The molecular orientation and adsorption of self-assembled monolayers/multilayers (SAMs) critically govern organic solar cell (OSC) performance via modulating thin-film conductivity. To elucidate this structure-property relationship, we synthesized a new SAM molecule, DM-BZCz, by introducing an electron-donating methoxyphenyl group. This unique molecular design endows DM-BzCz with a preferential vertical molecular orientation on ITO surfaces, leading to enhanced molecular ordering and packing density, as jointly confirmed by theoretical and experimental analyses. The resulting strengthened interfacial dipole promotes more efficient hole extraction, prolongs carrier lifetime, and significantly suppresses interfacial recombination. Consequently, devices based on ITO/SAMs exhibit an increased electrical conductivity from (291.78 S) is superior to that of BZCz (282.45 S), corroborating its superior interfacial characteristics. Therefore, DM-BZCz-based OSCs achieve a significantly improved power conversion efficiency (PCE) of 19.79% compared to the counterparts with methoxyphenyl-free SAMs (18.70%). Using PM1:L8-BO as the photoactive layer, DM-BZCz OSCs attain a remarkable PCE of 20.54% (certified 19.93%), among the highest for binary bulk-heterojunction OSCs. Furthermore, A large-area module (19.3 cm2) delivers a 15.30% PCE employing DM-BZCz SAMs. This work elucidates the structure-property link between SAM electronic structure, adsorption, conductivity, and optoelectronic performance, providing a route to unlock OSC efficiency potential.

The inherently high exciton binding energy and inefficient exciton dissociation in organic solar cells (OSCs) limit the simultaneous improvement of short-circuit current density (JSC) and open-circuit voltage (VOC), thereby constraining device performance. Here, we introduce an energy re-excitation (ERE) strategy using 2-(2-hydroxy-5-methylphenyl) benzotriazole (HMB) as an interfacial modulator. The ERE effect establishes interfacial energy gradients that enable UV photon recycling and regulate exciton dynamics. HMB promotes long-range exciton delocalization, reducing the binding energy by 73.9%, and enhances hybridization of charge-transfer states. Devices exhibit a high JSC of 28.56 mA cm-2 and a VOC of 0.865 V, while suppressing non-radiative losses (Delta E3 = 0.211 eV) and triplet exciton formation. Theoretical analysis reveals that ERE creates delocalized exciton reservoir and facilitates pi-pi stacking, improving charge transport. The devices applied to ternary PM6:D18:L8-BO systems achieve a power conversion efficiency of 20.5% (certified 19.84%). This provides a generalizable exciton-engineering framework for high-performance OSCs.

Carbon nanotubes (CNTs) are a type of field emission cathode material with broad application potential. Compared with hot filament cathodes, CNTs cathodes possess advantages such as low operating temperature and energy efficiency. In this article, a CNTs electron emitter is integrated into an ionization gauge featuring a straight electron path. A series of tests were performed on the CNTs cathode and the prototype gauge. The optimal operating potential of the prototype gauge was determined through simulations and experiments. The prototype achieved a sensitivity of 0.317 Pa-1 in argon and 0.240 Pa-1 in nitrogen. This prototype gauge exhibits good linearity in the range from 10-6 Pa to 10-3 Pa in argon and nitrogen, while its sensitivity fluctuations are 1.17 % and 3.2 %, and within half an hour, the sensitivity fluctuations in the two gases are 1.6 % and 2.2 % respectively. Under simulated normal operating conditions, the repeatability is less than 3 %. This novel developed ionization gauge has simultaneously achieved high sensitivity and good stability. This study provides insights for the application of CNTs cathodes in the ionization gauges.

The long-term stability of polycrystalline perovskite solar cells (PSCs) remains a major hurdle despite their high power conversion efficiencies (PCEs), underscoring the importance of eliminating all potential photodegradation pathways. While efforts have been devoted to address bulk and interfacial defect-induced photodegradation, those correlate to the microscale inter-grain carrier reactions intrinsic to the polycrystalline nature of PSCs remain unsolved. Here we uncover a defect-dependent asymmetric inter-grain recombination pathway that governs photodegradation in mixed-facet PSCs. By resolving the nature and evolution of facet-specific defects for the first time, we reveal that hetero-facet grain boundaries induce non-equilibrium hole accumulation at (111)-facet grain boundaries that unexpectedly accelerates their photodegradation, despite their superior intrinsic photostability. By introducing 3-fluorophenylethylammonium bromide that targets identified formamidinium vacancy defects at the (111)-facet grain boundaries, we homogenize the inter-grain recombination, yielding PSCs with PCEs approaching 26.55

Bulk heterojunction (BHJ) organic solar cells (OSCs) have achieved high efficiencies but suffer from poor morphological stability due to phase separation after long-term operation. Single-component OSCs (SCOSCs) based on double-cable polymers (DCP), offer improved stability through covalently linked donor and acceptor units. However, their efficiency remains limited by inefficient charge generation arising from extensive intermixed morphologies. Here, we report a fluorinated double-cable polymer, DCPY2-F, which achieves an outstanding efficiency of 14.8% with high short-circuit current density of 26.83 mA cm-2. Ultrafast pump-probe transient absorption spectroscopy reveals that fluorination of DCPY2 into DCPY2-F accelerates interfacial charge transfer and long-range charge separation dynamics. The pump-push-probe transient absorption spectroscopy and steady-state electroluminescence show that the faster interfacial charge transfer arises from a reduced reorganization energy and a correspondingly accelerated molecular reorganization process (2.5 ps vs. 0.8 ps). Despite comparable acceptor aggregate sizes with DCPY2, DCPY2-F also shows faster long-range charge separation dynamics, which we attribute to a narrower charge transfer states (CTs) energetic distribution. Molecular dynamics simulations further reveal that fluorination strengthens non-covalent interactions, promoting well-aligned intermolecular donor-acceptor interfaces. These structurally and energetically ordered interfacial CT states enable ultrafast and efficient charge generation. In corresponding binary blends, fluorination similarly enhances charge-transfer dynamics and photocurrent. These findings establish a unified fluorination strategy for accelerating charge generation dynamics in both SCOSCs and blends, and provide a mechanistic understanding for improving charge generation for high-performance single-component systems.

Mitigating irreversible reverse-bias-induced perovskite degradation is paramount for the commercial deployment of perovskite solar modules, especially ensuring their reliability under partial shading scenarios. In n-i-p perovskite solar cells (PSCs), perovskite decomposition under reverse-bias involves the initial iodide re-distribution, followed by its oxidation and subsequent ultraviolet (UV) activation into iodine radicals, finally triggering the degradation within the perovskite. This work presents a delicate iodine chelation engineering to directly restrain this failure mechanism by incorporating a tailored β-cyclodextrin sulfated sodium salt (S-β-CD) at the critical SnO2/perovskite buried interface. This iodine chelating agent simultaneously sequesters the reactive iodine species from perovskites and provides the intrinsic UV-protection at the front side, to interrupt the photolysis cascade, which significantly enhances the reverse-bias robustness of PSCs. We demonstrate an outstanding operational stability after the reverse-bias precondition (T80 = ~ 1000 h, ISOS-L-3), and more encouragingly, deliver a superior cyclic lifetime under the periodic reverse-bias and light soaking stress (T85 = ~ 1600 h, ISOS-V-1). This strategy offers a significant leap towards the reverse-bias reliability required for solar module applications in the real world.

The design of high-performance small-molecule acceptors (SMAs) for organic solar cells (OSCs) remains a central challenge, particularly under the growing demand for environmentally friendly processing conditions. While halogenation has been widely employed to optimize electronic structures and molecular packing, its reliance on toxic halogenated solvents and the limited tunability of intermolecular interactions highlight the need for alternative strategies. In this context, core functionalization with cyano (CN) groups provides a unique opportunity, as the CN unit combines strong electron-withdrawing ability, high polarity, and linear geometry, potentially offering synergistic regulation of both optoelectronic properties and supramolecular assembly. However, systematic studies on core cyanation remain scarce, and its precise role in balancing charge transfer, molecular ordering, and energy loss in OSCs has not been thoroughly clarified. Here, we report a cyano-functionalized benzo[a]phenazine (BP)-core SMA, denoted as NA8, to explore how core cyanation influences device performance. The introduction of the CN group reduces the intramolecular charge transfer, resulting in a blue-shifted absorption and a slightly enlarged optical bandgap compared with the non-cyanated analogue NA1. Despite this apparent drawback, NA8 demonstrates superior molecular packing, as evidenced by GIWAXS measurements showing a crystalline coherence length more than twice that of NA1 (101.3 & Aring; vs. 44.6 & Aring;). This improvement originates from the significantly enhanced dipole moment of NA8 (4.26 D vs. 2.21 D for NA1), which facilitates stronger electrostatic and noncovalent interactions (e.g., S & sdot;& sdot;& sdot;N and H & sdot;& sdot;& sdot;N contacts), thereby stabilizing more ordered packing motifs. At the blend-film level, AFM reveals that PM6:NA8 exhibits a rougher yet more clearly phase-separated morphology compared with PM6:NA1, providing continuous transport pathways. Photo-CELIV measurements confirm higher carrier mobility (2.36 x 10-4 cm2 V-1 s-1 vs. 1.29 x 10-4 cm2 V-1 s- 1), while transient absorption spectroscopy shows faster exciton dissociation and reduced bimolecular recombination. Together, these synergistic effects explain why the PM6:NA8 device achieves an outstanding power conversion efficiency of 19.04 % using non-halogenated o-xylene, compared with 15.14 % for PM6:NA1. The improvement primarily arises from the significantly enhanced short-circuit current density (27.35 mA cm- 2) and fill factor (78.3 %), while the open-circuit voltage is only moderately reduced (0.889 V vs. 0.914 V) due to increased reorganization energy associated with C-C bond vibrations in the CN-substituted BP core. Our study identifies core cyanation as a powerful molecular engineering strategy to concurrently tune energy levels, strengthen molecular packing, and optimize nanoscale morphology, providing valuable design guidance for next-generation organic photovoltaics.

Crystalline organic semiconductors are crucial for high‐performance optoelectronic devices due to their potential for high charge‐carrier mobility. Rubrene, in particular, exhibits exceptional hole transport in crystalline thin films; however, conventional thermal annealing methods often promote uncontrolled crystallisation and grain boundary formation, hindering lateral transport and device scalability. Here, a flexible femtosecond laser micromachining strategy is introduced to achieve localized crystallization and precise structural control in rubrene thin films. By utilizing a 200 fs laser at 514 nm, three laser‐based techniques are explored: defect seeding, spatially confined annealing, and micro‐patterned ablation – along with resistive heating using patterned indium tin oxide (ITO) substrates to induce and restrict crystal growth. Among these approaches, the resistive heating approach effectively enables deterministic crystallization with high spatial resolution, allowing for the formation of regularly spaced or isolated crystals. The findings outline a pathway for integrating localized crystallization techniques into device fabrication, offering new opportunities to reduce crosstalk and facilitate the miniaturization of organic electronic and optoelectronic systems.

Here, a donor-acceptor integrated polymer, PQIC, featuring a rigid π-conjugated framework, is reported, in which a Y-type small-molecule acceptor is covalently fused into a polymer donor backbone. PQIC exhibits balanced bipolar charge transport, reduced defect density, and high electroluminescence efficiency. When incorporated as a third component, it facilitates charge percolation, concurrently weakens electron-phonon coupling and lowers defect-state density, thereby alleviating recombination losses. As a result, PQIC-based ternary organic solar cells achieve a power conversion efficiency of 20.81% (third-party certified at 20.60%). In addition to high efficiency, the devices exhibit excellent stability, thick-film tolerance, and scalability, retaining ~85% of their initial efficiency after 2000 hours of maximum power point tracking, delivering 19.11% with a 300-nanometer-thick active layer, and reaching 19.78% for 1-square centimeter devices. These results highlight the potential of PQIC-based ternary systems for advancing organic solar cells.

Additives are widely used in organic photovoltaics (OPVs) to tune bulk-heterojunction morphology, most often through selective solvation or specific intermolecular interactions. Here, we introduce an alternative processing concept by employing n-octadecane (C18) as a chemically simple, electronically inert phase-change medium to minimize strong, directional additive-semiconductor interactions and enable a phase-transition-mediated kinetic pathway. In situ optical monitoring indicates a two-stage behavior: accelerated aggregation during casting and an annealing-enabled reorganization associated with a transient plasticization window. The resulting microstructure facilitates charge extraction and suppresses recombination. In PM6:Y6 devices, C18 increases the power conversion efficiency (PCE) from 17.28% to 18.89%, with concurrent gains in JSC and fill factor (FF); in a PM1:L8-BO:BTP-eC9 ternary system, the PCE improves from 18.88% to 20.75%. Benchmarking against the conventional high-boiling-point halogenated additive 1,8-diiodooctane (DIO) shows that C18 delivers higher efficiency and improved operational stability. These results establish a phase-change-mediated route for morphology programming in high-efficiency OPVs.

ABSTRACT Designing cathode interlayers (CILs) that simultaneously deliver high efficiency, operational stability, and broad thickness tolerance remains a critical challenge for organic solar cells (OSCs). Herein, trimesic acid (TMA) and phloroglucinol (PG), two small molecules featuring opposite central electrostatic potential (ESP) distributions, are employed as model systems to systematically elucidate their intermolecular interactions with the benchmark CIL material PDINN and to reveal the molecular origin of thickness sensitivity. Benefiting from complementary ESP matching, PG incorporation markedly enhances PDINN self‐doping, electrical conductivity, energy‐level alignment, and π–π stacking, while suppressing PDINN self‐agglomeration and reducing Ag electrode work function. These synergistic effects promote efficient charge extraction and transport and suppress non‐radiative recombination losses. As a result, OSCs with the PDINN:PG CIL achieve a power conversion efficiencie (PCE) of 20.0% (certified 19.5%), together with outstanding thickness tolerance, maintaining 87.0% of champion efficiency at 50 nm, and improved operational stability (80% after 600 h). Furthermore, perovskite‐organic tandem solar cells (TSCs) deliver a decent PCE of 26.4%. This work establishes an ESP‐guided molecular interfacial engineering strategy for thickness‐tolerant and durable CILs for next‐generation OSCs.

HCGs are widely used for ultra-high vacuum and space vacuum measurements due to their high-sensitivity and long-term stability. However, the indicated pressure of an HCG may deviate from the actual chamber pressure because the operating conditions during application differ from those during calibration. This deviation is particularly relevant for balance-chamber HCGs used in space vacuum measurements, where the ionization region is connected to the external vacuum environment through multistage conductance channels, leading to complex molecular transport behavior. In this study, the pressure deviation mechanism of balance-chamber HCGs is investigated by considering the coupled effects of thermal transpiration, thermal outgassing, and structural conductance. Based on free molecular flow theory and the Maxwell–Boltzmann velocity distribution, a pressure model is developed to describe the relationship between the internal gauge pressure and the external chamber pressure. The contributions of temperature gradients, outgassing sources, and structural parameters are analyzed through numerical simulations and experimental measurements. The results indicate that thermal transpiration is the dominant factor affecting pressure deviation at relatively higher pressures. With decreasing pressure, thermal outgassing from heated internal components becomes increasingly significant and limits the measurement accuracy in the ultra-high vacuum range. A structure-dependent correction exponent was introduced to account for the influence of the balance chamber on thermal transpiration behavior. After correction, the prediction deviation of the proposed model is reduced to within ±1%. The proposed model provides a quantitative approach for evaluating pressure deviations in HCGs with complex internal structures and improves the reliability of pressure interpretation for space vacuum measurements

This study focuses on the synthesis and the performance of non-fullerene acceptors (NFAs) with varying chlorine dispersion in organic solar cells (OSCs). Four chlorine-mediated acceptors, BO3Cl-a, BO3Cl-gamma, BO3Cl-beta, and BOEH3Cl-beta are synthesized with isomeric terminal groups and then integrated with donor PBDB-TF to fabricate OSCs. It finds that increased chlorine dispersion improves device efficiency with enhanced current and BOEH3Cl-beta-based devices achieving a power conversion efficiency (PCE) of over 19%, which is one of the highest values reported for asymmetrically chlorinated acceptors. In OSC devices, Enhanced exciton dissociation and reduced carrier recombination are observed with more chlorine dispersion, along with improved charge transport due to modulation of molecular packing in the active layer. Furthermore, transient absorption spectroscopy elucidates that chlorine dispersion augments exciton diffusion time, thereby elevating the current density of devices, while the branching strategy further amplify the exciton lifetime of BOEH3Cl-beta, preserving the value of short current in the face of spectral blue shifts of it. The findings suggest that chlorine-mediated dispersion is a key factor in enhancing OSC performance with improved current by progressive molecular packing arrangement and aggregation behaviors.

ABSTRACT Perovskite/organic tandem solar cells (TSCs) represent a compelling pathway toward high‐efficiency, solution‐processed photovoltaics; however, their performance remains constrained by voltage losses in wide‐bandgap (WBG) perovskite sub‐cells due to halide phase segregation and associated ion migration. Here, we address this challenge through rational molecular design of hydrogen‐bonding agents that precisely regulate crystallization dynamics. By incorporating an electron‐withdrawing sulfone group (‐SO 2 ) into diaminofluorene, the ‐NH 2 functionality is electronically reprogrammed from a cation‐coordinating base into a halide‐targeting hydrogen‐bond donor that selectively stabilizes bromide via directional N─H⋯Br − interactions. This electron‐deficient architecture stabilizes Br‐rich DMSO‐PbBr 2 /DTD intermediates, suppresses premature Br‐rich nucleation, and promotes uniform vertical and horizontal halide distribution during film formation. Simultaneously, it elevates the activation barrier for halide ion migration in WBG perovskites. Consequently, single‐junction 1.85 eV‐WBG perovskite solar cells achieve a champion power conversion efficiency (PCE) of 19.32%, with markedly enhanced operational stability under continuous illumination. When integrated into perovskite/organic TSCs, this strategy delivers an impressive PCE of 26.76% with an open‐circuit voltage ( V OC ) of 2.216 V, among the highest reported for perovskite/organic tandems. This work elucidates a structure–function paradigm for molecular regulation of halide chemistry in WBG perovskites and provides a generalizable route toward phase‐stable, high‐voltage tandem photovoltaics.

Flexible quantum-dot light-emitting diodes (QLEDs) based on silver-nanowires (AgNWs) transparent electrodes show great potential but suffer from surface roughness, poor wettability, and unstable interfaces. We propose a multifunctional interfacial engineering strategy using ZnMgO nanocrystals to address these issues. The ZnMgO layer acts as a nanoscale welding agent, preventing AgNWs sliding and improving mechanical stability while providing a smooth surface for uniform organic hole transport layer (HTL) deposition. As confirmed by capacitance-voltage (C-V) and single-carrier measurements, band alignment at the HTL/ZnMgO interface creates a low-barrier hole injection pathway, optimizing the charge balance. The resulting flexible QLED achieves 20.84% external quantum efficiency (EQE), 43,270 cd/m2 luminance, and excellent voltage tolerance, with brightness stable up to 10.8 V. The device retains over 80% performance after 2000 bending cycles. Moreover, this strategy achieves up to 27.52% EQE for flexible QLEDs based on conventional electrodes, indicating a scalable route for optoelectronics.

The developed MEMS capacitance diaphragm gauge (CDG) features a single-capacitance structure and operates in an electrostatic servo mode for vacuum measurement. In this mode, a servo voltage is applied between the diaphragm and the fixed electrode to electrostatically restore the diaphragm to its initial position; the applied voltage then serves as the pressure-dependent output. Both simulation and experimental results validate the working principle. Compared with the non-servo mode, the servo mode provides stable measurements, replaces capacitance-change detection with a constant-capacitance servo loop, and maintains a constant sensitivity over a wide pressure range. Over 1–1000 Pa, the non-servo mode exhibits a sensitivity that drops from 0.04 pF/Pa to 0.01 pF/Pa, with hysteresis errors of 26.49% and 20.97% obtained in two separate tests. In the servo mode, the sensitivity stays constant at 3.4 V2/Pa, and the hysteresis errors in two corresponding tests are reduced to 2.00% and 2.19%, respectively. These results demonstrate that the servo mechanism significantly enhances measurement linearity and suppresses hysteresis.

Organic solar cells (OSCs) achieve high photovoltaic output largely by regulating the nanoscale morphological structure of their photoactive layers. Trace doping has emerged as a promising strategy to simultaneously optimize morphological characteristics and charge dynamics; however, conventional p-or n-type dopants are often constrained by limited molecular diversity, complex screening processes, and the risk of inducing undesirable recombination pathways. Herein, we report a multifunctional trace dopant, a benzotriazole derivative (1-HB), featuring a molecular skeleton that is highly compatible with the acceptor material L8-BO. At an ultralow concentration (0.05 mg mL-1), 1-HB enables precise morphology regulation in PM6:L8-BO film. Comprehensive characterization reveals that 1-HB synergistically modulates crystallization dynamic behavior of both donor (PM6) and acceptor (L8-BO) phases via strong intermolecular interactions, leading to enhanced molecular packing, increased structural order, improved crystallinity and coherence length, and the construction of an optimal vertical phase separation gradient that facilitates efficient charge transport. Femtosecond transient absorption spectroscopy further demonstrates that 1-HB accelerates charge separation, reducing the hole transfer lifetime tau 1 from 2.047 ps to 0.858 ps, while simultaneously optimizing charge separation pathways by decreasing the contribution of slower processes from 26.4% to 19.5%. These combined effects facilitate ultrafast exciton dissociation and suppress bimolecular as well as trap-mediated recombination, which in turn effectively reduces non-radiative energy losses. Consequently, the optimized devices deliver a best power conversion efficiency (PCE)-19.98%, a remarkable improvement over the 18.41% of control devices, along with simultaneous enhancements in fill factor (FF), open-circuit voltage (VOC) and short-circuit current density (JSC). This acceptor-skeleton-matched trace doping strategy establishes a general molecular design paradigm for high-efficiency, low-dosage active layer dopants, offering substantial promise for advancing high-performance organic photovoltaics.

Perovskite‐based tandem solar cells represent a key technology for next‐generation photovoltaics. As an essential component, the carrier transport layer (CTL) encounters challenges such as poor interfacial contact and inefficient carrier transport in both single‐junction and tandem perovskite solar cells. Herein, it is demonstrated that inserting a 2,4,6‐Tris[3‐(diphenylphosphinyl)phenyl]‐1,3,5‐triazine (PO‐T2T) interlayer between C 60 and Atomic layer deposition (ALD) SnO X layers imparts multiple functional benefits: 1) The PO‐T2T interlayer re‐engineers the buried interface by establishing a more uniform surface potential and a favorable band alignment, thereby suppressing interfacial energetic disorder and enhancing electron‐extraction driving force, facilitating improved carrier transport; 2) The PO‐T2T interlayer provides nucleation sites for the uniform deposition of ALD SnO X and suppresses interfacial non‐radiative recombination, enabling improved heterointerface contact and enhanced device stability. As a result, high‐efficiency perovskite devices with enhanced operational stability are achieved: single‐junction wide‐bandgap (1.78 eV) perovskite cells with a power conversion efficiency (PCE) of 21.1%, and all‐perovskite tandem devices with PCEs of 28.5% (two‐terminal) and 29.3% (four‐terminal). This approach offers a promising strategy for advancing interfacial contact design in perovskite‐based tandem technology.