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The study examines the impact of the incorporation of quantum-sized nickel (Ni) nanoparticles in TiO2 (titanium dioxide) matrix at 1%, 3%, and 5% weight percentages by straightforward, easy, and potentially effective synthesis strategy of direct doping. The structural, morphological, optical, and electrical characterization studies of synthesized films are systematically done and the photovoltaic, photocatalytic applications are evaluated. The integration of nickel into TiO2 influences its photovoltaic properties by enhancing the open-circuit voltage (Voc). However, higher concentrations lead to increased recombination and defects, decreasing efficiency. On conducting photocatalytic studies, TiO2 doped with 1 wt. % nickel exhibits superior photocatalytic efficiency, surpassing that of undoped TiO2. This improvement in photovoltaic and photocatalytic performance is attributed to better charge separation and reduced recombination. However, optimizing nickel levels is crucial for maximizing benefits for the applications using the performed synthesis strategy. [ABSTRACT FROM AUTHOR]

We theoretically analyze the electronic transport properties of a monolayer graphene/insulator/superconductor (G I S) tunnel junction subject to a temperature gradient. For intrinsic graphene, the system shows always dissipative charge transport even in the presence of an electronic temperature difference between the two leads. Differently, the G I S produces a thermoelectric response when the graphene electrochemical potential is lifted to energies comparable to the zero-temperature gap of the superconductor, i.e., the system is particle–hole asymmetric. Indeed, the thermally biased G I S system is able to produce both a short-circuit Peltier current and an open-circuit Seebeck voltage. This thermoelectric effect is made of a linear conventional component, due to the intrinsic particle–hole asymmetry of the system, and a non-linear contribution, due to a further spontaneous particle–hole symmetry breaking. In most of the thermal and charge configurations of the G I S system, the linear component prevails. Concluding, the G I S system could be employed in the design of thermometers, electromagnetic radiation sensors, and heat engines with profound influence in superconducting quantum technologies. [ABSTRACT FROM AUTHOR]

The large Stokes shifts usually result in open circuit voltage (VOC) reduction, which will affect the photovoltaic performance of the material. Recently, three-dimensional organosulfide-halide perovskites (CYS)PbCl2 and (CYS)PbBr2 [CYS: +NH3(CH2)2S−] have received much attention in the photovoltaic field due to their higher stability and similar photoelectric properties (desirable direct bandgap, band dispersion, and light absorption) than MAPbX3 (X = Cl, Br, and I). Unfortunately, both materials exhibit large Stokes shifts emission. Thus, to be clear about their application prospects in the photovoltaic field, the origin of the large Stoke shift needs to be investigated. Moreover, the bandgaps of (CYS)PbBr2 (2.17 eV) and (CYS)PbCl2 (2.32 eV) are higher than the ideal bandgap value of (0.9–1.6 eV) for photovoltaic materials. Based on density functional theory, this paper explores the cause of large Stokes shifts and further improves the photovoltaic performance of the materials by halogen substitution. The calculation results show that the large Stokes shifts come from defect emission rather than intrinsic self-trapping emission and the I atom substitution can reduce the bandgap [(CYS)PbI2; gap = 1.85 eV] and enhance the optical absorption and carrier migration ability without destroying the direct bandgap. Our research will promote the experimental synthesis of more excellent perovskite photovoltaic materials. [ABSTRACT FROM AUTHOR]

Shunt resistance R sh is a critical parameter for photovoltaic cells designed for low light indoor applications because it negatively affects the open circuit voltage, fill factor, and conversion efficiency. Standard CIGS cells are known to have low R sh and are, therefore, unpromising candidates for indoor energy sources. In this paper, we extend the original work of Virtuani et al. by determining the electrical specifications of many CIGS cells with copper contents [Cu]/([Ga]+[In]) as low as 0.33 and gallium contents between 0.28 and 0.81. First, IV data are fitted by a standard single-diode electrical circuit model for each illumination, resulting in light-dependent parameters. Then, we use a procedure based on a single dataset of electrical variables, i.e., independent of light, corrected by the experimental collection function, which captures light-dependent physical mechanisms. In this way, we are able to correctly reproduce the illuminance dependence of the electrical response of the PV cell over three orders of magnitude, in particular with a fixed value of the shunt resistance. The highest R sh is obtained with a low copper composition of 0.5 , regardless of the gallium composition. [ABSTRACT FROM AUTHOR]

Ultra-thin solar cells display high intrinsic radiation tolerance, making them interesting for space applications. This study investigates the dependence of the open-circuit voltage degradation and overall current–voltage behavior of devices with 80 nm thick GaAs absorber layers, on their absorber layer doping concentration and the radiation type used to introduce damage. The radiation types used were 1 MeV electrons and 20 keV, 100 keV, and 1 MeV protons. It is shown that the open-circuit voltage degradation rate increases with absorber layer doping concentration. This is linked to the increase in trap-assisted tunneling enhancement of the recombination rate, facilitated by the increase in electric field strength in the absorber layer with doping concentration. Trap-assisted tunneling is also found to contribute to the high local ideality factors observed in these devices, exceeding values of 2, and to be responsible for the trend of an increasing ideality factor with doping concentration. The significant role of trap-assisted tunneling in the devices is established through fitting of dark current–voltage data using a custom recombination–generation model. An open-circuit voltage degradation rate and local ideality factor curves are also shown to vary with radiation type, despite accounting for their differences in non-ionizing energy loss. This is corroborated by corresponding trends in carrier lifetime damage constants, extracted from the fitting of the dark current–voltage curves. This suggests that the introduction or behavior of radiation damage differs between ultra-thin and conventional, thicker solar cells, where non-ionizing energy loss theory tends to be reliable, especially over the studied proton energy range. [ABSTRACT FROM AUTHOR]

A large open-circuit voltage (VOC) deficit is the major challenge hindering the efficiency improvement of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells. Cation substitution, or doping, is usually an effective strategy to achieve carrier regulation and improve efficiency. In this work, we developed a rare-earth element lanthanum (La) doped CZTSSe thin-film solar cell by directly introducing La3+ ions into the CZTS precursor solution. Such a proposed La doping approach could effectively enhance light harvesting, adjust the bandgap, and increase the electron diffusion length. Furthermore, appropriate concentrations of La doping can reduce harmful defect cluster. Benefiting from the La doping, the VOC significantly increases from 431 to 497 mV. Consequently, the power conversion efficiency is enhanced significantly from 6.54% (VOC = 431 mV, JSC = 25.50 mA/cm2, FF = 58.28%) for the reference cell to 10.21% (VOC = 497 mV, JSC = 35.20 mA/cm2, FF = 58.41%) for the optimized La-doped cell. This research provides a new direction for enhancing the performance of CZTSSe cells, offering promising prospects for the future of CZTSSe thin-film solar cells. [ABSTRACT FROM AUTHOR]

An analytical device physics model is presented for determining the energy conversion efficiency of semiconductor nanowire array-based radial (core–shell) p-i-n junction betavoltaic cells for two- and three-dimensional radioisotope source geometries. Optimum short-circuit current density J sc , open-circuit voltage V oc , fill factor F F , and energy conversion efficiency η are determined for various nanowire properties, including dopant concentration, nanowire length, core diameter, and shell thickness, for Si, GaAs, and GaP material systems. A maximum efficiency of 8.05 % was obtained for GaP nanowires with diameter 200 nm (p-core diameter, i-shell, and n-shell thicknesses of 24, 29.4, and 58.6 nm, respectively), length 10 μ m , acceptor and donor concentrations of 10 19 and 5 × 10 18 cm − 3 , respectively, and a 3D source geometry. [ABSTRACT FROM AUTHOR]

Ag-doping treatment is a popular method for enhancing the performance of kesterite-structured Cu2ZnSn(S,Se)4 (CZTSSe) solar cells. Among the various methods, incorporating a high concentration of Ag+ into an absorber surface has proven to be particularly effective. However, the exact mechanisms behind this improvement are still unclear. This study aims to investigate the key factors that improve device performance through simulation. Specifically, the influence of the change in the carrier density, CuZn antisite defects, interface defect density, and formation of an n-type AZTSSe surface after heavy surface Ag doping have been examined. The simulation results indicate that the formation of an n-type AZTSSe layer on an absorber surface can significantly improve the open circuit voltage (VOC) and overcome the efficiency saturation problem induced by severe interface recombination for CZTSSe devices with a negative conduction band offset (CBO), compared to other affecting factors. This is because the modified conduction band alignment and the realization of interface-type inversion reduce interface recombination and retard the Fermi level pinning. However, the formation of interface-type inversion does not significantly improve CZTSSe devices with a positive CBO, as these devices already have weaker interface recombination. This work implies that the formation of an n-type AZTSSe layer is crucial for further improving the performance of CZTSSe devices with a negative CBO and can pave the way for improving the performance of thin film solar cells with severe interface recombination. [ABSTRACT FROM AUTHOR]

All-inorganic CsPbI2Br inverted perovskite solar cells (PSCs) have drawn increasing attention because of their outstanding thermal stability and compatible process with tandem cells. However, relatively low open circuit voltage (Voc) has lagged their progress far behind theoretical limits. Herein, we introduce phenylmethylammonium iodide and 4-trifluoromethyl phenylmethylammonium iodide (CFPMAI) on the surface of a CsPbI2Br perovskite film and investigate their passivation effects. It is found that CFPMAI with a –CF3 substituent significantly decreases the trap density of the perovskite film by forming interactions with the under-coordinated Pb2+ ions and effectively suppresses the non-radiative recombination in the resulting PSC. In addition, CFPMAI surface passivation facilitates the optimization of energy-level alignment at the CsPbI2Br perovskite/[6,6]-phenyl C61 butyric acid methyl ester interface, resulting in improved charge extraction from the perovskite to the charge transport layer. Consequently, the optimized inverted CsPbI2Br device exhibits a markedly improved champion efficiency of 14.43% with a Voc of 1.12 V, a Jsc of 16.31 mA/cm2, and a fill factor of 79.02%, compared to the 10.92% (Voc of 0.95 V) efficiency of the control device. This study confirms the importance of substituent groups on surface passivation molecules for effective passivation of defects and optimization of energy levels, particularly for Voc improvement. [ABSTRACT FROM AUTHOR]

In this study, the degradation behavior of flexible GaInP/GaAs/InGaAs (IMM3J) solar cells and their metamorphic subcells under 1 MeV electron irradiation was investigated. The remaining factors such as short-circuit current density (Jsc), open-circuit voltage (Voc), and maximum power (Pmax) were 95.62, 85.52, and 79.73%, respectively, at an irradiation fluence of 2 × 1015 e/cm2. The spectral responses of the InGaAs and GaAs subcells degraded significantly, and the InGaAs subcell experienced greater degradation than the GaAs subcell after irradiation. In addition, the current-limiting unit was switched from GaInP to InGaAs after irradiation. Defect analysis by deep-level transient spectroscopy (DLTS) revealed that with increasing irradiation fluence, the defects that had the greatest impact on the performance of GaAs subcells were EV + 0.36 and EV + 0.42 eV. For InGaAs subcells, the defects that had the greatest impact on the performance were EV + 0.29 and EV + 0.24 eV. The decrease in the minority carrier lifetime is the main reason for the decrease in the electrical performance of solar cells, and the variation in the effective minority carrier lifetime (τeff) in the subcells with the irradiation fluence was calculated based on the DLTS results. At a fluence of 2 × 1015 e/cm2, the τeff of the GaAs and InGaAs subcells decreased from 2.93 × 10−10 and 9.10 × 10−10 s to 1.56 × 10−11 and 1.60 × 10−12 s, respectively. These results provide a reference for predicting the degradation of short-circuit current and open-circuit voltage of flexible IMM3J. [ABSTRACT FROM AUTHOR]

The ability to spatially resolve the carrier mobility profile along the cross section of micrometer-thin solar cells is vital, both for fundamental studies in photovoltaics and as quality control for reproducibly obtaining high conversion efficiencies in commercial solar cell modules. Presently, no technique capable of such an endeavor is available to the best of our knowledge. Here, we introduce a novel method capable of profiling the carrier mobility along the z axis in thin-film photovoltaics. Our setup is based on the integration of photogenerated charge extraction by linearly increasing voltage (p-CELIV) with a scanning confocal optical microscope (SCOM) toward a confocal and cross-sectional p-CELIV (cs-p-CELIV) system. As monomolecular recombination of excess carriers is the most frequent radiative pathway for electrons and holes in solar cells at low power density of illumination, while multimolecular recombination dominates at high power, enhanced multimolecular recombination occurs at the SCOM focal plane. Thus, the cs-p-CELIV signal provides enhanced information on the mobility of all of the cross-sectional layers except the focal plane. By scanning the focal plane along the z axis, the mobility profile can be derived. To demonstrate our technique, we use it to investigate the carrier mobility in three hydrogenated amorphous silicon (a-Si:H) solar cells. The mobility profiles obtained by cs-p-CELIV correlate well with well-known depletion layer effects and the H content profile in a-Si:H, which is measured independently. Our findings are in excellent agreement with models suggesting a critical role of Si–H bonding in locally determining the carrier mobility in a-Si:H. [ABSTRACT FROM AUTHOR]

Thermodynamics shows that the open-circuit voltage (V o c) of a solar cell is dependent on the external radiative efficiency at V o c . In planar solar cells with low photon recycling probability, this efficiency is limited to 2% due to total internal reflection of the emitted light, providing a penalty of 101 mV to the V o c . Tapered nanowire solar cells allow for an adiabatic expansion of the guided optical mode into air, allowing to reduce this loss. For this purpose, we first perform simulations of the photon escape probability in tapered nanowires with both finite difference time domain simulations as well as with rigorous coupled-wave analysis, showing photon escape probabilities up to 47.2% for normally tapered nanowires and up to 92% for inversely tapered nanowires. We subsequently show that by fine tuning the recipe for reactive ion etching of the tapered InP nanowires, we can decrease the nanowire tapering angle from 4.5° down to 1.8°, allowing to significantly increase the measured external radiative efficiency. We finally observe an open-circuit voltage of 0.746 V at a tapering angle of 2.46°. [ABSTRACT FROM AUTHOR]

We investigate microlenses that selectively focus the light on only a small fraction of all nanowires within an arrayed InP nanowire solar cell. The nano-concentration improves both the short-circuit current (J s c ) and the open-circuit voltage (V o c ) of the solar cell. For this purpose, polymethyl methacrylate microlenses with 6 μm diameter were randomly positioned on top of an arrayed nanowire solar cell with 500 nm pitch. The microlenses were fabricated by first patterning cylindrical micropillars, which were subsequently shaped as lenses by using a thermal reflow process. The quality of the microlenses was experimentally assessed by Fourier microscopy showing strong collimation of the emitted photoluminescence. By analyzing the slope of the integrated photoluminescence vs excitation density, we deduce a substantial enhancement of the external radiative efficiency of a nanowire array by adding microlenses. The enhanced radiative efficiency of the lensed nanowire array results in a clear enhancement of the open-circuit voltage for a subset of our solar cells. The microlenses finally also allow to increase the short-circuit current of our relatively short nanowires, providing a route to significantly reduce the amount of expensive semiconductor material. [ABSTRACT FROM AUTHOR]

Global energy shortage puts stringent demand for energy harvesters capable of transforming external green vibration sources into electrical power. Employing a self-biased magnetoelectric (ME) composite of FeCuNbSiB/Ni/PZT (lead zirconate titanate), a prototype of vibration energy harvester is designed and fabricated. The energy harvester has a circular orbit in which a permanent magnetic cylinder reciprocates once an initial kinetic energy is provided. Upon a vibration signal, like handshaking, movement of the permanent magnetic cylinder causes an alternative magnetic field, which was applied on the ME composite. Via magnetic-force-electrical coupling, the ME composite of FeCuNbSiB/Ni/PZT produces output voltage. Finite element simulation is carried out to reveal the underlying mechanism of the harvester. The analysis shows that a maximum output voltage of 7.63 V can be obtained once an original potential energy is applied for the magnet. In particular, the magnet moves back and forth automatically inside the circular orbit with no need to further apply the energy. The effectiveness of the energy output is experimentally verified. When handshaking the energy harvester, a maximum open-circuit voltage of 5.51 V can be generated. The study offers a solution for power supplying some miniaturized or portable devices, such as small hand set and pedometer. [ABSTRACT FROM AUTHOR]

Realizing the graded bandgap in absorber layer is very essential for high efficient thin film solar cells. However, such bandgap modification in kesterite-structured Cu2ZnSnSe4 is normally realized via high temperature sulfurization process (above 500°C), which is not only difficult to control the sulfurization depth, but also introduces additional deep defects because of the decomposition of absorber layer at such high temperature. In this study, a low-temperature sulfurization process (150°C) is developed. Such process not only inhibits the decomposition of Cu2ZnSnSe4 films and controls the elemental distribution very well, but also increase the surface bandgap of the absorber layer and form a gradient energy bandgap. Also, the density of deep-level defects in the Cu2ZnSnSe4 layer is reduced. As a consequence, the open circuit voltage of the solar cell is improved by 60 mV. This study paves the way towards the high efficient kesterite solar cell and other solar cells. [ABSTRACT FROM AUTHOR]

Here, we describe a fully in situ method of fabricating light-scattering structures on III-V materials that generates a rough morphology via vapor phase etching and redeposition. Fully in situ methods support higher industrial throughput by utilizing the growth reactor to generate the light-trapping structures after device growth without removal from the reactor. We use HCl and PH3 to etch and redeposit scattering morphologies on Ga0.5In0.5P in a dynamic hydride vapor phase epitaxy (D-HVPE) reactor. We show that the addition of PH3 leads to redeposition during the vapor phase HCl etching of Ga0.5In0.5P and that HCl flow rate and time exposed to HCl-PH3 each independently cause a linear increase in the redeposited feature size, indicating that redeposition proceeds by island growth in a III-Cl-limited, hydride-enhanced HVPE regime. Auger electron spectroscopy and scanning transmission electron microscopy with energy dispersive spectroscopy (STEM-EDS) reveal redeposition to be highly Ga-rich GaInP, i.e., Ga(In)P. The Ga-rich nature of the redeposition results from the higher thermodynamic driving force for Ga incorporation than for In during HVPE growth and the difference in the volatility of the III-Cl etch products. The resulting morphologies have high broadband scattering, as determined by normal specular reflectance and integrating sphere measurements, indicating effectiveness as light-scattering structures. In a 270-nm-thick GaAs photovoltaic device with a textured back surface, we achieve a 4.9% increase in short circuit current density (JSC) without any loss in open-circuit voltage (VOC) relative to a planar control using only a 60 s in situ texturing treatment. [ABSTRACT FROM AUTHOR]

Although two-dimensional (2D) transition metal oxide monolayers have shown potential for applications in metal-ion batteries, the heterostructures of this family are yet to be studied in details for energy storage applications. In this work, we have made the heterostructure by taking half-metallic ferromagnetic 2D transition metal oxide CoO 2 and semiconducting MnO 2 monolayers and demonstrated its potential application as a cathode material in lithium and sodium-ion batteries by performing first-principles calculations using density functional theory approach. We have systematically studied the electronic structure and stability of the MnO 2 / CoO 2 heterostructure. We have carefully examined the adsorption and diffusion behavior of metal ions (lithium and sodium). Our structure has offered a maximum adsorption energy of − 3.84 eV, which is greater than the adsorption energy of individual monolayers. We found that the lowest diffusion barrier is 0.4 eV for lithium ion and 0.32 eV for sodium ion. Also, our system has shown a maximum open circuit voltage of 2.18 V for lithium ion battery and 0.32 V for Na-ion battery. The specific capacity is found to be 584 mAh g − 1 for lithium ion and 529 mAh g − 1 for sodium ion battery. These findings can serve as a proof that the MnO 2 / CoO 2 heterostructure should be considered as a potential cathode for lithium- and sodium-ion batteries. [ABSTRACT FROM AUTHOR]

We report on the application of solution-based p-type electrical doping using 12-molybdophosphoric acid hydrate (PMA) to the fabrication of organic tandem solar cells. Such a doping approach leads to a spatially confined vertical doping profile down to a limited depth from the surface of polymer films, thus allowing the hole-collecting component of the charge recombination stack to be embedded in the photoactive layer of the bottom sub-cell. This simplifies the device architecture by removing the need for an extra dedicated hole-collecting layer. It is shown that this novel charge recombination stack comprising a PMA-doped bottom photoactive layer and a trilayer of Ag/AZO/PEIE is compatible with a solution-processed top photoactive layer. The fabricated inverted organic tandem solar cells exhibit an open-circuit voltage that is close to the sum of the open-circuit voltages of the individual sub-cells, and a fill factor that is close to the better fill factor of the two sub-cells. [ABSTRACT FROM AUTHOR]

In this study, a piezoelectric nanogenerator (PENG) based on multilayer composite fiber had good and stable piezoelectric output performance, which could realize biomechanical energy collection and human movement monitoring. The polyvinylidene fluoride‐hexafluoryl propylene (P(VDF‐HFP)) composite fiber doped with MXene was used as a promising piezoelectric functional layer (MPFP). By electrospinning, P(VDF‐HFP) composite fiber was constructed by alternating electrospinning with polyurethane (TPU) nanofibers layer by layer. The adoption of MXene as a functional filler promoted the transformation of P(VDF‐HFP) from α to piezoelectric β‐crystal, the piezoelectric β‐crystal content of P(VDF‐HFP) increased, and the dielectric properties and polarization levels were enhanced. At the same time, the multi‐layer structure design improved the piezoelectric sensitivity and mechanical properties of the composite fiber, and the composite fiber was more flexible and had longer tensile strain. With excellent dielectric and mechanical properties, 3MPFP/TPU/3MPFP/TPU multilayer composite fibers showed piezoelectric sensitivity of 10.88 V/kPa. Under the action of palm pressing, the PENG generated an open circuit voltage of 25 V, and the voltage signal of the device under different motion forms had specific characteristics such as peak value, frequency, and shape, which could be used to realize the analysis of human motion forms. This study provided an efficient, simple, and creative new idea for the application of flexible energy storage electronic devices, PENGs, and piezoelectric sensors. [ABSTRACT FROM AUTHOR]

Summary: Solar‐powered devices, such as wireless networks, are a crucial component of the Internet of Things (IoT). Designing and creating a solar cell architecture with an extended light absorption regime at a reasonable cost is therefore exceedingly important. All inorganic bismuth‐based Cs2AgBiI6 planar perovskite solar cells (PSCs) have garnered enormous significance due to their exceptional stability against oxygen, heat, and moisture. However, the power conversion efficiencies of Cs2AgBiI6‐based planar PSCs remain relatively low, primarily due to their limited light absorption range and interfacial charge recombination losses. This issue can be effectively addressed using a novel multi‐absorber architecture that incorporates dual absorbers with both lower band gap and wider band gap materials. This approach extends the light absorption range, enabling maximal utilization of the solar spectrum. Therefore, this article incorporates numerical modeling and guided optimization of ITO/ETL/Cs2AgBiI6/Fa0.75Cs0.25SnI3/HTL/Ag dual absorber‐based heterojunction structure to improvise the power conversion efficiency of Cs2AgBiI6‐based single‐absorber PSCs. The proposed configuration employs dual perovskite absorber layers (PALs) consisting of wide band gap Cs2AgBiI6 (1.6 eV) as the top absorber layer along with narrow bandgap Fa0.75Cs0.25SnI3 (1.27 eV) to act as the bottom absorber layer. Before evaluating the bilayer configuration, two standalone PSC architectures, namely, ITO/ETL/Fa0.75Cs0.25SnI3/HTL/Ag (D1)‐ and ITO/ETL/Cs2AgBiI6/HTL/Ag (D2)‐based PSC have been simulated and computed to perfectly fit the earlier anticipated state of art results. After effective validation of the photovoltaic parameters of the standalone architectures, both the absorber layers are appraised to constitute a dual active layer configuration ITO/ETL/Cs2AgBiI6/Fa0.75Cs0.25SnI3/HTL/Ag (D3) maintaining the overall absorber layer width constant to elevate the overall solar cell efficiency. Herein, a combination of various competent hole transport layers (HTLs) such as CBTS, CFTS, Cu2O, CuI, CuO, CuSCN, P3HT, PEDOT:PSS, and Spiro‐OMeTAD, as well as electron transport layers (ETLs) like C60, CeO2, IgZo, PCBM, TiO2, WS2, and ZnO, are adopted and compared to attain highly efficient bilayer PSC configuration. The crucial variables of all ETL‐ and HTL‐based proposed bilayer solar cell configurations including the thickness of PALs, the width of the carrier transport layers, defect densities of transport layers, the effect of operating temperature, series, and shunt resistances have been extensively optimized and tuned to attain preeminent photovoltaic power conversion efficiencies (PCEs) and quantum efficiencies (QEs). It has been well evinced that the proposed configuration with dual‐absorber layers could effectively widen the light absorption regime to the near‐infrared range and thus significantly contribute toward enhanced photovoltaic performance. The simulation results attained with SCAPS showcase the outstanding performance of the proposed dual active layer solar structure obtained with the combination of CuSCN HTL and TiO2 ETL pair. The work concludes a 35.01% optimized efficient ITO/TiO2/Cs2AgBiI6(PAL‐2)/Fa0.75Cs0.25SnI3(PAL‐1)/CuSCN/Ag bilayer solar cell configuration with enhanced short circuit current density (Jsc) of 32.24 mA/cm2, open circuit voltage (Voc) of 1.273 V, and 85.31% fill factor (FF) with 0.6‐ and 0.8‐μm PAL‐1 and PAL‐2 width respectively and 1014‐cm−3 defect density under AM1.G solar spectrum illumination with 1000‐W/m2 light power density. The proposed eco‐friendly solar structure will also help in providing power backup to the next‐generation communication units and devices. Notably the dual‐absorber structure integrating Cs2AgBiI6 and Fa0.75Cs0.25SnI3 materials demonstrates significant advantages in quantum efficiency and spectral coverage compared to using either material independently as single absorbers. The proposed model achieves a peak efficiency of approximately 93% across a spectral range of 300–975 nm, surpassing the 90% efficiency obtained with a single Cs2AgBiI6 absorber covering 300–700 nm. Moreover, it exceeds the 89% efficiency achieved by the single Fa0.75Cs0.25SnI3 absorber within the 300‐ to 974.5‐nm spectral range. Solar cells play a pivotal role in ensuring the sustainability, reliability, and cost efficiency of powering wireless nodes, especially in remote or environmentally sensitive areas where traditional power sources may be inadequate or unavailable. The proposed PSC, with a PCE of 35.01%, can generate 350.1 watts under standard test conditions. This provides sufficient power to support approximately 70 wireless nodes, including wireless sensor nodes, IoT devices, and others, each consuming approximately 5 watts of power. [ABSTRACT FROM AUTHOR]

Two-step photon upconversion solar cells (TPU-SCs) based on III–V semiconductors can achieve enhanced sub-bandgap photon absorption because of intraband transitions at the heterointerface. From a technological aspect, the question arose whether similar intraband transitions can be realized by using perovskite/III–V semiconductor heterointerfaces. In this article, we demonstrate a TPU-SC based on a CsPbBr3/GaAs heterointerface. Such a solar cell can ideally achieve an energy conversion efficiency of 48.5% under 1-sun illumination. This is 2.1% higher than the theoretical efficiency of an Al0.3Ga0.7As/GaAs-based TPU-SC. Experimental results of the CsPbBr3/GaAs-based TPU-SC show that both the short-circuit current JSC and the open-circuit voltage VOC increase with additional illumination of sub-bandgap photons. We analyze the excitation power dependence of JSC for different excitation conditions to discuss the mechanisms behind the enhancement. In addition, the observed voltage-boost clarifies that the JSC enhancement is caused by an adiabatic optical process at the CsPbBr3/GaAs heterointerface, where sub-bandgap photons efficiently pump the electrons accumulated at the heterointerface to the conduction band of CsPbBr3. Besides the exceptional optoelectronic properties of CsPbBr3 and GaAs, the availability of a CsPbBr3/GaAs heterointerface for two-step photon upconversion paves the way for the development of high-efficiency perovskite/III–V semiconductor-based single-junction solar cells. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) have gained significant attention due to the abundant availability and low cost of sodium. However, the search for high-performance anode materials remains a critical challenge in advancing SIB technology. Based on first-principles swarm-intelligence structure calculations, we propose a metallic 1T′-MoSP monolayer as an anode material that offers a remarkably high storage capacity of 1011 mA h g−1, an ultralow barrier energy of 0.04 eV, and an optimal open-circuit voltage of 0.29 V, ensuring high rate performance and safety. Additionally, the monolayer presents favorable wettability with commonly used SIB electrolytes. Even after adsorbing three-layer Na atoms, the 1T′-MoSP monolayer retains its metallic nature, ensuring excellent electrical conductivity during the battery cycle. These desirable properties make the 1T′-MoSP monolayer a promising anode material for SIBs. [ABSTRACT FROM AUTHOR]

Flexible perovskite solar cells (PSCs) have received great attention due to their low weight, high power ratio, and potential applications in wearable electronic products. The efficiency and stability of flexible PSCs are directly affected by the carrier extraction and transport capabilities of electron transport layer. Herein, efficient flexible PSCs are prepared through incorporating 2,5‐Furandicarboxylic acid (FDCA) multifunctional intermediate layer between tin oxide (SnO2) and perovskite, which can effectively eliminate defects at the interfacial to increase the electron mobility of the SnO2 layer, modify the surface of SnO2 to shift the conduction band upward to improve interface charge extraction, passivate the buried interface of perovskite to induce larger perovskite crystal growth, and establish a bridge between SnO2 and perovskite to improve charge collection efficiency. As a result, the rigid PSCs with FDCA display a champion power conversion efficiency (PCE) of 24.53% with a high open circuit voltage (VOC) of 1.204 V. Furthermore, the flexible device with FDCA achieves a high PCE of 22.10%, and preserve 90% of its initial PCE after aging for 500 h at ambient condition without encapsulation, and maintain 81% of its original PCE after 10,000 bending cycles. [ABSTRACT FROM AUTHOR]

Wide‐bandgap (WBG) perovskite solar cells (PSCs) can be combined with other narrow‐bandgap cells to form tandem solar cells (TSCs), which have excellent commercialization prospects. However, the component of WBG perovskite is complex, and the crystallization process is difficult to control. Various bulk and surface defects in polycrystalline films lead to severe nonradiative recombination of photogenerated carriers, resulting in severe open‐circuit voltage (VOC) loss in WBG PSCs. Herein, a zwitterionic additive is introduced to alleviate the VOC deficit. The sulfinyl group (–SO) in formamidine sulfinic acid (FSA) has a robust interaction with Pb2+, which retards the crystallization and improves the crystal quality in perovskite films. Furthermore, FSA has negatively charged centers (–SO2−) and positively charged centers (–C(NH2)2+), which can passivate the halogen and cation vacancies, respectively. The improved crystalline quality and passivated defects reduce the capture of carriers by defects and facilitate higher VOC. With this strategy, the 1.68 eV bandgap PSCs achieve a champion efficiency of 22.06% and a high VOC of 1.25 V (VOC loss = 0.43 V). Moreover, the 2‐terminal perovskite/silicon TSCs are fabricated with an extraordinary power conversion efficiency of 28.81%. [ABSTRACT FROM AUTHOR]

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The performance of composite-based triboelectric nanogenerators (C–TENGs) was significantly enhanced through laser surface patterning and graphite coating. The laser etching process produced accurate and consistent patterns, increasing surface area and improving charge accumulation. SEM imagery confirmed the structural differences and enhanced surface properties of the laser-etched C–TENGs. Graphite fibers further augmented the contact surface area, enhancing charge accumulation and diffusion. Experimental results demonstrated that the optimized C–TENGs, especially those with line patterns and graphite coating, achieved a maximal 98.87 V open-circuit voltage (VOC) and a 0.10 µA/cm2 short-circuit current density (JSC) under a 20 N external force. Environmental tests revealed a slight decrease in performance with increased humidity, while long-term stability tests indicated consistent performance over three weeks. Practical application tests showed the potential of C–TENGs integrated into wearable devices, generating sufficient energy for low-power applications, thereby highlighting the promise of these devices for sustainable energy solutions. [ABSTRACT FROM AUTHOR]

Surface modifications not only improve the corrosion resistance of Co-Cr-Mo dental alloys (Bego Wirobond® C) but also ensure their long-term performance and reliability in dental applications. This paper describes the preparation of single-layer TiO2-ZrO2 sol–gel coatings on the Co-Cr-Mo dental alloy using the method of dip-coating. The TiO2-ZrO2 sol–gel coatings were sintered at 300 and 500 °C. SEM analysis shows that sintering at 300 °C produces a uniform, slightly dense structure without micro-cracks, while sintering at 500 °C results in a denser structure with micro-cracks due to higher stress and shrinkage. EDS confirms that sintering temperature affects the elemental composition of the coating, with higher temperatures causing the volatilization or diffusion of Ti and Zr. Roughness measurements indicate that the Ra value increases with the sintering temperature, meeting dental application requirements. Electrochemical measurements by open-circuit potential, EIS, and cyclic potentiodynamic curves demonstrate that sintering temperature and saliva composition affect corrosion resistance, with NaF and mouthwashes (Listerine Total Care Teeth Protection® and Meridol®) generally increasing charge transfer resistance and double-layer capacitance. The ceramic TiO2-ZrO2 coatings significantly reduce pitting corrosion susceptibility at physiological and acidic pH, with the 500 °C sintered coating showing better protective properties. These findings highlight the potential of TiO2-ZrO2 coatings in enhancing the performance of Co-Cr-Mo dental alloys. [ABSTRACT FROM AUTHOR]

Biodegradable implants as bone fixations may present a safe alternative to traditional permanent implants, reducing the risk of infections, promoting bone healing, and eliminating the need for removal surgeries. Structural integrity is an important consideration when choosing an implant material. As a biodegradable implant is being resorbed, until the natural bone has regrown, the implant material needs to provide mechanical stability. However, the corrosive environment of the human body may affect the fatigue life of the material. Conversely, mechanical stress can have an effect on electrochemical corrosion processes. This is known as corrosion fatigue. In the presented work, an experimental setup and methodology was established to analyze the corrosion fatigue of experimental bioresorbable materials while simultaneously monitoring the electrochemical processes. A double-walled measurement cell was constructed for a three-point bending test in Dulbecco's Phosphate-Buffered Saline (DPBS− −), which was used as simulated body fluid (SBF), at 37 ± 1 °C. The setup was combined with a three-electrode setup for corrosion measurements. Rod-shaped zinc samples were used to validate the setup's functionality. Preliminary static and dynamic bending tests were carried out as per the outlined methodology to determine the test parameters. Open-circuit as well as potentiostatic polarization measurements were performed with and without mechanical loading. For the control, fatigue tests were performed in an air environment. The tested zinc samples were inspected via scanning electron microscopy (SEM). Based on the measured mechanical and electrochemical values as well as the SEM images, the effects of the different environments were investigated, and the setup's functionality was verified. An analysis of the data showed that a comprehensive investigation of corrosion fatigue characteristics is feasible with the outlined approach. Therefore, this novel methodology shows great potential for furthering our understanding of the effects of corrosion on the fatigue of biodegradable implant materials. [ABSTRACT FROM AUTHOR]

Interfacial ionic defects in perovskite solar cells (PSCs) significantly influence the efficiency and long‐term stability. In this study, primarily simulation‐assisted analyses are conducted to explore the capacitive effect of these defects on the performance of PSCs through impedance analysis. Simulated data indicate a decrease in capacitance with increasing frequency, leading to a higher built‐in potential (ΔVbi = 150 mV). Moreover, an increase in capacitance with increasing light intensity is observed. Additionally, reducing the ionic defect concentration at the interfaces (from 1019 to 1016 cm−3) results in more significant band bending and a higher Vbi. Potential solutions to mitigate interfacial ionic defects, including doping at transport layer interfaces are proposed. Doping at both interfaces introduces an energy spike (valence band offset) of 0.21 eV and a cliff (conduction band offset) of 0.16 eV, respectively, for holes and electrons, leading to an improvement in the open circuit voltage (VOC). Finally, experimental results demonstrate a notable enhancement in VOC of 0.04 V with the introduction of Li+ doping at the electron transport layer/perovskite interface. These findings provide essential perceptions for effectively mitigating the effect of interfacial ionic defects on the performance of PSCs and enhance their overall performance. [ABSTRACT FROM AUTHOR]

An analytical study of the effect of gadolinium-doped ceria (GDC) electrolyte parameters on the output voltage, output power, open circuit no-load voltage, and leakage current is carried out for solid oxide fuel cell (SOFC). Conductivity due to both ions and electrons is considered for GDC electrolytes. The model incorporates various polarization losses such as activation overpotential, concentration overpotential, and ohmic potential losses in order to study the effect of electrolyte parameters on output voltage. The output voltage and, hence, the power density obtained from the model closely match the experimental reports, thus validating the model. Subsequently, the open circuit no-load voltage model and no-load leakage current are used to study the effect of electrolyte thickness and electronic conductivity on it during no-load conditions. During loaded condition, the model relating the electronic current with the ionic current is employed to analyze the effect of various SOFC parameters governing the electronic current density. This study will be instrumental in designing SOFC with low leakage current density and high output power in order to enhance the performance of SOFC. [ABSTRACT FROM AUTHOR]

Herein, we reported the synthesis of MnO2/ZIF-8 composite by employing two-step synthetic procedure. The synthesized samples have been characterized by utilizing various sophisticated physicochemical technique such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray (EDX) spectroscopy. The synthesized MnO2/ZIF-8 has been used as counter electrode (CE) for the fabrication of dye-sensitized solar cells (DSSCs). The effect of annealing temperature was studied, and the highest efficiency of 7.2% with a decent open-circuit voltage (Voc) of 0.77 V was achieved at 200 °C. The obtained efficiency of 7.2% is reasonable in comparison to the platinum (Pt)-based DSSCs (7.4%). This work proposed the construction of Pt-free CE for the development of cost-effective DSSCs with reasonable performance in terms of efficiency. [ABSTRACT FROM AUTHOR]

The power conversion efficiency (PCE) of dye-sensitised solar cells (DSSCs) measures their solar energy conversion performance. With PCEs below 15%, significant energy loss occurs, leading researchers to seek improvements to reduce fossil fuel dependence and enhance DSSCs as an alternative energy source. However, predicting PCE theoretically is challenging due to its dependence on various parameters. In this work, the improved normal model was used to predict the PCE accurately using DFT and TD-DFT of four nanocomposites consisting of catechin natural compound attached to carboxylated graphene quantum dots (GQD) that have been further doped at the centre/edge and decorated with a boronic group. The nanocomposites have been adsorbed on a TiO2 cluster for PCE estimation. This is the first attempt of using decorated GQD with boronic groups in a DSSC and estimating its PCE. The results show that the PCE of catechin improved from 0.077% to the range of 3.96% – 12.61% (B1-CG-C@TiO2 – B2-CG-C@TiO2). This was due to the improved short-circuit current density ($J_{sc}$ J sc ) and fill factor (FF) of all the nanocomposites and the improved open-circuit voltage ($V_{oc}$ V oc ) of all nanocomposites except B1-CG-C@TiO2 in comparison to catechin. This means all the designed nanocomposites are more promising candidates than catechin. Highlights: Adsorption at carboxyl group is the most stable site among hydroxyl and GQD base. The improved normal model gives accurate $V_{oc}$ V oc results. All designed nanocomposites exhibited higher PCEs than isolated catechin. Edged doping exhibited the highest $V_{oc}$ V oc , high $J_{sc}$ J sc , and highest PCE of 12.61%. [ABSTRACT FROM AUTHOR]

The conversion of ambient mechanical vibrations into electricity using piezoelectric nanogenerators (PENGs) has garnered significant attention from researchers over the past few years, in light of its potential in wearable applications. The high flexibility and significant ferroelectricity of poly(vinylidene fluoride) (PVDF) make them the most promising candidates for PENG applications among polymer piezoelectric materials. In the present work, NiO nanoparticles were incorporated in different ratios into a PVDF matrix, and their potential for use in piezoelectric nanogenerators was investigated. The PVDF/NiO (5 wt.%) nanocomposite PENG exhibited the highest electrical output, with a 2.8-fold increase in open-circuit voltage and short-circuit current observed as compared to a bare PVDF-based PENG. However, a further increase in the compositional ratio of NiO led to a decrease in PENG output. The improved piezoelectricity in the PVDF/NiO (5 wt.%) nanocomposite is attributed to the enhanced polar phases and improved ferroelectricity of PVDF. Further confirmation of the improved piezoresponse was explored by measurement of the piezoelectric coefficient (d33) and dielectric study of the nanocomposites. The PENG electrical output was further simulated using the finite elemental method in COMSOL Multiphysics 5.5. The simulated results matched well with the experimental output, which confirmed the improved electrical performance of the PVDF/NiO nanocomposite-based PENGs. The enhanced performance of the nanocomposite PVDF film is attributed to the higher β phase in the PVDF. The efficiency of the PENG devices in motion-sensing applications was also explored. Different output voltage signals corresponding to different movements of the nanocomposite-based PENGs make the device compatible with sensor applications. [ABSTRACT FROM AUTHOR]

The performance of dye-sensitized solar cells (DSSC) primarily depends upon many factors, such as the thickness of the semiconductor layer at the working electrode, dye/sensitizer concentration, and electrolyte. A methodical study is required in one place to deliberate the impact of all these factors on DSSC performance for better understanding and further advancement of the technology. This work emphasizes optimizing the absorption layer, specifically investigating the relationship between the thickness of the TiO2 layer and the concentration of N719 dye. The objective is to elucidate the interconnected effects of these parameters on the overall performance of the device. Additionally, the optimization of electrolyte composition was done with varying concentrations of additives, such as iodine, 4-tert-butyl-pyridine (TBP), guanidinium thiocyanate (GuNCS), and 1-butyl-3-methylimidazolium iodide (BMII) of electrolyte. Initially, the devices with varying TiO2 absorption layers were fabricated. The efficiency, fill factor (FF), open-circuit voltage (VOC), and short-circuit current (ISC) of devices were studied. The drop in open-circuit voltage (VOC) was noticed with the increase in thickness of the TiO2 layer. The highest efficiency was observed at 7.17% with the device fabricated using 6 absorption layer (17.46 μm) of TiO2, 0.7 mM concentration of N719 dye, and 0.03-M iodine, 0.1-M GuNCS, 0.5-M TBP, and 0.6-M BMII in electrolyte. Future developments in this research could focus on further fine-tuning these parameters for improved efficiency and exploring additional innovations in DSSC technology, ultimately contributing to the advancement of sustainable and efficient solar energy conversion systems. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) made from biocompatible materials serve as promising integrated power sources for portable wearable electronics due to many advantages such as lightweight, high flexibility, simple technique, and excellent breathability. In this work, we report the fabrication of electrospun polycaprolactone micro-nanofiber films (s-PCL) and convex-microdome-patterned polydimethylsiloxane (c-PDMS) utilizing electrospinning and micromolding techniques. These materials, s-PCL and c-PDMS, are utilized as positively and negatively charged tribosurfaces, respectively, in the development of a bioTENG device. The developed TENG device can generate a superior power output of 2 mW with an open-circuit voltage (VOC) of 188 V and short-circuit current (ISC) of 18.5 µA, even under a low triggering frequency of 5 Hz. In addition, TENG possesses outstanding durability and output performance stability over a continuous operation of nearly 16,000 cycles. Furthermore, the TENG demonstrates its capacity to harvest mechanical energy and convert it into electricity, capable of directly illuminating more than 100 LEDs. The electrospun s-PCL- and c-PDMS-based TENG can be considered for self-powdered wearable devices attached to fingers, wrists, feet, and other human body parts. [ABSTRACT FROM AUTHOR]

In recent years, exploring interactions between sunlight, semiconducting minerals and microorganisms in nature has attracted great attention. However, relatively little research has been conducted on the interaction between minerals and microorganisms in the plain areas of the Yellow River Basin under sunlight. In this study, the mineral composition and microbial community of red soil from the Ningxia Plain, China were analyzed. X–ray diffraction (XRD) results showed that red soil contained semiconducting minerals such as birnessite, hematite and goethite. 16S rRNA analysis found that electroactive microorganisms such as Proteobacteria, Firmicutes and Actinobacteriota were enriched in in–situ microbial community of red soil. Afterwards, electrochemical tests such as linear sweep voltammetry (LSV) and I–t curves, indicated that red soil exhibited good semiconducting properties under light irradiation. Finally, a dual chamber system and electrochemical techniques were used to explore the electron transfer relationship between red soil and microorganisms. The open circuit voltage (350 mV) and maximum power density (1242.72 mW/m2) of red soil cathode system were significantly improved compared to blank graphite electrode, indicating that red soil could serve as electron acceptors for microbial extracellular respiration. Red soil electrode in live bacteria exhibited the highest photocurrent density (0.29 μA/cm2) and the lowest charge transfer resistance (Rct) (223 Ω) under light conditions, indicating that red soil accelerated the rapid transfer of electrons, reduced polarization loss, and enhanced extracellular electron transfer (EET) process under light conditions. This study demonstrated that the participation of semiconducting minerals in microbial EET processes under sunlight in the Ningxia Plain, China. [ABSTRACT FROM AUTHOR]

The introduction of porosity into ferroelectric ceramics can decrease the effective permittivity, thereby enhancing the open circuit voltage and electrical energy generated by the direct piezoelectric effect. However, the decrease in the longitudinal piezoelectric coefficient (d33) with increasing porosity levels currently limiting the range of pore fractions that can be employed. By introducing aligned lamellar pores into (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3, this paper demonstrates an unusual 22–41% enhancement in the d33 compared to its dense counterpart. This unique combination of high d33 and a low permittivity leads to a significantly improved voltage coefficient (g33), energy harvesting figure of merit (FoM33) and electromechanical coupling coefficient (k332$k_{33}^2$). The underlying mechanism for the improved properties is demonstrated to be a synergy between the low defect concentration and high internal polarizing field within the porous lamellar structure. This work provides insights into the design of porous ferroelectrics for applications related to sensors, energy harvesters, and actuators. [ABSTRACT FROM AUTHOR]

This study presents a significant advancement in tandem dye-sensitized solar cells (T-DSSCs) through the strategic synthesis of novel triazatruxene (TAT) sensitizers MS-1 and MS-2. These organic sensitizers demonstrate exceptional light-harvesting capacity and overall performance, pushing the boundaries of power conversion efficiency (PCE) in DSSCs. The MS-1-based DSSCs achieved an impressive PCE of 12.81%, while MS-2 sensitizers reached a notable 10.92%. These efficiencies represent significant improvements over the conventional N719 dye (7.60%), demonstrating the potential of metal-free organic sensitizers in DSSC technology. The key to these noteworthy results lies in the molecular design of the organic sensitizers. The triazatruxene donor segment in the MS-1 and MS-2 dyes, featuring a rigid structure and efficient intramolecular charge transfer (ICT), proved to be a game-changer for photovoltaic properties. Building on these results, we explored an innovative parallel tandem cell (PT-DSSC) configuration. By connecting separate cells containing N719 and MS-1 sensitizers, we achieved a record efficiency of 12.89% with enhanced short-circuit current density (JSC) and open-circuit voltage (VOC)compared to single-dye cells. This study highlights the potential of molecular engineering in organic sensitizers and device optimization to enhance DSSC performance, paving the way for further advancements in solar cell technology. [ABSTRACT FROM AUTHOR]

Energy harvesting from ambient sources present in the environment is essential to replace traditional energy sources. These strategies can diversify the energy sources, reduce maintenance, lower costs, and provide near-perpetual operation of the devices. In this work, a triboelectric nanogenerator (TENG) based on silane-coupled Linde type A/polydimethylsiloxane (LTA/PDMS) is developed for harsh environmental conditions. The silane-coupled LTA/PDMS-based TENG can produce a high output power density of 42.6 µW/cm2 at a load resistance of 10 MΩ and operates at an open-circuit voltage of 120 V and a short-circuit current of 15 µA under a damping frequency of 14 Hz. Furthermore, the device shows ultra-robust and stable cyclic repeatability for more than 30 k cycles. The fabricated TENG is used for the physiological monitoring and charging of commercial capacitors to drive low-power electronic devices. Hence, these results suggest that the silane-coupled LTA/PDMS approach can be used to fabricate ultra-robust TENGs for harsh environmental conditions and also provides an effective path toward wearable self-powered microelectronic devices. [ABSTRACT FROM AUTHOR]

Metal halide perovskite ferroelectrics combining spontaneous polarization and excellent semiconducting properties is an ideal platform for enabling self‐driven X‐ray detection. However, achievements to date have been only based on uniaxiality, which increases the complexity of device fabrication. Multi‐axial ferroelectric materials have multiple equivalent polarization directions, making them potentially amenable to multi‐axial self‐driven X‐ray detection, but the report on these types of materials is still a huge blank. Herein, a high‐quality (BA)2(EA)2Pb3I10 (1) biaxial ferroelectric single crystal was successfully grown, which exhibited significant spontaneous polarization along the c‐axis and b‐axis. Under X‐ray irradiation, bulk photovoltaic effect (BPVE) was exhibited along both the c‐axis and b‐axis, with open circuit voltages (Voc) of 0.23 V and 0.22 V, respectively. Then, the BPVE revealed along the inversion of polarized direction with the polarized electric fields. Intriguingly, due to the BPVE of 1, 1 achieved multi‐axial self‐driven X‐ray detection for the first time (c‐axis and b‐axis) with relatively high sensitivities and ultralow detection limits (17.2 nGyair s−1 and 19.4 nGyair s−1, respectively). This work provides a reference for the subsequent use of multi‐axial ferroelectricity for multi‐axial self‐driven optoelectronic detection. [ABSTRACT FROM AUTHOR]

Metal halide perovskite ferroelectrics combining spontaneous polarization and excellent semiconducting properties is an ideal platform for enabling self‐driven X‐ray detection. However, achievements to date have been only based on uniaxiality, which increases the complexity of device fabrication. Multi‐axial ferroelectric materials have multiple equivalent polarization directions, making them potentially amenable to multi‐axial self‐driven X‐ray detection, but the report on these types of materials is still a huge blank. Herein, a high‐quality (BA)2(EA)2Pb3I10 (1) biaxial ferroelectric single crystal was successfully grown, which exhibited significant spontaneous polarization along the c‐axis and b‐axis. Under X‐ray irradiation, bulk photovoltaic effect (BPVE) was exhibited along both the c‐axis and b‐axis, with open circuit voltages (Voc) of 0.23 V and 0.22 V, respectively. Then, the BPVE revealed along the inversion of polarized direction with the polarized electric fields. Intriguingly, due to the BPVE of 1, 1 achieved multi‐axial self‐driven X‐ray detection for the first time (c‐axis and b‐axis) with relatively high sensitivities and ultralow detection limits (17.2 nGyair s−1 and 19.4 nGyair s−1, respectively). This work provides a reference for the subsequent use of multi‐axial ferroelectricity for multi‐axial self‐driven optoelectronic detection. [ABSTRACT FROM AUTHOR]

Controlling crystal growth alignment in low-dimensional perovskites (LDPs) for solar cells has been a persistent challenge, especially for low-n LDPs (n < 3, n is the number of octahedral sheets) with wide band gaps (>1.7 eV) impeding charge flow. Here we overcome such transport limits by inducing vertical crystal growth through the addition of chlorine to the precursor solution. In contrast to 3D halide perovskites (APbX3), we find that Cl substitutes I in the equatorial position of the unit cell, inducing a vertical strain in the perovskite octahedra, and is critical for initiating vertical growth. Atomistic modelling demonstrates the thermodynamic stability and miscibility of Cl/I structures indicating the preferential arrangement for Cl-incorporation at I-sites. Vertical alignment persists at the solar cell level, giving rise to a record 9.4% power conversion efficiency with a 1.4 V open circuit voltage, the highest reported for a 2 eV wide band gap device. This study demonstrates an atomic-level understanding of crystal tunability in low-n LDPs and unlocks new device possibilities for smart solar facades and indoor energy generation. Controlling crystal growth alignment in wide bandgap low-dimensional perovskites has been a persistent challenge. Here, authors induce vertical crystal growth through the addition of chlorine to precursor solution, giving rise to a record power conversion efficiency of 9.4% for 2 eV bandgap devices. [ABSTRACT FROM AUTHOR]

A series of six DPP-based organic small molecule photovoltaic donor materials were designed and synthesized successfully. The targeted structural design and regulation of the materials were carried out in three steps. Firstly, the introduction of a π-bridge in the molecule enhances the intramolecular charge transfer (ICT) effect and improves the short-circuit current (Jsc) of the device. Secondly, different end groups were introduced to adjust the energy levels of molecules, to obtain more matching donor materials for acceptor materials. Finally, the molecular configuration was adjusted to meet the requirements of increasing the open circuit voltage (Voc). It is worth mentioning that for the end group regulation strategy, a small molecule donor was synthesized, in which fluorene-capped triarylamine as the electron-donating unit provided a reference for the future development of related donor materials. To our knowledge, the selection of triphenylamine and phenyl-carbazole as central nuclei for double-armed small molecule donors has been rarely reported. In this work, triphenylamine and phenyl-carbazole were used as the central nuclei of the A–π–D–π–A type molecular configuration, resulting in lower HOMO energy levels and higher Voc. As a result, without further optimization of the devices, the power conversion efficiency (PCE) of the photovoltaic device based on (DPP)2TPA was more than three times that of a previously reported device based on TPA-DPP-TPA, and the PCE of the device based on (DPP)2PCZ was more than twice that of a previously reported device based on SM1. Our work demonstrates that optimization of photovoltaic performance can be achieved through rational structural design and configuration regulation of the photovoltaic material, which provides important guidance for the development of novel photovoltaic materials in the future. [ABSTRACT FROM AUTHOR]

Palladium hydride (PdHx) is one of the well‐known electrocatalytic materials, yet its synthesis is still a challenge through an energy‐efficient and straightforward method. Herein, we propose a new and facile cyanogel‐assisted synthesis strategy for the preparation of PdH0.649 at a mild environment with NaBH4 as the hydrogen source. Unlike traditional inorganic Pd precursors, the unique Pd−CN−Pd bridge in Pdx[Pd(CN)4]y ⋅ aH2O cyanogel offers more favourable spatial sites for insertion of H atoms. The characteristic three‐dimensional backbone of cyanogel also acts as a support scaffold resulting in the interconnected network structure of PdH0.649. Due to the incorporation of H atoms and interconnected network structure, the PdH0.649 achieves a high half‐wave potential of 0.932 V, a high onset potential of 1.062 V, and a low activation energy, as well as a long‐term lifetime for oxygen reduction reaction. Theoretical calculation demonstrates a downshift of the d‐band centre of Pd in PdH0.649 owing to the dominant Pd−H incorporation that weakens the binding energies of the *OH intermediate species. Zn‐air batteries (ZAB) based on PdH0.649 exhibits high power density, competitive open circuit voltage, and good stability, exceeding that of commercial Pt black. This work not only opens up a new avenue for the development of high‐efficiency Pt‐free catalysts but also provides an original approach and insight into the synthesis of PdHx. [ABSTRACT FROM AUTHOR]

Solid biopolymer electrolytes for zinc primary battery based on cellulose acetate (CA) and zinc chloride (ZnCl2) have been prepared by solution casting technique with Dimethylformamide (DMF) as the solvent. X-ray diffraction analysis provides that biopolymer membrane 40 wt% of CA:60 wt% of ZnCl2 shows very high amorphous nature. Complex formation between biopolymer CA with ZnCl2 has been confirmed by FTIR measurements. Biopolymer membrane 40 wt% of CA:60 wt% of ZnCl2 shows a high zinc ionic conductivity of 3.04 × 10–3 S/cm calculated from impedance measurements. Wagner's Polarization measurements indicates that charge carriers are ions and the highest zinc ionic conductivity membrane has got low glass transition temperature 35 °C determined by DSC studies. The electrochemical stability of the highest zinc ion conductivity membrane is found to be 2.15 V by LSV technique. The cyclic stability of the prepared membrane has been determined by cyclic voltammetry analysis. Transport parameters such as Diffusion constant (D), mobility (μ) and relaxation time (τ) have been calculated for the biopolymer electrolytes. A primary zinc ion battery has been constructed using zinc plate as anode, highest zinc ion conducting membrane as an electrolyte and MnO2 as cathode shows an open-circuit voltage 1.55 V. The performance of the battery has been studied with various loads. [ABSTRACT FROM AUTHOR]

Diamond materials hold great potentials with favorable characteristics for betavoltaic cells, thanks to their simple structure, high conversion efficiency, and radiation robustness. However, to explore its efficiency limit is greatly hindered by the material growth, doping techniques, and device design as well. In this work, a device model based on a diamond metal/intrinsic/p-type (MIP) Schottky barrier architect is analyzed for an accurate prediction of the efficiency limit for the betavoltaic cell based on such a structure. The study takes various factors of significance into account on the betavoltaic cell device characteristics, including the radiation source, thickness and doping concentration of the intrinsic layer, metal work function, as well as the metal/diamond interface traps and traps in the bulk. The current–voltage characteristics and fundamental parameters of the betavoltaic cells are thoroughly analyzed. According to our results, an open-circuit voltage of 2.04 V, a short-circuit current density of 87 nA·cm−2, and a fill factor of 0.9 for the diamond MIP betavoltaic cell can be achieved, which give a maximum energy conversion efficiency of 10.7%, at optimal conditions using 50 nm thick Al metal as the contact layer, 9 μm thick and 1 × 1014 cm−3-doping intrinsic layer, and 10 μm thick and 2 × 1017 cm−3-doping p-layer under a 2 μm 63Ni irradiation. This work also discusses the impact of the interface/bulk traps on the barrier heights of practical Schottky diodes and the device's performance as well. [ABSTRACT FROM AUTHOR]

In this paper, the experimentally studied perovskite solar cell structure, ITO/SnO2/(FAPbI3) 1 − x (MAPbBr 3 − y Cly)x/Spiro-OMeTAD/Au, is considered as our primary cell structure. The Solar Cell Capacitance Simulator is used to investigate the cell performance. The cell performance is obtained after optimizing the influence of layer thickness (open circuit voltage = 1. 0 3 V, short circuit current = 2 5. 2 1 mA/cm2, fill factor = 6 5. 4 9 %, power conversion efficiency = 1 7. 0 2 %). In addition, various inorganic hole transporting layers are incorporated in place of Spiro-OMeTAD to improve cell stability and performance. Finally, with an open circuit voltage = 1. 1 3 V, a short circuit current = 2 7. 6 4 mA/cm2, a fill factor = 6 2. 1 5 %, and a power conversion efficiency = 19.55%, the optimized cell structure i.e., ITO/SnO2/(FAPbI3) 1 − x (MAPbBr 3 − y Cly)x/CulnSe2/Au, performs better. The cell performance is examined in relation to defect density in the absorber layer and at the layer interface. The primary cell results are also validated with the existing experimental results in the literature. This research will pave the way for the development of highly efficient mix-cation perovskite solar cells. [ABSTRACT FROM AUTHOR]

Wide-bandgap (WBG) perovskite solar cells (PSCs) are employed as top cells of tandem cells to break through the theoretical limits of single-junction photovoltaic devices. However, WBG PSCs exhibit severe open-circuit voltage (Voc) loss with increasing bromine content. Herein, inhomogeneous halogen-phase distribution is pointed out to be the reason, which hinders efficient extraction of carriers. We thus propose to form homogeneous halogen-phase distribution to address the issue. With the help of density functional theory, we construct a double-layer structure (D-2P) based on 2-(9H-Carbazol-9-yl)ethyl]phosphonic acid molecules to provide nucleation sites for perovskite crystallization. Homogeneous perovskite phase is achieved through bottom-up templated crystallization of halogen component. The efficient carrier extraction reduces the Shockley-Read-Hall recombination, resulting in a high Voc of 1.32 V. As a result, D-2P-treated device (1.75 eV) achieves a record power conversion efficiency of 20.80% (certified 20.70%), which is the highest value reported for WBG (more than 1.74 eV) PSCs. Wide-bandgap perovskite solar cells suffer from severe open-circuit voltage loss with increasing bromine content. Here, authors tackle this issue through homogeneous halogen-phase distribution realized by bottom-up templated crystallization and demonstrate tandem devices with efficiency of 28.08%. [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]

Sodium-ion batteries (SIBs) have emerged as a promising alternative to lithium-ion batteries (LIBs) due to the abundant availability of sodium, lower costs, and comparable electrochemical performance characteristics. A thorough understanding of their performance features is essential for the widespread adoption and application of SIBs. Therefore, in this study, we investigate the output characteristics and electrochemical impedance spectroscopy (EIS) features of sodium-ion batteries (SIBs) under various states. The research results show that, unlike conventional lithium iron phosphate (LFP) batteries, SIBs exhibit a strong linear relationship between state of charge (SOC) and open-circuit voltage (OCV) across various SOC and temperature conditions. Additionally, the discharge capacity of the battery remains relatively stable within a temperature range of 15 °C to 35 °C; when the temperatures are outside this range, the available capacity of the sodium-ion battery reduces significantly. Moreover, the EIS profiles in the high-frequency region are predominantly influenced by the ohmic internal resistance, which remains largely unaffected by SOC variations. In contrast, the low-frequency region demonstrates a significant correlation between SOC and impedance, with higher SOC values resulting in reduced impedance, indicated by smaller semicircle radii in the EIS curves. This finds highlights that EIS profiling can effectively monitor SOC and state of health (SOH) in SIBs, offering a clear correlation between impedance parameters and the battery's operational state. The research not only advances our understanding of the electrochemical properties of SIBs but also provides a valuable reference for the design and application of sodium-ion battery systems in various scenarios. [ABSTRACT FROM AUTHOR]