Browse Articles

Compacting Molecular Stacking and Inhibiting Self‐Aggregation in Fullerene Transporting Layer for Efficient and Stable Perovskite Solar Cells

Abstract The underdevelopment of electron transport layer (ETL) materials remains a critical bottleneck limiting the overall photovoltaic performance of inverted perovskite solar cells (PSCs). Fullerene derivatives, such as PCBM, are widely employed ETL materials in PSCs due to their excellent electron affinity and energy level alignment with the perovskite layer. However, PCBM suffers from high energy disorder, self‐aggregation predilection, and insufficient defect passivation ability, leading to significant charge carrier recombination and accumulation at interfaces. Herein, a phosphate‐substituted fullerene derivative, FuPE, is developed to enhance the performance of PCBM‐based ETLs for PSCs. Incorporating FuPE efficiently compacts molecular stacking, enforces crystallinity and intermolecular interaction, suppresses self‐aggregation, and improves interfacial compatibility of the FuPE:PCBM blend. Such endows the FuPE:PCBM blend film with enhanced electron mobility (0.183 cm 2  V −1  s −1 ), lower trap density, more uniform film morphology, and superior defect‐passivation ability, compared to the PCBM pristine one. Consequently, PSCs employing FuPE:PCBM as the ETL achieve reduced trap‐assisted recombination, enhanced charge carrier extraction, and thus a remarkable power conversion efficiency exceeding 26% alongside improved operational stability. This work highlights an effective strategy for optimizing fullerene‐based ETLs, advancing the development of highly efficient and durable PSCs.

A novel feature fusion model to mimic photographers’ active observation for scenery recomposition toward physical education

Green synthesis an eco-friendly route for the synthesis of iron oxide nanoparticles using aqueous extract of Thevetia peruviana and their biological activities

Charge‐Transport Divergence in Ultrastable Heterometal‐Oxo Clusters Exerting Significant Effect on Photoreactivity

Abstract The transfer path of photogenerated charges greatly affects the final photocatalytic performance, but this important fact has not been clearly demonstrated experimentally. Here, we construct an ultrastable crystalline catalytic system including three heterometal‐oxo clusters, Bi 8 M 7 ‐TBC4A (M = group IVB metal‐Ti/Zr/Hf), which include cubic metal‐oxo cluster core with eight Bi atoms at the vertices, one M atom at the body center, and six M atoms above the cubic face centers. It is worth noted that the change of group IVB elements in Bi 8 M 7 ‐TBC4A can specifically modulate the LUMO‐HOMO orbitals to distribute on different active metal atoms. This allows it to be an excellent model system to verify the effect of the transport paths of photogenerated charges on photoreactivity. In model reaction based on CO 2 photoreduction, Bi 8 Ti 7 ‐TBC4A displays superior photocatalytic CO 2 ‐to‐HCOOH conversion rate of 3580.02 µmol g −1 , which is twice that of Bi 8 Zr 7 ‐TBC4A and 4 times that of Bi 8 Hf 7 ‐TBC4A . In situ characterization accompanied by density functional theory (DFT) indicate that the difference in orbital hybridization between Bi and IVB group elements largely affects the orbital distribution of frontier molecular orbital levels in Bi 8 M 7 ‐TBC4A , leading to the transport of photogenerated charges to metal active sites with different reactivities, and thus widely differing photocatalytic performances. This is the first model catalyst system that explores the effect of different photogenerated charge transport pathways on photoreactivity.

A study on green innovation and entrepreneurship in the dual carbon era and its implications for the energy market

Spiro Units Embedded in the B/N Center for Constructing Highly Efficient Multiple Resonance TADF Emitters

Abstract Departing from conventional molecular design strategies that rely on spiro units merely as peripheral components (side chains, terminal groups, or linkage units), we fully or partially incorporate the rigid 9,9′‐spirobi[fluorene] (SF) unit into the boron/nitrogen multiple resonances (B/N‐MR) emitting core, thereby successfully developing a series of proof‐of‐concept isomerized multiple resonance thermally activated delayed fluorescence (MR‐TADF) emitters, namely SF‐BN1, SF‐BN2, SF‐BN3, and SF‐BN4. Remarkably, these novel emitters exhibit exceptionally narrow full‐width at half‐maximum (FWHM) values of 15–21 nm in dilute toluene solutions and high photoluminescence quantum yields (PLQYs) of up to 90% in doped films. The corresponding organic light‐emitting diode (OLED) based on SF‐BN1 achieved high external quantum efficiency (EQE) of up to 29.0%, with CIE coordinates of (0.13, 0.08), closely aligning with the BT.2020 blue emission standard. Sky‐blue OLEDs based on SF‐BN3 can achieve a high EQE of 29.8%, with a narrow FWHM value of 18 nm; the hyperfluorescent (HF) OLEDs based on SF‐BN3 improved the EQE of 35.5%. Moreover, we elucidated subtle variations in the connectivity of chemical functional groups within emitters and the polar environment and doping concentrations of OLEDs, which can significantly impact these isomers' optical and electroluminescent (EL) properties.

Unveiling the social fabric through a temporal, nation-scale social network and its characteristics

Cooperative Redox Reactions Encoded by Two Gene Clusters Enable Intermolecular Cycloaddition Cascade for the Formation of Meroaspochalasins

Abstract Meroaspochalasins (mAPOs) are a group of intricate heteromers comprising two distinct subunits, dienophile aspochalasin, and diene isobenzofuran, of which the biosynthetic mechanism is of great interest yet unrevealed. In this study, two independent biosynthetic gene clusters (BGCs), flas and epi , being responsible for the biosynthesis of aspochalasin B ( 7 ) and pre‐diene hemiacetal 21 (or 26 ), respectively, were identified in the filamentous fungus Aspergillus flavipes . In vivo and in vitro studies proved that a flavin adenine dinucleotide (FAD)‐dependent oxidase FlasF in the flas cluster catalyzes the crucial oxidation to generate diverse aspochalasin monomers, particularly the dienophile 7 . Interactive reduction catalyzed by the short‐chain alcohol dehydrogenase/reductase (SDR) FlasG and endogenous NADPH further increases the complexity of this anabolic network. The cytochrome P450 enzyme EpiC and SDR enzyme EpiD in the epi cluster collaboratively catalyze the formation of pre‐diene 21 (or 26 ), which can spontaneously dehydrate to yield a diene, leading to the nonenzymatic cascade of [4 π + 2 π ] Diels–Alder and formal [5 π + 2π] cycloaddition reaction to generate mAPO dimers and trimer progressively. Moreover, the FAD‐dependent oxidase EpiG catalyzes the hydroxylation at the C3 position of the diene as a critical step in the formation of mAPO trimers.

Li ₂₁ Ge ₈ P ₃ S ₃₄ : New Lithium Superionic Conductor with Unprecedented Structural Type

Abstract Lithium superionic conductors are pivotal for enabling all‐solid‐state batteries, which aim to replace liquid electrolytes and enhance safety. Herein, we report the discovery of an unprecedented lithium superionic conductor, Li 21 Ge 8 P 3 S 34 , featuring a novel structural type and a new composition in the Li–Ge–P–S system. This material exhibits high lithium ionic conductivity of approximately 1.0 mS cm −1 at 303 K with a low activation energy of 0.20(1) eV. It's unique crystal structure was elucidated using three‐dimensional electron diffraction (3D ED) and further refined through combined powder X‐ray and neutron diffraction analyses. The structure consists of alternating two‐dimensional slabs: one of corner‐sharing GeS 4 tetrahedra and the other of isolated PS 4 tetrahedra, enabling efficient lithium‐ion transport through a tetrahedrally interconnected network of 1D, 2D, and 3D diffusion pathways. This distinctive structural motif provides a novel design strategy for next‐generation solid electrolytes, broadening the structural landscape of lithium superionic conductors. With further advancements in compositional tuning and interfacial engineering, Li 21 Ge 8 P 3 S 34 could contribute to the development of high‐performance all‐solid‐state batteries.

B ← N Lewis Pair Fusion of <i>N</i> , <i>N</i> ‐Diaryldihydrophenazines: Effect on Structural, Electronic, and Emissive Properties

Abstract Doping of polycyclic aromatic hydrocarbons (PAHs) with boron and/or nitrogen is emerging as a powerful tool to tailor the electronic structure and photophysical properties. As N‐ doped analogues of anthracene, N,N ‐dihydrophenazines play important roles as redox mediators, battery materials, luminophores, and photoredox catalysts. Although benzannulation has been used successfully as a structural constraint to control the excited state properties, fusion of the N‐aryl groups to the phenazine backbone has rarely been explored. Herein, we report the first examples of dihydrophenazines, in which the N‐aryl groups are fused to the phenazine backbone via B←N Lewis pair formation. This results in structural rigidification, locking the molecules in a bent conformation, while also modulating the electronic structure through molecular polarization. B─N fusion in BNPz1−BNPz3 induces a quinoid resonance structure with significant C─N(py) double bond character and reduces the antiaromatic character of the central pyrazine ring. Borylation also lowers the HOMO/LUMO (highest occupied/lowest unoccupied molecular orbital) energies and engenders bathochromic shifts in the emission. Further rigidification in the solid state gives rise to enhanced emission quantum yields, consistent with aggregation‐induced emission enhancement (AIEE) observed upon water addition to solutions in tetrahydrofuran (THF). The demonstrated structural control and fine‐tuning of optoelectronic properties are of great significance to potential applications as emissive materials and in photocatalysis.

Highly Efficient Acceptors with a Nonaromatic Thianthrene Central Core for Organic Photovoltaics

Abstract Despite the great role in determining molecular packings and organic photovoltaic outcomes, very rare candidates could be employed as central cores in current high‐performance acceptors except diimide‐based moieties. Herein, a new type of central core of nonaromatic thianthrene is explored firstly, affording an exotic but structurally tailorable molecular platform for acceptor design. A unique puckered rather than planar conformation of central core is adopted, caused by the 4n πe − feature, great ring strain and largely the insufficient p–π orbital overlap of lone pair on sulfur of thianthrene and coterminous benzene planes. As a result, the absorption of thianthrene‐based acceptors (CS1, CS2, and CS3) shows unexpected blue shift comparing to the phenazine‐based counterpart (CH20), regardless of the intrinsically strong electron‐donating characteristic of low valence sulfur atoms. Even so, the desired molecular packing and fibrillary film morphology, assisted by the suitable chlorination on thianthrene, still contribute to the best device efficiency of 19.0% based on D18:CS2 blends. Such novel work renders an underdeveloped NFA platform with the potentials for achieving PCE of over 20%.

Anode Engineering with pH‐Neutral Conjugated Polyelectrolyte Enabling Over 19% Efficiency in Organic Solar Cells

Abstract The lack of effective hole‐transporting layers (HTLs) materials has become a significant bottleneck in the advancement of organic solar cells (OSCs). Particularly, to obtain sufficient doping properties, most HTLs have to be used by mixing with substantial amounts of acid, which causes serious corrosion problems. Herein, by optimizing molecular conformation, we designed and synthesized two conjugated polyelectrolytes (CPEs) that exhibited superior hole‐transporting capability without involving acid addition. The PEP‐BT features a planar conjugated backbone constructed from the nonfused segment, which leads to an enhanced doping effect and highly ordered molecular arrangement. and reduced π–π stacking from 4.13 to 3.85 Å. These contributed to the outstanding hole collection performance of polyoxometalate‐doped PEP‐BT:POM4 while maintaining a neutral pH. The binary OSC showed a photovoltaic efficiency of 19.16%, illustrating an unprecedented example that a CPE‐based HTL can provide a photovoltaic efficiency exceeding 19% in OSCs. Moreover, as another evidence of high‐performance HTL, the organic light‐emitting diode incorporating PEP‐BT:POM4 exhibited a superior luminous efficiency to the reference device, along with a decrease of 0.4 V for turn‐on voltage. The results from this work demonstrate the great potential of CPEs as HTL materials.

Duplication of the autism-related gene Chd8 leads to behavioral hyperactivity and neurodevelopmental defects in mice

Enabling static random-access memory cell scaling with monolithic 3D integration of 2D field-effect transistors

Frustrated phonon with charge density wave in vanadium Kagome metal

Electron displacement polarization of high-dielectric constant fiber separators enhances interface stability

Solid-state eutectic electrolyte via solvation regulation for voltage-elevated and deep-reversible Zn batteries

Chromatic forecasting hydrogels for anti-icing applications

Global land and carbon consequences of mass timber products

Abstract Mass timber products can reduce greenhouse gas emissions by replacing steel and cement. However, the increase in wood demand raises wood prices, and the environmental consequences of these market changes are unclear. Here we investigate the global carbon and land use impacts of adopting mass timber products, focusing on cross-laminated timber as a case study. Our results show that higher wood prices reduce the production of traditional wood products but expand productive forestland by 30.7–36.5 million hectares from 2020 to 2100 and lead to more intensive forest management. If the cumulative global cross-laminated timber production reaches 3.6 to 9.6 billion m3 by 2100, long-term carbon storage can increase by 20.3–25.2 GtCO2e, primarily in forests (16.1–17.7 GtCO2e) and in cross-laminated timber panels (4.1–8.1 GtCO2e). Including emission reductions from steel, cement, and traditional wood products, the net reduction of life-cycle greenhouse gas emissions will be 25.6–39.0 GtCO2e.

Anharmonic effects control interaction of carbyne confined in carbon nanotubes shaping their vibrational properties