Silicon/carbon composites,which integrate the high lithium storage performance of silicon with the exceptional mechanical strength and conductivity of carbon,will replace the traditional graphite electrodes for high-e...Silicon/carbon composites,which integrate the high lithium storage performance of silicon with the exceptional mechanical strength and conductivity of carbon,will replace the traditional graphite electrodes for high-energy lithium-ion batteries.Various strategies have been designed to synthesize silicon/carbon composites for tackling the issues of anode pulverization and poor stability in the anodes,thereby improving the lithium storage ability.The effect of the regulation method at each scale on the final negative electrode performance remains unclear.However,it has not been fully clarified how the regulation methods at each scale influence the final anode performance.This review will categorize the materials structure into three scales:molecular scale,nanoscale,and microscale.First,the review will examine modification methods at the molecular scale,focusing on the interfacial bonding force between silicon and carbon.Next,it will summarize various nanostructures and special shapes in the nanoscale to explore the construction of silicon/carbon composites.Lastly,the review will provide an analysis of microscale control approaches,focusing on the formation of composite particle with micron size and the utilization of micro-Si.This review provides a comprehensive overview of the multi-scale design of silicon/carbon composite anode materials and their optimization strategies to enhance the performance of lithium-ion batteries.展开更多
Post-earthquake rescue missions are full of challenges due to the unstable structure of ruins and successive aftershocks.Most of the current rescue robots lack the ability to interact with environments,leading to low ...Post-earthquake rescue missions are full of challenges due to the unstable structure of ruins and successive aftershocks.Most of the current rescue robots lack the ability to interact with environments,leading to low rescue efficiency.The multimodal electronic skin(e-skin)proposed not only reproduces the pressure,temperature,and humidity sensing capabilities of natural skin but also develops sensing functions beyond it—perceiving object proximity and NO2 gas.Its multilayer stacked structure based on Ecoflex and organohydrogel endows the e-skin with mechanical properties similar to natural skin.Rescue robots integrated with multimodal e-skin and artificial intelligence(AI)algorithms show strong environmental perception capabilities and can accurately distinguish objects and identify human limbs through grasping,laying the foundation for automated post-earthquake rescue.Besides,the combination of e-skin and NO2 wireless alarm circuits allows robots to sense toxic gases in the environment in real time,thereby adopting appropriate measures to protect trapped people from the toxic environment.Multimodal e-skin powered by AI algorithms and hardware circuits exhibits powerful environmental perception and information processing capabilities,which,as an interface for interaction with the physical world,dramatically expands intelligent robots’application scenarios.展开更多
Benefiting from the superior optoelectronic properties and low-cost manufacturing techniques,mixedhalide wide bandgap(WBG)perovskite solar cells(PSCs)are currently considered as ideal top cells for fabricating multi-j...Benefiting from the superior optoelectronic properties and low-cost manufacturing techniques,mixedhalide wide bandgap(WBG)perovskite solar cells(PSCs)are currently considered as ideal top cells for fabricating multi-junction or tandem solar cells,which are designed to beyond the Shockley-Queisser(S-Q)limit of single-junction solar cells.However,the poor long-term operational stability of WBG PSCs limits their further employment and hinders the marketization of multi-junction or tandem solar cells.In this review,recent progresses on improving environmental stability of mixed-halide WBG PSCs through different strategies,including compositional engineering,additive engineering,interface engineering,and other strategies,are summarized.Then,the outlook and potential direction are discussed and explored to promote the further development of WBG PSCs and their applications in multijunction or tandem solar cells.展开更多
The exploration of low bandgap perovskite material to approach Shockley-Queisser limit of photovoltaic device is of great significance,but it is still challenging.During the past few years,tin–lead(Sn-Pb)mixed perovs...The exploration of low bandgap perovskite material to approach Shockley-Queisser limit of photovoltaic device is of great significance,but it is still challenging.During the past few years,tin–lead(Sn-Pb)mixed perovskites with low bandgaps have been rapidly developed,and their single junction solar cells have reached power conversion efficiency(PCE)over 21%,which also makes them ideal candidate as low bandgap sub-cell for tandem device.Nevertheless,due to the incorporation of unstable Sn^(2+),the stability issue becomes the vital problem for the further development of Sn-Pb mixed perovskite solar cells(PSCs).In this review,we are dedicated to give a full view in current understanding on the stability issue of SnPb mixed perovskites and their PSCs.We begin with the demonstration on the origin of instability of Sn-Pb mixed perovskites,including oxidation of Sn^(2+),defects,and interfacial layer induced instability.Sequentially,the up-to-date developments on the stability improvement of Sn-Pb mixed perovskites and their PSCs is systematically reviewed,including composition engineering,additive engineering,and interfacial engineering.At last,the current challenges and future perspectives on the stability study of Sn-Pb mixed PSCs are discussed,which we hope could promote the further application of Sn-Pb mixed perovskites towards commercialization.展开更多
Quasi-two-dimensional(quasi-2D)perovskites with high stability usually suffers from poor device efficiency.Chemical tuning of the spacer cations has been an effective strategy to achieve efficient and stable quasi-2D ...Quasi-two-dimensional(quasi-2D)perovskites with high stability usually suffers from poor device efficiency.Chemical tuning of the spacer cations has been an effective strategy to achieve efficient and stable quasi-2D perovskite solar cells.Here,we demonstrate that 3-halogon-substituted benzylammonium iodide(3X-BAI,X=F,Cl,Br,I)can significantly affect the orientation of low-dimensional perovskites and charge transport from perovskite to hole extraction layer,as well as device performance.With 3Br-BAI,we achieve the highest device efficiency of 13.21%for quasi-2D perovskites with a nominal n=3 average composition.Our work provides a facile approach to regulate vertical crystal orientation and charge transport via tuning the molecular structure of organic spacer toward high performance quasi-2D perovskite solar cells.展开更多
Light-emitting diodes(LEDs)have wide applications in the areaof lighting,medical devices,display screens,etc.Owing to theexcellent optoelectronic properties and the facile solution proces-sing methods,organometal hali...Light-emitting diodes(LEDs)have wide applications in the areaof lighting,medical devices,display screens,etc.Owing to theexcellent optoelectronic properties and the facile solution proces-sing methods,organometal halide perovskites are extensively stu-died and proved to be promising light.emitting materials to fabri-cate LED devices[1-2].Generally,nonradiative recombination andlight trapping are two main factors to impede the efficiency en-hancement of LEDs,which are more serious in perovskite mate-rials for the high refractive index.展开更多
In practical lithium-sulfur batteries(LSBs),the shuttle effect and Li cycling coulombic efficiency(CE) are strongly affected by the physicochemical properties of solid electrolyte interphase(SEI).LiNO_(3) is widely us...In practical lithium-sulfur batteries(LSBs),the shuttle effect and Li cycling coulombic efficiency(CE) are strongly affected by the physicochemical properties of solid electrolyte interphase(SEI).LiNO_(3) is widely used as an additive in electrolytes to build a high-quality SEI,but its self-sacrificial nature limits the ability to mitigate the shuttle effect and stabilize Li anode during long-term cycling.To counteract LiNO_(3) consumption during long-term cycling without using a high initial concentration,inspired by sustainedrelease drugs,we encapsulated LiNO_(3) in lithiated Nafion polymer and added an electrolyte co-solvent(1,1,2,2-tetrafluoroethylene 2,2,2-trifluoromethyl ether) with poor LiNO_(3) solubility to construct highquality and durable F-and N-rich SEI.Theoretical calculations,experiments,multiphysics simulations,and in-situ observations confirmed that the F-and N-rich SEI can modulate lithium deposition behavior and allow persistent repair of SEI during prolonged cycling.Hence,the F-and N-rich SEI improves the Li anode cycling CE to 99.63% and alleviates the shuttle effect during long-term cycling.The lithium anode with sustainable F-and N-rich SEI shows a stable Li plating/stripping over 2000 h at 1 mA cm^(-2).As expected,Li‖S full cells with this SEI achieved a long lifespan of 250 cycles,far exceeding cells with a routine SEI.The Li‖S pouch cell based on F-and N-rich SEI also can achieve a high energy density of about300 Wh kg^(-1) at initial cycles.This strategy provides a novel design for high-quality and durable SEls in LSBs and may also be extendable to other alkali metal batteries.展开更多
Carbon-based microassemblies(CMs) have attracted significant attention in numerous applications due to their unique hierarchical structures and delicate building blocks,especially when hollow carbon spheres(HCSs) are ...Carbon-based microassemblies(CMs) have attracted significant attention in numerous applications due to their unique hierarchical structures and delicate building blocks,especially when hollow carbon spheres(HCSs) are reasonably introduced into the construction.Herein,a new design for novel HCSscombined CMs is proposed.Remarkably,the HCSs are linear carbon bubbles linked one-by-one, arranging into necklaces decorating on the graphene microfolds.Detailed thermal analysis confirm that high temperatures straighten the linked carbon bubbles into bamboo-like carbon nanofibers,evidently due to the attenuation of doping degree.Benefiting from the abundant active sites of carbon bubbles,the obtained CMs exhibit satisfactory electrocatalytic activity for oxygen reduction reactions.This work establishes a bridge to precisely control the synthesis of carbon-based hierarchical architectures.展开更多
Optical cavity has long been critical for a variety of applications ranging from precise measurement to spectral analysis.A number of theories and methods have been successful in describing the optical response of a s...Optical cavity has long been critical for a variety of applications ranging from precise measurement to spectral analysis.A number of theories and methods have been successful in describing the optical response of a stratified optical cavity,while the inverse problem,especially the inverse design of a displacement sensitive cavity,remains a significant challenge due to the cost of computation and comprehensive performance requirements.This paper reports a novel inverse design methodology combining the characteristic matrix method,mixed-discrete variables optimization algorithm,and Monte Carlo method-based tolerance analysis.The material characteristics are indexed to enable the mixed-discrete variables optimization,which yields considerable speed and efficiency improvements.This method allows arbitrary response adjustment with technical feasibility and gives a glimpse into the analytical characterization of the optical response.Two entirely different light-displacement responses,including an asymmetric sawtooth-like response and a highly symmetric response,are dug out and experimentally achieved,which fully confirms the validity of the method.The compact Fabry-Perot cavities have a good balance between performance and feasibility,making them promising candidates for displacement transducers.More importantly,the proposed inverse design paves the way for a universal design of optical cavities,or even nanophotonic devices.展开更多
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 ...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.展开更多
Expediting redox kinetics of sulfur species on conductive scaffolds with limited charge accessible surface is considered as an imperative approach to realize energy-dense and power-intensive lithium-sulfur(Li-S)batter...Expediting redox kinetics of sulfur species on conductive scaffolds with limited charge accessible surface is considered as an imperative approach to realize energy-dense and power-intensive lithium-sulfur(Li-S)batteries.In this work,the concept of concurrent hetero-/homo-geneous electrocatalysts is proposed to simultaneously mediate liquid-solid conversion of lithium polysulfides(LiPSs)and solid lithium disulfide/sulfide(Li_(2)S_(2)/Li_(2)S)propagation,the latter of which suffers from sluggish reduction kinetics due to buried conductive scaffold surface by extensive deposition of Li_(2)S_(2)/Li_(2)S.The selected model material to verify this concept is a two-in-one catalyst:carbon nanotube(CNT)scaffold supported iron-cobalt(Fe-Co)alloy nanoparticles and partially carbonized selenium(C-Se)component.The Fe-Co alloy serves as a heterogeneous electrocatalyst to seed Li_(2)S_(2)/Li_(2)S through sulphifilic active sites,while the C-Se sustainably releases soluble lithium polyselenides and functions as a homogeneous electrocatalyst to propagate Li_(2)S_(2)/Li_(2)S via solution pathways.Such bi-phasic mediation of the sulfur species benefits reduction kinetics of LiPS conversion,especially for the massive Li_(2)S_(2)/Li_(2)S growth scenario by affording an additional solution directed route in case of conductive surface being largely buried.This strategy endows the Li-S batteries with improved cycling stability(836 mA h g^(-1)after 180 cycles),rate capability(547 mA h g^(-1)at 4 C)and high sulfur loading superiority(2.96 mA h cm^(-2)at 2.4 mg cm^(-2)).This work hopes to enlighten the employment of bi-phasic electrocatalysts to dictate liquid-solid transformation of intermediates for conversion chemistry batteries.展开更多
The toxicity issue of lead hinders large-scale commercial production and photovoltaic field application of lead halide perovskites.Some novel non-or low-toxic perovskite materials have been explored for development of...The toxicity issue of lead hinders large-scale commercial production and photovoltaic field application of lead halide perovskites.Some novel non-or low-toxic perovskite materials have been explored for development of environmentally friendly lead-free perovskite solar cells(PSCs).This review studies the substitution of equivalent/heterovalent metals for Pb based on first-principles calculation,summarizes the theoretical basis of lead-free perovskites,and screens out some promising lead-free candidates with suitable bandgap,optical,and electrical properties.Then,it reports notable achievements for the experimental studies of lead-free perovskites to date,including the crystal structure and material bandgap for all of lead-free materials and photovoltaic performance and stability for corresponding devices.The review finally discusses challenges facing the successful development and commercialization of lead-free PSCs and predicts the prospect of lead-free PSCs in the future.展开更多
Solvent residue is inevitable to occur in solution processed thin films,but its influence on the thin film quality has not been identified and addressed to date.Methylammonium acetate(MAAc)ionic liquid has recently be...Solvent residue is inevitable to occur in solution processed thin films,but its influence on the thin film quality has not been identified and addressed to date.Methylammonium acetate(MAAc)ionic liquid has recently been realized as an environmentally friendly solvent for solution processed perovskites.The specific high viscosity,low vapor pressure and strong association with perovskite precursor of the MAAc solvent is a double-edged sword,which endowed an advantageously ambient air operational and anti-solvent free perovskite deposition,but the MAAc is likely to be retained within the film and bring in detrimental effects on device performance of the corresponding solar cells.Herein,we reported a novel route to eliminate the residual solvent via a facial hydrochloric acid(HCl)annealing post-treatment(HAAP).In particular,chemical displacement reaction between the incorporated HCl and residual MAAc can be initiated to form volatile MACl and HAc,efficiently extracting MAAc residue.In the meanwhile,the stimulated mass transport via downward penetration and upward escape can trigger secondary perovskite growth with enlarged grain size and smoothened surface,leading to reduced defect state and improved interfacial contact intimacy,and also partial chloride ions are able to enter the crystal lattice to stabilize perovskite phase structure.As a result,a champion efficiency up to20.78%originating from enhanced Voc was achieved,and more than 96%of its initial efficiency can be maintained after 1000 h shelf-storage.展开更多
Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.U...Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.Unambiguously fingerprinting rate-limited factors of low-temperature LMBs would encourage targeted approaches to promote performances.Herein,the charge transfer impedance across solid electrolyte interphase(SEI) is identified to restrict battery operation under low temperature,and we propose a facile approach on the basis of ambiently fostering SEI(af-SEI) to facilitate charge transfer.The concept of af-SEI stems from kinetic benefits and structural merits to construct SEI at ambient temperature over low temperature developed SEI that is temporally consuming to achieve steady state and that is structurally defective to incur dendrite growth.The af-SEI allows ionically conductive and morphologically uniform layer on the anode surface,which exhibits a lower resistance and induces an even deposition of Li in the subsequent low temperature battery operation.Armed with af-SEI,the LMBs deliver the improved rate performance and prolonged cycle life when subjected to low temperature cycling.This work unveils the underlying causes that limit low temperature LMB performances,and enlightens the facile test protocols to build up favorable SEI,beyond scope of material and morphology design.展开更多
Since it was first proposed,the space solar power station(SSPS)has attracted great attention all over the world;it is a huge space system and provides energy for Earth.Although several schemes and abundant studies on ...Since it was first proposed,the space solar power station(SSPS)has attracted great attention all over the world;it is a huge space system and provides energy for Earth.Although several schemes and abundant studies on the SSPS have been proposed and conducted,it is still not realized.The reason why SSPS is still an idea is not only because it is a giant and complex project,but also due to the requirement for various excellent space materials.Among the diverse required materials,we believe energy materials are the most important.Herein,we review the space energy conversion materials for the SSPS.展开更多
In order to balance electrochemical kinetics with loading level for achieving efficient energy storage with high areal capacity and good rate capability simultaneously for wearable electronics,herein,2 D meshlike vert...In order to balance electrochemical kinetics with loading level for achieving efficient energy storage with high areal capacity and good rate capability simultaneously for wearable electronics,herein,2 D meshlike vertical structures(NiCo_2 S_4@Ni(OH)_2) with a high mass loading of 2.17 mg cm^(-2) and combined merits of both 1 D nanowires and 2 D nanosheets are designed for fabricating flexible hybrid supercapacitors.Particularly,the seamlessly interconnected NiCo_2 S_4 core not only provides high capacity of 287.5 μAh cm^(-2) but also functions as conductive skeleton for fast electron transport;Ni(OH)_2 sheath occupying the voids in NiCo_2 S_4 meshes contributes extra capacity of 248.4 μAh cm^(-2);the holey features guarantee rapid ion diffusion along and across NiCO_2 S_4@Ni(OH)_2 meshes.The resultant flexible electrode exhibits a high areal capacity of 535.9 μAh cm^(-2)(246.9 mAh g^(-1)) at 3 mA cm^(-2) and outstanding rate performance with 84.7% retention at 30 mA cm^(-2),suggesting efficient utilization of both NiCo_2 S_4 and Ni(OH)_2 with specific capacities approaching to their theoretical values.The flexible solid-state hybrid device based on NiCo_2 S_4@Ni(OH)_2 cathode and Fe_2 O_3 anode delivers a high energy density of 315 μWh cm^(-2) at the power density of 2.14 mW cm^(-2) with excellent electrochemical cycling stability.展开更多
Fluorine substitution in molecular design has become an effective strategy for improving the overall performance of organic photovoltaics.In this study,three low-cost small molecules of spiro-linked hole transporting ...Fluorine substitution in molecular design has become an effective strategy for improving the overall performance of organic photovoltaics.In this study,three low-cost small molecules of spiro-linked hole transporting materials(SFX-O-2 F,SFX-m-2 F,and SFX-p-2 F) endowed with two-armed t rip he ny la mine moieties were synthesized via tuning of the fluorine substitution position,and they were employed for use in highly efficient perovskite solar cells(PSCs).Despite the fluorine substitution position playing a negligible role in the optical and electrochemical properties of the resulting small molecules,the photovoltaic performance thereof was observed to vary significantly.The planar n-i-p PSCs based on SFX-m-2 F demonstrated superior performance(18.86%) when compared to that of the corresponding SFX-o-2 F(9.7%) and SFX-p-2 F(16.33%) under 100 mW cm^(-2) AM1.5 G solar illumination,which is competitive with the performance of the benchmark spiro-OMeTAD-based device(18.98%).Moreover,the SFX-m-2 Fbased PSCs were observed to be more stable than the spiro-OMeTAD-based devices under ambient conditions.The improved performance of SFX-m-2 F is primarily associated with improved morphology,more efficient hole transport,and extraction characteristics at the perovskite/HTM interface.This work demonstrated the application of fluorination engineering to the tuning of material film morphology and charge transfer properties,showing the promising potential of fluorinated SM-HTMs for the construction of low-cost,high-efficiency PSCs.展开更多
The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase tr...The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase transition and defects-induced non-ideal interfacial recombination, which significantly induces energy loss and hinders the improvement of device performance. Herein, we employed 4-fluorophenylmethylammonium iodide(F-PMAI) to modulate surface structure and energy level alignment of the FA-based perovskite films. The superior optoelectronic films were obtained with reduced trap density, pure α-phase FAPbI_(3) and favorable energy band bending. The lifetime of photogenerated charge carriers increased from 489.3 ns to 1010.6 ns, and a more “p-type” perovskite film was obtained by the post-treatment with F-PMAI. Following this strategy, we demonstrated an improved power conversion efficiency of 22.59% for the FA-based PSCs with an open-circuit voltage loss of 399 m V.展开更多
Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial cont...Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial contact between commonly used hole transport layer(i.e., poly(3,4-ethylenedioxythio phene):poly(styrene sulfonate), PEDOT:PSS) and FASnI_(3) film, it is still challenging to effectively extract holes at the interface. Owing to the p-type nature of Sn-based perovskites, the efficient hole extraction is of particular significance to improve the PCE of their solar cells. In this work, for the first time, the role of chiral cations, a-methylbenzylamine(S-/R-/rac-MBA), in promoting hole transportation of FASnI_(3)-based PSCs is demonstrated. The introduction of MBAs is found to form 2D/3D film with lowdimensional structures locating at PEDOT:PSS/FASnI_(3) interface, which facilitates the energy level alignment and efficient charge transfer at the interface. Importantly, chiral-induced spin selectivity(CISS)effect of R-MBA_(2)SnI_(4)induced by chiral R-MBA cation is found to further assist the specific interfacial transport of accumulated holes. As a result, R-MBA-based PSCs achieve decent PCE of 10.73% with much suppressed hysteresis and enhanced device stability. This work opens up a new strategy to efficiently promote the interfacial extraction of accumulated charges in working PSCs.展开更多
Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonra...Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonradiative recombination losses.However,how these groups synergistically affect the enhancement beyond passivation is still unclear.Specifically,isomeric molecules with different substitution patterns or molecular shapes remain elusive in designing new organic additives.Here,we report two isomeric carbazolyl bisphosphonate additives,2,7-Cz BP and 3,6-Cz BP.The isomerism effect on passivation and charge transport process was studied.The two molecules have similar passivation effects through multiple interactions,e.g.,P=O···Pb,P=O···H–N and N–H···I.2,7-CzBP can further bridge the perovskite crystallites to facilitates charge transport.Power conversion efficiencies(PCEs)of 25.88%and 21.04%were achieved for 0.09 cm^(2)devices and 14 cm^(2)modules after 2,7-Cz BP treatment,respectively.The devices exhibited enhanced operational stability maintaining 95%of initial PCE after 1000 h of continuous maximum power point tracking.This study of isomerism effect hints at the importance of tuning substitution positions and molecular shapes for organic additives,which paves the way for innovation of next-generation multifunctional aromatic additives.展开更多
基金funded by the Research Fund of State Key Laboratory of Mesoscience and Engineering (MESO-23-T03)the National Natural Science Foundation (22278423)+1 种基金the National Key Research and Development Program of China (2022YFB3805602)the Science Foundation of China University of Petroleum,Beijing (2462021QNXZ007)。
文摘Silicon/carbon composites,which integrate the high lithium storage performance of silicon with the exceptional mechanical strength and conductivity of carbon,will replace the traditional graphite electrodes for high-energy lithium-ion batteries.Various strategies have been designed to synthesize silicon/carbon composites for tackling the issues of anode pulverization and poor stability in the anodes,thereby improving the lithium storage ability.The effect of the regulation method at each scale on the final negative electrode performance remains unclear.However,it has not been fully clarified how the regulation methods at each scale influence the final anode performance.This review will categorize the materials structure into three scales:molecular scale,nanoscale,and microscale.First,the review will examine modification methods at the molecular scale,focusing on the interfacial bonding force between silicon and carbon.Next,it will summarize various nanostructures and special shapes in the nanoscale to explore the construction of silicon/carbon composites.Lastly,the review will provide an analysis of microscale control approaches,focusing on the formation of composite particle with micron size and the utilization of micro-Si.This review provides a comprehensive overview of the multi-scale design of silicon/carbon composite anode materials and their optimization strategies to enhance the performance of lithium-ion batteries.
基金supports from the National Natural Science Foundation of China(61801525)the independent fund of the State Key Laboratory of Optoelectronic Materials and Technologies(Sun Yat-sen University)under grant No.OEMT-2022-ZRC-05+3 种基金the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(Grant No.sklpme2023-3-5))the Foundation of the state key Laboratory of Transducer Technology(No.SKT2301),Shenzhen Science and Technology Program(JCYJ20220530161809020&JCYJ20220818100415033)the Young Top Talent of Fujian Young Eagle Program of Fujian Province and Natural Science Foundation of Fujian Province(2023J02013)National Key R&D Program of China(2022YFB2802051).
文摘Post-earthquake rescue missions are full of challenges due to the unstable structure of ruins and successive aftershocks.Most of the current rescue robots lack the ability to interact with environments,leading to low rescue efficiency.The multimodal electronic skin(e-skin)proposed not only reproduces the pressure,temperature,and humidity sensing capabilities of natural skin but also develops sensing functions beyond it—perceiving object proximity and NO2 gas.Its multilayer stacked structure based on Ecoflex and organohydrogel endows the e-skin with mechanical properties similar to natural skin.Rescue robots integrated with multimodal e-skin and artificial intelligence(AI)algorithms show strong environmental perception capabilities and can accurately distinguish objects and identify human limbs through grasping,laying the foundation for automated post-earthquake rescue.Besides,the combination of e-skin and NO2 wireless alarm circuits allows robots to sense toxic gases in the environment in real time,thereby adopting appropriate measures to protect trapped people from the toxic environment.Multimodal e-skin powered by AI algorithms and hardware circuits exhibits powerful environmental perception and information processing capabilities,which,as an interface for interaction with the physical world,dramatically expands intelligent robots’application scenarios.
基金the National Natural Science Foundation of China(Grant Nos.51602149,61705102,61605073,61935017,91833304,and 91733302)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(Grant BK20200034)+5 种基金the Projects of International Cooperation and Exchanges NSFC(51811530018)the Startup Research Foundation from Nanjing Tech University(3827401783,3983500196)the Young 1000 Talents Global Recruitment Program of Chinathe Jiangsu Specially-Appointed Professor programthe“Six talent peaks”Project in Jiangsu Province,Chinafunding from the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germanys Excellence Strategy-EXC 2089/1-390776260(e-conversion)。
文摘Benefiting from the superior optoelectronic properties and low-cost manufacturing techniques,mixedhalide wide bandgap(WBG)perovskite solar cells(PSCs)are currently considered as ideal top cells for fabricating multi-junction or tandem solar cells,which are designed to beyond the Shockley-Queisser(S-Q)limit of single-junction solar cells.However,the poor long-term operational stability of WBG PSCs limits their further employment and hinders the marketization of multi-junction or tandem solar cells.In this review,recent progresses on improving environmental stability of mixed-halide WBG PSCs through different strategies,including compositional engineering,additive engineering,interface engineering,and other strategies,are summarized.Then,the outlook and potential direction are discussed and explored to promote the further development of WBG PSCs and their applications in multijunction or tandem solar cells.
基金financially supported by the National Natural Science Foundation of China(Grants 51972172,61705102,91833304 and 51802253)the Natural Science Basic Research Plan in Shaanxi Province of China(2019JM-326)+5 种基金the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z007)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(Grant BK20200034)the Young 1000 Talents Global Recruitment Program of ChinaJiangsu Specially Appointed Professor program“Six talent peaks”Project in Jiangsu Province,Chinathe Fundamental Research Funds for the Central Universities。
文摘The exploration of low bandgap perovskite material to approach Shockley-Queisser limit of photovoltaic device is of great significance,but it is still challenging.During the past few years,tin–lead(Sn-Pb)mixed perovskites with low bandgaps have been rapidly developed,and their single junction solar cells have reached power conversion efficiency(PCE)over 21%,which also makes them ideal candidate as low bandgap sub-cell for tandem device.Nevertheless,due to the incorporation of unstable Sn^(2+),the stability issue becomes the vital problem for the further development of Sn-Pb mixed perovskite solar cells(PSCs).In this review,we are dedicated to give a full view in current understanding on the stability issue of SnPb mixed perovskites and their PSCs.We begin with the demonstration on the origin of instability of Sn-Pb mixed perovskites,including oxidation of Sn^(2+),defects,and interfacial layer induced instability.Sequentially,the up-to-date developments on the stability improvement of Sn-Pb mixed perovskites and their PSCs is systematically reviewed,including composition engineering,additive engineering,and interfacial engineering.At last,the current challenges and future perspectives on the stability study of Sn-Pb mixed PSCs are discussed,which we hope could promote the further application of Sn-Pb mixed perovskites towards commercialization.
基金supported financially by the National Natural Science Foundation of China(61974066,61961160733,62005223)the National Science Fund for Distinguished Young Scholars(61725502)+2 种基金the Major Program of Natural Science Research of Jiangsu Higher Education Institutions of China(18KJA510002)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-024)the Synergetic Innovation Center for Organic Electronics and Information Displays。
文摘Quasi-two-dimensional(quasi-2D)perovskites with high stability usually suffers from poor device efficiency.Chemical tuning of the spacer cations has been an effective strategy to achieve efficient and stable quasi-2D perovskite solar cells.Here,we demonstrate that 3-halogon-substituted benzylammonium iodide(3X-BAI,X=F,Cl,Br,I)can significantly affect the orientation of low-dimensional perovskites and charge transport from perovskite to hole extraction layer,as well as device performance.With 3Br-BAI,we achieve the highest device efficiency of 13.21%for quasi-2D perovskites with a nominal n=3 average composition.Our work provides a facile approach to regulate vertical crystal orientation and charge transport via tuning the molecular structure of organic spacer toward high performance quasi-2D perovskite solar cells.
文摘Light-emitting diodes(LEDs)have wide applications in the areaof lighting,medical devices,display screens,etc.Owing to theexcellent optoelectronic properties and the facile solution proces-sing methods,organometal halide perovskites are extensively stu-died and proved to be promising light.emitting materials to fabri-cate LED devices[1-2].Generally,nonradiative recombination andlight trapping are two main factors to impede the efficiency en-hancement of LEDs,which are more serious in perovskite mate-rials for the high refractive index.
基金partially supported by grants from the National Natural Science Foundation of China (52072099, 52102228)Team program of the Natural Science Foundation of Heilongjiang Province, China (TD2021E005)+1 种基金The National general entrepreneurial practice program (202210231088S)The National general innovation training program (202210231076)。
文摘In practical lithium-sulfur batteries(LSBs),the shuttle effect and Li cycling coulombic efficiency(CE) are strongly affected by the physicochemical properties of solid electrolyte interphase(SEI).LiNO_(3) is widely used as an additive in electrolytes to build a high-quality SEI,but its self-sacrificial nature limits the ability to mitigate the shuttle effect and stabilize Li anode during long-term cycling.To counteract LiNO_(3) consumption during long-term cycling without using a high initial concentration,inspired by sustainedrelease drugs,we encapsulated LiNO_(3) in lithiated Nafion polymer and added an electrolyte co-solvent(1,1,2,2-tetrafluoroethylene 2,2,2-trifluoromethyl ether) with poor LiNO_(3) solubility to construct highquality and durable F-and N-rich SEI.Theoretical calculations,experiments,multiphysics simulations,and in-situ observations confirmed that the F-and N-rich SEI can modulate lithium deposition behavior and allow persistent repair of SEI during prolonged cycling.Hence,the F-and N-rich SEI improves the Li anode cycling CE to 99.63% and alleviates the shuttle effect during long-term cycling.The lithium anode with sustainable F-and N-rich SEI shows a stable Li plating/stripping over 2000 h at 1 mA cm^(-2).As expected,Li‖S full cells with this SEI achieved a long lifespan of 250 cycles,far exceeding cells with a routine SEI.The Li‖S pouch cell based on F-and N-rich SEI also can achieve a high energy density of about300 Wh kg^(-1) at initial cycles.This strategy provides a novel design for high-quality and durable SEls in LSBs and may also be extendable to other alkali metal batteries.
基金financially supported by the National Key R&D Program of China(2017YFA0207201)the National Natural Science Foundation of China(51872139,21905133,51902158)+4 种基金the NSF of Jiangsu Province(BK20170045)the Recruitment Program of Global Experts(1211019)the “Six Talent Peak”Project of Jiangsu Province(XCL-043)the Fundamental Research Funds for the Central Universities and the Recruitment Program of Global Experts(1211019,31020200QD041)the Jiangsu Province Postdoctoral Science Foundation(2019K191)。
文摘Carbon-based microassemblies(CMs) have attracted significant attention in numerous applications due to their unique hierarchical structures and delicate building blocks,especially when hollow carbon spheres(HCSs) are reasonably introduced into the construction.Herein,a new design for novel HCSscombined CMs is proposed.Remarkably,the HCSs are linear carbon bubbles linked one-by-one, arranging into necklaces decorating on the graphene microfolds.Detailed thermal analysis confirm that high temperatures straighten the linked carbon bubbles into bamboo-like carbon nanofibers,evidently due to the attenuation of doping degree.Benefiting from the abundant active sites of carbon bubbles,the obtained CMs exhibit satisfactory electrocatalytic activity for oxygen reduction reactions.This work establishes a bridge to precisely control the synthesis of carbon-based hierarchical architectures.
基金We are grateful for financial supports from National Natural Science Foundation of China(62004166)Natural Science Foundation of Ningbo(202003N4062)+2 种基金National Postdoctoral Program for Innovative Talents(BX20200279)Natural Science Basic Research Program of Shaanxi Province(2020JQ-199)Fundamental Research Funds for the Central Universities(31020190QD027).
文摘Optical cavity has long been critical for a variety of applications ranging from precise measurement to spectral analysis.A number of theories and methods have been successful in describing the optical response of a stratified optical cavity,while the inverse problem,especially the inverse design of a displacement sensitive cavity,remains a significant challenge due to the cost of computation and comprehensive performance requirements.This paper reports a novel inverse design methodology combining the characteristic matrix method,mixed-discrete variables optimization algorithm,and Monte Carlo method-based tolerance analysis.The material characteristics are indexed to enable the mixed-discrete variables optimization,which yields considerable speed and efficiency improvements.This method allows arbitrary response adjustment with technical feasibility and gives a glimpse into the analytical characterization of the optical response.Two entirely different light-displacement responses,including an asymmetric sawtooth-like response and a highly symmetric response,are dug out and experimentally achieved,which fully confirms the validity of the method.The compact Fabry-Perot cavities have a good balance between performance and feasibility,making them promising candidates for displacement transducers.More importantly,the proposed inverse design paves the way for a universal design of optical cavities,or even nanophotonic devices.
基金financially supported by the Natural Science Foundation of China(Grant Nos.52372226,52173263,62004167)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant Nos.2022JM-315,2023-JC-QN-0643)+4 种基金the National Key R&D Program of China(Grant No.2022YFB3603703)the Qinchuangyuan High-level Talent Project of Shaanxi(Grant No.QCYRCXM-2022-219)the Ningbo Natural Science Foundation(Grant No.2022J061)the Key Research and Development Program of Shaanxi(Grant No.2023GXLH-091)the Shccig-Qinling Program and the Fundamental Research Funds for the Central Universities。
文摘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.
基金supported by the National Natural Science Foundation of China(22379121)Shenzhen Foundation Research Program(JCYJ20220530112812028)+1 种基金Fundamental Research Funds for the Central Universities(G2022KY0606)Zhejiang Province Key Laboratory of Flexible Electronics Open Fund(2023FE005)。
文摘Expediting redox kinetics of sulfur species on conductive scaffolds with limited charge accessible surface is considered as an imperative approach to realize energy-dense and power-intensive lithium-sulfur(Li-S)batteries.In this work,the concept of concurrent hetero-/homo-geneous electrocatalysts is proposed to simultaneously mediate liquid-solid conversion of lithium polysulfides(LiPSs)and solid lithium disulfide/sulfide(Li_(2)S_(2)/Li_(2)S)propagation,the latter of which suffers from sluggish reduction kinetics due to buried conductive scaffold surface by extensive deposition of Li_(2)S_(2)/Li_(2)S.The selected model material to verify this concept is a two-in-one catalyst:carbon nanotube(CNT)scaffold supported iron-cobalt(Fe-Co)alloy nanoparticles and partially carbonized selenium(C-Se)component.The Fe-Co alloy serves as a heterogeneous electrocatalyst to seed Li_(2)S_(2)/Li_(2)S through sulphifilic active sites,while the C-Se sustainably releases soluble lithium polyselenides and functions as a homogeneous electrocatalyst to propagate Li_(2)S_(2)/Li_(2)S via solution pathways.Such bi-phasic mediation of the sulfur species benefits reduction kinetics of LiPS conversion,especially for the massive Li_(2)S_(2)/Li_(2)S growth scenario by affording an additional solution directed route in case of conductive surface being largely buried.This strategy endows the Li-S batteries with improved cycling stability(836 mA h g^(-1)after 180 cycles),rate capability(547 mA h g^(-1)at 4 C)and high sulfur loading superiority(2.96 mA h cm^(-2)at 2.4 mg cm^(-2)).This work hopes to enlighten the employment of bi-phasic electrocatalysts to dictate liquid-solid transformation of intermediates for conversion chemistry batteries.
基金financial support from the National Key Research and Development Program of China(Grant No.2017YFB0404501)the National Major Fundamental Research Program of China(Grant No.91833306)+7 种基金the National Natural Science Foundation of China(Grant Nos.62074083,62005131,61705111 and 61704091)the Science Fund for Distinguished Young Scholars of Jiangsu Province of China(Grant No.BK20160039)the Natural Science Foundation of Jiangsu Province(Grant Nos.BM2012010 and BK20170899)the Priority Academic Program Development of Jiangsu Higher Education Institutions(Grant No.YX030003)the Jiangsu National Synergetic Innovation Center for Advanced Materialsthe Synergetic Innovation Center for Organic Electronics and Information Displaysthe National Postdoctoral Program for Innovative Talents(Grant No.BX201700122)the Open Foundation from Jilin University(Grant Nos.IOSKL2017KF04 and IOSKL2018KF01)。
文摘The toxicity issue of lead hinders large-scale commercial production and photovoltaic field application of lead halide perovskites.Some novel non-or low-toxic perovskite materials have been explored for development of environmentally friendly lead-free perovskite solar cells(PSCs).This review studies the substitution of equivalent/heterovalent metals for Pb based on first-principles calculation,summarizes the theoretical basis of lead-free perovskites,and screens out some promising lead-free candidates with suitable bandgap,optical,and electrical properties.Then,it reports notable achievements for the experimental studies of lead-free perovskites to date,including the crystal structure and material bandgap for all of lead-free materials and photovoltaic performance and stability for corresponding devices.The review finally discusses challenges facing the successful development and commercialization of lead-free PSCs and predicts the prospect of lead-free PSCs in the future.
基金financially supported by the National Natural Science Foundation of China(Grants 51972172,61705102,61605073,61935017 and 91833304)Projects of International Cooperation and Exchanges NSFC(51811530018)+3 种基金the Young 1000 Talents Global Recruitment Program of Chinathe Jiangsu Specially Appointed Professor Program“Six talent peaks”Project in Jiangsu Province,Chinathe fellowship of China Postdoctoral Science Foundation(2020M672181)。
文摘Solvent residue is inevitable to occur in solution processed thin films,but its influence on the thin film quality has not been identified and addressed to date.Methylammonium acetate(MAAc)ionic liquid has recently been realized as an environmentally friendly solvent for solution processed perovskites.The specific high viscosity,low vapor pressure and strong association with perovskite precursor of the MAAc solvent is a double-edged sword,which endowed an advantageously ambient air operational and anti-solvent free perovskite deposition,but the MAAc is likely to be retained within the film and bring in detrimental effects on device performance of the corresponding solar cells.Herein,we reported a novel route to eliminate the residual solvent via a facial hydrochloric acid(HCl)annealing post-treatment(HAAP).In particular,chemical displacement reaction between the incorporated HCl and residual MAAc can be initiated to form volatile MACl and HAc,efficiently extracting MAAc residue.In the meanwhile,the stimulated mass transport via downward penetration and upward escape can trigger secondary perovskite growth with enlarged grain size and smoothened surface,leading to reduced defect state and improved interfacial contact intimacy,and also partial chloride ions are able to enter the crystal lattice to stabilize perovskite phase structure.As a result,a champion efficiency up to20.78%originating from enhanced Voc was achieved,and more than 96%of its initial efficiency can be maintained after 1000 h shelf-storage.
基金supported by the National Natural Science Foundation of China (22379121)Shenzhen Foundation Research Fund granted by the Shenzhen Science and Technology Innovation Committee (JCYJ20220530112812028)+1 种基金Fundamental Research Funds for the Central Universities (G2022KY0606)Zhejiang Province Key Laboratory of Flexible Electronics Open Fund (No. 2023FE005)。
文摘Despite being a leading candidate to meet stringent energy targets,lithium(Li) metal batteries(LMBs)face severe challenges at low temperatures such as dramatic increase in impedance,capacity loss and dendrite growth.Unambiguously fingerprinting rate-limited factors of low-temperature LMBs would encourage targeted approaches to promote performances.Herein,the charge transfer impedance across solid electrolyte interphase(SEI) is identified to restrict battery operation under low temperature,and we propose a facile approach on the basis of ambiently fostering SEI(af-SEI) to facilitate charge transfer.The concept of af-SEI stems from kinetic benefits and structural merits to construct SEI at ambient temperature over low temperature developed SEI that is temporally consuming to achieve steady state and that is structurally defective to incur dendrite growth.The af-SEI allows ionically conductive and morphologically uniform layer on the anode surface,which exhibits a lower resistance and induces an even deposition of Li in the subsequent low temperature battery operation.Armed with af-SEI,the LMBs deliver the improved rate performance and prolonged cycle life when subjected to low temperature cycling.This work unveils the underlying causes that limit low temperature LMB performances,and enlightens the facile test protocols to build up favorable SEI,beyond scope of material and morphology design.
基金Project supported by Fundamental Research Funds for the Central Universities(Grant No.FRF-TP-20-006A2).
文摘Since it was first proposed,the space solar power station(SSPS)has attracted great attention all over the world;it is a huge space system and provides energy for Earth.Although several schemes and abundant studies on the SSPS have been proposed and conducted,it is still not realized.The reason why SSPS is still an idea is not only because it is a giant and complex project,but also due to the requirement for various excellent space materials.Among the diverse required materials,we believe energy materials are the most important.Herein,we review the space energy conversion materials for the SSPS.
基金supported by the National Natural Science Foundation of China (Nos. 21975123, 61704076)the Natural Science Basic Research Program of Shaanxi (No. 2020JM-092)+2 种基金the Natural Science Foundation of Jiangsu Province (No. BK20171018)the Six Talent Peaks Project in Jiangsu Province (No. XCL-024)the Fundamental Research Funds for the Central Universities。
文摘In order to balance electrochemical kinetics with loading level for achieving efficient energy storage with high areal capacity and good rate capability simultaneously for wearable electronics,herein,2 D meshlike vertical structures(NiCo_2 S_4@Ni(OH)_2) with a high mass loading of 2.17 mg cm^(-2) and combined merits of both 1 D nanowires and 2 D nanosheets are designed for fabricating flexible hybrid supercapacitors.Particularly,the seamlessly interconnected NiCo_2 S_4 core not only provides high capacity of 287.5 μAh cm^(-2) but also functions as conductive skeleton for fast electron transport;Ni(OH)_2 sheath occupying the voids in NiCo_2 S_4 meshes contributes extra capacity of 248.4 μAh cm^(-2);the holey features guarantee rapid ion diffusion along and across NiCO_2 S_4@Ni(OH)_2 meshes.The resultant flexible electrode exhibits a high areal capacity of 535.9 μAh cm^(-2)(246.9 mAh g^(-1)) at 3 mA cm^(-2) and outstanding rate performance with 84.7% retention at 30 mA cm^(-2),suggesting efficient utilization of both NiCo_2 S_4 and Ni(OH)_2 with specific capacities approaching to their theoretical values.The flexible solid-state hybrid device based on NiCo_2 S_4@Ni(OH)_2 cathode and Fe_2 O_3 anode delivers a high energy density of 315 μWh cm^(-2) at the power density of 2.14 mW cm^(-2) with excellent electrochemical cycling stability.
基金financially supported by the China Scholarship Council(CSC) project(201808320023)the National Basic Research Program of China-Fundamental Studies of Perovskite Solar Cells(2015CB932200)+2 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Program for Changjiang Scholars and Innovative Research Team in University(IRT-15R37)NJUPT Culturing Project(NY218056 and NY219061)。
文摘Fluorine substitution in molecular design has become an effective strategy for improving the overall performance of organic photovoltaics.In this study,three low-cost small molecules of spiro-linked hole transporting materials(SFX-O-2 F,SFX-m-2 F,and SFX-p-2 F) endowed with two-armed t rip he ny la mine moieties were synthesized via tuning of the fluorine substitution position,and they were employed for use in highly efficient perovskite solar cells(PSCs).Despite the fluorine substitution position playing a negligible role in the optical and electrochemical properties of the resulting small molecules,the photovoltaic performance thereof was observed to vary significantly.The planar n-i-p PSCs based on SFX-m-2 F demonstrated superior performance(18.86%) when compared to that of the corresponding SFX-o-2 F(9.7%) and SFX-p-2 F(16.33%) under 100 mW cm^(-2) AM1.5 G solar illumination,which is competitive with the performance of the benchmark spiro-OMeTAD-based device(18.98%).Moreover,the SFX-m-2 Fbased PSCs were observed to be more stable than the spiro-OMeTAD-based devices under ambient conditions.The improved performance of SFX-m-2 F is primarily associated with improved morphology,more efficient hole transport,and extraction characteristics at the perovskite/HTM interface.This work demonstrated the application of fluorination engineering to the tuning of material film morphology and charge transfer properties,showing the promising potential of fluorinated SM-HTMs for the construction of low-cost,high-efficiency PSCs.
基金funded by the National Natural Science Foundation of China(62004165)the China Postdoctoral Science Foundation(2020M670036)+2 种基金the Natural Science Foundation of Shaanxi Province,China(2020JQ195)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-007,2020GXLH-Z-025)the Fundamental Research Funds for the Central Universities。
文摘The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase transition and defects-induced non-ideal interfacial recombination, which significantly induces energy loss and hinders the improvement of device performance. Herein, we employed 4-fluorophenylmethylammonium iodide(F-PMAI) to modulate surface structure and energy level alignment of the FA-based perovskite films. The superior optoelectronic films were obtained with reduced trap density, pure α-phase FAPbI_(3) and favorable energy band bending. The lifetime of photogenerated charge carriers increased from 489.3 ns to 1010.6 ns, and a more “p-type” perovskite film was obtained by the post-treatment with F-PMAI. Following this strategy, we demonstrated an improved power conversion efficiency of 22.59% for the FA-based PSCs with an open-circuit voltage loss of 399 m V.
基金financially supported by the Natural Science Foundation of China (Grants 51802253, 51972172, 61705102,61904152, and 91833304)the China Postdoctoral Science Foundation (Grant 2021M692630)+6 种基金the Natural Science Basic Research Plan in Shaanxi Province of China (2019JM-326)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University (No. 2020GXLH-Z-007)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China (Grant BK20200034)the Young 1000 Talents Global Recruitment Program of Chinathe Jiangsu Specially Appointed Professor programthe “Six talent peaks” Project in Jiangsu Province,Chinathe Fundamental Research Funds for the Central Universities。
文摘Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial contact between commonly used hole transport layer(i.e., poly(3,4-ethylenedioxythio phene):poly(styrene sulfonate), PEDOT:PSS) and FASnI_(3) film, it is still challenging to effectively extract holes at the interface. Owing to the p-type nature of Sn-based perovskites, the efficient hole extraction is of particular significance to improve the PCE of their solar cells. In this work, for the first time, the role of chiral cations, a-methylbenzylamine(S-/R-/rac-MBA), in promoting hole transportation of FASnI_(3)-based PSCs is demonstrated. The introduction of MBAs is found to form 2D/3D film with lowdimensional structures locating at PEDOT:PSS/FASnI_(3) interface, which facilitates the energy level alignment and efficient charge transfer at the interface. Importantly, chiral-induced spin selectivity(CISS)effect of R-MBA_(2)SnI_(4)induced by chiral R-MBA cation is found to further assist the specific interfacial transport of accumulated holes. As a result, R-MBA-based PSCs achieve decent PCE of 10.73% with much suppressed hysteresis and enhanced device stability. This work opens up a new strategy to efficiently promote the interfacial extraction of accumulated charges in working PSCs.
基金financially supported by the National Science Foundation of China(62474142)Natural Science Foundation of Shandong Province(No.ZR2024YQ070)。
文摘Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonradiative recombination losses.However,how these groups synergistically affect the enhancement beyond passivation is still unclear.Specifically,isomeric molecules with different substitution patterns or molecular shapes remain elusive in designing new organic additives.Here,we report two isomeric carbazolyl bisphosphonate additives,2,7-Cz BP and 3,6-Cz BP.The isomerism effect on passivation and charge transport process was studied.The two molecules have similar passivation effects through multiple interactions,e.g.,P=O···Pb,P=O···H–N and N–H···I.2,7-CzBP can further bridge the perovskite crystallites to facilitates charge transport.Power conversion efficiencies(PCEs)of 25.88%and 21.04%were achieved for 0.09 cm^(2)devices and 14 cm^(2)modules after 2,7-Cz BP treatment,respectively.The devices exhibited enhanced operational stability maintaining 95%of initial PCE after 1000 h of continuous maximum power point tracking.This study of isomerism effect hints at the importance of tuning substitution positions and molecular shapes for organic additives,which paves the way for innovation of next-generation multifunctional aromatic additives.
