On May 6, 2009, the X-ray imaging and biomedical application beamline(BL13W1) at Shanghai Synchrotron Radiation Facility(SSRF) officially opened to users, with 8–72.5 ke V X-rays. The experimental station is equipped...On May 6, 2009, the X-ray imaging and biomedical application beamline(BL13W1) at Shanghai Synchrotron Radiation Facility(SSRF) officially opened to users, with 8–72.5 ke V X-rays. The experimental station is equipped with four sets of X-ray CCD detectors of different pixel size(0.19–24 μm) for on-line phase-contrast imaging and micro-CT imaging with 0.8 μm spatial resolution and 1 ms temporal resolution. An in vivo microCT experiment for a living insect was realized in 4 s. An X-ray fluorescence detector is equipped for X-ray fluorescence mapping imaging and X-ray fluorescence micro-CT imaging with 50 μm spatial resolution. In order to meet different requirements from the users, several experimental methods, such as X-ray spiral micro-CT, Xray local micro-CT, X-ray fast micro-CT, X-ray grating-based differential micro-CT, X-ray fluorescence microCT and X-ray quantitative micro-CT have been developed, and nearly 60 papers related to those developments for this beamline have been published. Moreover, the beamline has realized the remote fast CT reconstruction,providing a great convenience for the users to process experimental data at their offices. As of August 2014,the beamline has offered the user beamtime of(23 145 h), from which 232 user papers have been published,including 151 SCI papers and 55 papers with SCI impact factor > 3. The quantity and quality of the user paper outcome keep a steady increase. Some typical user experimental results are introduced.展开更多
This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the...This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the past 5 years.The photon energy range of the beamline is 8–72.5 keV.Several sets of X-ray imaging detectors with different pixel sizes(0.19–24 lm)are used to realize X-ray microcomputed tomography(X-ray micro-CT)and X-ray in-line phase-contrast imaging.To satisfy the requirements of user experiments,new X-ray imaging methods and image processing techniques are developed.In vivo dynamic micro-CT experiments with living insects are performed in 0.5 s(sampling rate of 2 Hz,2 tomograms/s)with a monochromatic beam from a wiggler source and in 40 ms(sampling rate of 25 Hz,25 tomograms/s)with a white beam from a bending magnet source.A new X-ray imaging method known as move contrast X-ray imaging is proposed,with which blood flow and moving tissues in raw images can be distinguished according to their moving frequencies in the time domain.Furthermore,X-ray speckle-tracking imaging with twice exposures to eliminate the edge enhancement effect is developed.A high-precision quantification method is realized to measure complex three-dimensional blood vessels obtained via X-ray micro-CT.X-ray imaging methods such as three-dimensional X-ray diffraction microscopy,small-angle X-ray scattering CT,and X-ray fluorescence CT are developed,in which the X-ray micro-CT imaging method is combined with other contrast mechanisms such as diffraction,scattering,and fluorescence contrasts respectively.Moreover,an X-ray nano-CT experiment is performed with a 100 nm spatial resolution.Typical user experimental results from the fields of material science,biomedicine,paleontology,physics,chemistry,and environmental science obtained on the beamline are provided.展开更多
The Shanghai Synchrotron Radiation Facility (SSRF) is a low emittance third-generation synchrotron radiation light source. Some optics parameters of the storage ring were measured when commissioning. This report prese...The Shanghai Synchrotron Radiation Facility (SSRF) is a low emittance third-generation synchrotron radiation light source. Some optics parameters of the storage ring were measured when commissioning. This report presents the common methods for measuring some optics parameters of the storage ring, including the betatron tune, beta function, chromaticity, natural chromaticity and dispersion. The results and analysis of measurement for the optics parameters are given here, which are indispensable for the orbit correction of the accelerator and the nonlinear optimization.展开更多
Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we...Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we demonstrate CRE suppression with undetectable disturbance of the deposit on carbon-based surfaces.This was achieved by adding ammonium bicarbonate(NH4HCO_(3)),which benefits from the dissociation of NH_(4)HCO_(3) to produce NH_(4)^(+),as well as its decomposition into NH_(3) and CO_(2) molecules.Surprisingly,NH_(4)^(+) can also function as Na^(+)/K^(+)to suppress the CRE through cation interactions,although its hydrate state is only partially positively charged.Moreover,we successfully applied this approach to enhance the morphology,resistance,and color uniformity of deposits of graphene oxide quantum dots,conductive inks,and organic dyes,respectively.This study provides a practical strategy for improving the performance of fabricated devices and paves the way for the development of high-accuracy manufacturing techniques in diverse industries.展开更多
Intercalation of rare-earth(RE)into Pt offers an option to optimize the electronic structure of Pt-based catalysts by interaction effect,in which the synergistic catalytic sites are of great significance,yet the under...Intercalation of rare-earth(RE)into Pt offers an option to optimize the electronic structure of Pt-based catalysts by interaction effect,in which the synergistic catalytic sites are of great significance,yet the underpinning mechanism remains elusive.Herein,the introduction of silanol nests enables the alloy formation on the SiO_(2)surface.The amination modification is disclosed to induce the electron transfer from RE to Pt and weaken the adsorption of CO on electron-rich Pt species.In situ/operando spectroscopic analyses in conjunction with density functional theory calculations demonstrate the electronic couple of Pt atoms and adjacent Ce atoms concurrently achieves the enhancement of CO oxidation and suppression of H_(2)oxidation.Additionally,CO_(2)is readily desorbed from the Pt_(5)Ce(111)surface to enhance intrinsic activity and longevity.These findings provide an atomic-level insight into the synergistic catalytic sites on regulating the electronic state of the Pt-RE alloy catalysts toward highly selective oxidation reactions.展开更多
Perovskite solar cells(PSC)are considered as a promising photovoltaic technology due to their low cost and high efficiency exceeding 26.8%.Ultra-lightweight flexible perovskite solar cells(FPSCs)can be applied to many...Perovskite solar cells(PSC)are considered as a promising photovoltaic technology due to their low cost and high efficiency exceeding 26.8%.Ultra-lightweight flexible perovskite solar cells(FPSCs)can be applied to many fields such as architecture and portable devices.Although the photovoltaic conversion efficiency(PCE)of FPSC has exceeded 24%in the past few years,further application of FPSC is constrained by the challenges posed by limitation of critical material components.Here,we discussed recent research progress of key FPSC materials,mechanical endurance,low-temperature fabrication,etc.With the advantages of high brightness,collimation and resolution,we specially introduced the application of synchrotron radiation grazing incidence wide-angle X-ray scattering(GIWAXS)to directly observe the perovskite buried interface structure and corresponding mechanical stability of FPSCs without any damage.Finally,we summarize the challenges and propose an outlook about the large-scale preparation of efficient and stable FPSC modules.展开更多
Lead-tin(Pb-Sn)perovskites with an ideal bandgap of 1.34-1.40 eV show great promise in perovskite solar cells(PSCs).Recently,to address the environmental pollution and Sn^(2+)oxidation problems of dimethyl sulfoxide,m...Lead-tin(Pb-Sn)perovskites with an ideal bandgap of 1.34-1.40 eV show great promise in perovskite solar cells(PSCs).Recently,to address the environmental pollution and Sn^(2+)oxidation problems of dimethyl sulfoxide,methylammonium acetate(MAAc)ionic liquid has been developed as an alternative to fabricate ideal bandgap MAPb_(0.7)Sn_(0.3)I_(3)(1.36 eV)film via hot-casting in air.However,the spontaneous crystallization of Pb-Sn perovskite initiated by heat-induced supersaturation is fast and random,setting critical challenges in regulating crystal growth during the film-forming process.Herein,a lattice activation strategy is developed to control the crystallization dynamics of MAPb_(0.7)Sn_(0.3)I_(3)in MAAc to produce films with micrometer-sized grains in air.FA is shown to activate the crystal lattice that facilitates the formation of intermediates and balances the crystal growth of MAPb_(0.7)Sn_(0.3)I_(3),producing films with a grain size of 2.78±0.17μm.Furthermore,4-fluoro-phenethylammonium and phenethylammonium are adopted to passivate the defects in the film and promote the energy level alignment at the top interface,respectively.The optimized PSC device achieved an efficiency of 18.24%with a short-circuit current of 29.84 mA/cm^(2),which are both the highest values in 1.36 eV Pb-Sn PSCs to date.Notably,the unencapsulated devices show excellent storage and air stability under various conditions.展开更多
The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor...The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor crystallization,due to the coexistence of mixed intermediate phases.Here,we report an additive strategy for finely regulating the impurities in the intermediate phase of Cs_(0.25)FA_(0.75)Pb_(0.6)Sn_(0.4)I_(3)and,thereby,obtaining high-performance solar cells.We introduced d-homoserine lactone hydrochloride(D-HLH)to form hydrogen bonds and strong Pb-O/Sn-O bonds with perovskite precursors,thereby weakening the incomplete complexation effect between polar aprotic solvents(e.g.,DMSO)and organic(FAI)or inorganic(CsI,PbI_(2),and SnI_(2))components,and balancing their nucleation processes.This treatment completely transformed mixed intermediate phases into pure preformed perovskite nuclei prior to thermal anneal-ing.Besides,this D-HLH substantially inhibited the oxidation of Sn^(2+) species.This strategy generated a record efficiency of 21.61%,with a Voc of 0.88 V for an MA-free Sn-Pb device,and an efficiency of 23.82%for its tandem device.The unencapsulated devices displayed impressive thermal stability at 85℃ for 300 h and much improved continuous operation stability at MPP for 120 h.展开更多
Phase transition from form Ⅰ to form Ⅲ in syndiotactic polypropylene crystallized at different conditions during tensile deformation at different temperatures was investigated by using in situ synchrotron wide angle...Phase transition from form Ⅰ to form Ⅲ in syndiotactic polypropylene crystallized at different conditions during tensile deformation at different temperatures was investigated by using in situ synchrotron wide angle X-ray diffraction technique. In all cases, the occurrence of this phase transition was observed. The onset strain of this transition was found to be crystalline thickness decided by crystallization temperature and drawing temperature dependent. The effect of drawing temperature on this phase transition is understood by the changes in mechanical properties with temperature. Moreover, crystalline thickness dependency of the phase transition reveals that this form Ⅰ to from Ⅲ phase transition occurs first in those lamellae with their normal along the stretching direction which have not experienced stress induced melting and recrystallization.展开更多
X-ray speckle tracking based methods can provide results with best reported angular accuracy up to 2 nrad. However,duo to the multi-frame requirement for phase retrieval and the possible instability of the x-ray beam,...X-ray speckle tracking based methods can provide results with best reported angular accuracy up to 2 nrad. However,duo to the multi-frame requirement for phase retrieval and the possible instability of the x-ray beam, mechanical and background vibration, the actual accuracy will inevitably be degraded by these time-dependent fluctuations. Therefore,not only spatial position, but also temporal features of the speckle patterns need to be considered in order to maintain the superiority of the speckle-based methods. In this paper, we propose a parallel acquisition method with advantages of real time and high accuracy, which has potential applicability to dynamic samples imaging as well as on-line beam monitoring.Through simulations, we demonstrate that the proposed method can reduce the phase error caused by the fluctuations to1% at most compared with current speckle tracking methods. Meanwhile, it can keep the accuracy deterioration within0.03 nrad, making the high theoretical accuracy a reality. Also, we find that waveforms of the incident beam have a little impact on the phase retrieved and will not influence the actual accuracy, which relaxes the requirements for speckle-based experiments.展开更多
为进一步改善磁调制DCCT(Direct Current Current Transducer)的温度特性,将磁调制DCCT化整为零,利用灰色相关理论确定了DCCT各部分温度系数对整机的影响程度;同时,还提出了一种磁调制DCCT温度系数综合评价方法。根据磁调制DCCT的工作原...为进一步改善磁调制DCCT(Direct Current Current Transducer)的温度特性,将磁调制DCCT化整为零,利用灰色相关理论确定了DCCT各部分温度系数对整机的影响程度;同时,还提出了一种磁调制DCCT温度系数综合评价方法。根据磁调制DCCT的工作原理,把DCCT分为PCB(Printed Circuit Board)、线圈和取样电阻三部分,并分别测出DCCT整机、PCB、线圈和取样电阻的温度系数;然后,利用灰色相关理论对7个被测DCCT的各部分温度系数进行关联计算,获得相应的关联系数,从而确定DCCT温度特性的主要因素。根据DCCT温度特性的主、次要因素并结合工程实际,设定了概念DCCT作为参考,利用灰色相关理论计算出7个被测DCCT与参考DCCT的温度系数的灰色关联加权值,完成了被测磁调制DCCT温度性能的综合评价。最后,指出了降低DCCT整机温度敏感性的研究方向。展开更多
The domain purity,material crystallinity and distribution at the interface between the active layer and the transport layer have an important impact on the performance of organic solar cells(OSCs)and organic photodete...The domain purity,material crystallinity and distribution at the interface between the active layer and the transport layer have an important impact on the performance of organic solar cells(OSCs)and organic photodetectors(OPDs),while this focal issue has received less attention in previous studies.From this perspective,a new method to simultaneously enhance the performance of OSC and OPD is proposed,namely,using a sequential deposition method to first construct a compact stacking structure of dualdonor(D18-Cl:PTO2)eutectic in the donor layer,and then induce the ordered deposition of the acceptor(Y6).Compared with the conventional bulk heterojunction(BHJ),the active layer realized by this method not only improves the crystallinity and stacking order of the constituent material on the surface of the transport layer,but also regulates a good vertical distribution,which is conducive to improving the charge transport and extraction efficiency,reducing the leakage current,and enhancing the stability of the device.As a result,the OSC device based on the D18-Cl:PTO2/Y6 structure achieves a power conversion efficiency of up to 17.65%and good light-degradation stability,which is much better than that of BHJbased OSC(PCE of 16.37%).For the OPD,the dark current at reverse bias is reduced by more than an order of magnitude,and the maximum responsivity is improved to 0.52 A/W through the optimization of the donor phase at the interface.Moreover,the strategy does not require additional post-processing compared to the BHJ preparation,which reduces the device construction cost and process complexity,providing an effective way for developing high-performance organic optoelectronic devices.展开更多
Varying the film thickness is a precise route to tune the interfacial strain to manipulate the properties of the multiferroic materials.Here,to explore the effects of the interfacial strain on the properties of the mu...Varying the film thickness is a precise route to tune the interfacial strain to manipulate the properties of the multiferroic materials.Here,to explore the effects of the interfacial strain on the properties of the multiferroic BiFeO_3films,we investigated thickness-dependent structural and polarization evolutions of the BiFeO_3 films.The epitaxial growth with an atomic stacking sequence of BiO/TiO_2 at the interface was confirmed by scanning transmission electron microscopy.Combining X-ray diffraction experiments and first-principles calculations,a thickness-dependent structural evolution was observed from a fully strained tetragonality to a partially relaxed one without any structural phase transition or rotated twins.The tetragonality(c/a) of the BiFeO_3 films increases as the film thickness decreases,while the polarization is in contrast with this trend,and the size effect including the depolarization field plays a crucial role in this contradiction in thinner films.These findings offer an alternative strategy to manipulate structural and polarization properties by tuning the interfacial strain in epitaxial multiferroic thin films.展开更多
With the rapid rise in perovskite solar cells(PSCs)performance,it is imperative to develop scalable fabrication techniques to accelerate potential commercialization.However,the power conversion efficiencies(PCEs)of PS...With the rapid rise in perovskite solar cells(PSCs)performance,it is imperative to develop scalable fabrication techniques to accelerate potential commercialization.However,the power conversion efficiencies(PCEs)of PSCs fabricated via scalable two-step sequential deposition lag far behind the state-of-the-art spin-coated ones.Herein,the additive methylammonium chloride(MACl)is introduced to modulate the crystallization and orientation of a two-step sequential doctorbladed perovskite film in ambient conditions.MACl can significantly improve perovskite film quality and increase grain size and crystallinity,thus decreasing trap density and suppressing nonradiative recombination.Meanwhile,MACl also promotes the preferred face-up orientation of the(100)plane of perovskite film,which is more conducive to the transport and collection of carriers,thereby significantly improving the fill factor.As a result,a champion PCE of 23.14%and excellent longterm stability are achieved for PSCs based on the structure of ITO/SnO_(2)/FA_(1-x)MA_xPb(I_(1-y)Br_y)_3/Spiro-OMeTAD/Ag.The superior PCEs of 21.20%and 17.54%are achieved for 1.03 cm~2 PSC and 10.93 cm~2 mini-module,respectively.These results represent substantial progress in large-scale two-step sequential deposition of high-performance PSCs for practical applications.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.11475248 and 11105213)
文摘On May 6, 2009, the X-ray imaging and biomedical application beamline(BL13W1) at Shanghai Synchrotron Radiation Facility(SSRF) officially opened to users, with 8–72.5 ke V X-rays. The experimental station is equipped with four sets of X-ray CCD detectors of different pixel size(0.19–24 μm) for on-line phase-contrast imaging and micro-CT imaging with 0.8 μm spatial resolution and 1 ms temporal resolution. An in vivo microCT experiment for a living insect was realized in 4 s. An X-ray fluorescence detector is equipped for X-ray fluorescence mapping imaging and X-ray fluorescence micro-CT imaging with 50 μm spatial resolution. In order to meet different requirements from the users, several experimental methods, such as X-ray spiral micro-CT, Xray local micro-CT, X-ray fast micro-CT, X-ray grating-based differential micro-CT, X-ray fluorescence microCT and X-ray quantitative micro-CT have been developed, and nearly 60 papers related to those developments for this beamline have been published. Moreover, the beamline has realized the remote fast CT reconstruction,providing a great convenience for the users to process experimental data at their offices. As of August 2014,the beamline has offered the user beamtime of(23 145 h), from which 232 user papers have been published,including 151 SCI papers and 55 papers with SCI impact factor > 3. The quantity and quality of the user paper outcome keep a steady increase. Some typical user experimental results are introduced.
基金This work was supported by the National Key Research and Development Program of China(Nos.2017YFA0403801,2016YFA0401302,2017YFA0206004,2018YFC1200204)the National Major Scientific Instruments and Equipment Development Project of China(No.11627901).
文摘This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the past 5 years.The photon energy range of the beamline is 8–72.5 keV.Several sets of X-ray imaging detectors with different pixel sizes(0.19–24 lm)are used to realize X-ray microcomputed tomography(X-ray micro-CT)and X-ray in-line phase-contrast imaging.To satisfy the requirements of user experiments,new X-ray imaging methods and image processing techniques are developed.In vivo dynamic micro-CT experiments with living insects are performed in 0.5 s(sampling rate of 2 Hz,2 tomograms/s)with a monochromatic beam from a wiggler source and in 40 ms(sampling rate of 25 Hz,25 tomograms/s)with a white beam from a bending magnet source.A new X-ray imaging method known as move contrast X-ray imaging is proposed,with which blood flow and moving tissues in raw images can be distinguished according to their moving frequencies in the time domain.Furthermore,X-ray speckle-tracking imaging with twice exposures to eliminate the edge enhancement effect is developed.A high-precision quantification method is realized to measure complex three-dimensional blood vessels obtained via X-ray micro-CT.X-ray imaging methods such as three-dimensional X-ray diffraction microscopy,small-angle X-ray scattering CT,and X-ray fluorescence CT are developed,in which the X-ray micro-CT imaging method is combined with other contrast mechanisms such as diffraction,scattering,and fluorescence contrasts respectively.Moreover,an X-ray nano-CT experiment is performed with a 100 nm spatial resolution.Typical user experimental results from the fields of material science,biomedicine,paleontology,physics,chemistry,and environmental science obtained on the beamline are provided.
基金Supported by Major State Basic Research Development Program of China (2002CB713600)
文摘The Shanghai Synchrotron Radiation Facility (SSRF) is a low emittance third-generation synchrotron radiation light source. Some optics parameters of the storage ring were measured when commissioning. This report presents the common methods for measuring some optics parameters of the storage ring, including the betatron tune, beta function, chromaticity, natural chromaticity and dispersion. The results and analysis of measurement for the optics parameters are given here, which are indispensable for the orbit correction of the accelerator and the nonlinear optimization.
基金National Natural Science Foundation of China under Grant No.12005062(SS).National Natural Science Foundation of China under Grant No.11974366(HF).National Natural Science Foundation of China under Grant No.U1632135(HY)Fundamental Research Funds for the Central Universities,China(HF)。
文摘Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we demonstrate CRE suppression with undetectable disturbance of the deposit on carbon-based surfaces.This was achieved by adding ammonium bicarbonate(NH4HCO_(3)),which benefits from the dissociation of NH_(4)HCO_(3) to produce NH_(4)^(+),as well as its decomposition into NH_(3) and CO_(2) molecules.Surprisingly,NH_(4)^(+) can also function as Na^(+)/K^(+)to suppress the CRE through cation interactions,although its hydrate state is only partially positively charged.Moreover,we successfully applied this approach to enhance the morphology,resistance,and color uniformity of deposits of graphene oxide quantum dots,conductive inks,and organic dyes,respectively.This study provides a practical strategy for improving the performance of fabricated devices and paves the way for the development of high-accuracy manufacturing techniques in diverse industries.
基金financially supported by the National Natural Science Foundation of China(22468034)the Natural Science Foundation of Inner Mongolia(2021MS02008 and 2022MS02011)the Key Research and Development Project of Ordos(YF20240062)。
文摘Intercalation of rare-earth(RE)into Pt offers an option to optimize the electronic structure of Pt-based catalysts by interaction effect,in which the synergistic catalytic sites are of great significance,yet the underpinning mechanism remains elusive.Herein,the introduction of silanol nests enables the alloy formation on the SiO_(2)surface.The amination modification is disclosed to induce the electron transfer from RE to Pt and weaken the adsorption of CO on electron-rich Pt species.In situ/operando spectroscopic analyses in conjunction with density functional theory calculations demonstrate the electronic couple of Pt atoms and adjacent Ce atoms concurrently achieves the enhancement of CO oxidation and suppression of H_(2)oxidation.Additionally,CO_(2)is readily desorbed from the Pt_(5)Ce(111)surface to enhance intrinsic activity and longevity.These findings provide an atomic-level insight into the synergistic catalytic sites on regulating the electronic state of the Pt-RE alloy catalysts toward highly selective oxidation reactions.
基金supported by Photon Science Research Center For Carbon Dioxide,Project of the National Natural Science Foundation of China(22332003)supported by the National Natural Science Foundation of China(12175298,12075309)+10 种基金the National Natural Science Foundation of China(62404176)Shanghai Science and Technology Innovation Action Plan(22JC1403800)Shanghai Municipal Science and Technology Commission(23JC1403300)2022 Self Deployed Instrument Design Project of Shanghai Advanced Research Institutethe Research Grant from the Shanghai Sailing Program(17YF1423700)Shanghai Municipal Commission for Science and Technology(20ZR1464100)Youth Innovation Promotion Association CAS(2021284)Fudan University Talent Introduction Projectthe support from the China Postdoctoral Science Foundation(2023M742732)the Postdoctoral Fellowship Program of CPSF(GZC20241303)the Fundamental Research Funds for the Central Universities(XJSJ24100)。
文摘Perovskite solar cells(PSC)are considered as a promising photovoltaic technology due to their low cost and high efficiency exceeding 26.8%.Ultra-lightweight flexible perovskite solar cells(FPSCs)can be applied to many fields such as architecture and portable devices.Although the photovoltaic conversion efficiency(PCE)of FPSC has exceeded 24%in the past few years,further application of FPSC is constrained by the challenges posed by limitation of critical material components.Here,we discussed recent research progress of key FPSC materials,mechanical endurance,low-temperature fabrication,etc.With the advantages of high brightness,collimation and resolution,we specially introduced the application of synchrotron radiation grazing incidence wide-angle X-ray scattering(GIWAXS)to directly observe the perovskite buried interface structure and corresponding mechanical stability of FPSCs without any damage.Finally,we summarize the challenges and propose an outlook about the large-scale preparation of efficient and stable FPSC modules.
基金financially supported by the Natural Science Foundation of China(52372226,52202300,62288102,62350013,52303325)National Key Research and Development Program of China(2023YFB3608900)+5 种基金the Postdoctoral Fellowship Program ofthe China postdoctoral Science Foundation(CPSF)(Grant GZC20233506)the China Postdoctoral Science Foundation(Grant2024M764252)the Natural Science Foundation of Chongqing China(2023NSCQ-MSX0097)Guangdong Basic and Applied Basic Research Foundation(2024A1515010918)Shenzhen Science and Technology Program(Grant JCYJ20240813150819026)the Fundamental Research Funds for the Central Universities。
文摘Lead-tin(Pb-Sn)perovskites with an ideal bandgap of 1.34-1.40 eV show great promise in perovskite solar cells(PSCs).Recently,to address the environmental pollution and Sn^(2+)oxidation problems of dimethyl sulfoxide,methylammonium acetate(MAAc)ionic liquid has been developed as an alternative to fabricate ideal bandgap MAPb_(0.7)Sn_(0.3)I_(3)(1.36 eV)film via hot-casting in air.However,the spontaneous crystallization of Pb-Sn perovskite initiated by heat-induced supersaturation is fast and random,setting critical challenges in regulating crystal growth during the film-forming process.Herein,a lattice activation strategy is developed to control the crystallization dynamics of MAPb_(0.7)Sn_(0.3)I_(3)in MAAc to produce films with micrometer-sized grains in air.FA is shown to activate the crystal lattice that facilitates the formation of intermediates and balances the crystal growth of MAPb_(0.7)Sn_(0.3)I_(3),producing films with a grain size of 2.78±0.17μm.Furthermore,4-fluoro-phenethylammonium and phenethylammonium are adopted to passivate the defects in the film and promote the energy level alignment at the top interface,respectively.The optimized PSC device achieved an efficiency of 18.24%with a short-circuit current of 29.84 mA/cm^(2),which are both the highest values in 1.36 eV Pb-Sn PSCs to date.Notably,the unencapsulated devices show excellent storage and air stability under various conditions.
基金funded by the Natural Science Foundation of Shanghai(22ZR1428200)the National Natural Science Foundation of China(51950410581)+1 种基金the Shanghai Government(20JC141500)and CATL-SJTU joint funding.
文摘The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor crystallization,due to the coexistence of mixed intermediate phases.Here,we report an additive strategy for finely regulating the impurities in the intermediate phase of Cs_(0.25)FA_(0.75)Pb_(0.6)Sn_(0.4)I_(3)and,thereby,obtaining high-performance solar cells.We introduced d-homoserine lactone hydrochloride(D-HLH)to form hydrogen bonds and strong Pb-O/Sn-O bonds with perovskite precursors,thereby weakening the incomplete complexation effect between polar aprotic solvents(e.g.,DMSO)and organic(FAI)or inorganic(CsI,PbI_(2),and SnI_(2))components,and balancing their nucleation processes.This treatment completely transformed mixed intermediate phases into pure preformed perovskite nuclei prior to thermal anneal-ing.Besides,this D-HLH substantially inhibited the oxidation of Sn^(2+) species.This strategy generated a record efficiency of 21.61%,with a Voc of 0.88 V for an MA-free Sn-Pb device,and an efficiency of 23.82%for its tandem device.The unencapsulated devices displayed impressive thermal stability at 85℃ for 300 h and much improved continuous operation stability at MPP for 120 h.
基金financially supported by the National Natural Science Foundation of China(No.21134006)
文摘Phase transition from form Ⅰ to form Ⅲ in syndiotactic polypropylene crystallized at different conditions during tensile deformation at different temperatures was investigated by using in situ synchrotron wide angle X-ray diffraction technique. In all cases, the occurrence of this phase transition was observed. The onset strain of this transition was found to be crystalline thickness decided by crystallization temperature and drawing temperature dependent. The effect of drawing temperature on this phase transition is understood by the changes in mechanical properties with temperature. Moreover, crystalline thickness dependency of the phase transition reveals that this form Ⅰ to from Ⅲ phase transition occurs first in those lamellae with their normal along the stretching direction which have not experienced stress induced melting and recrystallization.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11675253 and 11505278)。
文摘X-ray speckle tracking based methods can provide results with best reported angular accuracy up to 2 nrad. However,duo to the multi-frame requirement for phase retrieval and the possible instability of the x-ray beam, mechanical and background vibration, the actual accuracy will inevitably be degraded by these time-dependent fluctuations. Therefore,not only spatial position, but also temporal features of the speckle patterns need to be considered in order to maintain the superiority of the speckle-based methods. In this paper, we propose a parallel acquisition method with advantages of real time and high accuracy, which has potential applicability to dynamic samples imaging as well as on-line beam monitoring.Through simulations, we demonstrate that the proposed method can reduce the phase error caused by the fluctuations to1% at most compared with current speckle tracking methods. Meanwhile, it can keep the accuracy deterioration within0.03 nrad, making the high theoretical accuracy a reality. Also, we find that waveforms of the incident beam have a little impact on the phase retrieved and will not influence the actual accuracy, which relaxes the requirements for speckle-based experiments.
文摘为进一步改善磁调制DCCT(Direct Current Current Transducer)的温度特性,将磁调制DCCT化整为零,利用灰色相关理论确定了DCCT各部分温度系数对整机的影响程度;同时,还提出了一种磁调制DCCT温度系数综合评价方法。根据磁调制DCCT的工作原理,把DCCT分为PCB(Printed Circuit Board)、线圈和取样电阻三部分,并分别测出DCCT整机、PCB、线圈和取样电阻的温度系数;然后,利用灰色相关理论对7个被测DCCT的各部分温度系数进行关联计算,获得相应的关联系数,从而确定DCCT温度特性的主要因素。根据DCCT温度特性的主、次要因素并结合工程实际,设定了概念DCCT作为参考,利用灰色相关理论计算出7个被测DCCT与参考DCCT的温度系数的灰色关联加权值,完成了被测磁调制DCCT温度性能的综合评价。最后,指出了降低DCCT整机温度敏感性的研究方向。
基金supported by the National Natural Science Foundation of China(NSFC,Nos.62075029,52130304,62105055 and U2032128)the International Cooperation and Exchange Project of Science and Technology Department of Sichuan Province(No.2020YFH0063)+2 种基金The China Postdoctoral Science Foundation(Nos.2020TQ0058 and 2021M7006)the Fundamental Research Funds for the Central Universities(No.ZYGX2021J017)Shanghai Natural Science Foundation(No.19ZR1463300)。
文摘The domain purity,material crystallinity and distribution at the interface between the active layer and the transport layer have an important impact on the performance of organic solar cells(OSCs)and organic photodetectors(OPDs),while this focal issue has received less attention in previous studies.From this perspective,a new method to simultaneously enhance the performance of OSC and OPD is proposed,namely,using a sequential deposition method to first construct a compact stacking structure of dualdonor(D18-Cl:PTO2)eutectic in the donor layer,and then induce the ordered deposition of the acceptor(Y6).Compared with the conventional bulk heterojunction(BHJ),the active layer realized by this method not only improves the crystallinity and stacking order of the constituent material on the surface of the transport layer,but also regulates a good vertical distribution,which is conducive to improving the charge transport and extraction efficiency,reducing the leakage current,and enhancing the stability of the device.As a result,the OSC device based on the D18-Cl:PTO2/Y6 structure achieves a power conversion efficiency of up to 17.65%and good light-degradation stability,which is much better than that of BHJbased OSC(PCE of 16.37%).For the OPD,the dark current at reverse bias is reduced by more than an order of magnitude,and the maximum responsivity is improved to 0.52 A/W through the optimization of the donor phase at the interface.Moreover,the strategy does not require additional post-processing compared to the BHJ preparation,which reduces the device construction cost and process complexity,providing an effective way for developing high-performance organic optoelectronic devices.
基金supported by the National Basic Research Program of China(Grant Nos.2012CB921403 and 2013CB328706)the National Natural Science Foundation of China(Grant Nos.10904030,11004238,11205235,11134012, 11404380,and 11474349)the Strategic Priority Research Program(B) of the Chinese Academy of Sciences(Grant No. XDB07030200)
文摘Varying the film thickness is a precise route to tune the interfacial strain to manipulate the properties of the multiferroic materials.Here,to explore the effects of the interfacial strain on the properties of the multiferroic BiFeO_3films,we investigated thickness-dependent structural and polarization evolutions of the BiFeO_3 films.The epitaxial growth with an atomic stacking sequence of BiO/TiO_2 at the interface was confirmed by scanning transmission electron microscopy.Combining X-ray diffraction experiments and first-principles calculations,a thickness-dependent structural evolution was observed from a fully strained tetragonality to a partially relaxed one without any structural phase transition or rotated twins.The tetragonality(c/a) of the BiFeO_3 films increases as the film thickness decreases,while the polarization is in contrast with this trend,and the size effect including the depolarization field plays a crucial role in this contradiction in thinner films.These findings offer an alternative strategy to manipulate structural and polarization properties by tuning the interfacial strain in epitaxial multiferroic thin films.
基金supported by the National Key Research and Development Program of China(2022YFB3803300)the National Natural Science Foundation of China(51673214)the State Key Laboratory of Powder Metallurgy,Central South University,China。
文摘With the rapid rise in perovskite solar cells(PSCs)performance,it is imperative to develop scalable fabrication techniques to accelerate potential commercialization.However,the power conversion efficiencies(PCEs)of PSCs fabricated via scalable two-step sequential deposition lag far behind the state-of-the-art spin-coated ones.Herein,the additive methylammonium chloride(MACl)is introduced to modulate the crystallization and orientation of a two-step sequential doctorbladed perovskite film in ambient conditions.MACl can significantly improve perovskite film quality and increase grain size and crystallinity,thus decreasing trap density and suppressing nonradiative recombination.Meanwhile,MACl also promotes the preferred face-up orientation of the(100)plane of perovskite film,which is more conducive to the transport and collection of carriers,thereby significantly improving the fill factor.As a result,a champion PCE of 23.14%and excellent longterm stability are achieved for PSCs based on the structure of ITO/SnO_(2)/FA_(1-x)MA_xPb(I_(1-y)Br_y)_3/Spiro-OMeTAD/Ag.The superior PCEs of 21.20%and 17.54%are achieved for 1.03 cm~2 PSC and 10.93 cm~2 mini-module,respectively.These results represent substantial progress in large-scale two-step sequential deposition of high-performance PSCs for practical applications.
