All inorganic CsPbI 3 perovskite solar cells based on carbon electrodes (C‐IPSCs) possess advantages of high stability and low cost, demonstrating great potential for commercial applications. However, the poor crystallinity of inorganic perovskite films and the interface defects induce massive nonradiative recombination, which limits the improvement of device efficiency and stability. Herein, a multifunctional small molecule, 3‐methylthio‐1‐propylammonium chloride (3MTPACl), is employed to simultaneously improve the crystallinity of inorganic perovskite films and passivate interface defects inside CsPbI 3 C‐IPSCs. It is demonstrated that the S and ammonium (NH 3 + ) of 3MTPACl can coordinate with uncoordinated Pb 2+ on the surface of CsPbI 3 films, passivate surface defects, and improve the energy level arrangement at the interface between CsPbI 3 /carbon electrode. Meanwhile, Cl − ions diffuse throughout the perovskite film from the top to the bottom and accumulate at both the upper and lower interfaces of the CsPbI 3 layer, promoting the formation of CsPbI 3 films with enlarged grain size and enhanced crystallinity. Consequently, defects at the TiO 2 /perovskite interface are effectively passivated, thereby facilitating electron extraction. Therefore, synergistic dual‐interface modification and crystallization regulation are achieved by 3MTPACl posttreatment, which greatly boosts the efficiency of CsPbI 3 C‐IPSC up to 17.61%, accompanied by enhanced humidity, thermal, and long‐term stability.

Formamidinium lead triiodide (FAPbI 3 ) perovskite solar cells remain central to next‐generation photovoltaic research because of their near‐optimal bandgap and high power conversion efficiencies, yet their long‐term operational stability continues to limit technological maturity. This review provides a comprehensive evaluation of recent advances aimed at stabilizing the photoactive α‐FAPbI 3 phase and mitigating the structural and defect processes that underpin degradation. We integrate these developments with original first‐principles density functional theory calculations that probe intrinsic phase energetics and reveal how targeted B‐site doping influences structural robustness. Strategies highlighted include lattice‐strain modulation, multifunctional defect‐passivation chemistries, machine‐learning‐assisted compositional design, and scalable vapor‐ and ink‐based fabrication techniques that bridge laboratory processing with industrial relevance. Together, these approaches outline the materials design principles and engineering innovations needed to advance FAPbI 3 towards durable, high‐efficiency perovskite photovoltaic technologies.

This study introduces a novel approach to fabricating large‐area perovskite active layers for carbon‐based perovskite solar cells (C‐PSCs) by leveraging electrodeposition, a low‐cost, scalable and yet underexplored processing route. The work focuses on the synthesis and comprehensive characterization of methylammonium lead iodide (MAPbI 3 ) perovskites incorporating a low bismuth additive content (0.85 mol%), representing the first systematic investigation of bismuth‐assisted MAPbI 3 films produced via electrodeposition. Despite the very low bismuth concentration, clear structure–property relationships were established by optimizing the conversion time, directly correlating processing conditions with optical, structural, and photovoltaic (PV) performance. A central innovation lies in the incorporation of bismuth, which not only modifies the perovskite crystallization but also markedly improves environmental stability. Long‐term aging tests under harsh conditions (90% RH, 30°C, 1000 h) revealed that these mixed perovskites maintain their microstructure and properties far better than MAPbI 3 . The devices fabricated with perovskites containing 0.85% Bi retain up to 70% of their initial efficiency even without encapsulation, compared to only 35% for MAPbI 3 ‐based controls. These results demonstrate the great potential of bismuth‐assisted electrodeposition for enabling durable, scalable perovskite PVs and offer a promising pathway toward sustainable C‐PSC manufacturing.

Perovskite solar cells (PSCs) are promising for high‐efficiency tandem devices exceeding the Shockley‐Queisser limit, whose performance is largely determined by individual subcells. A key, often overlooked factor is subcell orientation. While single‐junction cells are typically optimized for bottom illumination in pin configuration, tandem applications require illumination through the top transparent electrode. Depending on the illumination direction, performance losses are dominated by nonradiative recombination either at one of the interfaces between the perovskite and transport layers or within the bulk perovskite. Identifying which of these dominates the losses remains challenging. Here, we introduce an experimental method to identify the limiting nonradiative recombination pathway and its position in bifacial PSCs. By illuminating devices from either side with red, blue, and white light, the wavelength‐dependent fill factor response is used to probe the different recombination pathways. Extensive drift‐diffusion simulations, varying 35 parameters and modeling a wide variety of cells, reveal characteristic fill factor traces associated with four recombination scenarios and show 95% accuracy in identifying the dominant loss mechanism using this method. Finally, the method is applied to a vapor‐deposited, bifacial PSC for tandem applications, showing that the electron transport layer‐perovskite interface limits the performance of this particular device.

In the research of perovskite solar cells (PSCs), the introduction of passivation layers is a key strategy for enhancing both efficiency and stability. Employing the well‐established dip‐coating method in conjunction with effective passivation solutions for the preparation of passivation layers not only improves the power conversion efficiency (PCE) and stability of PSCs but also extends the applicability of this approach in the development and commercialization of PSCs. This work introduces a novel passivation method, termed the DATsO‐TBA‐Dip coating (DTD) passivation method, which combines DATsO, 2‐butanol (TBA), and the dip‐coating method. The DTD passivation method was applied to PSCs on glass substrates of different sizes (2 cm × 1.6 cm and 2.5 cm × 2.5 cm). The results demonstrated excellent film quality and significant enhancement in passivation performance. The optimized device achieved a maximum PCE of 22.5% (0.105 cm 2 ), representing a 2.2% improvement over the best‐performing untreated device. Additionally, the open‐circuit voltage ( V OC ) increased to 1.08 V, and the fill factor (FF) improved to 80.9%. Beyond the remarkable photoelectric performance, devices treated with the DTD passivation method also exhibited significantly improved stability, retaining 80% of the initial PCE after 1200 h.

Semitransparent perovskite solar cells based on FAPbI 3 offer a compelling alternative to wide‐bandgap counterparts, overcoming halide segregation, instability, and the limited efficiency of quasi‐2D systems. Optical modeling reveals that thinning the FAPbI 3 absorber balances visible transmittance and performance, with 140 and 160 nm layers delivering average visible transmittance of 24.2% and 18.2% alongside power conversion efficiency of 15.9% and 18.0%. Surface passivation with 4‐fluorophenylethylammonium iodide enhances V OC by over 100 mV and raises efficiency by more than 1%, as confirmed by photoluminescence and transient optoelectronic analyses showing reduced nonradiative losses and extended carrier lifetimes. Crucially, both passivated and unpassivated devices exhibit excellent stability despite reduced thickness. These results demonstrate thin FAPbI 3 as a robust platform for potential efficient and stable applications. A preliminary test employing 10 nm Ag layer yielded a device with a light utilization efficiency of 1.8%, establishing a promising baseline for semitransparent photovoltaic applications.

The appeal of organic solar cells (OSCs) as a source of environmentally friendly electricity is often negatively impacted by the common use of hazardous materials in their manufacturing, such as halogenated solvents. This study explores the fabrication and operational stability of PTQ‐2F:BTP‐4F‐based OSCs using halogenated (chloroform (CF), chlorobenzene) and nonhalogenated ( ortho ‐xylene ( o XY), 1,2,4‐trimethylbenzene) solvents in a hot‐solvent spin‐coating process. Initial power conversion efficiencies (PCEs) of up to 12.2% (CF) and 10.0% ( o XY) are achieved, with detailed morphological and performance analyses conducted via ex situ and operando grazing‐incidence small‐angle X‐ray scattering (GISAXS). Ex situ measurements reveal significant differences in bulk‐heterojunction nanostructures, with benzene‐based solvents producing domain size distributions distinct from CF‐processed films. Operando GISAXS connects real‐time degradation kinetics to the domain size evolution, highlighting solvent‐dependent kinetics. Halogenated solvents facilitate a gradual PCE decay, while nonhalogenated solvents exhibit a rapid initial burn‐in phase followed by stabilization, with o XY‐processed OSCs demonstrating superior long‐term stability. Morphological stability in o XY films originates from the limited coalescence of small polymer domains, retaining a more fine‐grained structure in the active layer. This study emphasizes the critical role of processing solvents in OSC performance and stability, positioning o XY as a sustainable candidate for scalable and eco‐friendly OSC fabrication.

Living biophotovoltaics (LBPVs) remain limited by the lack of biodegradable, highly conductive scaffolds capable of supporting dense microbial colonization and efficient electron extraction. In this study, graphene–thermoplastic starch (Gr–TPS) electrospun nanofibers are introduced for the first time as photoanode materials, establishing a renewable platform that integrates carbon nanotechnology with biopolymer engineering. The Gr–TPS network exhibits high porosity, hydrophilicity, and electrical percolation, enabling strong cyanobacterial attachment and enhanced extracellular electron transfer. When incorporated into an LBPV configuration, this architecture simultaneously captures photosynthetic and respiratory electron flows, yielding high photocurrent, a power density of 63.10 mW m −2 , and excellent operational stability. Diuron, glucose, and iodoacetate assays confirm tunable dual‐pathway electron harvesting, resulting in 372 μmol L −1 photosynthetic hydrogen and 11.37 μmol L −1 respiration‐derived hydrogen. These findings demonstrate that Gr–TPS nanofibers constitute a biodegradable, cost‐effective, and performance‐enhancing material class with significant potential to advance next‐generation solar‐to‐fuel biophotonic technologies.

Enhancing charge separation is an effective strategy for promoting the efficiency of photocatalysts.Because photocatalysts possess both polarization electric fields and interfacial built‐in electric fields, they can provide stronger driving forces for photogenerated charge carriers, thereby suppressing their recombination. Therefore, designing heterojunction photocatalysts that simultaneously possess polarization and interfacial electric fields is promising for achieving highly efficient photocatalysis. However, because of the difficulty of overcoming van der Waals interactions and surface energy, producing heterojunctions with stable built‐in electric fields in ferroelectric photocatalytic devices is still a challenging issue. In this article, an in situ surface activation salting method is proposed for synthesizing a bismuth‐based ferroelectric heterojunction photocatalyst (Bi 4 NbO 8 Br/BiVO 4 ) that possesses stable bridging bonds. The synergistic effect of the dual‐polarized electric field and the built‐in electric field at the interface greatly enhanced the separation and migration efficiency of photogenerated charges. Moreover, the nanoscale BiVO 4 modification broadened the visible light absorption range of the catalyst. As a result, Bi 4 NbO 8 Br/BiVO 4 achieved highly efficient photocatalytic synthesis of H 2 O 2 about 492.75 µmol L −1 h −1 , demonstrating excellent performance among similar photocatalysts. This article provides a certain experimental basis for the template design and construction of efficient bismuth‐based photocatalytic materials for synthesizing H 2 O 2 through artificial photosynthesis.

Perovskite/silicon tandem solar cells have achieved certified efficiencies approaching 35%, but further progress is constrained by the fixed silicon bandgap, current‐matching instability, and mechanical rigidity. All‐perovskite tandem solar cells (APTSCs) provide a promising route to overcome these limitations through tunable bandgaps, compositional flexibility, and low‐temperature processing. In particular, triple‐junction (3J) APTSCs show the potential to surpass 40% efficiency by stacking wide‐, intermediate‐, and narrow‐bandgap (WBG, IBG, NBG) subcells with complementary spectral utilization. This review summarizes recent advances toward stable and efficient 3J APTSCs, including halide homogenization and additive‐assisted crystallization for WBG absorbers, oxidation control and interface passivation for NBG subcells, and key considerations for IBG subcells, particularly the need for thermally stable surface passivation. In addition, we discuss the critical role of optoelectronic modeling at the 3J device level for managing parasitic optical losses and achieving accurate current matching across multilayer stacks. Collectively, these developments underscore the technological potential of all‐perovskite 3J tandems as a scalable and sustainable platform for next‐generation photovoltaics.