Alcohol-dispersed polymer complex as an effective and durable interface modifier for n-i-p perovskite solar cells

Abundant interfacial defects remain a significant challenge that hampers both the efficiency and stability of perovskite solar cells(PSCs).Herein,an alcohol-dispersed conducting polymer complex,denoted as PEDOT:F(Poly(3,4-ethylene dioxythiophene):Perfluorinated sulfonic acid ionomers),is introduced into the interface between perovskite and hole transporting layer in regular-structured PSCs.PEDOT:F serves as a multi-functional interface layer(filling grain boundaries and covering perovskite's grain-surface)to achieve a robust interaction with organic groups within perovskites,which could induce a structural transformation of PEDOT to increase its conductivity for the efficient hole-transport.Furthermore,the strong interaction between PEDOT and perovskites could promote an effective coupling of undercoordinated Pb~(2+)ions with the lone electron pairs near O&S atoms in PEDOT molecules,thereby enhancing defect passivation.Additionally,PEDOT:F with inherent hydrophobic properties prevents effectively moisture invasion into perovskites for the improved long-term stability of the PSCs.Consequently,the PEDOT:F-based PSCs achieved a champion efficiency of 24.81%,and maintained ca.92%of their initial efficiency after 7680 h of storage in a dry air environment,accompanied by the enhanced photothermal stability.

Self-polarized RGB device realized by semipolar micro-LEDs and perovskite-in-polymer films for backlight applications

In backlighting systems for liquid crystal displays,conventional red,green,and blue(RGB)light sources that lack polarization properties can result in a significant optical loss of up to 50%when passing through a polarizer.To address this inefficiency and optimize energy utilization,this study presents a high-performance device designed for RGB polarized emissions.The device employs an array of semipolar blueμLEDs with inherent polarization capabilities,coupled with mechanically stretched films of green-emitting CsPbBr3 nanorods and red-emitting CsPbI3-Cs4PbI6 hybrid nanocrystals.The CsPbBr3 nanorods in the polymer film offer intrinsic polarization emission,while the aligned-wire structures formed by the stable CsPbI3-Cs4PbI6 hybrid nanocrystals contribute to substantial anisotropic emissions,due to their high dielectric constant.The resulting device achieved RGB polarization degrees of 0.26,0.48,and 0.38,respectively,and exhibited a broad color gamut,reaching 137.2%of the NTSC standard and 102.5%of the Rec.2020 standard.When compared to a device utilizing c-plane LEDs for excitation,the current approach increased the intensity of light transmitted through the polarizer by 73.6%.This novel fabrication approach for polarized devices containing RGB components holds considerable promise for advancing next-generation display technologies.

A novel perylene diimide-based ionene polymer and its mixed cathode interlayer strategy for efficient and stable inverted perovskite solar cells

Inverted(p-i-n)perovskite solar cells(PerSCs)have attracted much attention owing to their low temperature processability,less hysteresis effect and easy integration as a subunit for the tandem device.The unsatisfactory interface contacts and energy level barrier between adjacent interlayers on the cathode side are one of the key challenges for the development of p-i-n PerSCs.Herein,perylene diimidebased(PDI)ionene polymer was synthesized and developed as a cathode interlayer(CIL)to enhance interface contact,reduce the energy level barrier and prevent the migration of I-ions.The compact PNPDI CIL with high conductivity and appropriate lowest unoccupied molecular orbital(LUMO)level,resulted in a high efficiency device(20.03%),which is higher than the control device with bathophenanthroline(Bphen)(19.48%).Bphen-based CIL shows better adjusting ability of the work function of cathode metal but exhibits poor film-forming property.So,the synergistic effect of 1+1>2 can be obtained by combining Bphen and PNPDI into one CIL.As expected,the device performance was further improved by using the mixed CIL of Bphen and PNPDI,and 21.46%power conversion efficiency(PCE)was achieved.What’s more,the compact and hydrophobic mixed CIL dramatically enhanced the resistance to I-ions and moisture,which led to much enhanced device stability.

Realization of High Efficient Ferroelectric Perovskite Nanoparticles in Biopolymer-Matrix Solar Cells under Low Lighting

The idea to use ferroelectric materials (PZN-PT) came from the fact that the ferroelectric nature could facilitate electric charges accumulation on the interfaces of the solar cell. Thus, it would increase the open circuit voltage Voc which could reach more than 10 V. This would directly impact the efficiency which is proportional to Voc, thus hoping to obtain solar efficiency never equaled by the halide perovskites which are less stable and less resistant in aggressive environments. In this work, the solar cells produced gave an exceptional record efficiency of 39.32% with a very high open circuit voltage (Voc) of 3.50 V, a short-circuit current density (Jsc) of 0.118 mA/cm2 and an FF of 0.72 measured in the positive polarization direction under 3825 lux (5.6 W/m2) lighting. The negative polarization direction under 4781 lux (7 W/m2) lightning gave a current density of 2 mA/cm2, an open circuit voltage of 2.30 V and an FF of 0.35.

Excitation-dependent perovskite/polymer films for ultraviolet visualization

Ultraviolet(UV)visualization has extensive applications in military and civil fields such as security monitoring,space communication,and wearable equipment for health monitoring in the internet of things(IoT).Due to their remarkable optoelectronic features,perovskite materials are regarded as promising candidates for UV light detecting and imaging.Herein,we report for the first time the excitationdependent perovskite/polymer films with dynamically tunable fluorescence ranging from green to magenta by changing the UV excitation from 260 to 380 nm.And they still render dynamic multicolor UV light imaging with different polymer matrixes,halogen ratios,and cations of perovskite materials.The mechanism of its fluorescence change is related to the chloride vacancies in perovskite materials.A patterned multi-color ultraviolet visualization pad is also demonstrated for visible conversion of the UV region.This technique may provide a universal strategy for information securities,UV visualizations,and dynamic multi-color displays in the IoT.

Recent advances and innovations in the design and fabrication of wearable flexible biosensors and human health monitoring systems based on conjugated polymers

Wearable biosensors have received great interest as patient-friendly diagnostic technologies because of their high flexibility and conformability.The growing research and utilization of novel materials in designing wearable biosensors have accelerated the development of point-of-care sensing platforms and implantable biomedical devices in human health care.Among numerous potential materials,conjugated polymers(CPs)are emerging as ideal choices for constructing high-performance wearable biosensors because of their outstanding conductive and mechanical properties.Recently,CPs have been extensively incorporated into various wearable biosensors to monitor a range of target biomolecules.However,fabricating highly reliable CP-based wearable biosensors for practical applications remains a significant challenge,necessitating novel developmental strategies for enhancing the viability of such biosensors.Accordingly,this review aims to provide consolidated scientific evidence by summarizing and evaluating recent studies focused on designing and fabricating CP-based wearable biosensors,thereby facilitating future research.Emphasizing the superior properties and benefits of CPs,this review aims to clarify their potential applicability within this field.Furthermore,the fundamentals and main components of CP-based wearable biosensors and their sensing mechanisms are discussed in detail.The recent advancements in CP nanostructures and hybridizations for improved sensing performance,along with recent innovations in next-generation wearable biosensors are highlighted.CPbased wearable biosensors have been—and will continue to be—an ideal platform for developing effective and user-friendly diagnostic technologies for human health monitoring.

Microwave shock motivating the Sr substitution of 2D porous GdFeO_(3) perovskite for highly active oxygen evolution

The incorporation of partial A-site substitution in perovskite oxides represents a promising strategy for precisely controlling the electronic configuration and enhancing its intrinsic catalytic activity.Conventional methods for A-site substitution typically involve prolonged high-temperature processes.While these processes promote the development of unique nanostructures with highly exposed active sites,they often result in the uncontrolled configuration of introduced elements.Herein,we present a novel approach for synthesizing two-dimensional(2D)porous GdFeO_(3) perovskite with A-site strontium(Sr)substitution utilizing microwave shock method.This technique enables precise control of the Sr content and simultaneous construction of 2D porous structures in one step,capitalizing on the advantages of rapid heating and cooling(temperature~1100 K,rate~70 K s^(-1)).The active sites of this oxygen-rich defect structure can be clearly revealed through the simulation of the electronic configuration and the comprehensive analysis of the crystal structure.For electrocatalytic oxygen evolution reaction application,the synthesized 2D porous Gd_(0.8)Sr_(0.2)FeO_(3) electrocatalyst exhibits an exceptional overpotential of 294 mV at a current density of 10 mA cm^(-2)and a small Tafel slope of 55.85 mV dec^(-1)in alkaline electrolytes.This study offers a fresh perspective on designing crystal configurations and the construction of nanostructures in perovskite.

High performance wide bandgap perovskite solar cell with low V_(OC) deficit less than 0.4 V

Wide bandgap perovskite solar cells(PSCs)have attracted significant attention because they can be applied to the top cells of tandem solar cells.However,high open-circuit voltage(V_(OC))deficit(>0.4 V)result from poor crystallization and high non-radiative recombination losses become a serious limitation in the pursuit of high performance.Here,the relevance between different Pbl_(2)proportions and performance parameters are revealed through analysis of surface morphology,residual stress,and photostability.The increase of Pbl_(2)proportion promotes crystal growth and reduces the work function of the perovskite film surface and promotes the energy level alignment with the carrier transport layer,which decreased the V_(OC)deficit.However,residual PbI_(2)exacerbated the stress level of perovskite film,and the resulting lattice disorder deteriorated the photostability of the device.Ultimately,after the synergistic passivation of residual PbI_(2)and PEAI,the V_(OC)achieves 1.266 V and V_(OC)deficit is less than 0.4 V,the record value in wide bandgap PSCs.

Lithium-Ion Charged Polymer Channels Flattening Lithium Metal Anode

The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth.Resolving this issue will be key to achieving high-performance lithium metal batteries(LMBs).Herein,we construct a lithium nitrate(LiNO_(3))-implanted electroactiveβphase polyvinylidene fluoride-co-hexafluoropropylene(PVDF-HFP)crystalline polymorph layer(PHL).The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels.These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes,decreasing the growth of lithium dendrites.The stretched molecular channels can also accelerate the transport of Li ions.The combined effects enable a high Coulombic efficiency of 97.0%for 250 cycles in lithium(Li)||copper(Cu)cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm^(-2)with ultrahigh Li utilization of 50%.Furthermore,the full cell coupled with PHL-Cu@Li anode and Li Fe PO_(4) cathode exhibits long-term cycle stability with high-capacity retention of 95.9%after 900 cycles.Impressively,the full cell paired with LiNi_(0.87)Co_(0.1)Mn_(0.03)O_(2)maintains a discharge capacity of 170.0 mAh g^(-1)with a capacity retention of 84.3%after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83.This facile strategy will widen the potential application of LiNO_(3)in ester-based electrolyte for practical high-voltage LMBs.

Ultraviolet‑Irradiated All‑Organic Nanocomposites with Polymer Dots for High‑Temperature Capacitive Energy Storage

Polymer dielectrics capable of operating efficiently at high electric fields and elevated temperatures are urgently demanded by next-generation electronics and electrical power systems.While inorganic fillers have been extensively utilized to improved high-temperature capacitive performance of dielectric polymers,the presence of thermodynamically incompatible organic and inorganic components may lead to concern about the long-term stability and also complicate film processing.Herein,zero-dimensional polymer dots with high electron affinity are introduced into photoactive allyl-containing poly(aryl ether sulfone)to form the all-organic polymer composites for hightemperature capacitive energy storage.Upon ultraviolet irradiation,the crosslinked polymer composites with polymer dots are efficient in suppressing electrical conduction at high electric fields and elevated temperatures,which significantly reduces the high-field energy loss of the composites at 200℃.Accordingly,the ultraviolet-irradiated composite film exhibits a discharged energy density of 4.2 J cm^(−3)at 200℃.Along with outstanding cyclic stability of capacitive performance at 200℃,this work provides a promising class of dielectric materials for robust high-performance all-organic dielectric nanocomposites.

Synthetic polymers:A review of applications in drilling fluids

With the growth of deep drilling and the complexity of the well profile,the requirements for a more complete and efficient exploitation of productive formations increase,which increases the risk of various complications.Currently,reagents based on modified natural polymers(which are naturally occurring compounds)and synthetic polymers(SPs)which are polymeric compounds created industrially,are widely used to prevent emerging complications in the drilling process.However,compared to modified natural polymers,SPs form a family of high-molecular-weight compounds that are fully synthesized by undergoing chemical polymerization reactions.SPs provide substantial flexibility in their design.Moreover,their size and chemical composition can be adjusted to provide properties for nearly all the functional objectives of drilling fluids.They can be classified based on chemical ingredients,type of reaction,and their responses to heating.However,some of SPs,due to their structural characteristics,have a high cost,a poor temperature and salt resistance in drilling fluids,and degradation begins when the temperature reaches 130℃.These drawbacks prevent SP use in some medium and deep wells.Thus,this review addresses the historical development,the characteristics,manufacturing methods,classification,and the applications of SPs in drilling fluids.The contributions of SPs as additives to drilling fluids to enhance rheology,filtrate generation,carrying of cuttings,fluid lubricity,and clay/shale stability are explained in detail.The mechanisms,impacts,and advances achieved when SPs are added to drilling fluids are also described.The typical challenges encountered by SPs when deployed in drilling fluids and their advantages and drawbacks are also discussed.Economic issues also impact the applications of SPs in drilling fluids.Consequently,the cost of the most relevant SPs,and the monomers used in their synthesis,are assessed.Environmental impacts of SPs when deployed in drilling fluids,and their manufacturing processes are identified,together with advances in SP-treatment methods aimed at reducing those impacts.Recommendations for required future research addressing SP property and performance gaps are provided.

Boosting oxygen reduction activity and CO_(2) resistance on bismuth ferrite-based perovskite cathode for low-temperature solid oxide fuel cells below 600℃

Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for LT-SOFCs.Sm doping can significantly enhance the electrocata lytic activity and chemical stability of cathode.At 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious degradation.The remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi level.Moreover,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) resistivity.This work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs.

Constructing low-dimensional perovskite network to assist efficient and stable perovskite solar cells

The use of low-dimensional(LD)perovskite materials is crucial for achieving high-performance perovskite solar cells(PSCs).However,LD perovskite films fabricated by conventional approaches give rise to full coverage of the underlying 3D perovskite films,which inevitably hinders the transport of charge carriers at the interface of PSCs.Here,we designed and fabricated LD perovskite structure that forms net-like morphology on top of the underlying three-dimensional(3D)perovskite bulk film.The net-like LD perovskite not only reduced the surface defects of 3D perovskite film,but also provided channels for the vertical transport of charge carriers,effectively enhancing the interfacial charge transfer at the LD/3D hetero-interface.The net-like morphological design comprising LD perovskite effectively resolves the contradiction between interfacial defect passivation and carrier extraction across the hetero-interfaces.Furthermore,the net-like LD perovskite morphology can enhance the stability of the underlying 3D perovskite film,which is attributed to the hydrophobic nature of LD perovskite.As a result,the net-like LD perovskite film morphology assists PSCs in achieving an excellent power conversion efficiency of up to 24.6%with over 1000 h long-term operational stability.

Stabilizing perovskite precursors with the reductive natural amino acid for printable mesoscopic perovskite solar cells

Solution processability significantly advances the development of highly-efficient perovskite solar cells.However,the precursor solution tends to undergo irreversible degradation reactions,impairing the device performance and reproducibility.Here,we utilize a reductive natural amino acid,Nacetylcysteine(NALC),to stabilize the precursor solution for printable carbon-based hole-conductorfree mesoscopic perovskite solar cells.We find that I_(2) can be generated in the aged solution containing methylammonium iodide(MI) in an inert atmosphere and speed up the MA-FA^(+)(formamidinium) reaction which produces large-size cations and hinders the formation of perovskite phase.NALC effectively stabilizes the precursor via its sulfhydryl group which reduces I_(2) back to I^(-)and provides H^(+).The NALC-stabilized precursor which is aged for 1440 h leads to devices with a power conversion efficiency equivalent to 98% of that for devices prepared with the fresh precursor.Furthermore,NALC improves the device power conversion efficiency from 16.16% to 18.41% along with enhanced stability under atmospheric conditions by modifying grain boundaries in perovskite films and reducing associated defects.

Boosting MA-based two-dimensional Ruddlesden-Popper perovskite solar cells by incorporating a binary spacer

Two-dimensional Ruddlesden-Popper(2DRP)perovskite exhibits excellent stability in perovskite solar cells(PSCs)due to introducing hydrophobic long-chain organic spacers.However,the poor charge transporting property of bulky organic cation spacers limits the performance of 2DRP PSCs.Inspired by the Asite cation alloying strategy in 3D perovskites,2DRP perovskites with a binary spacer can promote charge transporting compared to the unary spacer counterparts.Herein,the superior MA-based 2DRP perovskite films with a binary spacer,including 3-guanidinopropanoic acid(GPA)and 4-fluorophenethylamine(FPEA)are realized.These films(GPA_(0.85)FPEA_(0.15))_(2)MA_(4)Pb_5I_(16)show good morphology,large grain size,decreased trap state density,and preferential orientation of the as-prepared film.Accordingly,the present 2DRP-based PSC with the binary spacer achieves a remarkable efficiency of 18.37%with a V_(OC)of1.15 V,a J_(SC)of 20.13 mA cm^(-2),and an FF of 79.23%.To our knowledge,the PCE value should be the highest for binary spacer MA-based 2DRP(n≤5)PSCs to date.Importantly,owing to the hydrophobic fluorine group of FPEA and the enhanced interlayer interaction by FPEA,the unencapsulated 2DRP PSCs based on binary spacers exhibit much excellent humidity stability and thermal stability than the unary spacer counterparts.

Efficient and Stable Inverted Perovskite Solar Modules Enabled by Solid-Liquid Two-Step Film Formation

A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs.In this work,we adopted a solid-liquid two-step film formation technique,which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films.This method possesses the advantages of integrating vapor deposition and solution methods,which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform,large-area perovskite film.Furthermore,modification of the NiO_(x)/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization.As a result,a large-area perovskite film possessing larger grains,fewer pinholes,and reduced defects could be achieved.The inverted PSM with an active area of 61.56 cm^(2)(10×10 cm^(2)substrate)achieved a champion power conversion efficiency of 20.56%and significantly improved stability.This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.

Enhanced performance of solution-processed carbon nanotube transparent electrodes in foldable perovskite solar cells through vertical separation of binders by using eco-friendly parylene substrate

The successful utilization of an eco-friendly and biocompatible parylene-C substrate for high-performance solution-processed double-walled carbon nanotube(CNT)electrode-based perovskite solar cells(PSCs)was demonstrated.Through the use of a novel inversion transfer technique,vertical separation of the binders from the CNTs was induced,rendering a stronger p-doping effect and thereby a higher conductivity of the CNTs.The resulting foldable devices exhibited a power conversion efficiency of 18.11%,which is the highest reported among CNT transparent electrode-based PSCs to date,and withstood more than 10,000 folding cycles at a radius of 0.5 mm,demonstrating unprecedented mechanical stability.Furthermore,solar modules were fabricated using entirely laser scribing processes to assess the potential of the solution-processable nanocarbon electrode.Notably,this is the only one to be processed entirely by the laser scribing process and to be biocompatible as well as eco-friendly among the previously reported nonindium tin oxide-based perovskite solar modules.

Pressure-Induced Distinct Self-Trapped Exciton Emission in Sb^(3+)-Doped Cs_(2)NaInCl_(6)Double Perovskite

The Cs_(2)NaInCl_(6) double perovskite is one of the most promising lead-free perovskites due to its exceptional stability and straightforward synthesis.However,it faces challenges related to inefficient photoluminescence.Doping and high pressure are employed to tailor the optical properties of Cs_(2)NaInCl_(6).Herein,Sb^(3+)doped Cs_(2)NaInCl_(6)(Sb^(3+):Cs_(2)NaInCl_(6)) was synthesized and it exhibits blue emission with a photoluminescence quantum yield of up to 37.3%.Further,by employing pressure tuning,a blue stable emission under a very wide range from 2.7 GPa to 9.8 GPa is realized in Sb^(3+):Cs_(2)NaInCl_(6).Subsequently,the emission intensity of Sb^(3+):Cs_(2)NaInCl_(6) experiences a significant increase(3.3 times)at 19.0 GPa.It is revealed that the pressure-induced distinct emissions can be attributed to the carrier self-trapping and detrapping between Cs_(2)NaInCl_(6) and Sb^(3+).Notably,the lattice compression in the cubic phase inevitably modifies the band gap of Sb^(3+):Cs_(2)NaInCl_(6).Our findings provide valuable insights into effects of the high pressure in further boosting unique emission characteristics but also offer promising opportunities for development of doped double perovskites with enhanced optical functionalities.

Effect of drying methods on perovskite films and solar cells

The high efficiency,solution processibility,and flexibility of perovskite solar cells make them promising candidates for the photovoltaic industry[1−8].The deposition method is one of the most critical factors that affect the performance of perovskite films.Various deposition methods have been developed to make perovskite films,including spin-coating,slotdie coating.

Buried Interface Molecular Hybrid Enables Efficient Perovskite Solar Cells

Perovskite solar cells(PSCs)with a positive-intrinsicnegative(p–i–n,commonly referred to as“inverted”)structure are becoming commercially attractive due to their superior power conversion efficiency(PCE)and better operational stability as compared to the“normal”structure device.^([1–5])Nonetheless,further improvements in the device performance of inverted PSCs are hampered by interface losses,particularly where the buried interfaces are responsible for perovskite crystallization and chargecarrier extraction.^([6–9])