A summary of recent advances in spiro-OMeTAD-based HTMs for PSCs, covering four main aspects: (1) synthetic routes, (2) doping mechanisms, (3) degradation processes, and (4) strategies for enhancing stability.

The two-step sequential deposition method for perovskite solar cells (PSCs) is often limited by the dense PbI2 film morphology, leading to incomplete conversion, residual PbI2, and high defect density. This review consolidates research showing that engineering a porous PbI2 architecture is a universal and transformative solution. We categorize the key strategies: (1) Solvent Engineering: Using solvent extraction, vapor treatment, or anti-solvent methods to create rapid nanoporosity; (2) Molecular Additives: Lewis bases or volatile amines that coordinate with Pb2+, disrupting crystallization and forming porous scaffolds; (3) Ionic Liquids and Salts: Multi-functional agents templating porosity while passivating defects and boosting stability; (4) Sacrificial Agents and Frameworks: Pore-forming compounds or MOFs/COFs that provide predefined porous structures; (5) Interfacial Engineering: Substrate modifications or low-dimensional seeds guiding favorable PbI2 porosity. A porous PbI2 scaffold enhances organic salt diffusion, ensuring complete conversion to high-quality perovskite films with larger grains, improved crystallinity, and lower trap densities. This consistently yields PSCs with efficiencies >25%-26% and outstanding stability, often retaining >90% performance after thousands of hours. Controlling PbI2 morphology thus offers a scalable route to enhance perovskite photovoltaic performance and commercial viability.

Photocatalysis offers a promising approach for renewable energy conversion and storage, but short lifetimes of charge-separated states in photocatalysts due to charge recombination limit its utility. Here we report an organic molecule with an acceptor–donor–acceptor configuration that can self assemble into highly crystalline nanoparticles. Transient absorption spectroscopy reveals that these crystalline assemblies can induce an ultra-long-lived charge-separated state of up to 1.2 s, attributed to initial symmetry-breaking charge separation, followed by charge hopping across closely packed molecules. These self-assembled nanoparticles have an impressive photocatalytic H2 evolution rate of 126 mmol g−1 h−1 with an external quantum efficiency of 12 Achieving charge separation with minimal energy loss remains a key challenge in photocatalysis, but traditional approaches often suffer from rapid charge recombination or inefficient energy utilization. Now it has been shown that symmetry-breaking charge separation within organic crystalline nanoparticles can generate long-lived charge-separated states, enabling efficient photocatalytic hydrogen production.

The integration of biological catalysts with organic light-harvesting materials represents a rapidly advancing strategy for sustainable solar-to-chemical energy conversion. Recent advances demonstrate that photoexcited organic materials can effectively activate redox enzymes and whole-cell systems to catalyze fuel-forming reactions such as H2 evolution and CO2 fixation as well as selective oxidations and chiral transformations under mild conditions. This review summarizes recent advances in semiartificial photosynthesis driven by organic materials and presents a systematic overview of the major classes involved. In particular, it focuses on a) organic photosensitizers including molecular organic photosensitizers, carbon dots, graphene, carbon nitride, and organic aggregation nanoparticles (e.g., polymer dots/Pdots, molecule nanoparticles) as well as b) organic redox mediators. These materials are evaluated in terms of their photophysical properties, compatibility with biocatalysts, and their roles in photoinduced charge generation, charge separation, and interfacial electron transfer between abiotic and biotic components. Emerging trends toward mediator-free and water-driven systems, challenges related to photostability, biocompatibility, as well as paired redox catalysis generating value-added products are also discussed. Additionally, the effects of the sacrificial electron donor on biohybrid performance and development of biohybrid photoelectrochemical catalysis have been evaluated. Finally, this review aims to highlight the key scientific and technological questions that must be addressed to advance the field toward efficient, scalable, and environmentally benign biohybrid photocatalytic and photoelectrochemical platforms.

Herein, we report the fabrication of a high-performance fiber-shaped supercapacitor (FSSC) based on a hollow poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)/molybdenum disulfide (PEDOT:PSS/MoS₂) hybrid fiber electrode via a hydrothermal co-assembly strategy. A three-dimensionally interconnected composite fiber electrode was constructed by the liquid-phase co-assembly of PEDOT:PSS chains and MoS₂ nanosheets, followed by acid post-treatment. This rational design alleviates several core drawbacks of conventional MoS₂-based electrodes, including inferior electrical conductivity, severe lamellar restacking, and low active site utilization efficiency. The hollow microstructure, formed by in-situ gas evolution during synthesis, improves electrolyte penetration and expands the electrode-electrolyte contact area. Electrochemical measurements on symmetric solid-state FSSCs show that the optimized hybrid fiber delivers favorable volumetric and areal capacitances of 329.9 F cm⁻³ and 390.1 mF cm⁻² at a current density of 2 A cm⁻³ , alongside a capacitance retention of 65.8% (2 −20 A cm⁻³). The improved electrochemical behavior originates from synergistic effects between conductive PEDOT and pseudocapacitive MoS₂, and the unique hierarchical hollow morphology. This facile synthesis yields advanced fiber electrodes, showing promising applications of hollow PEDOT:PSS/MoS₂ hybrids for wearable energy storage.

Precise perovskite interface modification is regarded as a highly promising strategy to enhance the performance of efficient perovskite solar cells (PSCs). Herein, star-shaped small-molecule interface passivation material (IPM) TB-CZ (N,N',N″-((benzene-1,3,5-triyltris(1H-benzo[d]imidazole-2,1-diyl))tris(benzene-4,1-diyl))tris(9-ethyl-N-(9-ethyl-9H-carbazol-3-yl)-9H-carbazol-3-amine)) was designed and synthesized to regulate the perovskite/spiro-OMeTAD interface. The core of TB-CZ is a nitrogen-rich benzimidazole compound in which the C-N and C═N groups can effectively passivate the Pb2+ defects in perovskites through multidentate coordination interactions. The side chain is equipped with a methoxy-free carbazole group, a design that significantly improves the material solubility and thus enhances the quality of perovskite films. The perovskite modified by TB-CZ can effectively optimize its energy levels, promoting hole extraction and transport. Consequently, the TB-CZ-modified PSCs achieve a power conversion efficiency (PCE) of 24.9% at an active area of 0.055 cm2 and maintain a commendable PCE of 22.0% even at an upscaled active area of 1 cm2, thereby showcasing its outstanding performance. Moreover, the modified device demonstrates remarkable long-term stability by retaining 81% of its initial PCE after storage for 1000 h under ambient conditions without any encapsulation. This work provides a strategy for the rational design of star-shaped passivation materials to enhance the PCE and stability of the PSCs.

The rational design of hole transport materials (HTMs) through precise molecular energy level modulation and enhanced interfacial coupling, offers a promising approach for improving perovskite solar cells (PSCs) performance. In this study, we designed and developed three novel acridine-derivative HTMs, termed as TAO, TAS, and TASO2, featuring tailored highest occupied molecular orbital (HOMO) energies and strengthened interfacial interactions with the perovskites layer. The TAS-based device obtained a champion power conversion efficiency (PCE) of 25.6% and demonstrated outstanding environmental stability. These results highlight the crucial role of optimized energy level alignment and interfacial passivation in designing efficient and stable HTMs for perovskite photovoltaics.

The intrinsic acidity of PEDOT:PSS limits its application in narrow-bandgap Sn-Pb mixed perovskite solar cells (PSCs). Here, we introduce the multifunctional L-cysteine, as an efficient additive to modify PEDOT:PSS (L-PEDOT:PSS). The amino group in L-cysteine neutralizes the acidic sulfonate groups in PSS, while the thiol group acts as an interfacial reductant that suppresses Sn2+ oxidation. Moreover, L-cysteine doping enhances surface wettability and smoothness, leading to a vertically oriented grains and reduced trap-state density perovskite. The L-PEDOT:PSS also exhibits a slightly deeper HOMO energy level, resulting in improved energy-level alignment with the Sn-Pb perovskite layer. Consequently, Sn-Pb PSCs based on L-PEDOT:PSS achieve a champion power conversion efficiency of 22.27% and retain ∼90% of their initial performance after 1000 h—substantially surpassing control devices. This work demonstrates that L-PEDOT:PSS offers a simple yet effective strategy to improve both the efficiency and durability of Sn-Pb perovskite solar cells.

The development of hole transport materials (HTMs) is crucial for advancing the efficiency and long-term stability of perovskite solar cells (PSCs). To address the limitations of the conventional Spiro-OMeTAD, such as its complex synthesis and high production cost, we designed two novel carbazole-based HTMs, TCBZ-36 and TCBZ-27, through engineering the substitution position of the tricarbazole core. The 2,7-substitution of TCBZ-27 was found to significantly enhance hole mobility and conductivity while improving film morphology compared with its 3,6-substituted counterpart, TCBZ-36. These superior properties translated into outstanding device performance, achieving a champion power conversion efficiency (PCE) of 25.2% (Voc = 1.16 V, Jsc = 26.2 mA cm-2, and FF = 83.5%), along with exceptional storage stability in ambient environment. This study presents a cost-effective molecular design strategy that can simultaneously enhance the efficiency and stability of perovskite photovoltaic devices.

We have developed two new star-shaped donor-acceptor oligomers, named TxBT and TxNT, with a truxene donor core and either 2,1,3-benzothiadiazole (BT) or a naphtho[1,2-c:5,6-c ']bis[1,2,5]thiadiazole (NT) unit, respectively. Femtosecond transient absorption spectroscopy suggested that both oligomer nanoparticles (NPs) generate long-lived triplet charge-transfer (CT) states following photoexcitation, which undergo reductive quenching by ascorbate. TxNT NPs generate a larger population of reduced species that accumulate and escape recombination compared to TxBT NPs, indicating more efficient charge separation. TxNT NPs show significantly higher hydrogen evolution rate (54 mmol h-1 g-1) compared to TxBT NPs, which is comparable to the performance of the most efficient heterojunction polymer NP systems. Additionally, morphological analysis revealed that Pt deposition was significantly lower on TxBT than on TxNT NPs. These findings highlight the critical role of triplet CT states, tuning molecular energy levels, optimizing excited-state dynamics, and engineering NP architecture to increase photocatalytic hydrogen evolution of organic photocatalysts. To our knowledge, this is the first report where triplet CT states can mediate photocatalytic hydrogen evolution in donor-acceptor oligomer NPs.

Bio-hybrid photoelectrochemical (PEC) devices integrate the complementary advantages of both biocatalyst and abiotic components, providing opportunities for efficient catalysis under mild conditions with high selectivity and low over-potential. However, the practical applications of such devices depend on the stability and efficiency of the bio-abiotic interface, where suboptimal charge transfer, biocatalyst fragility, and scalability challenges persist. In this Perspective, we evaluate established strategies for wiring biocatalysts to electrode substrates within bio-hybrid PEC architectures, analyze their catalytic performance, and operational limitations, and underly mechanistic principles. Then, we highlight the integration of whole-cell biocatalysts with high-performance semiconductor scaffolds as a promising design paradigm, offering a scalable platform for sustainable, solar-driven chemical production.

In this article, we present a novel design of a perfect metasurface absorber (MSA) based on groove-ring-shaped (GRS) structure Ti3C2Tx MXene array, which demonstrates a significant potential of for enhanced refractive index (RI) sensing application in terahertz (THz) region. In contrast to the conventional metal-dielectric-metal (MDM) structures, the proposed design incorporates a lightweight material and eliminates the need for a sandwich configuration. Consequently, this innovation significantly simplifies the production process and reduces costs, which facilitates its application in industrial production. Numerical simulation reveals that the proposed MSA operates at 1.938 THz with a near-perfect absorbance of 99.93%, aligning closely with predictions from coupling mode theory (CMT) and equivalent circuit model (ECM). The perfect absorption exhibited by the designed structure is primarily attributed to the guided mode arising from critical resonance coupling. Furthermore, the geometric parameter tuning mechanism of the proposed MSA allows for precise and dynamic adjustments of both peak absorption frequency and absorptivity. This approach aims to establish an RI sensing platform characterized by high sensitivity, rapid response, and excellent stability. Our innovative MSA excels as an RI sensor, showcasing an impressive sensitivity of 1.79 THz/RIU. These findings pave the way for the development of highly efficient MSAs, which hold significant potential for applications in spectral imaging, thermal radiation absorption, and sensing technology within the THz frequency range.

Flexible transparent conducting electrodes (TCEs) are critically important for next-generation optoelectronics, attracting significant interest across diverse research fields. This study presents a clear and timely advance in their manufacturing by demonstrating a scalable, hybrid TCE. The authors combine blade-coated silver nanowires (AgNWs) with flexographically printed metal bus lines (MBLs), cap the structure with an indium zinc oxide (IZO) overcoat, and subsequently fuse the stack using intense pulsed light (IPL) photonic curing. This approach yields a multiscale conductor on polyethylene terephthalate (PET) substrates that simultaneously achieves low sheet resistance, high transparency across the visible and near-infrared spectrum, and low surface roughness. The work is explicitly framed around “green” manufacturing principles, emphasizing a low thermal budget, inherent compatibility with roll-to-roll (R2R) processing, and impressive line speeds of up to 11 m·min−1 in stitching mode. Moving beyond fundamental materials metrics, the authors underscore the device-level relevance of their TCE by fabricating p-i-n perovskite solar cells (PSCs). These devices achieved champion power conversion efficiencies (PCEs) of up to 12.2% (averaging ~10.5%), outperforming commercial PET/ITO-based controls by approximately 50%. In this commentary, we first recognize the study’s substantive contributions to scalable TCE fabrication. We then propose practical refinements that could further strengthen the scientific rigor and translational potential of the technology. Finally, we conclude with a constructive critique of several unresolved questions; addressing these would undoubtedly represent a significant advance for the field.

Accurate detection of molecules at ultra-low concentrations is essential for applications such as environmental monitoring, early-stage diagnostics, and precision medicine. Among various sensing platforms, optical fiber and waveguide-based systems are particularly valuable due to their immunity to electromagnetic interference, absence of electrical hazards, flexibility, and low attenuation over long distances. Lab-on-a-fiber (LoF) integrates sensing elements directly onto optical fibers, transforming them into versatile platforms for diverse sensing applications. However, LoF faces limitations in sensitivity due to the reliance on surface-adsorbed analytes and weak interactions with evanescent waves. Lab-in-a-fiber (LiF) sensors improve sensitivity by modifying the fiber's geometry to create microfluidic channels, but they are hindered by significant optical losses and structural complexity. To overcome these challenges, we propose a novel LiF sensor by coaxially grafting a hydrogel waveguide with optical fibers (LiF-hydrogel). This hybrid structure combines the advantages of conventional waveguides with the infiltrability properties of hydrogels, allowing analyte molecules to penetrate the wave guide and enhancing sensitivity. This design achieves an exceptionally low detection limit for the fluorescent spectrum of rhodamine B (Rh B), reaching approximately 2.0 x 10_ 20 M, equivalent to the detection of only 4-6 individual Rh B molecules. Furthermore, by embedding Rh B-lactam-ethylenediamine within the hydrogel waveguide, the LiF-hydrogel can selectively detect mercury (Hg2+) ions with a detection limit of approximately 1.0 x 10_13 M in aqueous solutions, underscoring its remarkable sensitivity.

Efficient photosensitizers are crucial for advancing solar energy conversion and storage technologies. In this study, we designed and synthesized a novel organic dye, denoted as YB6, for p-type dye-sensitized solar cells (p-DSCs) and photoelectrochemical H2O2 production. YB6 features an extended conjugated pi-bridge derived from indacenodithieno[3,2-b]thiophene and exhibits notable advantages: a two-fold higher molar extinction coefficient at its main absorption peak and a broader absorption as compared to the PB6 dye. In p-type dye-sensitized NiO photoelectrochemical cells, the YB6-based device demonstrated superior performance as compared to the PB6-based device. It delivered nearly a 50 % higher H2O2 production over 5 hours. Furthermore, when fabricated into p-DSCs, the YB6-based device exhibited a 33 % higher power conversion efficiency. This enhancement is caused by suppressed charge recombination from the dye structure, which in turn may be traced to a larger thermodynamic up-hill process for recombination losses in the YB6-based system.

By controlling the refractive index between the MIP sensing layer and the hybrid waveguide, the propagating light can be efficiently confined in the MIP layer for detection, resulting in a sub-aM detection limit in fluorescence detection.

Aiming at the low luminous‐efficiency of two‐dimensional (2D) perovskite, its quantum yield (QY) and stability are effectively improved by a fluorinated second insulator layer 3,4‐difluoroaniline (F 2 PA) outside of the first insulator 2‐(2,4‐difluorophenyl) ethylamine (FPEA). The QY of perovskite with two insulator layers is improved by 3.4‐time in contrast with its counterpart with one insulator, which originates from the defect suppression and reduction of exciton Bohr radius by the second layer. The optical stability has extended 1.5‐time by the introduced second layer, as an isolation role for inner decomposed products to volatilize and for outer water molecules to penetrate. The perovskite with two insulator layers retained 90% of its initial optical properties in relative humidity 90%–95% atmosphere for 600 h, meanwhile only 50% for its counterpart with one layer. Two‐more fluorine with stronger hydrophobicity can account for this feature. Adding a second insulator layer is an effective strategy to engineer 2D perovskites and push forward its applications in optoelectronic devices.

Optical upconversion via a multiphoton absorption processconvertsincoherent low-energy photons to shorter wavelengths. In this contribution,we report a solid-state thin film for infrared-to-visible upconversioncomposed of plasmonic/TiO2 interfaces. When excited at & lambda; = 800 nm, three photons are absorbed, leading to the excitationof TiO2 trap states into an emissive state in the visibledomain. The plasmonic nanoparticle enhances the light absorption capabilitiesof the semiconductor, increasing emission efficiency by 20 times.We demonstrate that the plasmonic nanoparticle only changes the opticalabsorption of the semiconductor; i.e., the process is purely photonic.The process occurs in the ultrafast domain (<10 ps), contrastingwith molecular triplet-triplet exciton annihilation, the commonlyused method in photon upconversion, in the nano- to microsecond timescales. The process utilizes pre-existing trap states within the semiconductorbandgap and involves three-photon absorption.

Despite considerable research efforts on photoelectrochemical water splitting over the past decades, practical application faces challenges by the absence of efficient, stable, and scalable photoelectrodes. Herein, we report a metal-halide perovskite-based photoanode for photoelectrochemical water oxidation. With a planar structure using mesoporous carbon as a hole-conducting layer, the precious metal-free FAPbBr 3 photovoltaic device achieves 9.2% solar-to-electrical power conversion efficiency and 1.4 V open-circuit voltage. The photovoltaic architecture successfully applies to build a monolithic photoanode with the FAPbBr 3 absorber, carbon/graphite conductive protection layers, and NiFe catalyst layers for water oxidation. The photoanode delivers ultralow onset potential below 0 V versus the reversible hydrogen electrode and high applied bias photon-to-current efficiency of 8.5%. Stable operation exceeding 100 h under solar illumination by applying ultraviolet-filter protection. The photothermal investigation verifies the performance boost in perovskite photoanode by photothermal effect. This study is significant in guiding the development of photovoltaic material-based photoelectrodes for solar fuel applications.

High band gap FAPbBr3 perovskite solar cells have attracted tremendous interest in recent years due to the high open circuit voltage and good stability. Commonly a two-step method is used to prepare the FAPbBr3 perovskite film. Here a mixed solvent approach for the second step is introduced. Formamidinium bromide (FABr) in 2-propanol and methanol mixture was applied in the second step, which resulted in favorable properties such as suitable solubility, high-quality crystallization, large grain size, improved charge extraction properties, and suppressed non-radiative recombination processes, and further enhance the power conversion efficiency (PCE) from 4.06 to 7.87%. As previously reported, methylammonium chloride (MACl) can help to improve the morphology and crystallinity of perovskite. To further prove the versatility of such a mixed solvent strategy and enhance the photovoltage performance, a small amount of MACl was added to the FABr solution with mixed solvents, and a high PCE of 9.23% was achieved under ambient conditions.