Antiferromagnets are promising candidates for next-generation spintronic devices owing to their negligible stray fields and ultrafast spin dynamics. The noncollinear antiferromagnet Mn_3Sn exhibits a large anomalous Hall effect (AHE). However, its specific noncollinear spin configuration leads to the forbiddance of the anomalous Hall conductivity from the (0001) basal plane, σ_(0001), limiting practical applications. Here, using first-principles density functional theory, we demonstrate that Mn enrichment in Mn_3Sn drives a magnetic transition from the coplanar 120^∘ spin configuration to a non-coplanar state with moments tilted toward the c-axis. This transition is primarily mediated by four-spin ring exchange interaction in the local triangular lattice, which breaks the time-reversal symmetry and generates a giant intrinsic anomalous Hall conductivity over the full three-dimensional space in Mn_3Sn. We predict that σ_(0001) reaches as high as ∼-468 Ω^-1·cm^-1, and an enhanced σ_(011̅0) of ∼-229 Ω^-1·cm^-1 is expected in light Mn self-doping of Mn_3Sn (Mn_3.125Sn_0.875). Unlike previously reported mechanisms relying on external magnetic fields or strain, our approach exploits intrinsic compositional tuning to stabilize a non-coplanar magnetic ground state for realizing a strong full-space AHE in antiferromagnets, providing another viable pathway toward high-performance, low-power spintronic devices.

Tin-based perovskite solar cells (TPSCs) are strongly limited by Sn2+ oxidation and vacancy defects, which increase nonradiative losses and accelerate oxygen (O2)-related degradation. Here, mercaptoethylammonium bromide (ESABr) is introduced to regulate these coupled degradation processes. The thiol group buffers Sn2+/Sn4+ redox chemistry, while ammonium–iodide interactions stabilize the Sn-I framework and Br- compensates iodide-deficient sites. This combined regulation reduces Sn4+ accumulation and vacancy-associated trap states, suppressing defect-assisted recombination and improving carrier transport. More importantly, systematic simultaneous light and O2 (light/O2) aging measurements reveal slower electronic, chemical, and structural deterioration in ESABr-treated films, accompanied by reduced reactive O2 species generation. The optimized TPSCs achieve a power conversion efficiency of 15.09%. Encapsulated devices further exhibit a T80 lifetime of 896 h under maximum power point (MPP) tracking in ambient air, more than six times that of the control devices. These results connect redox and vacancy regulation with suppressed O2-related degradation, providing a mechanistic basis for improving the operational stability of tin perovskite photovoltaics.

Low-bandgap (E-g similar to 1.25 eV) tin-lead perovskite solar cells hold great potential for constructing efficient all-perovskite tandem solar cells (TSCs). However, rapid degradation of perovskite precursor solutions, owing to easy oxidation of Sn2+, remains a major challenge. Here we elucidate oxidation pathways in Sn-Pb perovskite precursors. We further introduce basic amino acids and basic amino acids sulfate (BAAS) as proton scavengers, which stabilize the ink for over 300 days. BAAS neutralizes excess protons to mitigate dimethyl sulfoxide-driven oxidation reactions, whereas sulfate ions coordinate Sn2+ to passivate defects and regulate crystallization. The optimized low-bandgap perovskite solar cell achieves a power conversion efficiency of 24.06% with an open-circuit voltage of 0.905 V, enabling two-terminal all-perovskite TSCs with a power conversion efficiency of 30.24% (certified 29.56%). The BAAS-passivated TSCs retain over 85% of their initial performance after 1,000 hours of the maximum power point operation under 1-sun illumination.

The ultraviolet (UV) stability of low-bandgap Sn-Pb perovskite solar cells (PSCs) remains a significant obstacle to their practical deployment. Here, we elucidate the UV-induced degradation mechanism in state-of-the-art 1.25 eV PSCs through combined electrical, mechanical, and chemical analyses. Prolonged UV exposure results in efficiency loss, primarily due to reductions in short-circuit current and built-in voltage. Detailed characterization reveals a strongly asymmetric degradation pathway: illumination from the buried interface causes more severe defect formation, charge accumulation, and mechanical softening than illumination from the top surface. UV-driven photo-doping of the ITOnanocrystal interfacial modification layer, together with oxidation of Sn2+ at the buried perovskite interface, accelerates both electronic and structural deterioration, leading to reduced carrier extraction. Guided by these insights, we show that introducing a PMMA interfacial buffer layer effectively suppresses charge buildup and interfacial oxidation, offering substantially enhanced UV stability compared with both the ITO-nanocrystal baseline and PEDOT:PSS-substitution. (c) 2026 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

This review discusses how diverse strategies for buried interfaces, based on different hole transport layers, affect the photovoltaic performance of perovskite solar cells.

Self-assembled monolayers (SAMs) have become indispensable hole-selective contacts for high-efficiency inverted perovskite solar cells (PSCs). However, the intrinsically acidic head groups of conventional SAMs lead to interfacial inhomogeneity, limited charge transfer, and poor operational stability. Here, we introduce a family of alkali metal-based phosphonate salts (2PACz-M) through targeted head-group functionalization of the benchmark [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) SAM, achieving a chemically neutralized and electronically delocalized interface. The ionic phosphonate moiety enhances π-electron conjugation, improves energy-level alignment, and strengthens chemical coordination with metal oxide electrodes, resulting in homogeneous and stable surface coverage. Moreover, when combined with [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz), the mixed-SAM interface exhibits a synergistic effect that facilitates efficient hole extraction, suppresses non-radiative recombination, and reinforces environmental robustness. This interfacial engineering enables 1.55 eV PSCs to achieve a champion power conversion efficiency (PCE) of 26.88% with a fill factor (FF) of 86.57%, alongside a 23.32% PCE for a 29.7 cm2 module. The SAM synergy proves universal across perovskites of varied bandgaps, yielding two-terminal (2T) all-perovskite tandem solar cells with an enhanced PCE of 29.05%.

Solution-processed antisolvent-free perovskites (AFPs) are promising candidates for scalable photovoltaic (PV) production. However, achieving high-quality AFP films typically requires stringent processing conditions, limiting reliability in large-scale manufacturing. Here, we employ machine learning (ML) to identify solvent additives that modulate the ambient temperature (TA) processing window. This approach successfully reveals an additive that enables a record-wide TA window, from 16 degrees C to 28 degrees C, with constantly high power conversion efficiencies (PCEs) exceeding 24%. Mechanistically, in contrast to the previously reported solvent-lead iodide (PbI2) interaction model, we demonstrate that anchoring formamidinium (FA) cations with the additive to form stable adducts is essential. This interaction effectively suppresses crystallization kinetics, facilitating uniform precursor distribution and high-quality film formation. Importantly, these results challenge the conventional crystallization paradigm for solution-processed perovskites, which emphasizes rapid and complete nucleation during the initial stage of film deposition. Instead, we find that a uniform distribution of precursor ions, even without any nucleation, is sufficient to achieve high-quality perovskite thin films. This work not only demonstrates an effective ML-guided solvent selection strategy but also provides fundamental insight into the primary crystallization requirements for scalable production of high-quality perovskite PV thin films.

For low-bandgap tin-lead (LBG Sn-Pb) devices, conventional organic hole transport materials (HTMs) fail to balance efficiency and stability, drawing attention to inorganic nickel oxide (NiOx) as a promising alternative. However, the inferior compatibility between NiOx and Sn-Pb perovskite severely hinders the development of NiOx-based Sn-Pb perovskite solar cells (PSCs) due to mismatched energy levels and oxidizing active species. Here, we propose a versatile strategy by introducing ammonium 2-hydroxyethanesulphonate (AHES) on NiOx films to fabricate efficient and stable NiOx-based Sn-Pb PSCs. The ─SO3 - in AHES could react with NiOx to regulate film morphology and optimize energy level alignment. Meanwhile, the presence of ─OH in AHES acting as Lewis base provides lone pair electrons to form hydrogen bond to modulate the crystallization process and improve film uniformity, resulting in enhanced lattice strength. As a result, our NiOx-based Sn-Pb device yields an efficiency of 22.98% (versus 20.02% for control) and retains 80% of the initial efficiency after continuous 1-sun illumination after 212 h (versus 90 h for control), which is among the best NiOx-based Sn-Pb PSCs. Finally, the champion four-terminal (4T) all-perovskite tandem solar cell achieves a remarkable efficiency of 30.38%.

Tin-based perovskite solar cells (Sn-PSCs) employing poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) gas hole transport layer represent one of the most promising architectures. However, their performance is severely limited by the insulating and hygroscopic...

All-perovskite tandem solar cells (TSCs) offer a path to exceed the Shockley-Queisser limit of single-junction devices, yet their development is hindered by the inferior efficiency and stability of low-bandgap tin-lead (Sn-Pb) perovskite bottom cells. The inherent grain boundaries (GBs) in Sn-Pb perovskites feature detrimental p-type energy states and unfavorable upward energy band bending that promote non-radiative charge recombination and pathways for ion migration-induced degradation. Herein, we employ dipole management at GBs of Sn-Pb perovskite by 4-(trifluoromethyl)benzohydrazide (FBH), which effectively modulates the GB energy landscape throughout the film. The dipole effect reverses the top surface GB energy states to create downward bending of the energy band, promoting efficient charge separation at GBs. Concurrently, FBH treatment enhances perovskite film quality through grain growth regulation, defect passivation, and immobilization of FA+/I- ions. Consequently, the optimized Sn-Pb perovskite solar cell achieves a high efficiency of 23.25% with outstanding operation stability, i.e., keeping over 80% of its initial efficiency under 85°C thermal stress after 400 h and 90% of its original efficiency upon 1872 h in glove box. All-perovskite TSC obtains 29.67% efficiency and retains 90% of its initial efficiency after approximately 1000 h maximum power point tracking.

Wide-bandgap (WBG) perovskite solar cells are crucial for efficient perovskite/silicon tandem solar cells (PSTSCs). However, they often suffer from uncontrolled crystallization, phase instability, and non-radiative recombination losses due to crystallographic defects. Here, we report a facile strategy of regulating perovskite crystallization and passivating uncoordinated lead ions and halide vacancies by adding potassium cyanate (KOCN) into the perovskite precursor, which incorporates into the perovskite lattice to thereby suppressing non-radiative recombination. Moreover, KOCN modulates nucleation to promote a (110) orientation and releases strain. Consequently, KOCN-based 1.67 eV-WBG perovskite devices yield a champion efficiency of 23.60% with an impressive open-circuit voltage of 1.263 V and fill factor of 84.39%, enabling a 31.10% efficiency in two-terminal PSTSCs. After 1600 h of aging in the glovebox, the KOCN-doped device retains over 98% of its initial efficiency.

The development of colloidal quantum dot solar cells (CQDSCs) is currently constrained by the substantial open-circuit voltage (Voc) deficit and intricate fabrication processes. Here, we present a simplified device architecture achieved by synergistically combining a direct-synthesis colloidal quantum dot (CQD) ink with a facile methanol/oxalic acid modification of the Poly(3,4-ethylenedoxythiophene):polystyrene sulfonate (PEDOT:PSS) interlayer. This strategy simultaneously addresses the poor wettability of aqueous PEDOT:PSS on hydrophobic PbS-EDT layers and initiates critical chemical optimization. By selectively removing insulating PSS, the treatment fosters a dense, electronically uniform fibrous network. Crucially, this optimized interlayer exhibits a work function shift from -5.30 to -5.15 eV, which reduces the hole extraction barrier to the Ag electrode from 0.51 to 0.36 eV. This favorable energy alignment extends the carrier lifetime from 0.54 to 2.37 ms and accelerates charge extraction. Consequently, the Voc is boosted from 649 to 742 mV, propelling the power conversion efficiency to 13.97%. This work offers a robust, process-compatible interfacial strategy to unlock stable, high-voltage CQDSCs.

Single-junction photovoltaic technologies are approaching their practical efficiency limits. Perovskite-based multijunction solar cells offer a path beyond these limits through reduced thermalization losses and improved spectral utilization. Although tandem architectures are not new to the photovoltaic community, perovskite-based tandems have, for the first time, opened a realistic path toward gigawatt-scale deployment of this technology. Over the past decade, remarkable progress has been achieved, and the technology is now moving steadily toward industrial scaling. Beyond complementing crystalline silicon, perovskites constitute a versatile tandem device component that can be implemented in fully perovskite-based architectures, fabricated on diverse substrates, and even extended to triple or quadruple-junction configurations. However, this advancement introduces new technological challenges, particularly in the interconnection of perovskite sub-cells. Achieving reliable electrical coupling while maintaining interfacial and structural integrity is challenging, as high-efficiency devices often involve multiple solution-processed layers, where similar solvents used in adjacent sub-cells can cause interlayer dissolution or chemical degradation. Furthermore, film imperfections such as cracks, pinholes, and delamination - often driven by mechanical stress and accumulated strain - emerge frequently during fabrication and scale-up and require careful management. This perspective examines these interconnection-related challenges and charts future directions in perovskite-based multijunction solar cells beyond the general electronic view of recombination junctions.

Mixed-halide wide-bandgap (WBG) perovskites are commonly used for Si/perovskite tandem solar cells; however, their operational stability remains limited by halide segregation, greatly constraining the operational device lifetime. Recent research efforts have turned towards pure-iodide alternatives, which do not undergo halide segregation despite somewhat larger open-circuit voltage (V-OC) deficits. However, their potential to withstand harsh photothermal stressors (e.g., light + 85 degrees C heat), which is a crucial step towards an operational lifetime of 25 years, remains underexplored. Here, we present an optimized mixed-cation, dimethylammonium (DMA)-stabilized, pure-iodide Cs(0.3)DMA(0.2)MA(0.5)PbI(3) WBG cell (E-g: similar to 1.68 eV), with a V-OC of up to 1.25 V and the highest certified efficiency (>22%) for this system, achieved through a dual-layer passivation strategy. In contrast to the mixed-halide system, the pure-iodide composition maintains a stable emission yield and demonstrates remarkable resilience to the evolution of ionic losses and ion density under illumination and thermal aging. This results in negligible degradation during the maximum power point tracking at 40 degrees C and the longest reported projected T80 lifetime (8140 h) for WBG (similar to 1.65-1.73 eV) perovskites under 85 degrees C photothermal stress (ISOS-L-2). Our work provides a mechanistic basis for the exceptional stability of pure-iodide WBG perovskites and outlines a viable pathway toward highly efficient and durable perovskite tandem solar cells.

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.

A multifunctional guanidine additive regulates phase transition and defects in 1.67 eV perovskites, delivering 24.14% single-junction devices and 32.70% stable perovskite/silicon tandems.

Perovskite solar cells (PSCs) have achieved a power conversion efficiency (PCE) of over 27%, but further improvements of both PCEs and stability are needed for commercialization. One of the key factors hindering their development is the unpredictable residual strain in perovskites. The unstable octahedral structure of the perovskite cage leads to easy changes in bond lengths, bond angles, and crystal structure. It in turn generates, accumulates, and causes the non-uniform distribution of residual strain, ultimately affecting device performance. Therefore, given the versatility and precise tunability, residual strain engineering provides an effective pathway to optimize the performance of PSCs. This review summarizes the causes of residual strain during device fabrication and operation, qualitative/quantitative/auxiliary characterization methods, and various effective strain regulation methods in the past two years. Finally, unresolved scientific issues and future research directions in strain engineering are discussed. This comprehensive review aims to provide researchers with the latest advances in strain engineering, deepen fundamental understanding of strain effects, and eventually help enhance the performance of PSCs.

Control over crystallization pathways and halide distribution is essential for realizing efficient and stable wide-bandgap (WBG) perovskite solar cells (PSCs), yet most advances rely on additives while the intrinsic role of precursor stoichiometry remains insufficiently understood. Here we show that precursor stoichiometry, specifically the balance between FAX and PbX2 (X = I, Br), serves as an additive-free chemical lever that regulates precursor supersaturation and nucleation kinetics, thereby directing crystallization and halide homogenization in FA0.83Cs0.17Pb(IxBr1-x)3 perovskites. We identify a stoichiometric regime with a PbI2-to-total PbX2 ratio of ∼55-75% that minimizes supersaturation, increases nucleation energy barrier, and slows crystal formation, yielding perovskite films with full coverage, preferred crystallographic orientation, and reduced residual strain. The optimized chemistry enables efficient and photostable WBG PSCs across a broad bandgap range (∼1.67, 1.79, 1.85, and 1.93 eV), achieving champion power conversion efficiencies of ∼24.19%, 21.64%, 19.98%, and 16.83%, respectively. Furthermore, this strategy enables monolithic all-perovskite tandem solar cells that deliver ∼29.10% efficiency with >80% retention over 400 h of maximum-power-point tracking. By establishing mechanistic links between precursor stoichiometry, crystallization pathway, electronic homogeneity, and device stability, this work provides a rational and broadly applicable chemical framework for advancing WBG perovskites in single-junction and tandem photovoltaics.