Passivating the surface defects of three-dimensional(3D)perovskite layers with two-dimensional(2D)perovskites is a critical strategy for achieving high efficiency and stability in perovskite solar cells.However,the dy...Passivating the surface defects of three-dimensional(3D)perovskite layers with two-dimensional(2D)perovskites is a critical strategy for achieving high efficiency and stability in perovskite solar cells.However,the dynamic evolution of 2D/3D interfaces under external stimuli such as thermal stress and long-term illumination significantly impacts device performance.In this study,we systematically investigate the role of intermolecular interactions in governing ion migration at 2D/3D interfaces by physically stacking three 2D perovskite,(BA)_(2)PbI_(4)(BA=butylammonium),(PEA)_(2)PbI_(4)(PEA=phenethylammonium),and(BDA)PbI_(4)(BDA=1,4-butane diammonium),with 3D perovskite-MAPbI_(3)(MA=methylammonium),followed by thermal annealing;and subsequent characterization was carried out using ultraviolet-visible(UV-Vis)absorption and femtosecond-transient absorption(fs-TA)spectra.Our findings reveal that small MA^(+)ions migrate from the 3D perovskite into the 2D perovskites,forming quasi-2D perovskites and introducing new decay pathways,while BA^(+)and PEA^(+)ions back-incorporate into the 3D lattice,causing a slight blue shift of 2-3 nm in exciton peaks.Notably,no significant ion migration is observed at the(BDA)PbI_(4)/MAPbI_(3)interface due to strong hydrogen bonds,demonstrating superior robustness against ion movement.Further analysis indicates that the stability of 2D/3D interface is governed by intermolecular interactions,following the order:hydrogen bonds>π-πstacking>van der Waals forces.These findings highlight the pivotal role of molecular interactions in modulating ion migration at 2D/3D interfaces and provide a clear design principle for constructing stable 2D/3D heterojunctions by selecting diammonium cations with robust hydrogen bonds,offering key insights for the rational design of stable perovskite interfaces.展开更多
Although three-dimensional metal halide perovskites are promising candidates for direct X-ray detection,the ion migration of perovskites seriously affects the detector stability.Herein,face-/edge-shared 3D heterometal...Although three-dimensional metal halide perovskites are promising candidates for direct X-ray detection,the ion migration of perovskites seriously affects the detector stability.Herein,face-/edge-shared 3D heterometallic glycinate hybrid perovskitoid Pb_(2)CuGly_(2)X_(4)(Gly=-O_(2)C-CH_(2)-NH_(2);X=Cl,Br)single crystals(SCs),in which the adjacent lead halide layers are linked by large-sized Cu(Gly)_(2)pillars,are synthesized in water.The Cu(Gly)_(2)pillars in combination with face-/edge-shared inorganic skeleton are found able to synergistically suppress the ion migration,delivering a high ion migration activation energy(Ea)of 1.06 eV.The Pb_(2)CuGly_(2)Cl_(4)SC X-ray detector displays extremely low dark current drift of 1.20×10^(-9)nA mm^(-1)s^(-1)V^(-1)under high electric field(120 V mm^(-1))and continuous X-ray irradiation(2.86 Gy),and a high sensitivity of 9,250μC Gy^(-1)cm^(-2)is also achieved.More excitingly,the Pb_(2)CuGly_(2)Cl_(4)nanocrystal can be easily dispersed in water and directly blade-coated on thin-film transistor(TFT)array substrate,and the obtained Pb_(2)CuGly_(2)Cl_(4)-based TFT array detector offers an X-ray imaging capability with spatial resolution of 2.2 lp mm^(-1).展开更多
Aqueous zinc metal batteries(ZMBs)are vital to potable electronics and electric energy infrastructures because of their high energy conversion efficiency,high energy density,and environmental friendliness.However,ramp...Aqueous zinc metal batteries(ZMBs)are vital to potable electronics and electric energy infrastructures because of their high energy conversion efficiency,high energy density,and environmental friendliness.However,rampant zinc dendrite growth and side reactions on the Zn anode seriously impede the practical application of ZMBs.In this work,morpholine-crosslinked polyacrylamide hydrogel electrolytes(ploy(acrylamide),6m-PAM)are successfully developed to simultaneously regulate solvation shell to suppress side reactions and homogenize Zn^(2+)ion migration for dendrite-free ZMBs.Notably,the 6m-PAM electrolyte exhibits excellent mechanical strength of 50.6 kPa,high Zn^(2+)ion conductivity of 52 mS cm^(-1)at room temperature,and fast self-healing ability,providing stable and adaptable electrolyte-anode interfaces.Experimental and theoretical calculation results reveal that Zn^(2+)-N(morpholine)coordination interaction effectively reshapes the primary solvation shell of Zn^(2+),suppressing the activity of free water and Zn dendrites.As a result,the 6m-PAM electrolyte endows symmetric zinc cells with a long-term cycling life of 2000 h at 7.5 mA cm^(-2).Notably,Zn/Polyaniline(PANI)batteries equipped with 6m-PAM electrolytes also exhibit a high capacity of 124 mA h g^(-1)at 1 A g^(-1)and a long cycling life of 4000 times with a high-capacity retention of 98.3%,This functional crosslinked hydrogel electrolyte paves a new way to construct durable dendrite-free ZMBs.展开更多
In the past 10 years,perovskite solar cells(PSCs)have undergone extremely rapid development,with a record certified power conversion efficiency(PCE)of 26.7%,which is very close to the limit efficiency.However,the inhe...In the past 10 years,perovskite solar cells(PSCs)have undergone extremely rapid development,with a record certified power conversion efficiency(PCE)of 26.7%,which is very close to the limit efficiency.However,the inherent instability caused by ion migration impedes the realization of long-term operationally stable PSCs.In this review,the types and mechanisms of ion migration occurring in various functional layers of negative-intrinsic-positive(n-i-p)PSCs are summarized.Additionally,methods of suppressing ion migration are systematically discussed.Finally,the prospects of current challenges and future development directions are proposed to advance the achievement of high-performance regular PSCs with high stability and PCE.展开更多
Metal halide perovskites are emerging as the most promising candidate for the next-generation Photovoltaics(PV)materials,due to their superior optoelectronic properties and low cost.However,the resulting Perovskite so...Metal halide perovskites are emerging as the most promising candidate for the next-generation Photovoltaics(PV)materials,due to their superior optoelectronic properties and low cost.However,the resulting Perovskite solar cells(PSCs)suffer from poor stability.In particular,the temperature and light activated ionic defects within the perovskite lattice,as well as electric-field-induced migration of ionic defects,make the PSCs unstable at operating condition,even with device encapsulation.There is no doubt that the investigation of ion migration is crucial for the development of PSCs with high intrinsic stability.In this review,we first briefly introduce the origin and pathways of ion migration,and also the essential characterization methods to identify ion migration.Next,we discuss the impact of ion migration on the perovskite films and cells with respect to photoelectric properties and stability.Then,several representative strategies to suppress ion migration are systematically summarized in the context of composition engineering,additive engineering and interface engineering,with an in-depth understanding on the underlying mechanisms which may provide more clues for further fabrication of PSCs with improved stability.Finally,a perspective with some suggestion on future research directions and chemical approaches are provided to alleviate ion migration in perovskite materials and the entire devices.展开更多
Hybrid halide perovskites have great potential for applications in optoelectronic devices.However,the typical ion migration in perovskite could lead to the non-repeatability of electrical measurement,instability of ma...Hybrid halide perovskites have great potential for applications in optoelectronic devices.However,the typical ion migration in perovskite could lead to the non-repeatability of electrical measurement,instability of material,and degradation of device performance.The basic current–voltage behavior of perovskite materials is intricate due to the mixed electronic–ionic characteristic,which is still poorly understood in these semiconductors.Developing novel measurement schematic is a promising solution to obtain the intrinsic electrical performance without the interference of ion migration.Herein,we explore the pulse-voltage(PV)method on methylammonium lead tribromide single crystals to protect the device from the ion migration.A guideline is summarized through the analysis of measurement history and condition parameters.The influence of the ion migration on current–voltage measurement,such as repeatability and hysteresis loop,is under controlled.An application of the PV method is demonstrated on the activation energy of conductivity.The abruption of activation energy still exists near the phase transition temperature despite the ion migration is excluded by the PV method,introducing new physical insight on the current–voltage behavior of perovskite materials.The guideline on PV method will be beneficial for measuring halide perovskite materials and developing optoelectronic applications with new technique schematic.展开更多
Benefiting from the excellent properties such as high photoluminescence quantum yield(PLQY), wide gamut range,and narrow emission linewidth, as well as low-temperature processability, metal halide perovskite quantum d...Benefiting from the excellent properties such as high photoluminescence quantum yield(PLQY), wide gamut range,and narrow emission linewidth, as well as low-temperature processability, metal halide perovskite quantum dots(QDs)have attracted wide attention from researchers. Despite tremendous progress has been made during the past several years,the commercialization of perovskite QDs-based LEDs(PeQLEDs) is still plagued by the instability. The ion migration in halide perovskites is recognized as the key factor causing the performance degradation of PeQLEDs. In this review, the elements species of ion migration, the effects of ion migration on device performance and stability, and effective strategies to hinder/mitigate ion migration in PeQLEDs are successively discussed. Finally, the forward insights on the future research are highlighted.展开更多
The device preconditioning dependent hysteresis and the consequential performance degradation hinder the actual performance and stability of the perovskite solar cells. Ion migration and charge trapping in the perovsk...The device preconditioning dependent hysteresis and the consequential performance degradation hinder the actual performance and stability of the perovskite solar cells. Ion migration and charge trapping in the perovskite with large contribution from grain boundaries are the most common interpretations for the hysteresis. Yet, the high performing devices often include intermediate hole and electron transporting layers, which can further complicate the dynamical process in the device. Here, by using Kelvin Probe Force Microscopy and Confocal Photoluminescence Microscopy, we elucidate the impact of chargetransporting layers and excess MAI on the spatial and temporal variations of the photovoltage on the MAPbI3-based solar cells. By studying the devices layer by layer, we found that the light-induced ion migration occurs predominantly in the presence of an imbalanced charge extraction in the solar cells, and the charge transporting layers play crucial role in suppressing it. Careful selection and processing of the electron and hole-transporting materials are thus essential for making perovskite solar cells free from the ion migration effect.展开更多
Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar cells.Here,we report a comprehensive study of the int...Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar cells.Here,we report a comprehensive study of the interfacial degradation and ion migration at the interface between CH3NH3PbI3 perovskite layer and Ag electrode.Using in situ photoemission spectroscopy measurements,we found that the Ag electrode could induce the degradation of perovskite layers,leading to the formation of PbI2 and AgI species and the reduction of Pb^2+ions to metallic Pb species at the interface.The unconventional enhancement of the intensities of I 3d spectra provides direct experimental evidences for the migration of iodide ions from CH3NH3PbI3 subsurface to Ag electrode.Moreover,the contact of Ag electrode and perovskite layers induces an interfacial dipole of 0.3 eV at CH3NH3PbI3/Ag interfaces,which may further facilitate iodide ion diffusion,resulting in the decomposition of perovskite layers and the corrosion of Ag electrode.展开更多
The development of fast ionic conductors to improve the performance of electrochemical devices relies on expensive high-throughput(HT)density functional theory(DFT)calculations of transport properties.Machine learning...The development of fast ionic conductors to improve the performance of electrochemical devices relies on expensive high-throughput(HT)density functional theory(DFT)calculations of transport properties.Machine learning(ML)can accelerate HT workflows but requires high-quality data to ensure accurate predictions from trained models.In this study,we introduce the LiTraj dataset,which comprises 13,000 percolation and 122,000 migration barriers,and 1700 migration trajectories,calculated for Li-ion in diverse crystal structures using empirical force fields and DFT,respectively.With LiTraj,we demonstrate that classicalMLmodels and graph neural networks(GNNs)for structureto-property prediction of percolation and migration barriers can distinguish between“fast”and“poor”ionic conductors.Furthermore,we evaluate the capability of GNN-based universal ML interatomic potentials(uMLIPs)to identify optimal Li-ion migration trajectories.Fine-tuned uMLIPs achieve near-DFT accuracy in predicting migration barriers,significantly accelerating HT screenings of new ionic conductors.展开更多
All-inorganic perovskites are advantageous in terms of improved thermal stability compared to organic-inorganic counterparts.However,the ion migration-induced hysteresis significantly undermines the long-term operatio...All-inorganic perovskites are advantageous in terms of improved thermal stability compared to organic-inorganic counterparts.However,the ion migration-induced hysteresis significantly undermines the long-term operational stability of all-inorganic perovskite solar cells(PSCs),particularly in mixed halide perovskites.Herein,we report that tin-lead(Sn-Pb)alloying for all-inorganic mixed halide perovskites can effectively inhibit the ion migration behavior,as comprehensively revealed by the time-of-flight secondary ion mass spectrometry(TOF-SIMS),optical microscopy and galvanostatic measurements.On one hand,the small-sized Sn2+cations can tighten the lattice structure to enhance the Pb/Sn-X(X=I and Br)ionic bonds,thereby effectively immobilizing the halide ions.On the other hand,Sn substitution can significantly reduce anti-site defects,such as I_(Cs)and I_(Pb),which are considered potential pathways for ion migration.With these advantages,ion migration is greatly suppressed in Sn-Pb alloyed inorganic perovskites,resulting in reduced hysteresis and improved operational stability of PSC devices.展开更多
Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract in...Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract intensive studies of their advantages due to low-level ion migration and decent stability.However,there is still a lack of methods to precisely construct heterostructures and a fundamental understanding of their structure-dependent optoelectronic properties.Herein,a gas-phase method was developed to grow 2D perovskites directly on 3D perovskites with nanoscale accuracy.In addition,the larger steric hindrance of organic layers of 2D perovskites was proved to enable slower ion migration,which resulted in reduced trap states and better stability.Based on MAPbBr_(3)single crystals with the(PA)_(2)PbBr_(4)capping layer,the X-ray detector achieved a sensitivity of 22,245μC Gy_(air)^(−1)cm^(−2),a response speed of 240μs,and a dark current drift of 1.17.10^(–4)nA cm^(−1)s^(−1)V^(−1),which were among the highest reported for state-of-the-art perovskite-based X-ray detectors.This study presents a precise synthesis method to construct perovskite-based heterostructures.It also brings an in-depth understanding of the relationship between lattice structures and properties,which are beneficial for advancing high-performance and cost-effective X-ray detectors.展开更多
Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of pro...Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of products is profoundly influenced by the catalyst structure.In this study,Fe_(2)O_(3)-doped NiSO_(4)/Al_(2)O_(3) catalysts have been meticulously developed to facilitate the selective trimerization of propylene under mild conditions.Significantly,the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst demonstrates an enhanced reaction rate(48.5 mmol_(C3)/(g_(cat).·h)),alongside a high yield of C9(~32.2%),significantly surpassing the performance of the NiSO_(4)/Al_(2)O_(3) catalyst(C9:~24.1%).The incorporation of Fe_(2)O_(3) modifies the migration process of sulfate ions,altering the Lewis acidity of the electron-deficient Ni and Fe sites on the catalyst and resulting a shift in product distribution from a Schulz-Flory distribution to a Poisson distribution.This shift is primarily ascribed to the heightened energy barrier for theβ-H elimination reaction in the C6 alkyl intermediates on the doped catalyst,further promoting polymerization to yield a greater quantity of Type II C9.Furthermore,the validation of the Cossee-Arlman mechanism within the reaction pathway has been confirmed.It is noteworthy that the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst exhibits remarkable stability exceeding 80 h in the selective trimerization of propylene.These research findings significantly enhance our understanding of the mechanisms underlying olefin oligomerization reactions and provide invaluable insights for the development of more effective catalysts.展开更多
Bauxite residue,a highly saline solid waste produced from digestion of bauxite for alumina production,is hazardous to the environment and restricts vegetation establishment in bauxite residue disposal areas.A novel wa...Bauxite residue,a highly saline solid waste produced from digestion of bauxite for alumina production,is hazardous to the environment and restricts vegetation establishment in bauxite residue disposal areas.A novel water leaching process proposed here was used to investigate the dynamic migration and vertical distribution of saline ions in bauxite residue.The results show that water leaching significantly reduced the salinity of bauxite residue,leaching both saline cations Na+,K+,Ca2+and anions CO32-,SO42-,HCO3-.Na+and K+migrated from 40-50 to 20-30 cm of the column,presenting a high migration capacity.The migration capacity of Ca2+was lower and accumulated at 30-40 cm of the column.CO32-initially distributed at 20-30 cm of the column,subsequently transported to 30-40 cm of the column,and finally returned to 20-30 cm of the column along with evaporation.SO42-was originally distributed at 40-50 cm,but finally migrated to 20-30 cm of the column.Nevertheless,HCO3-remained at the bottom of the column,and its migratory was less affected by evaporation.展开更多
The inevitable ion migration that occurs within ionic polycrystalline perovskite film results in inferior longterm stability of perovskite solar cells(PVSCs)that cannot meet the commercial requirements.Here,a novel po...The inevitable ion migration that occurs within ionic polycrystalline perovskite film results in inferior longterm stability of perovskite solar cells(PVSCs)that cannot meet the commercial requirements.Here,a novel poly(ionic liquid)named poly-1-vinyl-3-propyltrimethoxysilane imidazolium chloride(PImIL-SiO)is first introduced into perovskite to strengthen grain boundaries(GBs)and construct dual-functional barriers against internal ion migration and external moisture erosion for fabricating highly efficient and stable PVSCs.PImIL-SiO-containing imidazoliumcations and pendant siloxane groups contribute to passivation of bulk defects and anchoring of GBs,which effectively hinders ion migration channels,thus reducing perovskite film phase separation and device hysteresis.Furthermore,the intrinsically hydrophobic PImIL-SiO automatically forms a secondary protective barrier to endow the perovskite film with ultrahigh moisture corrosion resistance through the hydrolyzation reaction of siloxane with the permeated moisture.Consequently,the PImIL-SiO-modified PVSCs achieve a champion power conversion efficiency(PCE)of 22.46%,accompaniedby excellent thermal andhumidity stabilities where the non-encapsulated devices retain 87%of the initial PCE after aging at 85℃for 250 h and>85%of the initial PCE over 1100 h in air with a relative humidity of 50–70%.展开更多
Narrowband photodetectors conventionally rely on optical structure design orbandpass filters to achieve the narrowband regime. Recently, a strategy forfilterless narrowband photoresponse based on the charge collection...Narrowband photodetectors conventionally rely on optical structure design orbandpass filters to achieve the narrowband regime. Recently, a strategy forfilterless narrowband photoresponse based on the charge collection narrowing(CCN) mechanism was reported. However, the CCN strategy requires an electrically and optically “thick” photoactive layer, which poses challenges in controlling the narrowband photoresponse. Here we propose a novel strategy forconstructing narrowband photodetectors by leveraging the inherent ion migration in perovskites, which we term “band modulation narrowing” (BMN). Bymanipulating the ion migration with external stimuli such as illumination,temperature, and bias voltage, we can regulate in situ the energy-band structure of perovskite photodetectors (PPDs) and hence their spectral response.Combining the Fermi energy levels obtained by the Kelvin probe force microscopy, the internal potential profiles from solar cell capacitance simulator simulation, and the anion accumulation revealed by the transient ion-drifttechnique, we discover two critical mechanisms behind our BMN strategy: theextension of an optically active but electronically dead region proximal to the top electrode and the down-bending energy bands near the electron transportlayer. Our findings offer a case for harnessing the often-annoying ionmigration for developing advanced narrowband PPDs.展开更多
Low-dimensional metal halide perovskites exhibit exceptional photoelectronicproperties and intrinsic stability, positioning them as a promising class of semiconductormaterials for light-emitting devices and photodetec...Low-dimensional metal halide perovskites exhibit exceptional photoelectronicproperties and intrinsic stability, positioning them as a promising class of semiconductormaterials for light-emitting devices and photodetectors. In thiswork, we present a millimeter-scale single crystal of mixed low-dimensional(one-dimensional–zero-dimensional [1D–0D]) organic lead iodide withwell-defined crystallinity. The fabricated single-crystal devices demonstratehigh-sensitivity photoresponse and x-ray detection performance. By spatiallyisolating organic molecules to form the mixed 1D–0D crystal structure, ionmigrations is effectively suppressed, resulting in a remarkable three orders ofmagnitude reduction in the dark current (56.4 pA @200 V) of the single-crystaldevices. Furthermore, by enhancing the background characteristics, weachieved an impressive low x-ray detection limit of 154.5 nGys^(-1) in the singlecrystaldevice. These findings highlight that the mixed 1D–0D organic leadiodide configuration efficiently controls ion migration within the crystal structure,offering a promising avenue for realizing high-performance perovskitebasedphotodetectors and x-ray detectors.展开更多
Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yiel...Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.展开更多
With the support of the National Natural Science Foundation of China,two original studies by the research group led by Prof.Gu Lin(谷林)and Prof.Zhang Qinghua(张庆华)from the Institute of Physics,Chinese Academy of Sc...With the support of the National Natural Science Foundation of China,two original studies by the research group led by Prof.Gu Lin(谷林)and Prof.Zhang Qinghua(张庆华)from the Institute of Physics,Chinese Academy of Sciences demonstrate the in-situ atomic-scale electrically induced展开更多
3D perovskite materials are advancing rapidly in the field of photovoltaics and light-emitting diodes,but the development in field effect transistors(FETs)is limited due to their intrinsic ion migration.Ion migration ...3D perovskite materials are advancing rapidly in the field of photovoltaics and light-emitting diodes,but the development in field effect transistors(FETs)is limited due to their intrinsic ion migration.Ion migration in perovskite FETs can screen the electric field of the gate and affect its modulation,as well as influence the charge carriers transport,leading to non-ideal device characteristics and lower device stability.Here,we provide a concise review that explains the mechanism of ion migration,summarizes the strategies for suppressing ion migration,and concludes with a discussion of the future prospects for 3D perovskite FETs.展开更多
基金supported by the Beijing Natural Science Foundation(2252013)the National Natural Science Foundation of China(U2230203,12404491)+1 种基金the Beijing National Laboratory for Condensed Matter Physics(2024BNLCMPKF008)the Fundamental Research Funds for Central Universities.
文摘Passivating the surface defects of three-dimensional(3D)perovskite layers with two-dimensional(2D)perovskites is a critical strategy for achieving high efficiency and stability in perovskite solar cells.However,the dynamic evolution of 2D/3D interfaces under external stimuli such as thermal stress and long-term illumination significantly impacts device performance.In this study,we systematically investigate the role of intermolecular interactions in governing ion migration at 2D/3D interfaces by physically stacking three 2D perovskite,(BA)_(2)PbI_(4)(BA=butylammonium),(PEA)_(2)PbI_(4)(PEA=phenethylammonium),and(BDA)PbI_(4)(BDA=1,4-butane diammonium),with 3D perovskite-MAPbI_(3)(MA=methylammonium),followed by thermal annealing;and subsequent characterization was carried out using ultraviolet-visible(UV-Vis)absorption and femtosecond-transient absorption(fs-TA)spectra.Our findings reveal that small MA^(+)ions migrate from the 3D perovskite into the 2D perovskites,forming quasi-2D perovskites and introducing new decay pathways,while BA^(+)and PEA^(+)ions back-incorporate into the 3D lattice,causing a slight blue shift of 2-3 nm in exciton peaks.Notably,no significant ion migration is observed at the(BDA)PbI_(4)/MAPbI_(3)interface due to strong hydrogen bonds,demonstrating superior robustness against ion movement.Further analysis indicates that the stability of 2D/3D interface is governed by intermolecular interactions,following the order:hydrogen bonds>π-πstacking>van der Waals forces.These findings highlight the pivotal role of molecular interactions in modulating ion migration at 2D/3D interfaces and provide a clear design principle for constructing stable 2D/3D heterojunctions by selecting diammonium cations with robust hydrogen bonds,offering key insights for the rational design of stable perovskite interfaces.
基金financially supported by the National Natural Science Foundation of China (62004089,62374053, 62474187 and 12235006)the Special Zone Support Program for Outstanding Talents of Henan University+4 种基金the Shenzhen Basic Research Program (JCYJ20220818101612027)the Guangdong Basic and Applied Basic Research Foundation (2024A1515012494)the Henan Province Postdoctoral Science Foundation (J23029Y)the Natural Science Foundation of Henan Province (232300420412)the Science and Technology Tackling Project of Henan Province (242102210160)
文摘Although three-dimensional metal halide perovskites are promising candidates for direct X-ray detection,the ion migration of perovskites seriously affects the detector stability.Herein,face-/edge-shared 3D heterometallic glycinate hybrid perovskitoid Pb_(2)CuGly_(2)X_(4)(Gly=-O_(2)C-CH_(2)-NH_(2);X=Cl,Br)single crystals(SCs),in which the adjacent lead halide layers are linked by large-sized Cu(Gly)_(2)pillars,are synthesized in water.The Cu(Gly)_(2)pillars in combination with face-/edge-shared inorganic skeleton are found able to synergistically suppress the ion migration,delivering a high ion migration activation energy(Ea)of 1.06 eV.The Pb_(2)CuGly_(2)Cl_(4)SC X-ray detector displays extremely low dark current drift of 1.20×10^(-9)nA mm^(-1)s^(-1)V^(-1)under high electric field(120 V mm^(-1))and continuous X-ray irradiation(2.86 Gy),and a high sensitivity of 9,250μC Gy^(-1)cm^(-2)is also achieved.More excitingly,the Pb_(2)CuGly_(2)Cl_(4)nanocrystal can be easily dispersed in water and directly blade-coated on thin-film transistor(TFT)array substrate,and the obtained Pb_(2)CuGly_(2)Cl_(4)-based TFT array detector offers an X-ray imaging capability with spatial resolution of 2.2 lp mm^(-1).
基金supported by the National Natural Science Foundation of China(22479022)the Natural Science Foundation of Liaoning Province(2020-MS-021)。
文摘Aqueous zinc metal batteries(ZMBs)are vital to potable electronics and electric energy infrastructures because of their high energy conversion efficiency,high energy density,and environmental friendliness.However,rampant zinc dendrite growth and side reactions on the Zn anode seriously impede the practical application of ZMBs.In this work,morpholine-crosslinked polyacrylamide hydrogel electrolytes(ploy(acrylamide),6m-PAM)are successfully developed to simultaneously regulate solvation shell to suppress side reactions and homogenize Zn^(2+)ion migration for dendrite-free ZMBs.Notably,the 6m-PAM electrolyte exhibits excellent mechanical strength of 50.6 kPa,high Zn^(2+)ion conductivity of 52 mS cm^(-1)at room temperature,and fast self-healing ability,providing stable and adaptable electrolyte-anode interfaces.Experimental and theoretical calculation results reveal that Zn^(2+)-N(morpholine)coordination interaction effectively reshapes the primary solvation shell of Zn^(2+),suppressing the activity of free water and Zn dendrites.As a result,the 6m-PAM electrolyte endows symmetric zinc cells with a long-term cycling life of 2000 h at 7.5 mA cm^(-2).Notably,Zn/Polyaniline(PANI)batteries equipped with 6m-PAM electrolytes also exhibit a high capacity of 124 mA h g^(-1)at 1 A g^(-1)and a long cycling life of 4000 times with a high-capacity retention of 98.3%,This functional crosslinked hydrogel electrolyte paves a new way to construct durable dendrite-free ZMBs.
基金financially supported by the National Natural Sci-ence Foundation of China(62274018,52462031)the Xinjiang Construction Corps Key Areas of Science and Technology Research Project(2023AB029)+1 种基金the Tianchi Talent Program of Xinjiang Uygur Autonomous Region(2024,Jiangzhao Chen)the Key Project of Chongqing Overseas Students Returning to China Entrepreneurship and Innovation Support Plan(cx2023006).
文摘In the past 10 years,perovskite solar cells(PSCs)have undergone extremely rapid development,with a record certified power conversion efficiency(PCE)of 26.7%,which is very close to the limit efficiency.However,the inherent instability caused by ion migration impedes the realization of long-term operationally stable PSCs.In this review,the types and mechanisms of ion migration occurring in various functional layers of negative-intrinsic-positive(n-i-p)PSCs are summarized.Additionally,methods of suppressing ion migration are systematically discussed.Finally,the prospects of current challenges and future development directions are proposed to advance the achievement of high-performance regular PSCs with high stability and PCE.
基金supported by the National Key Research and Development Program of China(2017YFA0206701,2020YFB1506400)the National Natural Science Foundation of China(51972004,21975028)the China Postdoctoral Science Foundation(2020M670040)。
文摘Metal halide perovskites are emerging as the most promising candidate for the next-generation Photovoltaics(PV)materials,due to their superior optoelectronic properties and low cost.However,the resulting Perovskite solar cells(PSCs)suffer from poor stability.In particular,the temperature and light activated ionic defects within the perovskite lattice,as well as electric-field-induced migration of ionic defects,make the PSCs unstable at operating condition,even with device encapsulation.There is no doubt that the investigation of ion migration is crucial for the development of PSCs with high intrinsic stability.In this review,we first briefly introduce the origin and pathways of ion migration,and also the essential characterization methods to identify ion migration.Next,we discuss the impact of ion migration on the perovskite films and cells with respect to photoelectric properties and stability.Then,several representative strategies to suppress ion migration are systematically summarized in the context of composition engineering,additive engineering and interface engineering,with an in-depth understanding on the underlying mechanisms which may provide more clues for further fabrication of PSCs with improved stability.Finally,a perspective with some suggestion on future research directions and chemical approaches are provided to alleviate ion migration in perovskite materials and the entire devices.
基金Project supported by the National Natural Science Foundation of China(Grant No.61805263)Shanghai Sailing Program,China(Grant No.18YF1426400).
文摘Hybrid halide perovskites have great potential for applications in optoelectronic devices.However,the typical ion migration in perovskite could lead to the non-repeatability of electrical measurement,instability of material,and degradation of device performance.The basic current–voltage behavior of perovskite materials is intricate due to the mixed electronic–ionic characteristic,which is still poorly understood in these semiconductors.Developing novel measurement schematic is a promising solution to obtain the intrinsic electrical performance without the interference of ion migration.Herein,we explore the pulse-voltage(PV)method on methylammonium lead tribromide single crystals to protect the device from the ion migration.A guideline is summarized through the analysis of measurement history and condition parameters.The influence of the ion migration on current–voltage measurement,such as repeatability and hysteresis loop,is under controlled.An application of the PV method is demonstrated on the activation energy of conductivity.The abruption of activation energy still exists near the phase transition temperature despite the ion migration is excluded by the PV method,introducing new physical insight on the current–voltage behavior of perovskite materials.The guideline on PV method will be beneficial for measuring halide perovskite materials and developing optoelectronic applications with new technique schematic.
基金supported by the Natural Natural Science Foundation of China (Grant Nos.61904081 and 51672132)the Natural Science Foundation of Jiangsu Province,China (Grant No.BK20190449)the Postdoctoral Research Funding Program of Jiangsu Province,China (Grant No.2020Z144)。
文摘Benefiting from the excellent properties such as high photoluminescence quantum yield(PLQY), wide gamut range,and narrow emission linewidth, as well as low-temperature processability, metal halide perovskite quantum dots(QDs)have attracted wide attention from researchers. Despite tremendous progress has been made during the past several years,the commercialization of perovskite QDs-based LEDs(PeQLEDs) is still plagued by the instability. The ion migration in halide perovskites is recognized as the key factor causing the performance degradation of PeQLEDs. In this review, the elements species of ion migration, the effects of ion migration on device performance and stability, and effective strategies to hinder/mitigate ion migration in PeQLEDs are successively discussed. Finally, the forward insights on the future research are highlighted.
基金supported by the MEYS project, Czech Republic [No.CZ.02.1.01/0.0/0.0/15_003/0000464 (CAP)]the ’Severo Ochoa’ program for Centers of Excellence in R&D [MINECO, Grant SEV2016-0686]+3 种基金the Natural Science Foundation of Jiangsu Province, China [BK20180601]the Fundamental Research Funds for the Central Universities [JUSRP11834, JUSRP11834B]the Jiangsu Postdoctoral Science Foundation [2018K112C, 2018K113C]funding from the Lab and Equipment Management of Jiangnan University (JDSYS201906)。
文摘The device preconditioning dependent hysteresis and the consequential performance degradation hinder the actual performance and stability of the perovskite solar cells. Ion migration and charge trapping in the perovskite with large contribution from grain boundaries are the most common interpretations for the hysteresis. Yet, the high performing devices often include intermediate hole and electron transporting layers, which can further complicate the dynamical process in the device. Here, by using Kelvin Probe Force Microscopy and Confocal Photoluminescence Microscopy, we elucidate the impact of chargetransporting layers and excess MAI on the spatial and temporal variations of the photovoltage on the MAPbI3-based solar cells. By studying the devices layer by layer, we found that the light-induced ion migration occurs predominantly in the presence of an imbalanced charge extraction in the solar cells, and the charge transporting layers play crucial role in suppressing it. Careful selection and processing of the electron and hole-transporting materials are thus essential for making perovskite solar cells free from the ion migration effect.
基金supported by the National Natural Science Foundation of China (No.21473178, No.21773222, No.21503203)the National Key R&D program of China (2017YFA0403403)+1 种基金the Key Program of Research and Development of Hefei Science Center of CAS(2017HSC-KPRD001)the Collaborative Innovation Center of Suzhou Nano Science and Technology
文摘Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar cells.Here,we report a comprehensive study of the interfacial degradation and ion migration at the interface between CH3NH3PbI3 perovskite layer and Ag electrode.Using in situ photoemission spectroscopy measurements,we found that the Ag electrode could induce the degradation of perovskite layers,leading to the formation of PbI2 and AgI species and the reduction of Pb^2+ions to metallic Pb species at the interface.The unconventional enhancement of the intensities of I 3d spectra provides direct experimental evidences for the migration of iodide ions from CH3NH3PbI3 subsurface to Ag electrode.Moreover,the contact of Ag electrode and perovskite layers induces an interfacial dipole of 0.3 eV at CH3NH3PbI3/Ag interfaces,which may further facilitate iodide ion diffusion,resulting in the decomposition of perovskite layers and the corrosion of Ag electrode.
基金the financial support of Russian Science Foundation project No.24-73-10204.
文摘The development of fast ionic conductors to improve the performance of electrochemical devices relies on expensive high-throughput(HT)density functional theory(DFT)calculations of transport properties.Machine learning(ML)can accelerate HT workflows but requires high-quality data to ensure accurate predictions from trained models.In this study,we introduce the LiTraj dataset,which comprises 13,000 percolation and 122,000 migration barriers,and 1700 migration trajectories,calculated for Li-ion in diverse crystal structures using empirical force fields and DFT,respectively.With LiTraj,we demonstrate that classicalMLmodels and graph neural networks(GNNs)for structureto-property prediction of percolation and migration barriers can distinguish between“fast”and“poor”ionic conductors.Furthermore,we evaluate the capability of GNN-based universal ML interatomic potentials(uMLIPs)to identify optimal Li-ion migration trajectories.Fine-tuned uMLIPs achieve near-DFT accuracy in predicting migration barriers,significantly accelerating HT screenings of new ionic conductors.
基金supported by National Natural Science Foundation of China(Nos.51925206 and 52461160328)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301)the Fundamental Research Funds for the Central Universities(20720220009,WK2490000002).
文摘All-inorganic perovskites are advantageous in terms of improved thermal stability compared to organic-inorganic counterparts.However,the ion migration-induced hysteresis significantly undermines the long-term operational stability of all-inorganic perovskite solar cells(PSCs),particularly in mixed halide perovskites.Herein,we report that tin-lead(Sn-Pb)alloying for all-inorganic mixed halide perovskites can effectively inhibit the ion migration behavior,as comprehensively revealed by the time-of-flight secondary ion mass spectrometry(TOF-SIMS),optical microscopy and galvanostatic measurements.On one hand,the small-sized Sn2+cations can tighten the lattice structure to enhance the Pb/Sn-X(X=I and Br)ionic bonds,thereby effectively immobilizing the halide ions.On the other hand,Sn substitution can significantly reduce anti-site defects,such as I_(Cs)and I_(Pb),which are considered potential pathways for ion migration.With these advantages,ion migration is greatly suppressed in Sn-Pb alloyed inorganic perovskites,resulting in reduced hysteresis and improved operational stability of PSC devices.
基金support from National Key Research and Development Program of China(2024YFE0217100)the National Natural Science Foundation of China(21905006,22261160370,and 62105075)+7 种基金the Guangdong Provincial Science and Technology Plan(2021A0505110003)the Natural Science Foundation of Hunan Province,China(2023JJ50132)Guangxi Department of Science and Technology(2020GXNSFBA159049 and AD19110030)the Shenzhen Science and Technology Program(SGDX20230116093205009,JCYJ20220818100211025 and 2022378670)the Natural Science Foundation of Top Talent of SZTU(GDRC202343)financial support of Innovation and Technology Fund(#GHP/245/22SZ)The University Grant Council of the University of Hong Kong(grant No.2302101786)General Research Fund(grant Nos.17200823 and 17310624)from the Research Grants Council.
文摘Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract intensive studies of their advantages due to low-level ion migration and decent stability.However,there is still a lack of methods to precisely construct heterostructures and a fundamental understanding of their structure-dependent optoelectronic properties.Herein,a gas-phase method was developed to grow 2D perovskites directly on 3D perovskites with nanoscale accuracy.In addition,the larger steric hindrance of organic layers of 2D perovskites was proved to enable slower ion migration,which resulted in reduced trap states and better stability.Based on MAPbBr_(3)single crystals with the(PA)_(2)PbBr_(4)capping layer,the X-ray detector achieved a sensitivity of 22,245μC Gy_(air)^(−1)cm^(−2),a response speed of 240μs,and a dark current drift of 1.17.10^(–4)nA cm^(−1)s^(−1)V^(−1),which were among the highest reported for state-of-the-art perovskite-based X-ray detectors.This study presents a precise synthesis method to construct perovskite-based heterostructures.It also brings an in-depth understanding of the relationship between lattice structures and properties,which are beneficial for advancing high-performance and cost-effective X-ray detectors.
文摘Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of products is profoundly influenced by the catalyst structure.In this study,Fe_(2)O_(3)-doped NiSO_(4)/Al_(2)O_(3) catalysts have been meticulously developed to facilitate the selective trimerization of propylene under mild conditions.Significantly,the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst demonstrates an enhanced reaction rate(48.5 mmol_(C3)/(g_(cat).·h)),alongside a high yield of C9(~32.2%),significantly surpassing the performance of the NiSO_(4)/Al_(2)O_(3) catalyst(C9:~24.1%).The incorporation of Fe_(2)O_(3) modifies the migration process of sulfate ions,altering the Lewis acidity of the electron-deficient Ni and Fe sites on the catalyst and resulting a shift in product distribution from a Schulz-Flory distribution to a Poisson distribution.This shift is primarily ascribed to the heightened energy barrier for theβ-H elimination reaction in the C6 alkyl intermediates on the doped catalyst,further promoting polymerization to yield a greater quantity of Type II C9.Furthermore,the validation of the Cossee-Arlman mechanism within the reaction pathway has been confirmed.It is noteworthy that the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst exhibits remarkable stability exceeding 80 h in the selective trimerization of propylene.These research findings significantly enhance our understanding of the mechanisms underlying olefin oligomerization reactions and provide invaluable insights for the development of more effective catalysts.
基金Project(41371475)supported by the National Natural Science Foundation of ChinaProject(201509048)supported by the Environmental Protection’s Special Scientific Research for Chinese Public Welfare Industry
文摘Bauxite residue,a highly saline solid waste produced from digestion of bauxite for alumina production,is hazardous to the environment and restricts vegetation establishment in bauxite residue disposal areas.A novel water leaching process proposed here was used to investigate the dynamic migration and vertical distribution of saline ions in bauxite residue.The results show that water leaching significantly reduced the salinity of bauxite residue,leaching both saline cations Na+,K+,Ca2+and anions CO32-,SO42-,HCO3-.Na+and K+migrated from 40-50 to 20-30 cm of the column,presenting a high migration capacity.The migration capacity of Ca2+was lower and accumulated at 30-40 cm of the column.CO32-initially distributed at 20-30 cm of the column,subsequently transported to 30-40 cm of the column,and finally returned to 20-30 cm of the column along with evaporation.SO42-was originally distributed at 40-50 cm,but finally migrated to 20-30 cm of the column.Nevertheless,HCO3-remained at the bottom of the column,and its migratory was less affected by evaporation.
基金supported by National Natural Science Foundation of China(NSFC)(grant nos.52063019,51973088,51833004,U20A20128).
文摘The inevitable ion migration that occurs within ionic polycrystalline perovskite film results in inferior longterm stability of perovskite solar cells(PVSCs)that cannot meet the commercial requirements.Here,a novel poly(ionic liquid)named poly-1-vinyl-3-propyltrimethoxysilane imidazolium chloride(PImIL-SiO)is first introduced into perovskite to strengthen grain boundaries(GBs)and construct dual-functional barriers against internal ion migration and external moisture erosion for fabricating highly efficient and stable PVSCs.PImIL-SiO-containing imidazoliumcations and pendant siloxane groups contribute to passivation of bulk defects and anchoring of GBs,which effectively hinders ion migration channels,thus reducing perovskite film phase separation and device hysteresis.Furthermore,the intrinsically hydrophobic PImIL-SiO automatically forms a secondary protective barrier to endow the perovskite film with ultrahigh moisture corrosion resistance through the hydrolyzation reaction of siloxane with the permeated moisture.Consequently,the PImIL-SiO-modified PVSCs achieve a champion power conversion efficiency(PCE)of 22.46%,accompaniedby excellent thermal andhumidity stabilities where the non-encapsulated devices retain 87%of the initial PCE after aging at 85℃for 250 h and>85%of the initial PCE over 1100 h in air with a relative humidity of 50–70%.
基金National Natural Science Foundation of China,Grant/Award Numbers:21972006,22275180,U2001217,22261160370,52202182Shenzhen Peacock plan,Grant/Award Number:KQTD2016053015544057+1 种基金Shenzhen Innovation Fund,Grant/Award Number:JCYJ20220818101018038Natural Sciences and Engineering Research Council of Canada,Grant/Award Number:RGPIN-2020-04239。
文摘Narrowband photodetectors conventionally rely on optical structure design orbandpass filters to achieve the narrowband regime. Recently, a strategy forfilterless narrowband photoresponse based on the charge collection narrowing(CCN) mechanism was reported. However, the CCN strategy requires an electrically and optically “thick” photoactive layer, which poses challenges in controlling the narrowband photoresponse. Here we propose a novel strategy forconstructing narrowband photodetectors by leveraging the inherent ion migration in perovskites, which we term “band modulation narrowing” (BMN). Bymanipulating the ion migration with external stimuli such as illumination,temperature, and bias voltage, we can regulate in situ the energy-band structure of perovskite photodetectors (PPDs) and hence their spectral response.Combining the Fermi energy levels obtained by the Kelvin probe force microscopy, the internal potential profiles from solar cell capacitance simulator simulation, and the anion accumulation revealed by the transient ion-drifttechnique, we discover two critical mechanisms behind our BMN strategy: theextension of an optically active but electronically dead region proximal to the top electrode and the down-bending energy bands near the electron transportlayer. Our findings offer a case for harnessing the often-annoying ionmigration for developing advanced narrowband PPDs.
基金Research Projects of Ganjiang InnovationAcademyNational Key Research andDevelopment Program of China,Grant/Award Number: 2022YFB1902700+2 种基金Natural Science Foundation of China,Grant/Award Number: 62374186Guangdong Natural Science Funds forDistinguished Young Scholars,Grant/Award Number: 2021B1515020105Youth Innovation Promotion AssociationCAS。
文摘Low-dimensional metal halide perovskites exhibit exceptional photoelectronicproperties and intrinsic stability, positioning them as a promising class of semiconductormaterials for light-emitting devices and photodetectors. In thiswork, we present a millimeter-scale single crystal of mixed low-dimensional(one-dimensional–zero-dimensional [1D–0D]) organic lead iodide withwell-defined crystallinity. The fabricated single-crystal devices demonstratehigh-sensitivity photoresponse and x-ray detection performance. By spatiallyisolating organic molecules to form the mixed 1D–0D crystal structure, ionmigrations is effectively suppressed, resulting in a remarkable three orders ofmagnitude reduction in the dark current (56.4 pA @200 V) of the single-crystaldevices. Furthermore, by enhancing the background characteristics, weachieved an impressive low x-ray detection limit of 154.5 nGys^(-1) in the singlecrystaldevice. These findings highlight that the mixed 1D–0D organic leadiodide configuration efficiently controls ion migration within the crystal structure,offering a promising avenue for realizing high-performance perovskitebasedphotodetectors and x-ray detectors.
文摘Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.
文摘With the support of the National Natural Science Foundation of China,two original studies by the research group led by Prof.Gu Lin(谷林)and Prof.Zhang Qinghua(张庆华)from the Institute of Physics,Chinese Academy of Sciences demonstrate the in-situ atomic-scale electrically induced
基金supported by the National Natural Science Foundation of China (62374104)the Shan-dong Postdoctoral Innovation Program (SDCX-ZG-202301004,SDBX2023043)+3 种基金the Natural Science Foundation of Shandong (ZR2021QB093)the Jinan Central Hospital Collaboration (1190022050)the First Cohort of Talent Research Projects from Qilu University of Technology,Shandong Academy of Sciences in 2023 (2023RCKY199)the Pilot Project for Integrating Science,Education and Industry from Qilu University of Technology,Shandong Academy of Sciences (2023PX019).
文摘3D perovskite materials are advancing rapidly in the field of photovoltaics and light-emitting diodes,but the development in field effect transistors(FETs)is limited due to their intrinsic ion migration.Ion migration in perovskite FETs can screen the electric field of the gate and affect its modulation,as well as influence the charge carriers transport,leading to non-ideal device characteristics and lower device stability.Here,we provide a concise review that explains the mechanism of ion migration,summarizes the strategies for suppressing ion migration,and concludes with a discussion of the future prospects for 3D perovskite FETs.
