Dopant-additive synergism enhances perovskite solar modules.

Perovskite solar cells (PSCs) are among the most promising photovoltaic technologies owing to their exceptional optoelectronic properties1,2. However, the lower efficiency, poor stability and reproducibility issues of large-area PSCs compared with laboratory-scale PSCs are notable drawbacks that hinder their commercialization3. Here we report a synergistic dopant-additive combination strategy using methylammonium chloride (MACl) as the dopant and a Lewis-basic ionic-liquid additive, 1,3-bis(cyanomethyl)imidazolium chloride ([Bcmim]Cl). This strategy effectively inhibits the degradation of the perovskite precursor solution (PPS), suppresses the aggregation of MACl and results in phase-homogeneous and stable perovskite films with high crystallinity and fewer defects. This approach enabled the fabrication of perovskite solar modules (PSMs) that achieved a certified efficiency of 23.30% and ultimately stabilized at 22.97% over a 27.22-cm2 aperture area, marking the highest certified PSM performance. Furthermore, the PSMs showed long-term operational stability, maintaining 94.66% of the initial efficiency after 1,000 h under continuous one-sun illumination at room temperature. The interaction between [Bcmim]Cl and MACl was extensively studied to unravel the mechanism leading to an enhancement of device properties. Our approach holds substantial promise for bridging the benchtop-to-rooftop gap and advancing the production and commercialization of large-area perovskite photovoltaics.

Oriented nucleation in formamidinium perovskite for photovoltaics.

The black phase of formamidinium lead iodide (FAPbI3) perovskite shows huge promise as an efficient photovoltaic, but it is not favoured energetically at room temperature, meaning that the undesirable yellow phases are always present alongside it during crystallization1-4. This problem has made it difficult to formulate the fast crystallization process of perovskite and develop guidelines governing the formation of black-phase FAPbI3 (refs. 5,6). Here we use in situ monitoring of the perovskite crystallization process to report an oriented nucleation mechanism that can help to avoid the presence of undesirable phases and improve the performance of photovoltaic devices in different film-processing scenarios. The resulting device has a demonstrated power-conversion efficiency of 25.4% (certified 25.0%) and the module, which has an area of 27.83 cm2, has achieved an impressive certified aperture efficiency of 21.4%.

Flexible solar cells based on foldable silicon wafers with blunted edges.

Flexible solar cells have a lot of market potential for application in photovoltaics integrated into buildings and wearable electronics because they are lightweight, shockproof and self-powered. Silicon solar cells have been successfully used in large power plants. However, despite the efforts made for more than 50 years, there has been no notable progress in the development of flexible silicon solar cells because of their rigidity1-4. Here we provide a strategy for fabricating large-scale, foldable silicon wafers and manufacturing flexible solar cells. A textured crystalline silicon wafer always starts to crack at the sharp channels between surface pyramids in the marginal region of the wafer. This fact enabled us to improve the flexibility of silicon wafers by blunting the pyramidal structure in the marginal regions. This edge-blunting technique enables commercial production of large-scale (>240 cm2), high-efficiency (>24%) silicon solar cells that can be rolled similarly to a sheet of paper. The cells retain 100% of their power conversion efficiency after 1,000 side-to-side bending cycles. After being assembled into large (>10,000 cm2) flexible modules, these cells retain 99.62% of their power after thermal cycling between -70 °C and 85 °C for 120 h. Furthermore, they retain 96.03% of their power after 20 min of exposure to air flow when attached to a soft gasbag, which models wind blowing during a violent storm.

Mechanical Fourier transform for programmable metamaterials.

Proactively programming materials toward target nonlinear mechanical behaviors is crucial to realize customizable functions for advanced devices and systems, which arouses persistent explorations for rapid and efficient inverse design strategies. Herein, we propose a "mechanical Fourier transform" strategy to program mechanical behaviors of materials by mimicking the concept of Fourier transform. In this strategy, an arbitrary target force-displacement curve is decomposed into multiple cosine curves and a constant curve, each of which is realized by a rationally designed multistable module in an array-structured metamaterial. Various target curves with distinct shapes can be rapidly programmed and reprogrammed through only amplitude modulation on the modules. Two exemplary metamaterials are demonstrated to validate the strategy with a macroscale prototype based on magnet lattice and a microscale prototype based on an etched silicon wafer. This strategy applies to a variety of scales, constituents, and structures, and paves a way for the property programming of materials.

A Breathable Fibrous Membrane with Coaxially Heterogeneous Conductive Networks toward Personal Thermal Management and Electromagnetic Interference Shielding.

The expeditious growth of wearable electronic devices has boomed the development of versatile smart textiles for personal health-related applications. In practice, integrated high-performance systems still face challenges of compromised breathability, high cost, and complicated manufacturing processes. Herein, a breathable fibrous membrane with dual-driven heating and electromagnetic interference (EMI) shielding performance is developed through a facile process of electrospinning followed by targeted conformal deposition. The approach constructs a robust hierarchically coaxial heterostructure consisting of elastic polymers as supportive "core" and dual-conductive components of polypyrrole and copper sulfide (CuS) nanosheets as continuous "sheath" at the fiber level. The CuS nanosheets with metal-like electrical conductivity demonstrate the promising potential to substitute the expensive conductive nano-materials with a complex fabricating process. The as-prepared fibrous membrane exhibits high electrical conductivity (70.38 S cm-1 ), exceptional active heating effects, including solar heating (saturation temperature of 69.7 °C at 1 sun) and Joule heating (75.2 °C at 2.9 V), and impressive EMI shielding performance (50.11 dB in the X-band), coupled with favorable air permeability (161.4 mm s-1 at 200 Pa) and efficient water vapor transmittance (118.9 g m-2 h). This work opens up a new avenue to fabricate versatile wearable devices for personal thermal management and health protection.

Full-Color "Off-On" Thermochromic Fluorescent Fibers for Customizable Smart Wearable Displays in Personal Health Monitoring.

Responsive thermochromic fiber materials capable of miniaturization and integrating comfortably and compliantly onto the soft and dynamically deforming human body are promising materials for visualized personal health monitoring. However, their development is hindered by monotonous colors, low-contrast color changes, and poor reversibility. Herein, full-color "off-on" thermochromic fluorescent fibers are prepared based on self-crystallinity phase change and Förster resonance energy transfer for long-term and passive body-temperature monitoring, especially for various personalized customization purposes. The off-on switching luminescence characteristic is derived from the reversible conversion of the dispersion state and fluorescent emission by fluorophores and quencher molecules, which are embedded in the matrix of a phase-change material, during the crystallizing/melting processes. The achievement of full-color fluorescence is attributed to the large modulation range of fluorescence colors according to primary color additive theory. These thermochromic fluorescent fibers exhibit good mechanical properties, fluorescent emission contrast, and reversibility, showing their great potential in flexible smart display devices. Moreover, the response temperature of the thermochromic fibers is controllable by adjusting the phase-change material, enabling body-temperature-triggered luminescence; this property highlights their potential for human body-temperature monitoring and personalized customization. This work presents a new strategy for designing and exploring flexible sensors with higher comprehensive performances.

Effects of Inorganic Salts on the Phase Separation of Partially Miscible Solutes.

Partially miscible solutions with a lower critical solution temperature have promising applications in the field of physical chemistry. To better guide the utilization of these solutions in practice, we conduct an in-depth study about the phase separation behavior of the solution added with inorganic salts. The addition of the inorganic salts into the solution is found to consequently reduce the phase separation temperature. The variation of concentrations of inorganic salts does not notably affect the mass fraction of the separation. Moreover, the addition of inorganic salts in the solutions at lower mass fractions improves the separation mass fraction, while the addition of inorganic salts decreases the separation mass fraction at the mass fractions above 30%. It sheds light on selecting the proper mass fractions and inorganic salt concentrations. Furthermore, we explore the phase separation behavior of mixed solutions under different inorganic salt additions by means of a high-speed camera. The phase separation behavior under different inorganic salt systems shows a similar trend. However, calcium ions and Fe3+ ions in the solutions can greatly decrease the rate of droplet coalescence and result in an increase in phase separation. For better regulating the solutions with a lower critical solution temperature through inorganic salts, sodium chloride or potassium chloride is recommended with an appropriate concentration.

Spatial transcriptomics reveals heterogeneity of macrophages in the tumor microenvironment of granulomatous slack skin.

Granulomatous slack skin (GSS) is an extremely rare subtype of cutaneous T-cell lymphoma accompanied by an abundant number of macrophages and is clinically characterized by the development of pendulous skin folds. However, the characteristics of these macrophages in GSS remain unclear. Here, we conducted a spatial transcriptomic study on one frozen GSS sample and drew transcriptomic maps of GSS for the first time. Gene expression analysis revealed the enrichment of three clusters with macrophage transcripts, each exhibiting distinct characteristics suggesting that their primary composition consists of different subpopulations of macrophages. The CD163+ /CD206+ cluster showed a tumor-associated macrophage (TAM) M2-like phenotype and highly expressed ZFP36, CCL2, TNFAIP6, and KLF2, which are known to be involved in T-cell interaction and tumor progression. The APOC1+ /APOE+ cluster presented a non-M1 or -M2 phenotype and may be related to lipid metabolism. The CD11c+ /LYZ+ cluster exhibited an M1-like phenotype. Notably, these cells strongly expressed MMP9, MMP12, CHI3L1, CHIT1, COL1A1, TIMP1, and SPP1, which are responsible for extracellular matrix (ECM) degradation and tissue remodeling. This may partially explain the symptoms of cutaneous relaxation in GSS. Further immunohistochemistry on four GSS cases demonstrated that CD11c predominantly marked granulomas and multinucleated giant cells, whereas CD163 was mainly expressed on scattered macrophages, appearing as a mutually exclusive pattern. The expression pattern of MMP9 overlapped with that of CD11c, implying that CD11c+ macrophages may be a source of MMP9. Our data shed light on the characteristics of macrophages in the GSS microenvironment and provide a theoretical basis for the application of MMP9 inhibitors to prevent cutaneous relaxation of GSS. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Scalable Fabrication of Electrospun True-Nanoscale Fiber Membranes for Effective Selective Separation.

Electrospun fibers have received wide attention in various fields ranging from the environment and healthcare to energy. However, nearly all electrospun fibers suffer from a pseudonanoscale diameter, resulting in fabricated membranes with a large pore size and limited separation performance. Herein, we report a novel strategy based on manipulating the equilibrium of stretch deformation and phase separation of electrospun jets to develop true-nanoscale fibers for effective selective separation. The obtained fibers present true-nanoscale diameters (∼67 nm), 1 order of magnitude less than those of common electrospun fibers, which endows the resultant membranes with remarkable nanostructural characteristics and separation performances in areas of protective textiles (waterproofness of 113 kPa and breathability of 4.1 kg m-2 d-1), air filtration (efficiency of 99.3% and pressure drop of 127.4 Pa), and water purification (flux of 81.5 kg m-2 h-1 and salt rejection of 99.94%). This work may shed light on developing high-performance separation materials for various applications.

Multiscale Synergetic Bandgap/Structure Engineering in Semiconductor Nanofibrous Aerogels for Enhanced Solar Evaporation.

Solar-driven interface evaporation has been identified as a sustainable seawater desalination and water purification technology. Nonetheless, the evaporation performance is still restricted by salt deposition and heat loss owing to weak solar spectrum absorption, tortuous channels, and limited plane area of conventional photothermal material. Herein, the semiconductor nanofibrous aerogels with a narrow bandgap, vertically aligned channels, and a conical architecture are constructed by the multiscale synergetic engineering strategy, encompassing bandgap engineering at the atomic scale and structure engineering at the nano-micro scale. As a proof-of-concept demonstration, a Co-doped MoS2 nanofibrous aerogel is synthesized, which exhibits the entire solar absorption, superhydrophilic, and excellent thermal insulation, achieving a net evaporation rate of 1.62 kg m-2 h-1 under 1 sun irradiation, as well as a synergistically efficient dye ion adsorption function. This work opens up new possibilities for the development of solar evaporators for practical applications in clean water production.

Two-Dimensional Nanofibrous Networks by Superspreading-Based Phase Inversion for High-Efficiency Separation.

Two-dimensional (2D) nanomaterials have been widely applied as building blocks of nanoporous materials for high-precision separations. However, most existing 2D nanomaterials suffer from poor continuity and a lack of interior linking, resulting in deteriorated performance when assembled into macroscopic bulk structures. Here, a unique superspreading-based phase inversion technique is proposed to directly construct 2D nanofibrous networks (NFNs) from a polymer solution. By tailoring capillary behavior, polymer solution droplets evolve into ultrathin liquid films through superspreading; manipulating phase instability, subsequently, enables the liquid film to phase invert into continuous nanostructured networks. The assembled single-layered NFNs possess integrated structural superiorities of 1D nanoscale fiber diameter (∼40 nm) and 2D lateral infinity, exhibiting a weblike nanoarchitecture with extremely small through-pores (∼100 nm). Our NFNs show remarkable performances in air filtration (PM0.3 removal) and water purification (microfiltration level). This creation of such attractive 2D fibrous nanomaterials can pave the way for versatile high-performance separation applications.

High-Performance Waterproof, Breathable, and Radiative Cooling Membranes Based on Nanoarchitectured Fiber/Meshworks.

Smart membranes with protection and thermal-wet comfort are highly demanded in various fields. Nevertheless, the existing membranes suffer from a tradeoff dilemma of liquid resistance and moisture permeability, as well as poor thermoregulating ability. Herein, a novel strategy, based on the synchronous occurrence of humidity-induced electrospinning and electromeshing, is developed to synthesize a dual-network structured nanofiber/mesh for personal comfort management. Manipulating the ejection, deformation, and phase separation of spinning jets and charged droplets enables the creation of nanofibrous membranes composed of radiative cooling nanofibers and 2D nanostructured meshworks. With a combination of a true-nanoscale fiber (∼70 nm) in 2D meshworks, a small pore size (0.84 µm), and a superhydrophobic surface (151.9°), the smart membranes present high liquid repellency (95.6 kPa), improved breathability (4.05 kg m-2 d-1), and remarkable cooling performance (7.9 °C cooler than commercial cotton fabrics). This strategy opens up a pathway to the design of advanced smart textiles for personal protection.

Dopant-Free Pyrene-Based Hole Transporting Material Enables Efficient and Stable Perovskite Solar Cells.

Dopant-free hole transporting materials (HTMs) is significant to the stability of perovskite solar cells (PSCs). Here, we developed a novel star-shape arylamine HTM, termed Py-DB, with a pyrene core and carbon-carbon double bonds as the bridge units. Compared to the reference HTM (termed Py-C), the extension of the planar conjugation backbone endows Py-DB with typical intermolecular π-π stacking interactions and excellent solubility, resulting in improved hole mobility and film morphology. In addition, the lower HOMO energy level of the Py-DB HTM provides efficient hole extraction with reduced energy loss at the perovskite/HTM interface. Consequently, an impressive power conversion efficiency (PCE) of 24.33 % was achieved for dopant-free Py-DB-based PSCs, which is the highest PCE for dopant-free small molecular HTMs in n-i-p configured PSCs. The dopant-free Py-DB-based device also exhibits improved long-term stability, retaining over 90 % of its initial efficiency after 1000 h exposure to 25 % humidity at 60 °C. These findings provide valuable insights and approaches for the further development of dopant-free HTMs for efficient and reliable PSCs.

Electrospinning Photocatalysis Meet In Situ Irradiated XPS: Recent Mechanisms Advances and Challenges.

Producing solar fuels over photocatalysts under light irradiation is a considerable way to alleviate energy crises and environmental pollution. To develop the yields of solar fuels, photocatalysts with broad light absorption, fast charge carrier migration, and abundant reaction sites need to be designed. Electrospun 1D nanofibers with large specific areas and high porosity have been widely used in the efficient production of solar fuels. Nevertheless, it is challenging to do in-depth mechanism research on electrospun nanofiber-based photocatalysts since there are multiple charge transfer routes and various reaction sites in these systems. Here, the basic principles of electrospinning and photocatalysis are systemically discussed. Then, the different roles of electrospun nanofibers played in recent research to boost photocatalytic efficiency are highlighted. It is noteworthy that the working principles and main advantages of in situ irradiated photoelectron spectroscopy (ISI-XPS), a new technique to investigate migration routes of charge carriers and identify active sites in electrospun nanofibers based photocatalysts, are summarized for the first time. At last, a brief summary on the future orientation of photocatalysts based on electrospun nanofibers as well as the perspectives on the development of the ISI-XPS technique are also provided.

Ultralight and Superelastic Curly Micro/Nanofibrous Aerogels by Direct Electrospinning Enable High-Performance Warmth Retention.

Extremely low temperature has posed huge burden on the public safety concerns and global economics, thereby calling for high-performance warmth retention materials to resist harsh environment. However, most present fibrous warmth retention materials are limited by their large fiber diameter and simple stacking structure, leading to heavy weight, weak mechanical property, and limited thermal insulation performance. Herein, an ultralight and mechanically robust polystyrene/polyurethane fibrous aerogel by direct electrospinning for warmth retention is reported. Manipulation of charge density and phase separation of charged jet allows for the direct assembly of fibrous aerogels consisting of interweaved curly wrinkled micro/nanofibers. The resultant curly wrinkled micro/nanofibrous aerogel possesses low density of 6.8 mg cm-3 and nearly full recovery from 1500-cycle deformations, exhibiting both ultralight feature and superelastic property. The aerogel also shows low thermal conductivity of 24.5 mW m-1  K-1 , making synthetic warmth retention materials superior to down feather possible. This work may shed light on developing versatile 3D micro/nanofibrous materials for environmental, biological, and energy applications.

Janus Dual Self-Strengthening Structure of Bi2 O3 /Gd2 O3 Nanofibrous Membranes for Superior X-Ray Shielding.

Bi2 O3 /rare earth oxide biphasic absorbers are attractive for high-efficiency X-ray shielding due to the complementary X-ray absorption effects. However, its application is severely hindered by poor interphasic contact. Here, a new Janus interface engineering strategy is reported for the construction of continuous and flexible Bi2 O3 /Gd2 O3 crystal nanofibrous membranes (FJNMs) with micro/nano dual self-strengthening interphasic adhesion. This strategy facilitates online micro-interlocking between Bi2 O3 /Gd2 O3 nanofibers and in situ nano-grain fusion between Bi2 O3 /Gd2 O3 crystals, significantly enhancing the adhesive strength at the Bi2 O3 /Gd2 O3 interface. Additionally, the synergistic shielding effect from Bi2 O3 /Gd2 O3 absorption and multiple reflections in Bi2 O3 and Gd2 O3 crystal lattices make the nanofibrous membranes a superior X-ray radiation barrier. The FJNMs demonstrate integrated features of exceptional X-ray shielding efficiency (91%-100%), robust interfacial adhesion (lap-shear strength >3.8 MPa), prominent flexibility, lightweight, and outstanding breathability. The design concepts of fibrosing biphasic absorber assemblies pave the way for asymmetrically assembling biphasic materials, setting the stage for a fundamental shift in next-generation radiation shielding materials.

Electrospun Nanofibrous Membranes: A Versatile Medium for Waterproof and Breathable Application.

Waterproof and breathable membranes that prevent liquid water penetration, while allowing air and moisture transmission, have attracted significant attention for various applications. Electrospun nanofiber materials with adjustable pore structures, easily tunable wettability, and good pore connectivity, have shown significant potential for constructing waterproof and breathable membranes. Herein, a systematic overview of the recent progress in the design, fabrication, and application of waterproof and breathable nanofibrous membranes is provided. The various strategies for fabricating the membranes mainly including one-step electrospinning and post-treatment of nanofibers are given as a starting point for the discussion. The different design concepts and structural characteristics of each type of waterproof and breathable membrane are comprehensively analyzed. Then, some representative applications of the membranes are highlighted, involving personal protection, desalination, medical dressing, and electronics. Finally, the challenges and future perspectives associated with waterproof and breathable nanofibrous membranes are presented.

Di-(2-ethylhexyl) phthalate aggravates psoriasis-like skin lesions: In vitro and in vivo evaluation.

Di-(2-ethylhexyl) phthalate (DEHP), which is a widely used phthalate (PAE), has recently received public attention owing to it causing health problems. The aim of this study was to elucidate the aggravating effects of DEHP on psoriasis and skin toxicity. Human keratinocyte (HaCaT) cells were treated with gradient concentrations of DEHP, and mice with imiquimod (IMQ)-induced psoriasiform dermatitis were hypodermically injected with 40 µg/kg/day of DEHP for seven consecutive days. The skin condition was assessed based on the psoriasis area and severity index score, which indicated the deterioration of IMQ-induced psoriasis-like skin lesions after DEHP exposure. To further analyze the effect of DEHP on psoriasis, the proliferation, inflammation, and tight junction (TJ) damage were examined, which correlated with the development and severity of psoriasis. The results showed that DEHP promoted proliferation both in vivo and in vitro, which manifested as epidermal thickening; an increase in cell viability; upregulation of Ki67, CDK2, cyclinD1, and proliferating cell nuclear antigen; and downregulation of p21. An excessive inflammatory response is an important factor that exacerbates psoriasis, and our results showed that DEHP can trigger the release of inflammatory cytokines as well as the infiltration of T cells. TJ disorders were found in mice and cells after DEHP treatment. Additionally, p38 mitogen-activated protein kinase (MAPK) was strongly activated during this process, which may have contributed to skin toxicity caused by DEHP. In conclusion, DEHP treatment promotes proliferation, inflammation, TJ disruption, and p38 MAPK activation in HaCaT cells and psoriasis-like skin lesions.

Ln-MOF Based Ratiometric Luminescent Sensor for the Detection of Potential COVID-19 Drugs.

Countless people have been affected by the COVID-19 pandemic on a global scale. Favipiravir, has shown potential as an effective drug for SARS-CoV-2, attracting scientists' attention. However, overuse of Favipiravir easily leads to serious side effects, requiring real-time monitoring in body fluids. Given this, a new lanthanide metal-organic framework (MOF) was prepared under solvothermal conditions from either Eu (Eu-MOF or (1)) or Tb (Tb-MOF or (2)) using the highly delocalized imidazoledicarboxylic acid linker H2 L (H2 L=5-(4-(imidazol-1-yl) phenyl) isophthalic acid) and could be successfully applied to selective optical detection of Favipiravir. In this MOF framework, the organic linker H2 L provides a high excitation energy transfer efficiency that can sensitize luminescence in lanthanides. In addition, through deliberate tuning of Eu/Tb molar ratio and reaction concentration in the lanthanide framework, ratiometric recyclable luminescent Eux Tb1-x -MOF nanoparticles with open metal sites have been constructed, which present a high detection sensitivity (Ksv =1×107 [M-1 ], detection limit is 4.63 nM) for Favipiravir. The detection mechanism is discussed with the help of Density Functional Theory (DFT) calculations that sheds light over the selective sensing of Favipiravir over other related COVID-19 drug candidates. Finally, to explore the practical application of Favipiravir sensing, MOF based thin films have been used for visual detection of Favipiravir and recycled 5 times.

Andrographolide induced ferroptosis in multiple myeloma cells by regulating the P38/Nrf2/HO-1 pathway.

Andrographis paniculata is used as a functional food in Asia. Andrographolide (Andro), a diterpene lactone isolated from Andrographis paniculata, has been reported to have potent anticancer activity. Multiple myeloma (MM), the second most common malignant tumor in hematology, is incurable. Ferroptosis, a type of cell death driven by iron-dependent lipid peroxidation, has shown potential in the treatment of various cancers. However, previous studies have not demonstrated whether Andro inhibits the development of MM via ferroptosis or any other mechanism. In the present study, we observed that Andro induced cell death, G0/G1 cell cycle arrest and evoked oxidative stress in MM cells. Interestingly, these phenomena were accompanied by increases in intracellular and mitochondrial Fe2+ and lipid peroxidation levels. Furthermore, treatment with ferroptosis inhibitors rescued Andro-induced cell death, which indicated that ferroptosis contributed to this phenomenon. Mechanistic examination showed that Andro may block the Nrf2/HO-1 signaling pathway by activating P38, thereby inducing ferroptosis. Moreover, inhibition of P38 expression rescued Andro-induced cell death, changes in the level of Nrf2 and HO-1 expression, Fe2+ and lipid peroxidation. Taken together, our findings suggest that Andro induces ferroptosis in MM cells via the P38/Nrf2/HO-1 pathway, providing a potential preventative and therapeutic approach for MM.