Lithium‑sulfur batteries (LSBs) suffer from lithium polysulfide (LiPS) shuttling and slow redox kinetics. To mitigate these issues, we report an efficient electrocatalytic interlayer based on a FeCoNiCrMn high-entropy alloy embedded in N-doped carbon nanofibers (HEA@NCNF). The multi-metallic HEA offers abundant active sites, while the N-doped carbon shell not only prevents HEA particle agglomeration and metal leaching, but also establishes a three-dimensional conductive network. Combined X-ray photoelectron spectroscopy and density functional theory calculations elucidate the underlying mechanism: electron modulation from the N-doped carbon layer raises the d-band center of the HEA, thereby strengthening LiPS adsorption and promoting its electrocatalytic conversion. Consequently, the HEA@NCNF interlayer functions as an efficient "trap-and-convert" reactor for LiPSs, which simultaneously suppresses shuttle effects and accelerates redox kinetics. The cells with HEA@NCNF demonstrate exceptional cycling and rate performance, with a capacity decay of only 0.023% per cycle over 1500 cycles at 1C. Remarkably, this superior performance extends to challenging conditions, including high sulfur loading (≥ 7 mg cm-2), lean electrolyte, and high-rate operation. This work demonstrates a strategy of integrating HEAs with conductive N-doped carbon matrices to create a synergistic trap-convert mediator for LiPSs.

Lithium‑sulfur batteries (LSBs) suffer from sluggish sulfur redox kinetics and the polysulfide shuttle effect. Herein, we report a noble-metal-free MnFeCoNiCu high-entropy alloy (FCNMC-HEA) electrocatalyst uniformly supported on multi-walled carbon nanotubes (MWCNT), rationally designed via an electronegativity-guided strategy. By introducing low-electronegativity Mn and high-electronegativity Cu into a FeCoNi medium-entropy alloy (MEA) matrix, we create a gradient electronegativity distribution that drives directional electron transfer between adjacent metal sites, resulting in a significant upshift of the d-band center toward the Fermi level. The resultant FCNMC-HEA/MWCNT/S cathode delivers exceptional electrochemical performance, including a high discharge capacity of 1393.0 mAh g−1 at 0.1C, an impressive rate capability of 436.2 mAh g−1 at 14C, and outstanding long-term cycling stability with an ultra-low capacity decay rate of 0.058% per cycle over 900 cycles at 1C. This work demonstrates that electronegativity-guided d-band center modulation is a powerful strategy for designing advanced high-entropy alloy electrocatalysts, providing a universal design principle for high-performance LSBs and other electrochemical energy storage systems.

The incorporation of the Se element in CdTe solar cells is critical, while the low bandgap CdSexTe1-x, formed by the interdiffusion of CdTe and CdSe during device preparation, can promote the carrier lifetime. Different window layers formed by CdSe w/o MZO or CdS have different Se distributions. This paper systematically evaluates the influence of four types of window layers (CdSe, CdS/CdSe, MZO/CdSe and MZO/CdS/CdSe) on the performance of CdTe solar cells, and focuses on the correlation between the window layers and the Se distribution characteristic, carrier recombination mechanism, and device efficiency. The results show that CdSe and MZO/CdS/CdSe window layer devices achieve Eff of 15.21% and 14.40%, respectively. The CdSe and MZO/CdS/CdSe devices exhibit relatively high Ea of 1.41 eV and 1.39 eV from J-V-T measurements, coupled with high Rrec of 9458 Q and 8293 Q, respectively. This indicates suppressed recombination, suggesting that non-radiative recombination is reduced. In contrast, the CdS/CdSe and MZO/CdSe devices show lower performance. Their extrapolated Ea values are 1.25 eV and 1.31 eV, with correspondingly lower Rrec values of 2207 Q and 3304 Q. These results point to faster recombination rates and an increased proportion of non-radiative recombination, consistent with their suboptimal Eff. Detailed analysis of Se distribution reveals that S-Se interdiffusion in S-containing devices results in the x-value decrease (highest value of Se content in CdSexTe1-x), thereby suppressing the long-wavelength expansion. In devices of S-free window layers, the formed CdSexTe1-x alloy has a relatively higher x-value, allowing the long-wavelength response to extend beyond 850 nm. It can be concluded that CdSe is the optimal window layer for CdTe Solar Cells, which can both form a desirable Se distribution and a good junction with less interface recombination.

Lithium‑sulfur batteries (LSBs) are regarded as a promising next-generation energy storage system due to their high theoretical energy density. However, the shuttle effect of lithium polysulfides (LiPSs) and sluggish sulfur conversion kinetics remain major bottlenecks for practical applications. Herein, we propose and implement a "vacancy and heteroatom doping dual-modulation" strategy to synthesize phosphorus-doped FeS catalysts enriched with sulfur vacancies (P-4-FeS). We reveal a volcano-type relationship between sulfur vacancy concentration and catalytic activity in the FeS system, with an optimal vacancy concentration (4-FeS) exhibiting the best catalytic performance. Further introduction of phosphorus doping effectively supports structural stability, overcoming the long-standing trade-off between high activity and poor stability. The P-4-FeS catalyst significantly enhances LiPS adsorption, charge transfer, and redox kinetics. Consequently, LSBs with the S/P-4-FeS cathode deliver outstanding rate capability (557.3 mAh g-1 at 7C) and exceptional long-term cycling stability (an ultralow capacity decay rate of 0.034% per cycle over 1400 cycles at 1C). Moreover, under a high sulfur loading of 6.0 mg cm-2 and a lean electrolyte condition (electrolyte/sulfur = 5 μL mg-1), the battery achieves a high areal capacity of 4.16 mAh cm-2 with excellent capacity retention. This dual-modulation strategy offers a versatile approach for designing highly active and stable electrocatalysts for high-energy-density LSBs.

High-entropy alloys (HEAs) offer a promising solution to address the persistent challenges of the lithium polysulfide (LiPS) shuttle effect and sluggish conversion kinetics during the discharge process of lithium-sulfur (Li-S) batteries. However, the intricate synergistic mechanisms involving their multi-component atomic interactions remain poorly understood. Herein, we rationally designed and successfully synthesized PtNiCoFeW HEAs (PNCFW-HEAs) as model catalysts. Through comprehensive characterization techniques, including Xray absorption fine structure spectroscopy, complemented by in situ experiments and theoretical calculations based on density functional theory, d-band center theory, and frontier molecular orbital analysis, we elucidate the catalytic origins of PNCFW-HEAs in Li-S batteries. Our results demonstrate that hybridization of metal 3d orbitals in PNCFW-HEAs induces substantial modifications to the electronic structure, accompanied by significant electron redistribution. This phenomenon facilitates the optimization of the d-band center, which moves closer to the Fermi level. Furthermore, a reduced energy gap between HOMO and LUMO indicates strong interactions between PNCFW-HEAs and Li2S4, enhancing LiPS adsorption and significantly accelerating the critical conversion step from Li2S4 to Li2S. Consequently, the S/PNCFW-HEA cathode exhibits exceptional cycling stability: it maintains a capacity decay rate of only 0.036% per cycle over 1000 cycles at 1C and demonstrates stable performance for more than 560 cycles even at a high rate of 5C. This work not only validates the immense potential of HEAs to mitigate the polysulfide shuttle effect and enhance reaction kinetics but also establishes crucial design principles for developing high-performance Li-S battery catalysts.

A crown ether named dibenzo-18-crown-6 is introduced to modify the interface between the perovskite and the electron transport layers. Due to its unique electron cavity and electron-rich system, it effectively passivates defects and simultaneously suppresses cation migration, thereby achieving a high power conversion efficiency of 24.19% with excellent stability.

Tunnel Oxide-Passivated Back Contact solar cells represent a next-generation photovoltaic technology with significant potential for achieving both high efficiency and low cost. This study addresses the challenge of low bifaciality inherent to the rear-side structure of TBC cells. Using the Quokka3 simulation and assuming high-quality surface passivation and fine-line printing accuracy, a systematic optimization was conducted. The optimization encompassed surface morphology, optical coatings, bulk material parameters (carrier lifetime and resistivity), and rear-side geometry (emitter fraction, metallization pattern and gap width). Through a multi-parameter co-optimization process aimed at enhancing conversion efficiency, a simulated conversion efficiency of 27.26% and a bifaciality ratio of 92.96% were achieved. The simulation analysis quantified the trade-off relationships between FF, bifaciality, and efficiency under different parameter combinations. This enables accurate prediction of final performance outcomes when prioritizing different metrics, thereby providing scientific decision-making support for addressing the core design challenges in the industrialization of TBC cells.

Lithium-sulfur batteries (LSBs) are regarded as a promising next-generation energy-storage technology due to their ultrahigh theoretical energy density, abundance of sulfur, and low cost. However, their practical application is still hindered by several challenges, most notably the shuttle effect of soluble lithium polysulfides (LiPSs), which leads to rapid capacity decay, limited cycle life, and poor rate performance. In this work, we introduce a VO2-MXene composite as a functional coating on the separator. Within this system, oxygen-deficient VO2-x provides abundant oxygen vacancy (Ov) and reversible insertion/extraction sites, while MXene acts as a highly conductive polar scaffold. The intimate heterointerface formed between VO2 and MXene promotes electron transport and stabilizes the electrode architecture. Notably, asymmetric Ti-O-V orbital hybridization (AOH) at the interface greatly enhances the thermodynamic stability of oxygen vacancy in VO2. The combined action of stabilized Ov and the polar MXene enables strong chemical anchoring of Li2Sn species, suppresses their dissolution toward the anode, mitigates self-discharge and capacity fade, and thus effectively restrains the shuttle effect. LSBs equipped with the VO2-x/MXene-modified separator exhibit excellent electrochemical performance: at 1 C, an initial specific discharge capacity of 936.9 mAh g- 1 is achieved, and 722.3 mAh g- 1 is retained after 300 cycles. This study offers a new strategy for developing high-performance LSBs and presents an effective route to alleviate polysulfide shuttling and sluggish conversion kinetics.

Most existing studies on high-entropy alloy (HEA) sulfur electrocatalysts rely on changing elemental species to adjust their affinity for lithium polysulfides (LiPSs) and matching redox catalytic activity, so as to alleviate the intrinsic trade-off between LiPS adsorption and desorption. In this work, interconnected carbon fibers (CF) modified with CrMnFeCoNi HEA nanoparticles of tunable atomic ratios are synthesized to uncover the correlation between catalytic activity and surface electronic configuration toward efficient sulfur electrocatalysis. Combining density functional theory (DFT) calculations and systematic experimental characterizations, we demonstrate that tuning the atomic ratios of metallic elements within CrMnFeCoNi HEA can redistribute their surface charge, shift the positions of the d-band center, and ultimately regulate their adsorption affinity toward LiPSs. The optimized HEA catalyst achieves a favorable balance between adsorption and desorption, which drastically boosts the catalytic efficiency of LiPS conversion. Consequently, the cell based on the optimized CF/HEA-1 interlayer delivers a high reversible capacity of 938 mAh g⁻1 and maintains stable long-term cycling over 2000 cycles at 1.0 C, corresponding to an ultralow capacity decay rate of 0.022% per cycle. This work proposes a feasible electronic modulation strategy to optimize HEA catalytic behavior, providing valuable guidance for the design of advanced lithium-sulfur battery electrocatalysts.

Understanding how lithium ions (Li+) dynamically couple with electronic orbitals during redox remains a fundamental challenge in lithium-sulfur batteries (LSBs), where sluggish Li2S <-> polysulfides (LiPS) conversion limits kinetics. Here, we reveal an orbital-resolved mechanism in which Li+ from LiPS undergoes reversible insertion/extraction at N-C defect sites in Co@NCNT during charge/discharge. Depth-resolved X-ray photoelectron spectroscopy and in situ X-ray diffraction directly capture the associated electronic and structural evolution. Inverse and ultraviolet photoemission spectroscopy (IPES/UPS) identifies the origin of this behavior as orbital overlap of Co 3d-Li 2s states. Coupling with Ti3C2 strengthens this overlap, thus enabling energetically favorable Li+ accommodation and accelerating bidirectional LiPS conversion. Density functional theory (DFT) calculations further confirmed the orbital alignment and Li+ interaction energetics. This mechanism enables a Co@NCNT/Ti3C2-based LSB to deliver 1388.5 mAh g- 1 at 0.1 C, 559.2 mAh g- 1 at 5 C, and stable cycling over 700 cycles with suppressed shuttle effects. A pouch cell coupled Co@NCNT/Ti3C2-modified separator achieves an energy density of 312.2 Wh kg- 1 and retains 93.9 % capacity after 100 cycles. These findings establish orbitalresolved Li+ accommodation as a governing principle for sulfur redox chemistry, offering a new paradigm for orbital engineering in energy storage systems.

The glass frit composition in silver paste is critical to the Ag-Si contact resistance of crystalline silicon solar cells and thus the device's power conversion efficiency (PCE). Glass frits employ silicon dioxide as the primary network former to construct an amorphous network, with additives such as PbO, Bi2O3, and TeO2 used to regulate their structural stability, high-temperature wettability, and interfacial reactivity. However, existing studies have predominantly focused on the regulation of glass frit properties by components like Bi2O3 and TeO2, while the systematic impact mechanism of the PbO/SiO2 molar ratio-a core parameter-remains insufficiently elucidated. In this work, a series of glass frits with varying PbO/SiO2 molar ratios were synthesized. The effects of the ratio on the glass transition temperature (Tg) and amorphous structure were characterized, and the frits were formulated into silver paste for application in monocrystalline silicon solar cells to evaluate their regulatory effects on Ag-Si contact resistance and cell performance. The experimental results show that as the PbO/SiO2 molar ratio decreases from 10 to 2, the interfacial specific contact resistance initially decreases and then increases. At an optimal PbO/SiO2 molar ratio of 6, the glass frit achieves an optimal balance between the glass transition temperature (288 degrees C) and high-temperature reactivity, forming a continuous amorphous layer and uniformly distributed silver nanoparticles at the interface. This reduces the specific contact resistance to as low as 0.79 m Omega cm(2), which is an similar to 8% reduction compared to groups with extreme PbO/SiO2 molar ratios, and increases the corresponding cell PCE to 23.65% (an improvement of similar to 1 percentage point).

Co-based transition-metal oxides are promising electrocatalysts for lithium-sulfur batteries (LSBs). However, their catalytic performance is fundamentally constrained by the low-spin state of octahedral Co3+ (t2g causes insufficient availability of the eg orbitals for effective polysulfide binding. Herein, we propose a spin-state engineering strategy through superexchange interactions to precisely regulate eg orbital electron occupation. Partial substitution of Co3+ with Mn3+ in LaCoO3 activates superexchange interactions along the Mn3+-O2--Co3+ pathway. This drives charge transfer from Co3+ to Mn3+ through the bridging oxygen, induces a rearrangement of the Co3+ d-orbital electrons, and ultimately promotes a transition to the intermediate spin state with enhanced eg occupancy. Supported by combined electrochemical analysis and theoretical calculations, we establish a volcano-shaped structure-activity relationship linking spin state with sulfur-reduction reaction (SRR) activity. The intermediate-spin state of LaCo0.75Mn0.25O3 achieves an optimal adsorption strength and rapid SRR kinetics, promoting a uniform three-dimensional growth mode for Li2S deposition. As a result, the S/LaCo0.75Mn0.25O3 cathode achieves an ultralow capacity decay rate of only 0.026 % per cycle over 1000 cycles at 2 C. This super-exchange mediated spin-state regulation strategy opens a new avenue for designing efficient electrocatalysts for LSBs.

The bis-phosphonic acid groups of 1,4-phenylenebis(phosphonic acid) passivate defects at the buried interface, enabling 1.66 eV WBG PSCs with a high V oc of 1.195 V, 21.79% efficiency, and enhanced stability.

Although metallic aluminum (Al) is an attractive back electrode material for cadmium telluride (CdTe) solar cells due to its low cost and suitability for large-area deposition, its low work function has hindered widespread application. To overcome this challenge, we designed and implemented a molybdenum-chromium (Mo/Cr) interfacial modification layer. A comprehensive comparative analysis was carried out to evaluate the electrical characteristics, interfacial transport properties, and device performance of the Al, Mo/Cr-modified Al and Au electrodes. The results reveal that the Mo/Cr interfacial modification layer effectively improves Al-electrode interfacial transport properties and conductivity and also blocks the diffusion of Al atoms. The optimized device with a Mo/Cr-modified Al electrode achieved a champion efficiency of 15.68%, closely approaching 15.88% of the expensive, high-work-function gold (Au) reference and significantly surpassing 13.83% of the Al electrode. Furthermore, it exhibited excellent mechanical adhesion and wear resistance, with a critical load of 0.62 mN, substantially higher than the 0.45 and 0.42 mN for the Al and Au electrodes, respectively. This electrode architecture offers a low-cost, highly durable, and high-performance alternative to noble-metal contacts, showing great potential for facilitating the large-scale commercialization of thin-film photovoltaic technology.

Introducing a 2D perovskite layer on the surface of 3D perovskite has been broadly recognized as an effective strategy to enhance the performance of perovskite solar cells (PSCs). However, the mechanism governing the 2D phase formation remains uncertain. In this work, the phase transitions of 2D perovskite during spin-coating and annealing processes has been investigated. Our findings reveal a dimensional phase shift from low to high n-value 2D phases, driven by the release of organic cations during annealing. Additionally, the spin-coating process exhibited concentration-dependent behavior, where higher n-octylamine hydrobromide (OABr) concentrations predominantly formed n = 1 phases. These observations highlight the complexity of the 2D phase composition at the 2D/3D interface. The coexistence of various 2D phases significantly influences device performance, as a conflict between n = 1 and n ≥ 2 phases was identified. Through forming a well-balanced proportion of different 2D phases, we achieved a wide-bandgap perovskite solar cell with a significantly improved power conversion efficiency of 19.29%. This work suggests the critical roles of phase dynamics and n-value distribution in optimizing 2D/3D interfaces for advancing high-performance wide-bandgap PSCs.

The design of an efficient catalyst is crucial for sulfur reduction reaction (SRR) in lean electrolyte lithium-sulfur (Li–S) batteries. However, most existing catalysts primarily focus on polysulfide-catalyst interactions and generally demonstrate high activity only with an excessive electrolyte. In this study, we propose high-entropy alloy (HEA) composite to enhance the SRR under lean-electrolyte conditions by optimizing the solvent-catalyst interaction. As evidenced by in situ spectroscopy, nuclear magnetic resonance (NMR), density functional theory (DFT) calculations, and experimental investigations, the strong interaction between the solvent and HEA catalysts enables the Li–S battery to achieve a high capacity of 1007.9 mAh/g with a low E/S ratio of 10 µL/mg, and capacity retention of 77 % after 200 cycles at lower E/S ratio of 4.5 µL/mg. The enhanced SRR performance in lean electrolyte conditions is primarily attributed to d–d electron interactions among the constituent metals and the presence of multiple active sites with optimized energy barriers in the HEA catalysts. This work underscores the significance of solvent-catalyst interactions in regulating the SRR of lean electrolyte Li–S battery and offers insights into the rational design of HEA catalysts to advance Li−S batteries.

Doping the absorber layer is a critical process for enhancing the performance of polycrystalline CdSeTe solar cells. Replacing traditional Cu doping with Group V dopants offers a pathway to fabricate devices with improved efficiency and stability. However, the dopant activation rate in polycrystalline structures remains low, typically only a few percent. While rapid thermal annealing (RTA) has been successfully employed to achieve high activation rates in single-crystal CdTe devices, its application to polycrystalline CdSeTe solar cells has been scarcely reported. In this study, we systematically applied multi-step annealing to investigate the dopant activation of in-situ As-doped polycrystalline CdSeTe devices. Our findings reveal that polycrystalline devices exhibit significantly lower thermal tolerance than their single-crystal counterparts, sustaining only short-duration annealing at 500 degrees C. Furthermore, although Cl diffusion during RTA can degrade device performance, we observed that trace amounts of CdCl2 vapor can help stabilize device efficiency.

The integration of solar energy into rechargeable battery systems represents a pivotal advancement in sustainable energy technology. Herein, we develop a photo-assisted lithium-sulfur battery (PALSB) that synergistically enables light energy harvesting, conversion, and electrochemical energy storage. Its multifunctional photocathode consists of 2D polycrystalline La0.65Sr0.35Co0.20Ni0.19Fe0.24Cr0.18Cu0.19O3 high-entropy oxide (LSCO-HEO) nanosheets with grain boundaries. Owing to the distinct surface work functions of its crystal facets, a spontaneously formed built-in electric field at the binary facet junction effectively suppresses the recombination of photogenerated carriers, thereby substantially enhancing photo-chemical-electrical energy conversion efficiency. Moreover, optimal band alignment between LSCO-HEOs and polysulfides enables direct participation of photoexcited electrons and holes in sulfur reduction and oxidation, respectively. Light-induced electron redistribution in LSCO-HEOs generates more dynamic and complementary highly active catalytic sites that effectively inhibit polysulfide shuttling, lower Li2S nucleation barriers, and enhance sulfur redox reaction kinetics. As a result, the PALSB achieves an ultra-high photoelectric energy conversion efficiency of 12.98% and exhibits exceptional cycling stability over 1000 cycles at 8.0 C, with a minimal capacity decay of only 0.025% per cycle. This work introduces a breakthrough strategy for direct solar-to-chemical energy conversion within batteries, opening avenues for high-efficiency photoelectrochemical energy storage.

Enhancing the efficiency and stability of perovskite solar cells is critical for commercialization. As short-circuit density approaches the Shockley-Queisser limit, improving open-circuit voltage and fill factor becomes essential, achievable through interface engineering. SnO2, employed as a buried electron transport layer, not only influences the deposition of perovskite film but also poses significant stability. Here, we introduce a multifunctional amphiphilic molecule, hydroxyl-terminated perfluoroalkyl sulfonamide, into the buried interface. The C-F long chain facilitates hydroxyl groups anchoring on the SnO2 surface, while the sulfonyl groups occupy oxygen vacancies, thereby reducing undercoordinated Sn4+. Simultaneously, the sulfonyl groups interact with uncoordinated Pb2+ in the adjacent perovskite film, further suppressing interfacial defects. This strategy yields a champion power conversion efficiency of 23.26%. Moreover, the long C-F chains act as a hydrophobic barrier against moisture ingress, enabling the unencapsulated devices to retain 73.8% of initial PCE after 1320 h under ambient condition (50%-60% relative humidity), while only 69.4% for reference one. Furthermore, posttreatment with quaternary ammonium iodide creates a dual-passivated interface. This suppresses halide ion migration and photoinduced phase segregation, boosting the PCE to 24.64%. These results underscore the critical role of multifunctional organic molecular passivation at interface in achieving both high-performance and durable perovskite photovoltaics.

Back surface engineering is one of the ways to further improve the conversion efficiency of the CdTe solar cells. In this work, as an oxide mixture, Cu x In y O is synthesized by low-temperature solution processing and successfully applied to the CdTe solar cells in the form of amorphous nanoparticles. The XPS results reveal changes in the chemical states of Te and O, and the KPFM demonstrate that a similar to 350 mV electric field has been introduced at the CdTe back surface, which means effective chemical passivation and field passivation were induced, resulting in the suppression of carrier recombination and the increase of carrier lifetime at the back interface of the devices. Finally, compared to the control devices, the conversion efficiency of the devices with Cu x In y O buffer layer improved from 12.44% to 15.35%, attributed to the increase in the fill factor from 65.52% to 72.48% and the open-circuit voltage from 723 mV to 798 mV.