumped storage generators, a stator fault diagnosis method based on an improved short-time Fourier transform (STFT)-support vector data description (SVDD) hybrid algorithm is proposed. This method establishes a fault model for inter-turn short circuits in the stator windings of pumped storage generators and analyzes the electrical and magnetic states associated with such faults. Based on the three-phase current signals observed during an inter-turn short circuit fault in the stator windings, the three-phase currents are first converted into two-phase currents using the principle of equal magnetic potential. Then, the STFT is applied to transform the time-domain signals of the stator’s two-phase currents into frequency-domain signals, and the resulting fault current spectrum is input into the improved SVDD network for processing. This ultimately outputs the diagnosis result for inter-turn short circuit faults in the stator windings of the pumped storage generator. Experimental results demonstrate that this method can effectively distinguish between normal and faulty states in pumped storage generators, enabling the diagnosis of inter-turn short circuit faults in stator windings with low cross-entropy loss. Through analysis, under small data sample conditions, the accuracy of the proposed method in this paper can be improved by up to 7.2%. In the presence of strong noise interference, the fault diagnosis accuracy of the proposed method remains above 90%, and compared to conventional methods, the fault diagnosis accuracy can be improved by up to 6.9%. This demonstrates that the proposed method possesses excellent noise robustness and small sample learning ability, making it effective in complex, dynamic, and noisy environments.

Degradation Mechanism and Online Electrical Monitoring Techniques of Stator Winding Insulation in Inverter-Fed Machines: A Review

Inverter-fed machines are widely used in electric vehicle drive systems and have shown a trend toward high voltage and frequency in recent years. They are subjected to multiple types of stress during operation, causing potential short-circuit fault damage to the stator winding insulation. Online condition monitoring of the insulation before or in the early stage of the short circuit fault can effectively reduce maintenance costs and ensure its health. This paper reviews and summarizes the deterioration mechanism and the recent online electrical monitoring techniques. First, four types of failure stress and each type’s failure factors and mechanisms are analyzed. The coupling effect and overall process of multi-physical fields on stator insulation failure are considered. Secondly, the latest online electrical monitoring technologies are summarized. Each technique’s principles, methods, advantages, and disadvantages are analyzed. Finally, existing problems and possible directions for improvement in current research are discussed, focusing on their feasibility and accuracy in practical applications.

Phthalocyanine and metal phthalocyanine are hole transport buffer layers for perovskite solar cell fabrication

This approach allows you to more accurately evaluate the performance of solar panels and identify any prob- lems or degradation in their operation. The LUMO value of mPc closer to the LUMO value of CH3NH3I3PbClx increased conversion energy and short circuit current density (Jsc), which reached a maxi- mum value of 15.97 mA/cm² using the HTL layer of CuPc, and the open circuit voltage (Voc) reached a max- imum at 0.97 V. The change in Jsc corresponds to the fill factor (FF) change. The filling factor (FF) reached a maximum value of 67.35 % when using the HTL layer of CuPc and a minimum value (FF) of 54.23 % when using the HTL layer of H2Pc. The lowest series resistance (R1) and interface resistance (R3) of 11.2 and 39.9 Ohms, respectively, were shown with the HTL layer of CuPc, Capacitive element CPE1 — 305 pF, Ca- pacitive element CPE2 — 0.95 pF. CPE (Constant Phase Element) is an element used in equivalent circuits to describe the non-ideal dielectric properties of materials. The decrease in CPE1 may indicate a decrease in the heterogeneity of the dielectric properties of the perovskite material after coating with different HTL mPc lay- ers. This may be due to changes in structure or mutual actions between layers as a result of exposure to dif- ferences in energy levels.

Supramolecular polymer cross-linking gel electrolyte for highly stable quasi-solid-state lithium metal batteries

Lithium (Li) metal batteries have the advantage of high energy density, but the Li dendrites risk piercing the separator and causing a short circuit in the battery. Replacing the liquid electrolytes with gel electrolytes is considered an effective strategy to solve the issues. Herein, a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based gel electrolyte, improved with multifunctional supramolecular polymer (MSP), was prepared to enhance the cycling stability and energy density of quasi-solid-state Li metal batteries. The MSP addictive constructs a cross-linked network structure with PVDF-HFP matrix and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) through hydrogen bonding, improving the mechanical strength of the composite gel electrolyte (PH-10%MSP-GE) to against the growth of Li dendrites. Moreover, the pre-lithiated sulfonic acid groups, conductive polyether groups of MSP, and the attraction of TFSI– anions, promote the Li-ion transportation of the composite gel electrolyte. Finally, the Li||Li symmetric cell cycle stably for over 450 h. The Li||LiFePO4 full cell demonstrates a high energy density and excellent cycling stability for over 600 cycles, with a capacity retention rate of up to 98.7%. This work provides valuable insights into the preparation of multifunctional composite gel polymer electrolytes and competitive quasi-solid-state Li metal batteries.

Thermal runaway prevention through scalable fabrication of safety reinforced layer in practical Li-ion batteries

Integrating safety features to cut off excessive current during accidental internal short circuits in Li-ion batteries (LIBs) can reduce the risk of thermal runaway. However, making this concept practical requires overcoming challenges in both material development and scalable manufacturing. Here, we demonstrate the roll-to-roll production of a safety reinforced layer (SRL) on current collectors at a rate of 5 km per day. The SRL, made of molecularly engineered polythiophene (PTh) and carbon additives, interrupts current flow during voltage drops or overheating without adversely affecting battery performance. Impact testing on 3.4-Ah pouch cells shows that the SRL reduces battery explosions from 63% to 10%. This work underscores the potential of integrating material science with manufacturing technology to enhance battery safety.

Study of the State Primary Measurement Standard of the Unit of Phase Shift Angle Between Two Voltages

Phase measurements are necessary for determining main parameters of the oscillatory process in complex electrical networks. Most often, it is precisely the phase shift angle (PSA) between two oscillatory processes of the same frequency that is measured. An essential indicator of the quality of electrical energy is the coefficient of asymmetry in a three-phase electrical network, which depends on the load of consumers in this network. This indicator is affected by a short circuit between two phase voltages. Phase measurement standards, phase meters, and phase converters are included in the measuring equipment for phase measurements. They are widely used in such fields as radiolocation, radio navigation, non-destructive testing, radio engineering, telecommunications, acoustics, metallurgy, machine and aircraft industry, space industry, as well as in scientific research and defence. The State Measurement Standard of Ukraine of the PSA unit between two voltages in the frequency range from 0.01 Hz to 10 MHz is maintained at the State Enterprise “UKRMETRTESTSTANDARD”, Kyiv. It provides metrological traceability of phases measured in the country. The main components of the standard were calibrated at the PTB, the National Metrology Institute of Germany. In Ukraine, numerous measurement standards and measurement instruments for phase measurements (more than 500.000 units) are used, in particular, phase calibrators, phase meters, phase shifters, synchronoscopes etc. Regular study of metrological characteristics of the DETU 09-07-11 measurement standard is conducted both in the main (from 5 Hz to 200 kHz) and in the extended (from 0.01 Hz to 10 MHz) frequency range. The PSA values obtained as a result of the research in the main frequency range do not exceed 0.001° (which is maximum according to measurements at all calibration points 0.00015°), and in the extended frequency range – 0.01° (which is maximum according to measurements at all calibration points 0.0053°). To eliminate the systematic measurement uncertainty component of the phase measurement standard, a special calibration is regularly performed using a set of resistive and capacitive phase bridges.

Self-powered temperature-changing system driven by wind energy

Research on outdoor, mobile, and self-powered temperature-control devices has always been highly regarded. These devices can reduce energy consumption for cooling and heating, and they have broad market prospects. On this basis, a rotary disc-shaped triboelectric nanogenerator (TENG) with a maximum open-circuit voltage of 6913 V, a maximum short-circuit current of 85 μA, and a maximum transferred charge of 1.3 μC was prepared. We synthesized a ferroelectric ceramic composed of 0.15PbTiO3–0.85PbSc0.5Ta0.5O3 (0.15PT–0.85PST), which exhibited excellent electrothermal effects at room temperature. By quenching, the electrothermal effect (Δ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta$$\\end{document}Tmax) and energy harvesting properties of the device were 1.574 K and 0.542 J/cm3, respectively. Then, for the first time, we proposed a self-powered temperature quantification control system with a rotary disc-shaped TENG. This device effectively harnessed wind and water energy, in addition to other types of energy. The system consisted of energy collecting cups, a rotating disc-shaped FEP–rabbit fur TENG, a circuit management module, and a ferroelectric ceramic chip array. Through the circuit management module, the system converted external wind energy into a high-voltage electric field at the two ends of the 0.15PT–0.85PST ceramic chip to fully stimulate the electrothermal effect. At a speed of 200 rpm, the temperature change in the insulated cup within 276 s was 0.49 K, and the volume of the insulated cup was 300 times greater than that of the 0.15PT–0.85PST ceramic chip. Compared with the results reported in previous work, the cooling and heating times were both reduced by 31%, and the temperature changes for both cooling and heating increased by 81%. Moreover, the heating and cooling temperatures of the device optimized on this basis were increased to 1.19 K and 0.93 K, respectively. The great improvement in the temperature variation performance confirmed the great potential of the device for commercialization. This research could serve as a reference for reducing energy consumption for cooling and heating, and it meets the international energy policies of carbon dioxide emission peaking and carbon neutrality.

Triboelectric Nanogenerators Based on Transition Metal Carbo-Chalcogenide (Nb2S2C and Ta2S2C) for Energy Harvesting and Self-Powered Sensing.

With burgeoning considerations over energy issues and carbon emissions, energy harvesting devices such as triboelectric nanogenerators (TENGs) are developed to provide renewable and sustainable power. Enhancing electric output and other properties of TENGs during operation is the focus of research. Herein, two species (Nb2S2C and Ta2S2C) of a new family of 2D materials, Transition Metal Carbo-Chalcogenides (TMCCs), are first employed to develop TENGs with doping into Polydimethylsiloxane (PDMS). Compared with control samples, these two TMCC-based TENGs exhibit higher electric properties owing to the enhanced permittivity of PDMS composite, and the best performance is achieved at a concentration of 3wt. ‰ with open circuit voltage (Voc) of 112V, short circuit current (Isc) of 8.6µA and charge transfer (Qsc) of 175nC for Nb2S2C based TENG, and Voc of 127V, Isc of 9.6µA, and Qsc of 230nC for Ta2S2C based TENGs. These two TENGs show a maximum power density of 1360 and 911mWm-2 respectively. Moreover, the tribology performance is also evaluated with the same materials, revealing that the Ta2S2C/PDMS composite as the electronegative material presented a lower coefficient of friction (COF) than the Nb2S2C/PDMS composite. Their applications for energy harvesting and self-powered sensing are also demonstrated.

Boosting efficiency in dual-absorber RbPbBr3 perovskite solar cell: the role of two-dimensional GeS and SnS2 as electron transport layers

This paper presents a comprehensive investigation into the electrical characteristics of a perovskite solar cell. The n-i-p cell is based on a low band gap rubidium–lead-bromide (RbPbBr3) perovskite with an energy level of 1.31 eV. The study also evaluates the impact of high mobility two-dimensional GeS and SnS2 as electron transport layers (ETLs) on the cell’s performance. These ETLs have a wide band gap and provide a hole blocking layer due to their high valence band-offset. Additionally, a thin film MoTe2 with a band gap of 1 eV is considered as a complementary absorber for capturing near-infrared solar spectrum. The investigation focuses on the influence of critical physical and structural design parameters on the electrical parameters of the cell. The optimized device with SnS2 as the ETL exhibits a power conversion efficiency (PCE) of 25.03%, an open circuit voltage of 0.95 V, a short circuit current density of 33 mA cm−2, and a fill factor of 80.31%. Similarly, the device with GeS as the ETL achieves a PCE of 25.14%, an open circuit voltage of 0.96 V, a short circuit current density of 33.01 mA cm−2, and a fill factor of 80.66%. Furthermore, a statistical analysis is conducted by calculating the coefficient of variation to assess the sensitivity of the cell’s electrical measures to the variation of design parameters and operating temperature. The results highlight that defects in the absorber layer, work function of the back contact, and ambient temperature are critical design parameters that can significantly impact the device performance. Overall, the utilization of high mobility wide band gap ETLs, in combination with the low band gap perovskite, offers a promising approach for the design of high-performance solar cells.

Visualization of stepwise electrode decomposition in a nail penetrated commercial lithium-ion cell using low-temperature synchrotron X-ray computed tomography

The transition towards zero carbon emissions in power generation hinges on the integration of efficient electrical energy storage systems, with lithium-ion batteries (LIBs) positioned as a pivotal technology. While generally safe, deviations in their operational guidelines due to manufacturing defects or misuse can lead to critical safety concerns, notably thermal runaway (TR) events. Internal short circuits (ISCs) are primary initiators of TR within LIBs. For abuse testing, ISCs are often triggered by nail penetration. This study explores the morphological changes and mechanisms underlying ISC-induced TR in LIBs using operando synchrotron X-ray computed tomography (SXCT) at subzero temperatures. A novel cryogenic setup was developed to control a stepwise temperature increase in the damaged sample while monitoring electrochemical characteristics and simultaneously enabling acquisition of high-resolution SXCT images. The findings reveal that conducting nail penetration at minus 80 °C prevents immediate TR, enabling detailed analysis of subsequent structural and electrochemical behavior during controlled thawing. Thus, the initiation of TR processes at localized ISC sites has been observed, evidenced by voltage fluctuations and morphological changes, such as cathode material cracking and decomposition. These results underscore the importance of temperature control in mitigating TR risks and provide critical insights into the internal dynamics of LIBs under abusive conditions. The developed cryogenic SXCT methodology offers a powerful tool for non-destructive, high-resolution investigation of battery failure mechanisms, contributing to the enhancement of LIB safety.

Parametric optimization for the performance analysis of novel hybrid organo-perovskite solar cell via SCAPS-1D simulation

The perovskite and organic solar cells are becoming the most cognizant of the photovoltaic communities. The Spiro-OMeTAD organic hole transport layer (HTL) shows a significant impact on the CH3NH3SnI3 perovskite solar cell (PSC) with TiO2 as the electron transport layer (ETL). So, we optimized the physical and electrical parameters of the organic HTL. Electrical optimization shows that the power conversion efficiency (PCE) of the cell can reach up to 18.10% for the electron affinity of the organic HTL material of about 2.5eV. Further, the interpretation of the practical scale of series and shunt resistance reveals the maximum PCE of the cell as 13.30% at 0.5Ωcm2 and 1×106Ωcm2 respectively. Also, the performance of the cell is analyzed for the hole mobility of the organic HTL material, which revealed the best PCE of the cell to 13.31%. Moreover, the physical parameters are also optimized for the cell performance with illumination intensities which pointed out that the performance of the novel organic HTL perovskite solar cell is optimum for illumination intensity around 0.5Sun (500Wm-2). Finally, the overall light harnessing efficiency or PCE of the proposed solar cell is declared to be 13.30%, and the other performance parameters as open circuit voltage (Voc), short circuit current (Jsc), and fill factor (FF) are 0.764V, 25.86mAcm−2 and 67.29%, respectively.

Numerical simulations of novel multi- chalcogenide CuAgBeSnSe4 based thin film solar cell with over 24% efficiency using SCAPS-1D

Abstract For solar cell applications, the multi-chalcogenide CuAgBeSnSe4 (CABTSe) shows promise as a potential absorbing material. In this study, numerical simulations were conducted for the ITO/CABTSe/Ag2S/Au structure, which was screened from a group of 50 CABTSe-based thin film solar cells (TFSCs) using the SCAPS-1D code. We explored the influence of various parameters such as thickness, doping concentration, defect density, mobility, and electron affinity on the photovoltaic performance of the screened device. Under optimized parameters, the open circuit voltage, short circuit current, filling factor, and efficiency of the photovoltaic device were 1.099 V, 25.5 mA/cm2, 86.48%, and 24.24%, respectively. This study provides an effective approach for using CABTSe-based TFSCs as a replacement for traditional Cu2ZnSn(S,Se)4-based TFSCs.

Tracing Root Causes of Electric Vehicle Fires

As electric vehicles (EVs) emerge as the backbone of modern transportation, the concurrent uptick in battery fire incidents presents a disconcerting challenge. To tackle this issue effectively, it is imperative to pierce beyond the superficial causes of lithium‐ion battery (LIB) failures—such as equipment malfunctions or physical damage—and to excavate the underlying triggers. This nuanced approach is pivotal to refining EV quality, diminishing fire incidents, and bolstering consumer trust. While issues that are readily apparent to consumers, like spontaneous battery degradation, vehicular collisions, or submersion, may seem like the primary culprits, they merely scratch the surface of a more complex problem. The true mechanisms behind these fires involve internal and external short circuits, yet these explanations fall short in providing actionable guidance for manufacturers or end‐users to enhance LIB safety. The heart of the issue is identifying the root causes that bridge failure triggers and resulting fires. A total of 20 root causes are identified, linking them to real‐world scenarios like overcharging causing internal shorts or wire harness issues leading to external shorts. With this insight, stakeholders can more effectively investigate and understand EV LIB fire incidents, bolstering EV safety and reliability, and promoting consumer confidence.

Elastomeric Sensor-Triboelectric Nanogenerator Coupled System for Multimodal Strain Sensing and Organic Vapor Detection.

Stretchable, flexible sensors are one of the most critical components of smart wearable electronics and Internet of Things (IoT), thereby attracting multipronged research interest in the last decades. Following miniaturization and multicomponent development of several sensors in one could further propel the demand for wireless, multimodal platforms. Greener substitutes to conventional sensors that can operate in a self-powered configuration are highly desirable in terms of all-in-one sensor utilities. However, fabrication of composite-based ultrastretchable, self-powered sensors with multifunctionality, robustness, and conformability is still only partially achieved and, therefore, demands further investigation. In this work, we report a triboelectric nanogenerator (TENG)-based multifunctional strain and organic vapor sensor using cross-linked ethylene propylene diene monomer (EPDM) elastomer and conducting carbon black as active fillers in the presence of an ionic liquid. The resulting piezoresistive sensor demonstrates ultrahigh gauge factor (GF > 220k) and wide range strain sensitivity and is, therefore, suitable for subtle-to-high frequency motion detection devices. Supported by excellent triboelectric outputs (force sensitivity 0.5 V/N in the range of 50-300 N, maximum output voltage VOC ∼ 178 V, short circuit current ISC ∼ 18 μA, maximum power density 0.11 mW/cm2), the hybrid sensors offer remarkable mechanical toughness and seamless voltage generation under contact-separation, even after several thousand cycles of operations. Furthermore, the sensor substrates exhibited reproducible organic vapor-sensing behavior, with high responsivity of 1.92 and 1 for ethanol and acetone, respectively, under flowing vapor conditions. This work lays a strong foundation for developing a truly multimodal, TENG-based, self-powered organic vapor and strain sensors.

Scaling Behavior in the Spectral and Power Density Dependent Photovoltaic Response of Hot Polaronic Heterojunctions

AbstractStrongly correlated manganites can be considered as model systems for the study of photovoltaic harvesting of hot polarons that can be excited from the electronically ordered ground state. In order to gain basic understanding of hot polaron harvesting, the deviations of the photovoltaic response of a heterojunction with polaronic absorber from a conventional semiconductor are analyzed. Specifically, the spectral and photon power density dependence of the open circuit voltage Uoc and the short circuit current density Jsc in heterojunctions consisting of orbital ordered Pr1‐xCaxMnO3 (x = 0.1, PCMO) thin films epitaxially grown on single crystalline (100) SrTiO3 (STO) and Nb‐doped (100) SrTiO3 (STNO) substrates are investigated. The observed behavior is fundamentally different from conventional solar cells, in which Uoc is limited by fast carrier relaxation to the band edges. Whereas the spectral and photon power dependence of Uoc of conventional semiconductor junctions is well described by the Shockley‐Queisser (SQ) theory, the hot polaron junctions surprisingly show a scaling law behavior of Uoc. Such scaling laws otherwise apply to equilibrium order parameters in second‐order phase transitions. It is concluded that its physical origin is the unique dependence of the quasi‐Fermi level splitting on temperature, photon energy, and power density in a hot polaron system.

Performance analysis and optimization of SnSe thin-film solar cell with Cu2O HTL through a combination of SCAPS-1D and machine learning approaches

Tin selenide (SnSe) is an auspicious light-harvesting material in photovoltaic (PV) technology due to its larger absorption coefficients and earth-abundance nature. However, because of the potential difficulty of defect-free fabrication, and non-optimized electron transport layer (ETL) and hole transport layer (HTL) alignment, it could no longer achieve its realistic objectives. Therefore, designing a suitable SnSe-based PV device with an appropriate ETL and HTL is crucial to achieving optimum performance. In this research, we proposed a novel heterojunction thin-film solar cell (TFSC) configuration of Ni/Cu2O/SnSe/WS2/FTO/Al and simulated its PV performance metrics using SCAPS-1D solar cell simulation software. This research additionally provided a comparative performance analysis of the SnSe TFSC with numerous ETLs and HTLs. It is evident that the suggested TFSC with WS2 ETL and Cu2O HTL creates appropriate band alignment with the SnSe light harvesting layer, which reduces charge recombination at both the ETL/absorber and absorber/HTL interfaces. Here, the impact of absorber layer thickness, doping concentration, bulk defect density, and defect density at the ETL/absorber and absorber/HTL interfaces is investigated. Besides, the impact of radiative recombination, back contact metal work function, and working temperature are carefully examined. After optimization of all the material properties, a maximum efficiency of 29.31 % with open circuit voltage (Voc) of 0.89 V, short circuit current density (Jsc) of 38.23 mA/cm2, and fill-factor (FF) of 86.30 % were attained for the SnSe-based proposed structure. Furthermore, a supervised linear regression machine learning algorithm is employed to investigate how the behavior of the material attributes affects the solar cell's designed PV performance. Overall, our findings can be helpful to experimentalists to fabricate inexpensive, highly efficient, and Cd-free SnSe-based heterostructure solar cells in the near future.

Examining three distinct rheological models with flexoelectric effect to investigate Love‐type wave velocity in bedded piezo‐structure

AbstractThe transference of the surface seismic wave at the loosely bonded common interface of a visco‐piezo composite structure is examined in the current work. With the flexoelectric effect taken into account, the structure is composed of a viscoelastic layer embedded on a piezoelectric substrate. The shear stiffness of the upper layer is thought to be described by a Kelvin–Voigt model. An analytical separable of variable method is used to derive the complex dispersion relation for both electrically open and short circuit scenarios. A numerical example is presented to demonstrate the significant influence of several influencing parameters on the wave's phase velocities and attenuation coefficients. Additionally, a graphic comparison of three rheological models – the Maxwell, Newton and Kelvin–Voigt models – is covered. Results indicate that the attenuation curve pertaining to the Maxwell and Newton model is lowest than on the Kelvin–Voigt model. Some major outcomes are highlighted here as: the prominent influence of bonding parameter is well‐proportional to the phase velocity and inversely proportional to the attenuation coefficient, and flexoelectricity has an intensive impact on both phase velocity and attenuation coefficient curves. This theoretical study leads to understanding the piezo‐flexo coupling and its potential application to design the sensors, actuators, energy harvesters and nano‐electronics.

Optimizing sensitizer concentration from senna tora leaves for enhanced interfacial interactions in dye-sensitized solar cells

A novel approach is adopted for the determination of the optimum concentration of natural dye powder extracted from the leaves of Senna Tora in the solvent ethanol and soak the TiO2 coated FTO substrate to be used as photoanode of dye sensitized solar cell (DSSC). Various concentration (0.5 g/15 ml, 0.75 g/15 ml, 1 g/15 ml and 1.5 g/15 ml) of the dye powder in ethanol is subjected for UV–Visible, FTIR and PL Spectroscopic studies. Solar cells are fabricated with the sensitizer in Photoanode, I-/I3- electrolyte and counter electrode of graphite coated FTO are subjected for JV characterization to determine the best concentration of dye to give good photoconversion efficiency. From the study, it is found that, among the four concentrations of the dye in ethanol for the extraction of the dye, 1.5 g in 15 ml of ethanol has shown higher efficiency of 2.29 % with fill factor, short circuit current density and open circuit voltage of 0.84, 2.64 mA/cm2 and 1.03 V.