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Unmanned aerial vehicles (UAVs) nowadays are getting soaring importance in many aspects like agricultural and military fields. A hybrid power system is a promising solution toward high energy density and power density demands for UAVs as it integrates power sources like internal combustion engine (ICE), fuel cell (FC) and lowcapacity lithium-polymer (LIPO) batteries. For robust energy management, accurate state-of-charge (SOC) estimation is indispensable, which necessitates open circuit voltage (OCV) determination and parameter identification of battery. The presented research demonstrates the feasibility of carrying out incremental OCV test and even dynamic stress test (DST) by making use of the hybrid powered UAV system itself. Based on battery relaxation terminal voltage as well as current wave excitation, novel methods for OCV determination and parameter identification are proposed. Results of SOC estimation against DST through adaptive unscented Kalman filter (AUKF) algorithm show that parameters and OCV identified with longer relaxation time don't yield better SOC estimation accuracy. Besides, it also discloses that OCV played the vital role in affecting SOC estimation accuracy. A detailed analysis is presented showing that mean discharging rate and current wave amplitude are the major factors which affect the quality of OCV identified related to SOC estimation accuracy. [ABSTRACT FROM AUTHOR]

The current study presents six D-π-A configured non-fullerene acceptor chromophores (BTI1-BTI6) derived from benzotriindole compound end-capped with hexyldicyanovinyl groups, referred to as BTI (2 T-DCV-Hex)3, through structural tailoring of different terminal acceptors. Optoelectronic characteristics of newly designed chromophores were determined via DFT study at B3LYP/6-31G (d,p) functional. Various analyses such as frontier molecular orbitals, density of states (DOS), transition density matrix (TDM), binding energy (Eb), and open circuit voltage (Voc) were conducted. All the derivatives exhibited a comparable band gap (2.45–2.70 eV) manifesting absorption bands in the UV-Visible spectrum (590–463 nm), in solvent as well as in gaseous phase. Interestingly, smaller Eb values of 0.170 and -0.099 eV were observed for BTI5 and BTI6, respectively, suggesting a greater degree of charge transfer and improved exciton dissociation in these derivatives. These findings are further supported by TDM and DOS analyses, which confirm that all the studied compounds exhibit a higher charge transfer rate from highest occupied orbital to lowest unoccupied orbital (HOMO to LUMO). In conclusion, the good photovoltaic response observed for all the compounds suggests that these chromophores are reasonable candidates for development of efficient organic solar cells. [ABSTRACT FROM AUTHOR]

In recent years, we have witnessed significant advancements in the production of solar cells with a reduction in cost and an increase in their efficiency. One of the stages in creating advancements in new cells is evaluating their performance under different conditions using simulations before their fabrication. In this article, the structure of a multi-junction solar cell composed of Ge layers, InAlGaAs alloys, and InAlGaP alloys will be comprehensively examined. To achieve the highest efficiency, the lowest absorbing layer of the solar cell (Ge solar cell) will initially be optically simulated and then electrically simulated. After optimizing the Ge solar cell, the intermediate layers between the cells (tunnel junctions) and then the upper absorbing layers will be optimized in sequence. Optimization of solar cells in each absorbing layer refers to selecting the appropriate thickness, impurity density, and molar percentage of the layers to achieve the highest efficiency. According to simulation results, an efficiency of over 49% has been achieved for the 5-junction cell. [ABSTRACT FROM AUTHOR]

Currently, polycyclic aromatic compounds in organic solar cells (OSCs) have gained substantial consideration in research communities due to their promising characteristics. Herein, polycyclic aromatic hydrocarbons (PAHs) core-based chromophores (TTFD1-TTFD6) were designed by structural modifications of peripheral acceptor groups into TTFR. The density functional theory (DFT) and time dependent density functional theory (TD-DFT) calculations were carried out at B3LYP/6-311G (d, p) functional to explore insights for their structural, electronic, and photonic characteristics. The structural modulation unveiled notable electronic impact on the HOMO and LUMO levels across all derivatives, leading to decreased band gaps. All the designed compounds exhibited band gap ranging from 2.246 to 1.957 eV, along with wide absorption spectra of 897.071-492.274 nm. An elevated exciton dissociation rate was observed due to the lower binding energy values (Eb = 0.381 to 0.365 eV) calculated in the derivatives compared to the reference (Eb = 0.394 eV). Furthermore, data from the transition density matrix (TDM) and density of states (DOS) also corroborated the effective charge transfer process. Comparable results of Voc for reference and designed chromophores were obtained via HOMOdonor−LUMOPC71BM. The declining Voc order values was noted as TTFD5 > TTFD6 > TTFD4 > TTFD3 > TTFD2 > TTFD1 > TTFR. Interestingly, TTFD5 was found with the smallest energy gap and highest absorption value, resulting in better charge transference among all the derivatives. The results illustrated that the modification in indenofluorene based chromophores with end-capped small acceptors proved to be a significant approach in achieving favorable photovoltaic properties. [ABSTRACT FROM AUTHOR]

A photodiode based on zinc oxide is fabricated using a direct current DC sputtering system. The effect of the nitrogen (N) ratio to argon (Ar) on photoelectrical properties is investigated via current-voltage characteristics. The nitrogen is varied within the 0–100 cm3 range, while the argon is maintained constant during the deposition process. The Au/ZnO:N/nSi/Au photodiode exhibited a high rectification factor around 105. According to high obtained value of ideality factor n ~3 a non-ideal behavior of Au/ZnO:N/nSi/Au photodiode is revealed. Saturation current (Is) and barrier height (φB) are found to be around 1 nA and 0.84 eV, respectively. Besides, the series resistance of 100 Ω is calculated by Cheung method. The Au/ZnO:N/nSi/Au heterostructure exhibited a high photosensitivity of 104. The sputtered as-grown ZnO films on glass are characterized by SEM and EDX facilities. The grain sizes are found to be around 24 nm. [ABSTRACT FROM AUTHOR]

This study reports the room temperature testing of an InGaAs/InP photodetector, biased under linear sweep and/or parametric bias voltage for both modulated, and unmodulated 1550 nm wavelength illuminations. Charge transport of the photo-generated carriers is probed under absorber's electric field manipulations via parametric control of applied bias, readout element, and light intensity. The device exhibits three different illumination intensity dependent current signatures. Speed of the employed device is enhanced under relatively stronger electric fields ensuring higher drift, and reduced transit times. A three order reduction in the gain setting of the readout element results in ∼ 235 times large peak-current under 20 times smaller pulsed illumination of 0.2 μ W . This electric field enhancement decreases rise, and fall times under pulsed illumination from 225 ns to 115 ns , and 1.553 μ s to 1.143 μ s , respectively. But, the large photodetection plausibility, and reduced transit times ensuring relatively fast speed comes at the expense of ~ 5 order high noise activity in the device. It is also inferred that, overall noise spectrum of the device is not decided by simple generational processes in the absorber, but through the actual proportion of photo-generated carriers taking part in the real charge transport. [ABSTRACT FROM AUTHOR]

Metal halide perovskites are promising light absorbers for multijunction photovoltaic applications because of their remarkable bandgap tunability, achieved through compositional mixing on the halide site. However, poor energy‐level alignment at the interface between wide‐bandgap mixed‐halide perovskites and charge‐extraction layers still causes significant losses in solar‐cell performance. Here, the origin of such losses is investigated, focusing on the energy‐level misalignment between the valence band maximum and the highest occupied molecular orbital (HOMO) for a commonly employed combination, FA0.83Cs0.17Pb(I1‐xBrx)3 with bromide content x ranging from 0 to 1, and poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine] (PTAA). A combination of time‐resolved photoluminescence spectroscopy and numerical modeling of charge‐carrier dynamics reveals that open‐circuit voltage (VOC) losses associated with a rising energy‐level misalignment derive from increasing accumulation of holes in the HOMO of PTAA, which then subsequently recombine non‐radiatively across the interface via interfacial defects. Simulations assuming an ideal choice of hole‐transport material to pair with FA0.83Cs0.17Pb(I1‐xBrx)3 show that such VOC losses originating from energy‐level misalignment can be reduced by up to 70 mV. These findings highlight the urgent need for tailored charge‐extraction materials exhibiting improved energy‐level alignment with wide‐bandgap mixed‐halide perovskites to enable solar cells with improved power conversion efficiencies. [ABSTRACT FROM AUTHOR]

The discovery of novel electrode materials based on two-dimensional (2D) structures is critical for alkali metal-ion batteries. Herein, we performed first-principles computations to investigate functionalized MXenes, Mo2BT2 (T = O, S), which are also regarded as B-based MXenes, or named as MBenes, as potential anode materials for Li-ion batteries and beyond. The pristine and T-terminated Mo2BT2 (T = O, S) monolayers reveal metallic character with higher electronic conductivity and are thermodynamically stable with an intrinsic dipole moment. Both Mo2BO2 and Mo2BS2 monolayers exhibit high theoretical Li/Na/K storage capacity and low ion diffusion barriers. These findings suggest that functionalized Mo2BT2 (T = O, S) monolayers are promising for designing viable anode materials for high-performance alkali-ion batteries. [ABSTRACT FROM AUTHOR]

To improve the efficacy of organic solar cells (OSCs), novel small acceptor molecules (CTD1–CTD7) were designed by modification at the terminal acceptors of reference compound CTR. The optoelectronic properties of the investigated compounds (CTD1–CTD7) were accomplished by employing density functional theory (DFT) in combination with time-dependent density functional theory (TD-DFT). The M06 functional along with a 6-311G(d,p) basis set was utilized for calculating various parameters such as: frontier molecular orbitals (FMO), absorption maxima (λmax), binding energy (Eb), transition density matrix (TDM), density of states (DOS), and open circuit voltage (Voc) of entitled chromophores. A red shift in the absorption spectra of all designed chromophores (CTD1–CTD7) was observed as compared to CTR, accompanied by low excitation energy. Particularly, CTD4 was characterized by the highest λmax value of 685.791 nm and the lowest transition energy value of 1.801 eV which might be ascribed to the robust electron-withdrawing end-capped acceptor group. The observed reduced binding energy (Eb) was linked to an elevated rate of exciton dissociation and substantial charge transfer from central core in HOMO towards terminal acceptors in LUMO. These results were further supported by the outcomes from TDM and DOS analyses. Among all entitled chromophores, CTD4 exhibited bathochromic shift (685.791 nm), minimum HOMO/LUMO band gap of 2.347 eV with greater CT. Thus, it can be concluded that by employing molecular engineering with efficient acceptor moieties, the efficiency of photovoltaic materials could be improved. [ABSTRACT FROM AUTHOR]

Lead halide perovskites have revolutionized the field of optoelectronics (such as photovoltaics and light emitting diodes) demonstrating extraordinary material properties despite being formed at low temperatures. However, ion migration in the bulk or at the interfaces results in stability issues especially in devices where metal electrodes directly interface with the perovskite film. Utilizing the switchable photovoltaic phenomenon (SPV) in halide perovskites as a measure of ion migration and electrochemical reactions within them, Cs0.05MA0.15FA0.70PbI2.5Br0.5 triple cation perovskite, widely used in photovoltaics is evaluated. The various factors determining the SPV, including electric field magnitudes, type of metal contacts, Illumination conditions, and temperature is systematically measured. This study reveals the roles of electrode work functions and reactivities on ion migration and local electronic structure modulation. ITO electrodes demonstrated the highest open‐circuit voltage (Voc) about 0.85 V while Ag electrodes developed conductive filaments. However, the Voc distribution for Ti and Cr electrodes shows a more pronounced linear correlation with the poling electric field strength. Insights from this lateral design are directly relevant to transistor and memristor architectures and offer inputs into the design of perovskite‐based photovoltaic/optoelectronic devices. [ABSTRACT FROM AUTHOR]

This paper reports the fabrication and 60Co gamma radiation effects on the silicon heterojunction solar cells (SHJ). The SHJ solar cells were fabricated by using physical vapor deposition technique. An n-type Si wafer was used as a substrate. The intrinsic layer, hole selective layer and transparent conductive oxide were deposited above the substrate. A complete SHJ solar cell was fabricated in dimension of 1 × 1 cm2. The illuminated I–V characteristics of SHJ solar cell with A.M 1.5 are done using the solar simulator. The different electrical characteristics of solar cell such as short circuit current (Isc), open circuit voltage (Voc), fill factor (FF) and conversion efficiency (η) were studied. The fabricated SHJ solar cell displayed a conversion η of 9.09%, a Voc of 0.733 V, an Isc of 19.14 mA, and an FF of 64.74%. The fabricated SHJ solar cells are subjected to doses of 60Co gamma radiation ranging from 100 krad to 100 Mrad. As the gamma dose aincreased, the solar cell output parameters also reduced. FF decreased from 64.74 to 57.16%, and Voc decreased from 0.73 to 0.66 V. The Isc decreased to 7.825 from 19.14 mA. The η decreased from 9.09 to 2.98% for the fabricated silicon SHJ solar cell. [ABSTRACT FROM AUTHOR]

The field of organic solar cells has witnessed notable advancements in the past few years, mostly due to the development of novel materials for the active layer. The current investigations reveal the potential of nine previously unexplored molecules (TP1–TP9) designed by end group modification of TPT4F molecule. These molecules were investigated at MPW1PW91/6‐31G (d, p) with DFT and TD‐DFT approach to study the various photovoltaic and geometrical parameters. The results obtained through computations indicated improvement in the investigated parameters. The terminal group modification shifted the absorption maximum towards longer wavelength in the UV‐visible region. Highly conjugated modified acceptors reduced the band gap. The lower excitation energies increased the rate of charge transfer. The designed molecules showed improved excited state lifetime in comparison to the reference. The open circuit voltage was determined using the PTB7 polymer, which exhibited a noticeable improvement, especially in TP1 (1.70 eV), TP3 (1.75 eV), TP4 (1.68 eV), TP6 (1.85 eV), and TP7 (1.75 eV) when compared with reference (1.59 eV). Moreover, charge transfer investigations of designed molecules with PTB7 complex were performed by analyzing the concentration of charge transfer over molecular orbitals, that is, HOMO to LUMO. All of the preceding investigations targeted to achieve high‐efficiency organic cells reveal that the altered molecules can be considered effective candidates to tackle future energy problems. [ABSTRACT FROM AUTHOR]

Photoinduced intermolecular charge transfer (PICT) determines the voltage loss in bulk heterojunction (BHJ) organic photovoltaics (OPVs), and this voltage loss can be minimized by inducing efficient PICT, which requires energy‐state matching between the donor and acceptor at the BHJ interfaces. Thus, both geometrically and energetically accessible delocalized state matching at the hot energy level is crucial for achieving efficient PICT. In this study, an effective method for quantifying the hot state matching of OPVs was developed. The degree of energy‐state matching between the electron donor and acceptor at BHJ interfaces was quantified using a mismatching factor (MF) calculated from the modified optical density of the BHJ. Furthermore, the correlation between the open‐circuit voltage (Voc) of the OPV device and energy‐state matching at the BHJ interface was investigated using the calculated MF. The OPVs with small absolute MF values exhibited high Voc values. This result clearly indicates that the energy‐state matching between the donor and acceptor is crucial for achieving a high Voc in OPVs. Because the MF indicates the degree of energy‐state matching, which is a critical factor for suppressing energy loss, it can be used to estimate the Voc loss in OPVs. [ABSTRACT FROM AUTHOR]

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Most investigations on flow batteries (FBs) make the assumption of perfectly mixed electrolytes inside the tanks without estimating their likelihood, while specific analyses are missing in the literature. This paper presents a pioneering investigation of the electrolyte flow dynamics inside FB tanks. This study considers the Open Circuit Voltage (OCV) measured at the stack of a 9 kW/27 kWh Vanadium FB with 500 L tanks. Order-of-magnitude estimates of the measured dynamics suggest that differences in densities and viscosities of the active species drive gradients of concentrations with different patterns in the positive and negative tanks and in charge and discharge, affected by current and flow rate, which result in significant deviation from homogeneity, affecting the State of Charge (SoC) of the electrolytes flowed into the stack and thus the FB performance. In particular, stratifications of the inlet electrolytes may appear which are responsible for delays in reaching the outlets, with initial plateau and following step (s) in the SoC at the stack. These events can have a major impact in the performance of industrial FBs with large tanks and suggest that specific tank designs may improve the overall dynamics, calling for further analysis. [ABSTRACT FROM AUTHOR]

Continuous monitoring of large-scale solar photovoltaic (PV) installations is necessary to check the deterioration and monitor the performance of the PV plant. Fault diagnosis is crucial to ensure the PV plant operates safely and reliably. This paper presents a diagnosis methodology based on current-voltage (I-V) and PV characteristics to monitor and assess the behavior of solar PV. In this paper, I-V curve characterization using an I-V curve tracer is used to check the deterioration and diagnosis of the PV panels. The real-time performance of the 50.4 kWp rooftop solar grid interfaced PV plant is investigated and analyzed using I-V and PV curve tracers in real-time conditions. The overall performance of solar PV is assessed on a real-time test system in different scenarios such as variable climatic conditions, partial shading conditions, aging of solar panels, short circuit conditions, and dust decomposition. Furthermore, the performance assessment of solar PV is evaluated using performance indicators such as open circuit voltage index, short circuit current index, fill factor, and performance ratio. [ABSTRACT FROM AUTHOR]

Context: The purpose of the S01–S05 series of end-capped modified donor chromophores is to amplify the energy conversion efficiency of organic solar cells. Using quantum chemical modeling, the photophysical and photoelectric characteristics of the S01–S05 geometries are examined. Method: The influence of side chain replacement on multiple parameters, including the density of states (DOS), molecular orbital analysis (FMOS), exciton-binding energy (Eb), molecular electrostatic potential analysis, dipole moment (μ), and photovoltaic characteristics including open circuit voltage (VOC), and PCE at minimal energy state geometries, has been investigated employing density functional theory along with TD-DFT analysis. The molar absorption coefficient (λmax) of all the proposed compounds (S01–S05) was efficiently enhanced by the terminal acceptor alteration technique, as demonstrated by their scaling up with the reference molecule (SR). Among all molecules, S04 has shown better absorption properties with a red shift in absorption having λmax at 845 nm in CHCl3 solvent and narrow energy gap (EG) 1.83 eV with least excitation energy (Ex) of 1.4657 eV. All created donors exhibited improved FF and VOC than the SR, which significantly raised PCE and revealed their great efficiency as OSC. Consequently, the results recommended these star-shaped molecules as easily attainable candidates for constructing extremely efficient OSCs. [ABSTRACT FROM AUTHOR]

We have simulated the effect of changing the end groups in BTP core with five organic units of 1,3-Indandione (IN), 2-thioxothiazolidin-4-one (Rhodanine), propanedinitrile (Malononitrile), (2-(6-oxo-5,6-dihydro-4H-cyclopenta[c]thiophen-4-ylidene)malononitrile) (CPTCN) and 2-(3-oxo-2,3-dihydroinden-1-ylidene (IC), and two halogenated units of (4F) IC and (4Cl) IC on the optical and photovoltaic properties of the BTP DA'D core molecular unit. Thus modified, seven molecular structures are considered and their optical properties, including HOMO and LUMO energies and absorption spectra are simulated in this paper. On the basis of HOMO and LUMO energies, it is found that two of the seven molecules, BTP-IN and BTP-Rhodanine, can act as donors and the other four, BTP-(4F) IC, BTP-(4Cl) IC, BTP-CPTCN and BTP-IC, as acceptors in designing bulk heterojunction (BHJ) organic solar cells (OSCs). Using these combinations of donors and acceptors in the active layer, eight BHJ OSCs, such as BTP-IN: BTP-(4F) IC, BTP-IN: BTP-(4Cl) IC, BTP-IN: BTP-CPTCN, BTP-IN: BTP-IC, BTP-Rhodanine: BTP-(4F) IC, BTP-Rhodanine: BTP-(4Cl) IC, BTP-Rhodanine: BTP-CPTCN and BTP-Rhodanine: BTP-IC, are designed, and their photovoltaic performance is simulated. The photovoltaic parameters J s c , V o c and FF for all eight BHJ OSCs and their power conversion efficiency (PCE) are simulated. It is found that the BHJ OSC of the BTP-IN: BTP-CPTCN donor–acceptor blend gives the highest PCE (14.73%) and that of BTP-Rhodanine: BTP-(4F) IC gives the lowest PCE (12.07%). These results offer promising prospects for the fabrication of high-efficiency BHJ OSCs with the blend of both donor and acceptor based on the same core structure. [ABSTRACT FROM AUTHOR]

Context: Various innovative molecules have been designed and explored for use in organic photovoltaics. In this study, we devised novel molecules (KZ1–KZ7) specifically for organic solar cells (OSCs). The newly formulated acceptor compounds possess a lower bandgap (Eg = 1.85–2.02), along with bathochromic shift (λmax = 713–788 nm) compared to the reference (Eg = 2.04 eV and λmax = 774 nm). Moreover, the FMO results identified the distinct charge transfer from HOMO to LUMO, which was strongly corroborated by the TDM maps. Similarly, the new designed molecules show less excitation energy (Ex = 1.31–1.54(gas)) than reference (Ex = 1.72). Likewise, all designed molecules (KZ1–KZ7) have demonstrated an analogous open circuit voltage (Voc) with the donor polymer PTB7-Th. All seven designed molecules (KZ1–KZ7) exhibited more fill factor ranging from 97.08 to 97.29 than reference 95.25 and PCE of between 8 and 20% at short circuit current densities of 9, 12, and 15 mA cm−2. Overall, the findings support that designed molecules can be potential molecules for future practical applications. Methods: Geometric calculations were conducted with Gaussian 09W software, and the findings were visualized using Gauss View software. DFT and TD-DFT were employed to evaluate various parameters for R and designed molecules (KZ1–KZ7). Firstly, four functionals including B3LYP, CAM-B3LYP, MPW1PW91, and ωB97XD with 6-31G(d,p) DFT level were applied to R to decide the best level for results. After appropriate analysis, the MPW1PW91/6-31G(d,p) was selected for further examination by comparing the experimental and DFT-based absorption graphs of R. External and internal reorganization energy are the two main factors contributing to reorganization energy. External energy refers to changes in external environment, while internal energy deals with information related to internal geometrical symmetry or the internal environment. The effect of outside factors or external reorganizational energy is omitted because it creates too little change. [ABSTRACT FROM AUTHOR]

BACKGROUND: Microbial desalination cell (MDC) is a new technology in the use of electrical energy for water desalination and wastewater treatment. RESULTS: Open circuit (OC) and closed circuit (CC) modes were successfully simulated with initial TDS concentrations of 10 g/L and 10–15 g/L, respectively (an external resistance of only 150 Ω was applied for CC). After 160 h of operation, the maximum OC voltage, desalination efficiency and COD removal efficiency were 809 mV, 32.2% and 79.2%, respectively. The maximum voltage was also obtained when the external resistances were 150 Ω (423.4 and 438 mV) for the initial NaCl concentrations (10 and 15 g/L) in the central chamber, respectively. Moreover, the maximal desalting and COD removal efficiencies after 24 h run‐time were (30% and 28%) and (24% and 25%) for initial NaCl concentrations (10 or 15 g/L) in the central chamber, respectively. Maintaining pH (8.61, 7.01) to (7.85, 7.8) in anode and cathode chambers was studied. This research accurately depicted microbial desalination's efficiency in generating OC voltages and CC electrical energy via Box–Behnken Design Distribution (BBD). Investigated factors' interactions (initial salt/COD concentrations, time) on CC system's energy efficiency. Resulted in peak productivity at (1.85 mW), OC reaching (1100 mV). CONCLUSION: Finally, the research paper gave exciting results in improving the efficiency of the microbial desalination cell to increase the ability to produce electrical energy and desalinate water. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The power conversion efficiency (PCE) of single-junction perovskite solar cells (PSCs) has reached 26.1% in small-scale devices. However, defects at the bulk, surface, grain boundaries, and interfaces act as non-radiative recombination centers for photogenerated electron-hole pairs, limiting the open-circuit voltage and PCE below the Shockley–Queisser limit. These defect states also induce ion migration towards interfaces and contribute to intrinsic instability in PSCs, reducing the quasi-Fermi level splitting and causing anomalous hysteresis in the device. The influence of defects becomes more prominent in large-area devices, demonstrating much lower PCE than the lab-scale devices. Therefore, commercializing PSCs faces a big challenge in terms of rapid decline in working performance due to these intrinsic structural defects. This paper provides a comprehensive review of recent advances in understanding the nature and the classification of defects, their impact on voltage losses, device parameters, intrinsic stability, and defect quantification and characterization techniques. Novel defect passivation techniques such as compositional engineering, additive engineering, post-treatments, dimensionality engineering, and interlayer engineering are also reviewed, along with the improvements in PCE and stability based on these techniques for both small-area devices and large-area roll-to-roll coated devices. [ABSTRACT FROM AUTHOR]

The structural, optical, electronic and photovoltaic properties of non-fullerene molecular entity were analyzed by using density functional theory method MPW1PW91/6-31G (d, p). The simulated results of all the modeled molecules proved them as more efficient molecules for practical use in organic solar cell. Their good solution process-ability and interface (new modeled molecules: PBDBT) success made high value fill factor and open circuit voltage. Comparatively, BDCl2F-DS was proved to be an outstanding material with open-circuit voltage (1.71 eV) and fill factor (92.25%). Assumption of a similar value of short circuit current from the reference work PCE was estimated. By doing so, outstanding calculated PCE values (in the range of 27.36% to 33.76%) made newly modeled molecules an advancement in investigation of unfused non-fullerene acceptors. All the properties were studied using concepts of DFT method MPW1PW91/6-31G (d, p) and Marcus theory. The estimated LHE, free energy of electrons injection and regeneration have extraordinary values which are essential parameters for short circuit current estimation. The compatibility of donor and acceptor interfaces was proved successful by testing Voc values (in the range of 1.61 eV to 1.71 eV) with donor PBDBT. The FF was found in range of 91–92% in all designed molecules. Lastly, Power conversion efficiency of modelled molecules was estimated which was found up to 33.76%. [ABSTRACT FROM AUTHOR]

The photovoltaic and optical properties of 6,6′‐dibromoindigotin (DBI) crystal under changing solvent polarity are investigated through DFT analysis. It includes geometry optimization, global reactivity, UV–vis analysis, open circuit voltage (Voc), FMOs, and NBO analysis. The highest HOMO‐LUMO gap (Egap) value is found for the gaseous phase (1.82 eV), while the lowest Egap is found for dichloro methane (1.64 eV), and intermediate values with the other solvents. The molecule has a high IP of 2.48 eV, low EA of 0.74 eV, moderate polarity, and hardness (η). The maximum absorption wavelengths (λmax) of the compound in different solvents are dichloromethane and DMSO (373 nm), chloroform (372 nm), methanol and water (371 nm), toluene (367 nm), and gaseous (356 nm). Their Voc range is 0.2–0.28 eV. Among all, chloroform demonstrates the highest performance with a fill factor (FF) of 0.8630, normalized open circuit (Nor. Voc) of 31.69 eV, and Jsc of 26.47 mA cm−2. Toluene also shows promising results with an FF of 0.8060, Nor. Voc of 19.71 eV, and Jsc of 21.19 mA cm−2. Water, although not as effective as other solvents, still exhibits respectable values with an FF of 0.8315, Nor. Voc of 23.96 eV, and Jsc of 24.63 mA cm−2. [ABSTRACT FROM AUTHOR]

Applications for Wireless Sensor Network (WSN) require cheap, highly efficient, smaller dimension Schottky-barrier (SB) solar cells. Currently, results of the SB solar cells' Open Circuit Voltage (Voc), Minority Carrier Lifetime (teff) and Power Conversion Efficiency (PCE) are discouraging. Graphene Oxide (GO) appears to be the solution because of its better surface passivation property. In this work, GO as an interfacial layer, is investigated with a simulation model and results are verified experimentally by fabrication. Novelty of this work is a change in the deposition process of GO and inclusion of an Oxide layer between the Silicon and GO. The average Voc of the proposed solar cell is increased by 4% and the minority carrier lifetime is enhanced by ~10% which is expected to increase the PCE. The noteworthy improvement of the silicon surface passivation is attributed to the dangling bond saturation which results in reduced carrier recombination. This investigation leads us to a solar cell that can be fabricated with low cost at lower thermal temperature which is a very efficient alternative to power sensor nodes that are deployed in large numbers in WSN applications. [ABSTRACT FROM AUTHOR]

The adoption of photovoltaic (PV) solar systems has been rapidly increasing due to their cost-effectiveness and easy installation. However, the non-linearity of PV panels can hinder their ability to provide maximum power output. To achieve optimal efficiency, it is crucial to track the control point based on irradiance and temperature values. This study proposes an analytical control method that employs the open circuit voltage to track the maximum power point of a PV panel that is connected to a DC microgrid via a DC–DC boost converter. The proposed model considers the temperature effect on both diode saturation current and current generated by irradiance for higher sensitivity. To validate the accuracy of the proposed model, the PV panel installed at the Technopark campus of Gazi University was used for experimentation. The performance indicators, mean absolute percentage error (MAPE) and R2, were calculated to assess the differences between the values calculated from the proposed model and those observed from the experiments. The results indicate an error value of 3.9% and a compatibility of 95.9% based on MAPE and R2, respectively. These findings demonstrate the success of the proposed model. [ABSTRACT FROM AUTHOR]

Because of its exceptional qualities, such as high energy density, extended lifespan, and low self-discharge, lithium-ion (Li-ion) batteries have grown in popularity in recent years. However, the maximum temperature that these batteries can endure while in use is essential to their safety and effectiveness. The Taguchi technique, a statistical strategy that permits efficient evaluation of multiple experimental parameters, has been utilized by the researchers to improve this. This study has changed six input elements, each with five levels, including battery diameter, height, capacity, activation energy, density, and final state of charge, in order to identify the best settings to optimize the maximum temperature of lithium ion batteries. The study's findings have been validated by using an analysis of variance (ANOVA). The study has discovered that the diameter and the height of the battery have been the most critical parameters in determining the maximum temperature of the battery. This approach discovers perfect circumstances that can increase Li-ion battery performance and potentially broaden their use in a variety of applications. In order to simulate the design, the researchers have used the COMSOL Multiphysics software to create a Li-ion battery pack that could withstand 50°C and have conducted a transient analysis over 0.2 hours in order to observe the increase in temperature due to internal resistance, electrochemical reactions, and ambient temperature. This approach can eliminate design problems that arise from the traditional trial-and-error method by tuning the control parameters examined in this study. This approach can streamline the design process of Li-ion battery packs for specific applications, making it more efficient. [ABSTRACT FROM AUTHOR]

The power conversion efficiency (PCE) of ternary polymer solar cells (PSCs) with non-fullerene has a phenomenal increase in recent years. However, improving the open circuit voltage (Voc) of ternary PSCs with non-fullerene still remains a challenge. Therefore, in this work, machine learning (ML) algorithms are employed, including eXtreme gradient boosting, K-nearest neighbor and random forest, to quantitatively analyze the impact mechanism of Voc in ternary PSCs with the double acceptors from the two aspects of photovoltaic materials. In one aspect of photovoltaic materials, the doping concentration has the greatest impact on Voc in ternary PSCs. Furthermore, the addition of the third component affects the energy offset between the donor and acceptor for increasing Voc in ternary PSCs. More importantly, to obtain the maximum Voc in ternary PSCs with the double acceptors, the HOMO and LUMO energy levels of the third component should be around (−5.7 ± 0.1) eV and (−3.6 ± 0.1) eV, respectively. In the other aspect of molecular descriptors and molecular fingerprints in the third component of ternary PSCs with the double acceptors, the hydrogen bond strength and aromatic ring structure of the third component have high impact on the Voc of ternary PSCs. In partial dependence plot, it is clear that when the number of methyl groups is four and the number of carbonyl groups is two in the third component of acceptor, the Voc of ternary PSCs with the double acceptors can be maximized. All of these findings provide valuable insights into the development of materials with high Voc in ternary PSCs for saving time and cost. [ABSTRACT FROM AUTHOR]

This study reported the activity of catalysts synthesized from platinum and molybdenum alloys in different atomic ratios and used as cathode electrocatalysts in the PEMFC. The structural properties of PtMo/C and Pt/C catalysts were analyzed by XRD analysis. The composition and distribution of these alloys in Vulcan XC-72R Carbon were determined by SEM and EDX techniques. CV studies assessed electrochemical properties such as ORR and ECSA activity. The performance of PEMFC cathodes that supplied pure hydrogen and oxygen was examined using polarization curves at different temperatures. Another way to improve the cathodic reaction is to use ozone as a potent oxidizing agent. It was measured that the OCV of the H 2 /O 3 PEM fuel cell was 1.60 V, much greater than the open circuit voltage of the traditional H 2 /O 2 PEM fuel cell. The PtMo/C catalyst achieved its highest power density of 137 mWcm−2 at 70 °C, 128 mWcm−2 at 60 °C, 101 mWcm−2 at 50 °C, and 85 mWcm−2 at 40 °C when exposed to H 2 /O 2. As the temperature of the cell was raised, it was seen that the catalyst's catalytic activity increased. The maximum power density was detected to be inversely related to the rise in temperature when ozone was used. At low current densities, however, ozone was observed to greatly boost activation polarization. [Display omitted] • The use of PtMo/C catalyst as a cathode affects the power density of the cell. • PtMo/C produces the highest power density in a PEM fuel cell when using H 2 /O 2. • Using H 2 /O 3 , the PtMo/C catalyst gave the best results in the low-current density region. • The PtMo/C catalyst has the best activity at increasing cell temperature when using H 2 O 2. [ABSTRACT FROM AUTHOR]

A series of alkyl‐group‐functionalized, aniline‐ and indoline‐donor‐based, unsymmetrical visible‐light‐active squaraine dyes, AM1‐3, were designed and synthesized. Dye‐sensitized solar cell (DSSC) devices were fabricated with both I−/I3− and [Cu(tmby)2]+/2+ electrolytes. DSSC devices sensitized with the AM1 and AM2 dyes showed relatively high‐power conversion efficiency of 7.44 % and 7.22 %, respectively with I−/I3− in the absence of chenodeoxycholic acid (CDCA) than those of the AM3 dye (5.41 %). The [Cu(tmby)2]+/2+ electrolyte along with poly(3,4‐ethylenedioxythiophene) (PEDOT) as cathode material showed excellent open‐circuit potentials (VOC) of 1030, 1025, and 1001 mV with the DSSC efficiency of 8.05 %, 7.96 %, and 5.84 %, respectively, for the AM1, AM2, and AM3 dyes in the absence of CDCA. Here, the AM1 dye exhibited the maximum DSSC efficiency of 8.05 % and VOC of 1030 mV, which is the highest obtained efficiency and VOC for the visible‐light active zwitterionic unsymmetrical‐squaraine dye with copper‐based electrolyte. [ABSTRACT FROM AUTHOR]

The construction of an aluminum-sodium hypochlorite battery is addressed. The battery was made from household chemicals and products obtained from a typical supermarket. The proposed small-scale battery design is easy to assemble and only one cell is needed to light a red light emitting diode (LED). [ABSTRACT FROM AUTHOR]

Many problems arise in the operation of photovoltaic systems. Each of these problems affects the operation of photovoltaic systems by reducing the power of the entire system. Some problems can be avoided during the design of photovoltaic systems. For example, when designing photovoltaic systems, it is possible to eliminate the shading of photovoltaic panels from surrounding objects. It is also necessary to look at the shading from neighboring photovoltaic panels when designing photovoltaic systems. It is necessary to calculate the inclination of the sunlight based on the position of the sun and calculate the distance between the two panels accordingly. However, some problems appear during the operation of photovoltaic systems. These problems can be partially eliminated. The magnitude of the series resistance can be eliminated by reducing the transition resistance throughout the system. The paper describes these problems and their possible solutions in practice. In the practical part, we focused on simulations and experiments in the field of photovoltaic systems (PV). The simulations focused on both the influence of temperature and the series resistance of photovoltaic panels on the production of electricity. The experiments were focused on the influence of various faults/defects on the power and V-A characteristics of photovoltaic panels connected in strings. The paper also discusses the impact of bypass diodes on the operation of photovoltaic systems and determines the need to use bypass diodes. [ABSTRACT FROM AUTHOR]

The efficiency of solar cells depends on the quality of passivation of surface. The quality of passivation is analyzed as a function of the dependence of the open circuit voltage on the light intensity. Therefore, in this article, the dependence of the photoelectric parameters of the silicon-based solar cell on the light intensity was studied. According to the obtained results, it was found that the variation of the short-circuit current through light intensity is equal to 25.6 mA/suns·cm². The agreement of the results obtained in research and modeling with the results of experiments proves the validity and correctness of the model. In this paper, the Sentaurus TCAD model of a silicon-based solar cell is experimentally verified. So, the dependence of the open circuit voltage of the silicon-based solar cell on the light intensity was studied through modeling and experiment. The functional dependence of the open circuit voltage obtained in the modeling satisfied the experiment. Therefore, the model of the solar cell created in Sentaurus TCAD is suitable for research. So, we can use model created in Sentaurus TCAD in our further researches. In addition, the fill factor of solar cell increased with increasing intensity. This proves that the resistive properties of the solar cell are improving. [ABSTRACT FROM AUTHOR]

Vanadium redox flow batteries (VRFB) are a fertile energy storage technology especially for customized storage applications with special energy and power requirements. The dimensioning and control of these storages is mostly calculated beforehand using battery models in embedded simulation structures. To cover various stack designs, chemistries, application strategies and system architectures, battery simulation models should be validated with different experimental input data and thus show universal functionality. In this study the functionality of a grey box VRFB model using current, voltage and state of charge (SOC) of a 10 kW/100 kWh VRFB as input data are validated for an adapted input data set using of a 5 kW/10 kWh VRFB. This model is designed for stationary applications of VRFB only. The contribution of this study is (i) to apply a suitable SOC conversion method to the raw data from the used 5 kW VRFB system, (ii) to adapt the modeling code for broader use and integration of the SOC conversion, (iii) to validate the functionality and (iv) to investigate the influence of constant current and constant voltage phases in the raw data on the accuracy of the model. A comparison of experimental data between different redox flow batteries shows that most VRFB measure the open circuit voltage (OCV) to calculate the SOC of the battery. Using the calculated SOC as an input data the proposed simulation model need to be adapted and a method is applied to use OCV input data for model validation. Although simulation models in general often assume linearity between SOC and OCV, the study showed sufficient accuracy using polynomic fitting of second order. Applying a parametrization process the results of the simulation model are compared to the raw data and the scope of application of the grey box VRFB model is defined. While using the dominant constant current phase for the charging and discharging cycle, the grey box simulation model has been sufficiently parametrized and validated for adapted input data. [ABSTRACT FROM AUTHOR]

[Display omitted] • Application of [Fe 4 S 4 ] to metal-ion batteries is studied using DFT calculations. • Embedding [Fe 4 S 4 ]2+ clusters in metal–organic frameworks generates high voltage. • The electrochemical performance is based on an intercalation mechanism. • Among the screened material pairs, Zn2+-BMOF shows the highest efficiency. [Fe 4 S 4 ] clusters have served as molecular batteries and charge transfer centers in many biosystems. However, their potential as electrode materials has been overlooked amidst the ever-increasing studies on various materials in the search for efficient battery compositions. To evaluate their electrochemical efficiency as electrode materials, we focused on the use of two important oxidation states, [Fe 4 S 4 ]2+ and [Fe 4 S 4 ]⁰, in a series of Li-, Na-, K-, Mg-, Ca-, and Zn-ion batteries. We also assessed the effect of metal–organic framework (MOF) formation on their performance by studying [Fe 4 S 4 ]2+-1,4-benzenedithiolate MOF (BMOF) and its carboxylate-based counterpart (CMOF). Our model-based Density Functional Theory (DFT) calculations indicated that oxidation of the cluster to [Fe 4 S 4 ]2+ and MOF formation significantly improve the electrochemical efficiency of the cluster. Among the studied electrode materials and metals, the BMOF combination with Mg0 and Zn2+ presented the best electrochemical performance. Notably, our periodic calculations indicated an open circuit voltage of 4.32 V for the Zn2+-BMOF system, suggesting a promising performance for BMOF compared to other cathode/negative electrode materials. Our atomic and electronic structure analyses indicated that intercalation is the underlying electrochemical mechanism. [ABSTRACT FROM AUTHOR]

In the search for next-generation energy storage devices, superior-performance alternative electrode materials based on two-dimensional materials for rechargeable metal-ion batteries are essential. Here, we explored group III and IV functionalization of 2D Ti 2 B, Ti 2 BX 2 (X=Si, Ge, P, As) as anode materials for Li and Na ion batteries using first-principles calculations. The structures had excellent metallic properties and demonstrated energetically favorable adsorptions for metal ions. Analyzing charge transfer and electronic band structures, silicon and phosphorous-functionalized Ti 2 B (Ti 2 BSi 2 and Ti 2 BP 2) showed the most potential. The energy band diagrams showed that both Ti 2 BSi 2 and Ti 2 BP 2 had metallic characteristics after Li and Na-ion adsorption, which offered considerable advantage for rechargeable-ion batteries. The structures exhibited low energy barriers for Li and Na-ion migration. The minimum energy barriers calculated for Na were 0.08 eV for Ti 2 BSi 2 and 0.24 eV for Ti 2 BP 2. Theoretical specific capacity and open circuit voltage were calculated using maximum layer adsorption. For both Li and Na, high values of specific capacity and low values of open circuit voltage (¡ 1 V) were found. Ti 2 BSi 2 had the best performance, with a theoretical specific capacity of 1647.10 and 1317.68 mA h/g for Li and Na, respectively. Its open circuit voltages for Li and Na were 0.65 and 0.38 V. The insights of this study will be beneficial in fabricating high-performing Ti 2 BX 2 -based anodes for rechargeable Li and Na ion batteries. [Display omitted] • Functionalized 2D MBene Ti 2 B were explored for potential applications as anode materials in rechargeable ion batteries. • Functionalized Ti 2 B structures were both dynamically and energetically stable, with excellent metallic characteristics. • High theoretical specific capacity, low open circuit voltage, and low diffusion barriers were revealed for the proposed functionalized structures. • Comparative analysis with literature verifies that the proposed structures demonstrated significant promise as anode materials. [ABSTRACT FROM AUTHOR]

LiFePO4 batteries are increasingly utilized in electric vehicles due to their superior safety. Accurate state estimation is the basis for the safe and reliable application of LiFePO4 batteries. However, the flat voltage characteristics of LiFePO4 batteries lead to state estimation closed-loop correction as its inherent contradiction. To address this challenge, a model-based SOC estimation method combining proportional-integral-differential (PID) observer and improved extended Kalman filter (EKF) is developed according to different open-circuit-voltage (OCV) ranges, specific processes include: First, an exponentially weighted moving average algorithm with a temperature compensation factor is presented to compensate for the errors in the identified OCV. Secondly, the combination of the PID observer and EKF is chosen adaptively to update SOC within distinct OCV ranges, differentiated by the identified OCV. To achieve optimization of the PID parameters and temperature compensation factors across varying temperatures, an enhanced whale optimization algorithm is developed. To validate the developed method, a series of experiments are performed across a range of temperatures and with multiple driving profiles. The results show that the developed method not only guarantees maximum absolute error of <3 %, but also can converge quickly in the early stage. • A temperature compensation factor (T c) is used to reduce the error of identified OCV based on EWMA-FFRLS. • A PIDO combined with an improved AEKF is presented to accelerate the SOC convergence speed. • An AEKF-PIDO-integrated US-EKF framework is developed to enhance SOC estimation of LiFePO4 battery. • An improved WOA is introduced to adjust the PIDO parameters and T c at different temperatures. [ABSTRACT FROM AUTHOR]

In this theoretical research, four distinct acceptor molecules (M-M3) having structural configuration A 2 -D-π-A 1 -π-D-A 2 have been designed through terminal acceptor and linker alteration. The DFT-based approach B3LYP/6–31 G (d, p) has been used to study the photovoltaic properties of designed molecules. A number of characteristics of these molecules have been assessed comprehensively. The designed molecules M-M3 have exhibited lower energy gap (1.56–1.63 eV) as compared to the reference molecule (E g = 1.70eV). A red shift in absorption was observed for all the molecules (λ max = 964 –1005 nm) as compared to the reference molecule (λ max = 693 nm). Nearly identical outcomes from density of states and frontier molecular orbitals for all the altered molecules show that electron density is evenly dispersed across the entire molecules. Additionally, their slightly greater dipole moment and smaller excitation energy as compared to reference molecule are responsible for their remarkable charge transfer because of better separation of electron-hole pair (exciton). Calculating open circuit voltage of the examined acceptor molecules with respect to P113 donor have revealed that all the newly proposed molecules M-M3 exhibit higher V OC (1.25–1.36 eV) and FF. The results of this study imply that the fabrication of solar cells using these designed acceptor molecules may result in high photovoltaic yield. [Display omitted] • Four novel diketopyrrolopyrrole based acceptor molecules (M-M3) were proposed. • All the molecules were analyzed computationally by Gaussian 09 using DFT. • Designed molecules exhibited lower band gap and a bathochromic shift in λ max. • Designed molecules show raised open circuit voltage and FF. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) systems can generate less energy than expected owing to inefficiency of the inverter, deterioration of the PV modules or conditions of partial shading and soiling. The monitoring and diagnosis techniques of PV systems are therefore quite important to recognize the causes of the performances reduction and optimize the PV energy production. For a more in-depth diagnostic capability, it would be necessary to know the short-circuit current (Isc) and the open-circuit voltage (Voc) of the PV system. These quantities are indeed useful to recognize non-uniform operating conditions of the PV modules (partial shadings, malfunctions, generic electro-optical mismatch conditions), estimate the PV module junction temperature and the voltage temperature coefficient. However, so far, these quantities cannot be measured by the inverter in operative conditions. With this contribution we propose and test a new electronic interface for a more advanced diagnostics of the PV system to be easily installed between the PV string and the inverter, able to measure the values of Isc and Voc as well as the inverter voltage, current and power working points, avoiding any downtime of the PV system and minimizing the power losses during the diagnosis activity. [ABSTRACT FROM AUTHOR]

The state of charge (SOC) is critical for the safety and reliable utilization of the battery. However, SOC estimation accuracy of lithium iron phosphate (LiFePO4) battery is a challenging task because of its flat voltage plateau and its performance is affected greatly by temperature. An improved open circuit voltage (OCV) combined with coulomb counting (CC) method based on the dual input model of ambient temperature and OCV is proposed. This approach is employed to obtain the initial value of SOC based on the dual input model over a wide range of temperature, and to establish SOC estimation model of modified CC with Simulink. The temperature entropy coefficient and differential analysis has been analyzed under different SOC conditions. The SOC maximum errors predicted by the proposed OCV-CC method maintain within 3.10%, while the maximum errors of the traditional OCV-CC increase from 4.78% to 23.64% under the temperature of 35°C ~−15°C. The results show the estimation accuracy of SOC using the proposed OCV-CC method is improved obviously, especially under low temperature. [ABSTRACT FROM AUTHOR]

This paper present device model simulation describing the current-voltage characteristics of polymer/fullerene bulk heterojunction solar cell. In the research paper an organic photovoltaic device with PPV/PCBM [poly (2-methoxy-5-{3',7'-dimethyloctyloxy}-p-phenylene vinylene) and {6,6}- phenyl C61-butyric acid methyl ester] was simulated via Silvaco TCAD 2-D simulation tool. PCBM acts as acceptor and PPV is donor. The models used to simulate the device were Langevin for recombination, s.binding and a.singlet. Simulation of these type of devices is an vital approach to project and predict the cell performance. Under the illumination of one sun (AM 1.5) the simulated organic cell showed a short circuit current density (JSC) of 28 A/m2, open circuit voltage (VOC) of 0.84 Volt and a fill factor (FF) of 52.51%, the resulting maximum efficiency of the PPV/PCBM organic solar cell is 1.22%. [ABSTRACT FROM AUTHOR]

Herein, based on the reviewed literature, the current marketability challenges faced by kesterite CZTS based-solar cells is addressed. A knowledge update about the attempts to reduce the open circuit voltage deficit of kesterite CZTS solar cells will be addressed, with a focus on the impact of Cu/Zn order/disorder and of Se doping. This review also presents the strengths and weaknesses of the most commercially attractive synthesis methods for synthesizing thin kesterite CZTS films for photovoltaic applications. [ABSTRACT FROM AUTHOR]

State of Charge (SoC) is a parameter used to determine the current capacity on a battery as well as indicate the operational characteristics. The SoC is an important parameter for optimizing battery utilization in many applications requiring DC current source. However, estimating the SoC value is the major problem since it cannot be measured directly. In this study, we proposed SoC measurement method based on analysis internal resistance of battery. The internal resistance is correlated with the parameters of the magnitude of the terminal voltage and open circuit. Both voltages come from the influence of current during the charging-discharging process. We report that the proposed method has successfully obtained the correlation between the SoC and the internal resistance value for two process, which are the charging- and discharging process. [ABSTRACT FROM AUTHOR]

Anaerobic digestion (AD) can produce renewable energy and reduce carbon emissions, but the energy conversion efficiency is still limited in some waste streams. This study tested the effect of applied voltage removal for microbial electrolysis cells (MECs) treating primary sewage sludge. Two MECs were operated in parallel: a MEC-0.3 V with an applied voltage of 0.3 V and a MEC-OCV with open circuit voltage. Both reactors were inoculated with seed sludge originating from a MEC at 0.3 V applied voltage, and three batch cycles were operated for 36 d. The methane production of the MEC-OCV was 3759 mL/L in the first cycle and 2759 mL/L in the second cycle, which was similar (105% and 103%, respectively) to that of the MEC-0.3 V. However, in the third cycle, the methane production of the MEC-OCV (1762 mL/L) was 38.8% lower than that of the MEC-0.3 V (4545 mL/L). The methane contents in the biogas were 68.6–74.2% from the MEC-OCV, comparable to those from the MEC-0.3 V (66.6–71.1%). These results indicate that not only the MEC-0.3V but also the MEC-OCV outperformed AD in terms of methane yield and productivity, and the promotion using MEC-derived inoculum persisted equally with the MEC-OCV for two batch cycles after removing the applied voltage. Therefore, a MEC operation with cycled power supply may be beneficial in reducing the electric energy usage and improving the biogas production performance, compared to conventional AD. [ABSTRACT FROM AUTHOR]

State of Charge (SOC) is the ratio of current versus total capacity of the battery. In the context of Battery Management System (BMS), the SOC is estimated by using a battery model. In this research, three battery models were presented, including (1) Thevenin battery model, (2) modified Thevenin battery model, and (3) simple battery model. Then, the SOC of those battery models was estimated using Coulomb Counting, Open Circuit Voltage (OCV), and Kalman Filter method. The simulation evaluated the performance of the SOC estimation methods, including the correctability of SOC initialization error. The simulation results showed that the proposed battery models could accurately estimate SOC. In terms of SOC initialization error, the Coulomb Counting, OCV Model 1, and OCV Model 2 could not correct the initialization error of SOC. However, the application of OCV Model 3 and Kalman Filter could provide an accurate SOC estimation with excellent correction of SOC initialization error. Compared to OCV model 3, the error correction in the Kalman Filter method was performed 25 minutes faster. Therefore, this finding suggests that Kalman Filter is the most suitable estimation method for BMS due to the high accuracy of SOC estimation (RMSE = 0.0014) and fast correction of SOC initialization error (time < 20 seconds). [ABSTRACT FROM AUTHOR]

[Display omitted] • 1,3,4-oxadiazole derivatives were designed for efficient NLO response. • A larger NLO for 6-oxza is attributed to its lowest transition energy of 3.78 eV. • Unlike PCM solvation method, the gas and COSMO salvation methods show good agreements. • Frequency-dependent γ values revealed that derivatives are suitable for wide range of frequency and laser application. • For photovoltaic applications, the V oc and ΔG reg for 6-oxza are found to be 2.22 and 1.87 eV. The science of organic optical and nonlinear optical (NLO) materials has been captivating the scientific community owing to their extensive applications in optoelectronics, OLEDs, and telecommunications. This study presents the design and investigation of novel organic compounds of pyrene and 1,3,4-oxadiazole derivatives (1-oxza to 6-oxza), featuring various push–pull combinations. Quantum chemical calculations were employed to determine linear polarizabilities (α) and third-order NLO polarizabilities (γ). Notably, the largest average third-order NLO polarizability value was found to be 254.9 × 10−36 esu for the finely tuned push–pull system 6-oxza , which is ∼35 times greater than that of the prototype NLO molecule of p -nitroaniline (p -NA). Among the derivatives, 1-oxza exhibits the highest linear isotropic polarizability (α iso) value of 61.59 × 10−24 esu, while 5 -oxza displays the highest linear anisotropic polarizability (α aniso) value of 60.09 × 10−24 esu. A notable increase of approximately ∼1 to ∼2 times in < γ > is observed for selected compounds (1-oxza , 4-oxza , 6-oxza), indicating that the Conductor-like Screening Model (COSMO) overestimates the values compared to the polarizable continuum model (PCM) and gas phases. Solvent significantly enhances third-order NLO polarizability amplitudes depending upon solvent polarity and strength of substitution groups. We calculated the frequency-dependent third-order NLO polarizability of 6-oxza at laser wavelengths ranging from 1400 to 1970 nm. The second hyperpolarizability EFISHG process (γ(−2ω; ω, ω, 0)) was calculated at a laser wavelength of 1400 nm, and the γ-amplitude was found to be 400.1 × 10−36 esu. The remarkable hyperpolarizability response in the gas phase is corroborated by TD-DFT calculations, which reveal a larger transition dipole moment of 3.062 and a lower transition energy of 3.780 eV as origin of larger hyperpolarizability for 6-oxza. A comprehensive analysis was performed based on FMOs for designed compounds to elucidate the intramolecular charge transfer (ICT) mechanisms and observed a notable reduction in energy band gap 4.89 eV for 6-oxza, which is responsible for enhanced NLO response. Additionally, DOS maps revealed the quantitative contributions of HOMOs and LUMOs for crucial electronic states related to the efficient ICT process. Additionally, we analyzed the photovoltaic properties and found that 6-oxza has the highest dye regeneration and the lowest open-circuit voltages of 1.89 eV and 2.22 eV, respectively. Our designed model compounds can put real-time such compounds under spotlight of scientific interests which seeks more efficient optical and NLO properties. [ABSTRACT FROM AUTHOR]

Within this piece of research, the performances of pure B 2 CN 3 nanosheet (PB 2 CN 3 NS) and its doped structure with Si atoms (SB 2 CN 3 NS) as the anode materials of K-ion batteries (KIBs) were investigated using DFT. The findings showed that PB 2 CN 3 NS and SB 2 CN 3 NS are highly capable of adsorbing K with acceptable adhesion energy (AE). Also, because of the negative adhesion of K+, in comparison with K, K+ donated more electrons on PB 2 CN 3 NS and SB 2 CN 3 NS. Based on the results, SB 2 CN 3 NS provided an ideal condition for the K atoms to migrate on the surfaces of PB 2 CN 3 NS and SB 2 CN 3 NS because of their lower energy barrier. The computed theoretical storage capacity was approximately 1347 mAh.g−1 after the adhesion maximum K atoms onto PB 2 CN 3 NS and SB 2 CN 3 NS. This value is higher the values reported for many anodes materials fabricant in recent years. The open circuit voltage (V OC) of PB 2 CN 3 NS and SB 2 CN 3 NS were also found to be low, which were 0.19 and 0.25 V, respectively. The outcomes within this study can provide useful insights into producing highly efficient anodes for KIBs. [ABSTRACT FROM AUTHOR]

Currently, A−π−A configured molecules (TTP1-TTP6) were designed from the reference compound (TPPR) by modifying the terminal acceptors for photovoltaic materials. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) using the M06/6-311G(d,p) functional were employed to analyze the photonic and electronic properties of the newly designed derivatives. Various analyses; frontier molecular orbitals (FMOs), density of states (DOS), absorption spectra (λ max), transition density matrix (TDM), binding energy (E b), hole-electron and open circuit voltage (V oc) were performed to explore the photovoltaic properties of triphenylpyridine based compounds. The structural modulation with acceptor moieties significantly tuned their HOMO and LUMO levels, resulting in reduced band gaps (2.833–3.037 eV). They also exhibited broader absorption spectra (λ max) ranging from 482.560 to 514.756 nm as compared to the reference compound (486.289 nm). Notably, TPP3 showed the good photovoltaic response as it displayed the least energy gap (2.833 eV) with lower binding energy (0.415 eV) and bathochromic shift (512.798 nm) in absorption spectra as compared to all other derivatives. Beside this, a comparative study with spiro-OMeTAD and P3HT standard hole transport materials illustrated that these materials can also be utilized as effective photovoltaic materials. [ABSTRACT FROM AUTHOR]

It has been reported that a solar cell containing a 1.077 eV bandgap absorber can achieve actual open circuit voltage up to 0.93 V and power conversion efficiency up to 35% at 300 K when the cell is irradiated by the air mass 1.5 global solar spectrum [M. S. Reza et al. Opt. Commun. 561 (2024) 130511]. These simulated open circuit voltage and power conversion efficiency values exceed the ideal detailed balance-limiting values. Even in the "limiting case" of small defect concentration and large acceptor doping concentration, the modeled open circuit voltage and power conversion efficiency are unphysical because they exceed the well-known detailed balance limit. Therefore, the results presented by Reza et al. are incorrect. • Ideal performance of a 1.077 eV solar cell determined from detailed balance. • Maximum open circuit voltage is 0.8373 V (AM1.5G, 300 K). • Maximum power conversion efficiency is 32.19% (AM1.5G, 300 K). [ABSTRACT FROM AUTHOR]

Designing efficient, non-fused ring-based organic solar cells (OSCs) with high open circuit voltage is a significant challenge. The present research proposes seven novel moieties generated from an existing 4T2CSi–4F (R) asymmetric molecule to increase efficiency. The density functional theory (DFT) was used to examine several essential characteristics like optical, electronic, and efficiency-related properties of molecules. It is revealed that newly presented molecules have superior features that are required to manufacture efficient organic solar cells. They exhibit a lower band gap between 2.05 and 2.34 eV and have a planar shape. Six moieties exhibit lower excitation energy values in the gas and chloroform phases, and five moieties have more excellent dipole moments than the R molecule. UA1 and UA2 show remarkable enhancement in the optoelectronic properties, exhibiting the greater λ max at 773 nm and a smaller excitation energy of 1.60 eV. All the newly presented molecules have lower ionization potential and reorganization energies of the electron. The open circuit voltage (V oc) of five newly designed molecules is greater, varying from 1.40 to 1.55 eV, than R (V oc = 1.38 eV). Furthermore, the newly designed molecules, except UA1 and UA2, show more excellent fill factor (FF) than the R molecule. This significant increase in efficiency-associated metrics (FF and V oc) suggests that these molecules may be effectively implemented to manufacture an upgraded version of OSCs. • Seven new molecules were designed for improving the optoelectronic properties. • All the molecules were processed computationally by using DFT approach. • Newly designed molecules have small bandgap, less excitation energies. • Designed molecules show improved light harvesting efficiency, electron mobility and electronic cloud dispersion, open circuit voltage and FF which makes them superior choice as compared to reference molecule. [ABSTRACT FROM AUTHOR]

In current study, six novel selenopheno-thiophene (ST) core-based chromophores (SePTD1- SePTD6) with A-D-A configuration were designed via structural tailoring with terminal acceptors of SePTR. The optoelectronic and photovoltaic properties of SePTD1-SePTD6 were explored through TDDFT/DFT approaches. The B3LYP/6–31 G(d,p) level was chose through benchmarked study with the help of DFT and experimental UV-Vis values of SePTR. All tailored chromophores exhibited a comparatively smaller band gap (2.144–2.003 eV), along with a significant bathochromic shift (676.8–724.2 nm) and an increased rate of charge transference then reference chromophore (2.119 eV and 686.6 nm). Among all derivatives, SePTD2 exhibited some unique characteristics such as, least HOMO/LUMO energy gap (2.003 eV), highest absorption values (665.4 nm in gas and 724.2 nm in solvent), least binding energy (0.291 eV) and also significant value of open circuit voltage (1.860 V). The aforementioned findings suggest that employing molecular engineering with extended acceptors enhances the photovoltaic performance of non-fullerene materials, thereby encouraging experimentalists to develop highly efficient photovoltaic devices. • Designing of selenopheno thiophene core-based chromophores for OSCs. • Structural modeling with π -spacer and acceptor moieties. • Exploration of photovoltaic behavior of designed chromophores. • Study of key electronic properties at B3LYP/6–31 G(d,p) functional. • Utilization of TD-DFT approach for FMOs and UV-Vis analyses. [ABSTRACT FROM AUTHOR]