Fluorinated and nitrogen-doped graphdiyne(F/N-GDY)have been used in the active layer of perovskite solar cells(PSCs)for the first time.The introduction of heteroatoms turns out to be an effective method for boosted so...Fluorinated and nitrogen-doped graphdiyne(F/N-GDY)have been used in the active layer of perovskite solar cells(PSCs)for the first time.The introduction of heteroatoms turns out to be an effective method for boosted solar cells performance,which increases by 32.8%and 33.0%,better than the pristine or GDY doped PSCs.The enhanced performance can be attributed firstly to the superiority of F/N-GDY originated from the unique structure and optoelectronic properties of GDY.Then,both can further reduce surface defects and improve surface and bulk crystallinity than pristine GDY.What's more,efficiency increase caused by F-GDY is mainly attributed to the improvement of fill factor(FF),while the higher short-circuit current(Jsc)plays more important role by N-GDY doping.Most importantly,the detailed mechanism brought about by doping of F-GDY or N-GDY is expounded by systematical characterizations,especially the synchrotron radiation technique.Doping of F-GDY causes Pb and forms new Pb-F bonds between F-GDY and Pb ions.Doping of N-GDY or GDY brings about Pb(N-GDY doping induces more deviation than that of GDY due to the participation of imine N),improving its electron density and conductivity.展开更多
The multilayer Laue lens(MLL) is a diffractive focusing optical element which can focus hard X-rays down to the nanometer scale. In this study, a WSi_(2)/Si multilayer structure consisting of 1736 layers, with a 7.2-n...The multilayer Laue lens(MLL) is a diffractive focusing optical element which can focus hard X-rays down to the nanometer scale. In this study, a WSi_(2)/Si multilayer structure consisting of 1736 layers, with a 7.2-nm-thick outermost layer and a total thickness of 17 μm, is prepared by DC magnetron sputtering. Regarding the thin film growth rate calibration, we correct the long-term growth rate drift from 2 to 0.6%, as measured by the grazing incidence X-ray reflectivity(GIXRR). A one-dimensional line focusing resolution of 64 nm was achieved,while the diffraction efficiency was 38% of the-1 order of the MLL Shanghai Synchrotron Radiation Facility(SSRF) with the BL15U beamline.展开更多
Gold nanoparticle arrays fabricated via layerby-layer technique were investigated using grazing-incidence small-angle X-ray scattering(GISAXS) method.Samples containing two gold nanoparticle layers that were separated...Gold nanoparticle arrays fabricated via layerby-layer technique were investigated using grazing-incidence small-angle X-ray scattering(GISAXS) method.Samples containing two gold nanoparticle layers that were separated by 5,11,15 and 21 poly electrolyte(PE) interlayers were studied.By using different X-ray incident angles,correlations of gold nanoparticles(GNPs) in the same layer and in two different layers were investigated.It is found that both sideway correlations between GNPs in the same layer and vertical correlation between two gold nanoparticle layers depend on the thickness of PE interlayers.According to sideway correlation,the size of GNPs is determined to be(13.0±0.5) nm in all of the four samples,which was also proved by scanning electron microscopy(SEM) and theoretical calculation of form factor of spherical particles.From vertical correlation,distance between two gold nanoparticle layers was determined for sample with 11,15 and 21 PE layers.These distances can be reasonably explained with the number of PE layers and the thickness of single PE layer.These results indicate that by repeated depositing of oppositely charged PE layers,a true three-dimensional(3 D) nanostructure can eventually be designed.展开更多
The introduction of solvent additives is one of the most common approaches for enhancing the power conversion efficiency of organic solar cells(OSCs).However,the use of solvent additives has some negative effects,and ...The introduction of solvent additives is one of the most common approaches for enhancing the power conversion efficiency of organic solar cells(OSCs).However,the use of solvent additives has some negative effects,and an understanding of how solvent additives affect OSCs is currently limited.In this study,we developed an in situ grazing incidence wide-angle X-ray scattering(GIWAXS)technique in the SAXS beamline(BL16 B1)at the Shanghai Synchrotron Radiation Facility,and the additive effects of1,8-diiodoctane(DIO)on the performance and morphology evolution of the PTB7-Th/PC71 BM device was investigated in depth.The results revealed that the crystal size increased with the volume ratio of DIO,and a drastic evolution of lattice space and crystal coherence length was observed during thermal annealing for the first time,to our knowledge.The discrete PC71BM molecules dissolved by DIO have an effect similar to that of the nucleating agent for PTB7-Th,boosting the crystallization of PTB7-Th,reducing phase separation,and inducing more drastic morphological evolution during thermal annealing.Our results provide a deep perspective for the mechanism of solvent additives,while also showing the significance and feasibility of the in situ GIWAXS technique we developed at BL16 B1.展开更多
Purpose A new mobile grazing-incidence X-ray absorption fine spectroscopy(GIXAFS)endstation was developed at Beijing Synchrotron Radiation Facility(BSRF)to improve the function of general XAFS beamlines and extend the...Purpose A new mobile grazing-incidence X-ray absorption fine spectroscopy(GIXAFS)endstation was developed at Beijing Synchrotron Radiation Facility(BSRF)to improve the function of general XAFS beamlines and extend their capabilities to a wider user community.Methods We developed a facile GIXAFS endstation through modifying the regular XAFS in grazing-incidence geometry.Additionally,a soller slit,filter,photographic film and tiny lead sheets were assembled to improve the signal-to-noise ratio of XAFS data.Furtherly,combined with time-resolved quick scanning XAFS(QXAFS)techniques,the systems can perform in situ XAFS measurement to study materials under operando condition.Results The GIXAFS had been used to collect the Ga K-edge XAFS of InGaN thin film on sapphire substrate,which demonstrated that signal-to-noise ratio of XAFS data had been greatly improved through suppressing the effect of substrate diffractions.Moreover,the feasibility of GIXAFS-QXAFS combination was illustrated with in situ exploring the degradation of organic-inorganic perovskites under X-ray radiation.Conclusion A new mobile and facile GIXAFS endstation has been developed for thin films study.Based on the photographic film and lead sheets,the contamination of the XAFS from the matrix is minimized.Further combined with QXAFS techniques,the systems are used to reveal the X-ray-induced organic-inorganic perovskite thin films photodegrading process,which proved their successful application in the time-resolved measurements,extending the capabilities of general beamlines available to a wider user community.展开更多
Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport...Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport layers in solar cells.Various strategies have been applied to achieve optimal electrical properties,including base solution post-treatments.However,the working mechanism and the exact details of the structural transformations induced by base post-treatments are still unclear.In this work,we present a comparative study on the post-treatment effects of using three common and green alkali base solutions:namely LiOH,NaOH,and KOH.The structural modifications induced in the film by the base post-treatments are studied by techniques including atomic force microscopy,grazing-incidence wide-angle X-ray scattering,ultraviolet–visible–near-infrared spectroscopy,and attenuated total reflectance Fourier-transform infrared spectroscopy.Base-induced structural modifications are responsible for an improvement in the TE power factor of the films,which depends on the basic solution used.The results are explained on the basis of the different affinity between the alkali cations and the PSS chains,which determines PEDOT dedoping.The results presented here shed light on the structural reorganization occurring in PEDOT:PSS when exposed to high-pH solutions and may serve as inspiration to create future pH-/ion-responsive devices for various applications.展开更多
In or Ga gradients in the Cu(In1-xGax)Se2(CIGS)absorbing layer lead to change the lattice parameters of the absorbing layer,giving rise to the bandgap grading in the absorbing layer which is directly associated with t...In or Ga gradients in the Cu(In1-xGax)Se2(CIGS)absorbing layer lead to change the lattice parameters of the absorbing layer,giving rise to the bandgap grading in the absorbing layer which is directly associated with the degree of absorbing ability of the CIGS solar cell.We tried to characterize the depth profile of the lattice parameters of the CIGS absorbing layer using a glancing incidence X-ray diffraction(GIXRD)technique,and then investigate the bandgap grading of the CIGS absorbing layer.When the glancing incident angle increased from 0.50 to 5.00°,the a and c lattice parameters of the CIGS absorbing layer gradually decreased from 5.7776(3)to 5.6905(2)?,and 11.3917(3)to 11.2114(2)?,respectively.The depth profile of the lattice parameters as a function of the incident angle was consistent with vertical variation in the compositionof In or Ga with depth in the absorbing layer.The variation of the lattice parameters was due to the difference between the ionic radius of In and Ga co-occupying at the same crystallographic site.According to the results of the depth profile of the refined parameters using GIXRD data,the bandgap of the CIGS absorber layer was graded over a range of 1.222-1.532 eV.This approach allows to determine the In or Ga gradients in the CIGS absorbing layer,and to nondestructively guess the bandgap depth profile through the refinement of the lattice parameters using GIXRD data on the assumption that the changes of the lattice parameters or unit-cell volume follow a good approximation to Vegard’s law.展开更多
基金supported financially by the National Key Research and Development Program of China(Nos.2018YFA0703504 and 2017YFA0403403)the National Basic Research Program of China(No.2016YFA0203200)+1 种基金the National Natural Science Foundation of China(Nos.21971242,11705211,and U1532104)Young Scientist Innovative Foundation of IHEP(Nos.E05469U2 and Y95461C).
文摘Fluorinated and nitrogen-doped graphdiyne(F/N-GDY)have been used in the active layer of perovskite solar cells(PSCs)for the first time.The introduction of heteroatoms turns out to be an effective method for boosted solar cells performance,which increases by 32.8%and 33.0%,better than the pristine or GDY doped PSCs.The enhanced performance can be attributed firstly to the superiority of F/N-GDY originated from the unique structure and optoelectronic properties of GDY.Then,both can further reduce surface defects and improve surface and bulk crystallinity than pristine GDY.What's more,efficiency increase caused by F-GDY is mainly attributed to the improvement of fill factor(FF),while the higher short-circuit current(Jsc)plays more important role by N-GDY doping.Most importantly,the detailed mechanism brought about by doping of F-GDY or N-GDY is expounded by systematical characterizations,especially the synchrotron radiation technique.Doping of F-GDY causes Pb and forms new Pb-F bonds between F-GDY and Pb ions.Doping of N-GDY or GDY brings about Pb(N-GDY doping induces more deviation than that of GDY due to the participation of imine N),improving its electron density and conductivity.
基金the National Natural Science Foundation of China(Nos.12005250,U1932167,and U1432244).
文摘The multilayer Laue lens(MLL) is a diffractive focusing optical element which can focus hard X-rays down to the nanometer scale. In this study, a WSi_(2)/Si multilayer structure consisting of 1736 layers, with a 7.2-nm-thick outermost layer and a total thickness of 17 μm, is prepared by DC magnetron sputtering. Regarding the thin film growth rate calibration, we correct the long-term growth rate drift from 2 to 0.6%, as measured by the grazing incidence X-ray reflectivity(GIXRR). A one-dimensional line focusing resolution of 64 nm was achieved,while the diffraction efficiency was 38% of the-1 order of the MLL Shanghai Synchrotron Radiation Facility(SSRF) with the BL15U beamline.
基金financially supported by the Framework Programme 7 Project NANOGOLD (No.ERAS-989409)。
文摘Gold nanoparticle arrays fabricated via layerby-layer technique were investigated using grazing-incidence small-angle X-ray scattering(GISAXS) method.Samples containing two gold nanoparticle layers that were separated by 5,11,15 and 21 poly electrolyte(PE) interlayers were studied.By using different X-ray incident angles,correlations of gold nanoparticles(GNPs) in the same layer and in two different layers were investigated.It is found that both sideway correlations between GNPs in the same layer and vertical correlation between two gold nanoparticle layers depend on the thickness of PE interlayers.According to sideway correlation,the size of GNPs is determined to be(13.0±0.5) nm in all of the four samples,which was also proved by scanning electron microscopy(SEM) and theoretical calculation of form factor of spherical particles.From vertical correlation,distance between two gold nanoparticle layers was determined for sample with 11,15 and 21 PE layers.These distances can be reasonably explained with the number of PE layers and the thickness of single PE layer.These results indicate that by repeated depositing of oppositely charged PE layers,a true three-dimensional(3 D) nanostructure can eventually be designed.
基金supported by the National Natural Science Foundation of China(Nos.U1932118,2005324)the National Key R&D Program of China(Nos.2017YFA0403002,2018YFB0704201)。
文摘The introduction of solvent additives is one of the most common approaches for enhancing the power conversion efficiency of organic solar cells(OSCs).However,the use of solvent additives has some negative effects,and an understanding of how solvent additives affect OSCs is currently limited.In this study,we developed an in situ grazing incidence wide-angle X-ray scattering(GIWAXS)technique in the SAXS beamline(BL16 B1)at the Shanghai Synchrotron Radiation Facility,and the additive effects of1,8-diiodoctane(DIO)on the performance and morphology evolution of the PTB7-Th/PC71 BM device was investigated in depth.The results revealed that the crystal size increased with the volume ratio of DIO,and a drastic evolution of lattice space and crystal coherence length was observed during thermal annealing for the first time,to our knowledge.The discrete PC71BM molecules dissolved by DIO have an effect similar to that of the nucleating agent for PTB7-Th,boosting the crystallization of PTB7-Th,reducing phase separation,and inducing more drastic morphological evolution during thermal annealing.Our results provide a deep perspective for the mechanism of solvent additives,while also showing the significance and feasibility of the in situ GIWAXS technique we developed at BL16 B1.
基金support by the National Key Research and Development Program of China(Grant No.2017YFA0403400)the National Natural Science Foundation of China(NSFC)(U1932201,U2032202)
文摘Purpose A new mobile grazing-incidence X-ray absorption fine spectroscopy(GIXAFS)endstation was developed at Beijing Synchrotron Radiation Facility(BSRF)to improve the function of general XAFS beamlines and extend their capabilities to a wider user community.Methods We developed a facile GIXAFS endstation through modifying the regular XAFS in grazing-incidence geometry.Additionally,a soller slit,filter,photographic film and tiny lead sheets were assembled to improve the signal-to-noise ratio of XAFS data.Furtherly,combined with time-resolved quick scanning XAFS(QXAFS)techniques,the systems can perform in situ XAFS measurement to study materials under operando condition.Results The GIXAFS had been used to collect the Ga K-edge XAFS of InGaN thin film on sapphire substrate,which demonstrated that signal-to-noise ratio of XAFS data had been greatly improved through suppressing the effect of substrate diffractions.Moreover,the feasibility of GIXAFS-QXAFS combination was illustrated with in situ exploring the degradation of organic-inorganic perovskites under X-ray radiation.Conclusion A new mobile and facile GIXAFS endstation has been developed for thin films study.Based on the photographic film and lead sheets,the contamination of the XAFS from the matrix is minimized.Further combined with QXAFS techniques,the systems are used to reveal the X-ray-induced organic-inorganic perovskite thin films photodegrading process,which proved their successful application in the time-resolved measurements,extending the capabilities of general beamlines available to a wider user community.
基金the Zernike Institute for Advanced Materials for the startup fundsChina Scholarship Council(201606340158)。
文摘Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such as sensors,thermoelectric(TE)generators,and hole transport layers in solar cells.Various strategies have been applied to achieve optimal electrical properties,including base solution post-treatments.However,the working mechanism and the exact details of the structural transformations induced by base post-treatments are still unclear.In this work,we present a comparative study on the post-treatment effects of using three common and green alkali base solutions:namely LiOH,NaOH,and KOH.The structural modifications induced in the film by the base post-treatments are studied by techniques including atomic force microscopy,grazing-incidence wide-angle X-ray scattering,ultraviolet–visible–near-infrared spectroscopy,and attenuated total reflectance Fourier-transform infrared spectroscopy.Base-induced structural modifications are responsible for an improvement in the TE power factor of the films,which depends on the basic solution used.The results are explained on the basis of the different affinity between the alkali cations and the PSS chains,which determines PEDOT dedoping.The results presented here shed light on the structural reorganization occurring in PEDOT:PSS when exposed to high-pH solutions and may serve as inspiration to create future pH-/ion-responsive devices for various applications.
基金supported by Korea Research Institute of Standards and Science(KRISS–2019–GP2019-0014)。
文摘In or Ga gradients in the Cu(In1-xGax)Se2(CIGS)absorbing layer lead to change the lattice parameters of the absorbing layer,giving rise to the bandgap grading in the absorbing layer which is directly associated with the degree of absorbing ability of the CIGS solar cell.We tried to characterize the depth profile of the lattice parameters of the CIGS absorbing layer using a glancing incidence X-ray diffraction(GIXRD)technique,and then investigate the bandgap grading of the CIGS absorbing layer.When the glancing incident angle increased from 0.50 to 5.00°,the a and c lattice parameters of the CIGS absorbing layer gradually decreased from 5.7776(3)to 5.6905(2)?,and 11.3917(3)to 11.2114(2)?,respectively.The depth profile of the lattice parameters as a function of the incident angle was consistent with vertical variation in the compositionof In or Ga with depth in the absorbing layer.The variation of the lattice parameters was due to the difference between the ionic radius of In and Ga co-occupying at the same crystallographic site.According to the results of the depth profile of the refined parameters using GIXRD data,the bandgap of the CIGS absorber layer was graded over a range of 1.222-1.532 eV.This approach allows to determine the In or Ga gradients in the CIGS absorbing layer,and to nondestructively guess the bandgap depth profile through the refinement of the lattice parameters using GIXRD data on the assumption that the changes of the lattice parameters or unit-cell volume follow a good approximation to Vegard’s law.
