Chromium-Based Metal–Organic Framework as A-Site Cation in CsPbI2Br Perovskite Solar Cells

Inorganic CsPbI_xBr_3−x perovskite solar cells (PSCs) have gained enormous interest due to their excellent thermal stabilities. However, their intrinsically poor moisture stability hampers their further development. Herein, a chromium-based metal–organic framework group is intercalated inside the inorganic Pb I framework, resulting in a new multiple-dimensional electronically coupled CsPbI₂Br perovskite. In this structurally and electronically coupled perovskite, the π-conjugated terpyridyl can delocalize the excited valence electrons of metal Cr³⁺ ion, enabling multi-interactive charge-carrier transport channels within CsPbI₂Br perovskites. The stability and efficiency of the produced devices are substantially enhanced in comparison to their counterparts with only a pristine CsPbI₂Br active layer. The optimized all-inorganic PSC yields a power conversion efficiency (PCE) as high as 17.02%. Remarkably, the stabilized device retains 80% of its PCE after 1000 h in the ambient atmosphere. This study provides a new paradigm toward addressing the stability challenge of the inorganic perovskite while enhancing its carrier transport ability.     

Dual Sub-Cells Modification Enables High-Efficiency n–i–p Type Monolithic Perovskite/Organic Tandem Solar Cells

Monolithic perovskite/organic tandem solar cells (POTSCs) have attracted increasing attention owing to ability to overcome the Shockley–Queisser limit. However, compromised sub-cells performance limits the tandem device performance, and the power conversion efficiency (PCE) of POTSCs is still lower than their single-junction counterparts. Therefore, optimized sub-cells with minimal energy loss are desired for producing high-efficiency POTSCs. In this study, an ionic liquid, methylammonium acetate (MAAc), is used to modify wide-bandgap perovskite sub-cells (WPSCs), and bathocuproine (BCP) is used to modify small-bandgap organic solar cells. The Ac⁻ group of MAAc can effectively heal the Pb defects in the all-inorganic perovskite film, which enables a high PCE of 17.16% and an open-circuit voltage (V_oc) of 1.31 V for CsPbI_2.2Br_0.8-based WPSCs. Meanwhile, the BCP film, inserted at the ZnO/organic bulk-heterojunction (BHJ) interface, acts as a space layer to prevent direct contact between ZnO and the BHJ while passivating the surface defects of ZnO, thereby mitigating ZnO defect-induced efficiency loss. As a result, PM6:CH1007-based SOSCs exhibit a PCE of 15.46%. Integrating these modified sub-cells enable the fabrication of monolithic n–i–p structured POTSCs with a maximum PCE of 22.43% (21.42% certified), which is one of the highest efficiencies in such type of POTSCs.     

Stabilization of α-phase FAPbI3 via Buffering Interfacial Region for Efficient p–i–n Perovskite Solar Cells

Formamidinium lead triiodide (FAPbI₃) with an ideal bandgap and good thermal stability has received wide attention and achieved a record efficiency of 26% in n–i–p (regular) perovskite solar cells (PSCs). However, imperfect FAPbI₃ formation on the typical hole transport layer (HTL), high interfacial trap-state density, and unfavorable energy alignment between the HTL and FAPbI₃ result in the inferior photovoltaic performance of p–i–n (inverted) PSCs with FAPbI₃ absorber. Herein, the α-phase FAPbI₃ is stabilized by constructing a buffer interface region between the NiO_x HTL and FAPbI₃, which not only diminishes NiO_x/FAPbI₃ interfacial reactions and defects but also facilitates carrier transport. Upon the construction of a buffer interface region, FAPbI₃ inverted PSC exhibits a high-power conversion efficiency of 23.56% (certified 22.58%) and excellent stability, retaining 90.7% of its initial efficiency after heating at 80 °C for 1000 h and 84.6% of the initial efficiency after operating at the maximum power point under continuous illumination for 1100 h. Besides, as a light-emitting diode device, the FAPbI₃ inverted PSC can be directly lit with an external quantum efficiency of 1.36%. This study provides a unique and efficient strategy to advance the application of α-phase FAPbI₃ in inverted PSCs.     

Dual Role of Cu-Chalcogenide as Hole-Transporting Layer and Interface Passivator for p–i–n Architecture Perovskite Solar Cell

Inorganic hole-transport layers (HTLs) are widely investigated in perovskite solar cells (PSCs) due to their superior stability compared to the organic HTLs. However, in p–i–n architecture when these inorganic HTLs are deposited before the perovskite, it forms a suboptimal interface quality for the crystallization of perovskite, which reduces device stability, causes recombination, and limits the power conversion efficiency of the device. The incorporation of an appropriate functional group such as sulfur-terminated surface on the HTL can enhance the interface quality due to its interaction with perovskite during the crystallization process. In this work, a bifunctional Al-doped CuS film is wet-deposited as HTL in p–i–n architecture PSC, which besides acting as an HTL also improves the crystallization of perovskite at the interface. Urbach energy and light intensity versus open-circuit voltage characterization suggest the formation of a better-quality interface in the sulfide HTL–perovskite heterojunction. The degradation behavior of the sulfide-HTL-based perovskite devices is studied, where it can be observed that after 2 weeks of storage in a controlled environment, the devices retain close to 95% of their initial efficiency.     

Highly Stable n–i–p Structured Formamidinium Tin Triiodide Solar Cells through the Stabilization of Surface Sn2+ Cations

Improving the performance, reproducibility, and stability of Sn-based perovskite solar cells (PSCs) with n–i–p structures is an important challenge. Spiro-OMeTAD [2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene], a hole transporting material (HTM) with n–i–p structure, requires the oxygen exposure after addition of Li-TFSI [Lithium bis(trifluoromethanesulfonyl)imide] as a dopant to increase the hole concentration. In Sn-based PSC, Sn²⁺ is easily oxidized to Sn⁴⁺ under such a condition, resulting in a sharp decrease in efficiency. Herein, a formamidinium tin triiodide (FASnI₃)-based PSCs fabricated using DPI-TPFB [4-Isopropyl-4′-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate] instead of Li-TFSI are reported as a dopant in Spiro-OMeTAD. The DPI-TPFB enables the fabrication of PSCs with an efficiency of up to 10.9%, the highest among FASnI₃-based PSCs with n–i–p structures. Moreover, ≈80% of the initial efficiency is maintained even after 1,597 h under maximum power point tracking conditions. In particular, the encapsulated device does not show any decrease in efficiency even after holding for 50 h in the 85 °C/85% RH condition. The high efficiency and excellent stability of PSCs prepared by doping with DPI-TPFB are attributed to not only increasing electrical conductivity by acting as a Lewis acid, but also stabilizing Sn²⁺ through coordination with Sn²⁺ on the surface of FASnI₃.     

Manifestation of Flexible p–i–n Solar Cells Fabricated Using HWCVD in WSN Application

Wireless Personal Communications - The wireless sensor network (WSN) consist of battery-powered sensor nodes which are self-configured and are deployed for monitoring several physical or...     

Diverse Metal–Organic Framework Architectures for Electromagnetic Absorbers and Shielding

Metal–organic frameworks (MOFs) and their derivatives, featuring unique 3D microstructures and enhanced electromagnetic properties, are illuminating infinite possibilities for electromagnetic functional materials and devices, receiving significant attention from domestic and foreign researchers. Herein, the design strategy of the MOF monomer is investigated, and the electromagnetic response mechanism is systematically analyzed. Research is emphatically introduced regarding MOF-based materials in microwave absorption and electromagnetic interference shielding. Finally, a clear insight on the quickly growing field is given, and the current challenges and future research directions are summarized and predicted.     

Novel Metal–Organic Framework Cocrystal Strategy for Significantly Enhancing Photocatalytic Performance

Owing to their high carrier recombination speed and low spectral utilization, it is difficult to further improve the performance of photocatalysts. In this study, a novel metal–organic framework (MOF) self-assembled cocrystal material is developed. The guest molecule is inserted and self-assembled with the existing MOF ligand to form an organic cocrystal. The highly ordered molecular arrangement and tight intermolecular distances between donor and acceptor molecules promote a strong π–π charge transfer interaction, facilitating the migration and separation of photogenerated charge carriers. In addition, efficient redshifts in the absorption wavelength enhance the response to visible light. Further, the unique porous structure of MOFs is beneficial for increasing the interfacial area of photocatalytic reactions, and metal ions can become the center of photogenerated carrier capture, effectively inhibiting carrier recombination. Consequently, the MOF cocrystal demonstrates remarkable efficiency in the degradation of pollutants in water, achieving a noteworthy removal efficiency of 95.31% within 15 min. Moreover, the photocatalyic reaction kinetics constant of the MOF cocrystal is 46.5 times higher, indicating the success of this new strategy in developing highly efficient photocatalytic systems.     

Self-Assembled Nanoporous Metal–Organic Framework Monolayer Film for Osmotic Energy Harvesting

Osmotic energy represents a promising energy resource because it is sustainable and environmentally benign. Subnanoscale channels are considered as a competitive platform for generating this blue energy due to their highly selective and ultrafast ion transport. However, fabricating functional subnanochannels capable of high energy output remains challenging. Here, a heterogeneous subnanochannel membrane formed by coating a functionalized self-assembled metal−organic framework (MOF) monolayer (SAMM) film on a porous anodic aluminum oxide membrane, is reported. The SAMM film, with a thickness of ≈160 nm, is fabricated by self-assembly of poly(methyl methacrylate-co-vinylimidazole)-modified UiO-66-NH₂ nanoparticles at the water−air interface. In the SAMM, imidazole and NH₂ groups provide abundant positive charges, while the angstrom-scale windows act as ionic filters for selective screening of anions with different hydration diameters. As a result, the heterogeneous membrane exhibits excellent capacity for anion-selective transport, which contributes to an optimal osmotic power of 6.76 W m⁻² under a 100-fold NaCl gradient, as well as a high Cl⁻/SO₄²⁻ selectivity of ≈42.2. Further, the output power is increased to 10.5 W m⁻² by methylating imidazole moieties on the MOF surface. This work provides a facile and modular approach to fabricate subnanochannels for enabling highly selective and efficient osmotic energy conversion.     

Asymmetric Polymer Electrolyte Constructed by Metal–Organic Framework for Solid-State,Dendrite-Free Lithium Metal Battery

Solid-state polymer electrolytes (SPEs) with flexibility, easy processability, and low cost have been regarded as promising alternatives for conventional liquid electrolytes in next-generation high-safety lithium metal batteries. However, SPEs generally suffer poor strength to block Li dendrite growth during the charge/discharge process, which severely limits their wide practical applications. Here, a rational design of 3D cross-linked network asymmetric SPE modified with a metal–organic framework (MOF) layer on one side is proposed and prepared through an in-situ polymerization process. In such unique asymmetric SPEs, the nanoscale MOF layer acts as a shield that effectively suppresses the growth of Li dendrites and regulates the uniform Li⁺ transport, and the polymer electrolyte can be scattered in the whole cell to endow the smooth transmission of Li⁺. As a result, the asymmetric SPE exhibits high ionic conductivity, wide electrochemical window, high thermal stability and safety, which endows the Li/Li symmetrical cell with outstanding cyclic stability (operate well over 800 h at a current density of 0.1 mA cm⁻² for the capacity of 0.1 mAh cm⁻²).     

Wrapping up Metal–Organic Framework Crystals with Carbon Nanotubes

The presence of tetrazine units in the organic nodes of UiO-68-TZCD controls the formation of ultrathin coatings of single-wall nanotubes that decorate the surface of the crystal. These crystal hybrids can be prepared straightforwardly in one step and are extraordinarily respectful with the properties of the framework for combination of mesoporosity and surface areas ≈4.000 m² g⁻¹, with excellent stability in water, and conductivities at room temperature of 4 × 10⁻² S cm⁻¹ even at very low carbon weight contents (2.3 wt.%).     

Metal–Organic Framework-Derived N-Doped Carbon with Controllable Mesopore Sizes for Low-Pt Fuel Cells

Mesoporous structure of carbon materials plays an important role in electrocatalyst design. Constructing carbon supports with tunable mesopores has long been a challenge. Herein, the elaborate regulation of mesopores in N-doped carbon materials is reported by pyrolyzing energetic metal-triazolate (MET) frameworks with different particle sizes and at different ramp rates. Higher thermal transfer rates brought about by smaller particle size and higher ramp rate lead to more violent decomposition with a large number of gases producing, which in turn result in larger mesopores in the derivatives. Consequently, a series of N-doped carbon materials with controllable mesopores are obtained. As a proof-of-concept, ultrafine Pt nanoparticles are enveloped inside these mesopores to acquire high-performance electrocatalysts for oxygen reduction reaction. The optimized catalyst achieves high mass activity of 1.52 A mg_Pt⁻¹ at 0.9 V_iR-free and peak power density of 0.8 W cm⁻² (H₂-Air) with an ultralow Pt loading of 0.05 mg_Pt cm⁻² at cathode in fuel cells, highlighting the great advantages of MET-derived carbon materials with controllable mesopores in the preparation of advanced electrocatalysts.     

Improving the Power Conversion Efficiency of Organic Solar Cell by Blending with CdSe/ZnS Core–Shell Quantum Dots

We have blended poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C₆₁ butyric acid methyl ester (PCBM) with CdSe/ZnS core–shell quantum dots (QDs) as the active layer to produce organic solar cells (OSC). The size of the CdSe/ZnS core–shell QDs was determined to be about 4 nm using transmission electron microscopy. The OSC were characterized by measuring the absorption spectra, current–voltage characteristics, and external quantum efficiency (EQE) spectra. The samples doped with 0.5 wt.% CdSe/ZnS core–shell QDs exhibited higher power conversion efficiency (PCE) than samples doped with other concentrations of QDs. The PCE of the OSC increases from 2.10% to 2.38% due to an increase of the short circuit current density (J _sc) from 6.00 mA/cm² to 6.25 mA/cm². The open circuit voltage (V _oc) was kept constant when comparing OSC that were undoped and doped with 0.5 wt.% CdSe/ZnS core–shell QDs. These CdSe/ZnS core–shell QDs can increase optical absorption as well as provide extra exciton dissociation and additional electric pathways in hybrid OSC.     

A 3D Cu-Naphthalene-Phosphonate Metal–Organic Framework with Ultra-High Electrical Conductivity

A conductive phosphonate metal–organic framework (MOF), [{Cu(H₂O)}(2,6-NDPA)_0.5] (NDPA = naphthalenediphosphonic acid), which contains a 2D inorganic building unit (IBU) comprised of a continuous edge-sharing sheet of copper phosphonate polyhedra is reported. The 2D IBUs are connected to each other via polyaromatic 2,6-NDPA's, forming a 3D pillared-layered MOF structure. This MOF, known as TUB40, has a narrow band gap of 1.42 eV, a record high average electrical conductance of 2 × 10² S m⁻¹ at room temperature based on single-crystal conductivity measurements, and an electrical conductance of 142 S m⁻¹ based on a pellet measurement. Density functional theory (DFT) calculations reveal that the conductivity is due to an excitation from the highest occupied molecular orbital on the naphthalene-building unit to the lowest unoccupied molecular orbital on the copper atoms. Temperature-dependent magnetization measurements show that the copper atoms are antiferromagnetically coupled at very low temperatures, which is also confirmed by the DFT calculations. Due to its high conductance and thermal/chemical stability, TUB40 may prove useful as an electrode material in supercapacitors.     

Low Voltage Flash Memory Cells Using SiGe Quantum Dots for Enhancing F-N Tunneling

提出了一种用于半导体闪速存储器单元的新的Si/SiGe量子点/隧穿氧化层/多晶硅栅多层结构,该结构可以实现增强F-N隧穿的编程和擦除机制.模拟结果表明该结构具有高速和高可靠性的优点.测试结果表明该结构的工作电压比传统NAND结构的存储器单元降低了4V.采用该结构能够实现高速、低功耗和高可靠性的半导体闪速存储器.     

Metal–Organic Framework-Integrated Composites for Bone Tissue Regeneration

Metal–organic frameworks (MOFs) exhibit exceptional characteristics, including high porosity and adjustable properties, rendering them highly suitable for biomedical applications. Recently, researchers have directed their attention toward the integration of MOFs into composites for bone tissue regeneration (BTE), presenting distinct advantages over conventional substitutes. In this comprehensive review, the authors delve into the latest advancements concerning MOF-integrated composites for BTE. This exploration encompasses an examination of the properties of MOFs and the various synthesis techniques employed to fabricate these materials. Furthermore, the diverse applications of MOF-integrated composites in BTE are investigated, encompassing areas such as antibacterial properties, osteogenic differentiation, angiogenesis, and immunomodulation. By providing a comprehensive overview of the ongoing research on MOF-integrated composites for BTE, this study holds the promise of yielding innovative solutions within the realm of orthopedics.     

Implanting of Single Zinc Sites into 2D Metal–Organic Framework Nanozymes for Boosted Antibiofilm Therapy

Design of nanozymes with catalytic active sites at atomic-scale not only improves the atomic utilization, but also provides a well-defined coordination structure for nanozymes’ catalytic mechanism research. Herein, a surfactant-assisted method is reported for preparing 2D metal–organic frameworks based single zinc sites nanozyme (SZN-MOFs) through assembling preformed Zn single-atom coordinated porphyrin precursors into ultrathin MOF nanosheets. The Zn atom loading weight ratio in SZN-MOFs is up to 4.6 wt.%. The SZN-MOFs exhibit extraordinary peroxidase-like activity, which can effectively catalyze H₂O₂ into hydroxyl radicals. The catalytical mechanism is elucidated and the origin of the high peroxidase-like activity of SZN-MOFs is rationalized using density functional theory calculations. Finally, it is demonstrated that the SZN-MOFs present great promises for in vitro and in vivo antibiofilm activity under a low concentration of H₂O₂. This study not only develops a surfactant-assisted method for fabricating MOF-based single sites nanozyme, but also manifests the applications in the field of antibiofilm therapy.     

Highly CO2 Selective Metal–Organic Framework Membranes with Favorable Coulombic Effect

The topology and chemical functionality of metal–organic frameworks (MOFs) make them promising candidates for membrane gas separation; however, few meet the criteria for industrial applications, that is, selectivity of >30 for CO₂/CH₄ and CO₂/N₂. This paper reports on a dense CAU-10-H MOF membrane that is exceptionally CO₂-selective (ideal selectivity of 42 for CO₂/N₂ and 95 for CO₂/CH₄). The proposed membrane also achieves the highest CO₂ permeability (approximately 500 Barrer) among existing pure MOF membranes with CO₂/CH₄ selectivity exceeding 30. State-of-the-art atomistic simulations provide valuable insights into the outstanding separation performance of CAU-10-H at the molecular level. Adsorbent–adsorbate Coulombic interactions are identified as a crucial factor in the design of CO₂-selective MOF membranes.     

Stabilizing Redox-Active Hexaazatriphenylene in a 2D Conductive Metal–Organic Framework for Improved Lithium Storage Performance

Organic redox-active materials are promising electrode candidates for lithium-ion batteries by virtue of their designable structure and cost-effectiveness. However, their poor electrical conductivity and high solubility in organic electrolytes limit the device's performance and practical applications. Herein, the π-conjugated nitrogen-containing heteroaromatic molecule hexaazatriphenylene (HATN) is strategically embedded with redox-active centers in the skeleton of a Cu-based 2D conductive metal–organic framework (2D c-MOF) to optimize the lithium (Li) storage performance of organic electrodes, which delivers improved specific capacity (763 mAh g⁻¹ at 300 mA g⁻¹), long-term cycling stability (≈90% capacity retention after 600 cycles at 300 mA g⁻¹), and excellent rate performance. The correlation of experimental and computational results confirms that this high Li storage performance derives from the maximum number of active sites (CN sites in the HATN unit and CO sites in the CuO₄ unit), favorable electrical conductivity, and efficient mass transfer channels. This strategy of integrating multiple redox-active moieties into the 2D c-MOF opens up a new avenue for the design of high-performance electrode materials.     

A Conductive 2D Conjugated Tetrathia[8]circulene-Based Nickel Metal–Organic Framework for Energy Storage

Herein, a novel D₄ symmetrical redox-active ligand tetrathia[8]circulene-2,3,5,6,8,9,11,12-octaol (8OH-TTC) is designed and synthesized, which coordinates with Ni²⁺ ions to construct a 2D conductive metal-organic framework (2D c-MOF) named Ni-TTC. Ni-TTC exhibits typical semiconducting properties with electrical conductivity up to ≈1.0 S m⁻¹ at 298 K. Furthermore, magnetism measurements show the paramagnetic property of Ni-TTC with strong antiferromagnetic coupling due to the presence of semiquinone ligand radicals and Ni²⁺ sites. In virtue of its decent electrical conductivity and good redox activity, the gravimetric capacitance of Ni-TTC is up to 249 F g⁻¹ at a discharge rate of 0.2 A g⁻¹, which demonstrates the potential of tetrathia[8]circulene-based redox-active 2D c-MOFs in energy storage applications.