A cobalt-free perovskite-type Ba0.5Sr0.5A10.1Fe0.9O3-δ （BSAF） chemically studied as solid oxide fuel cell （SOFC） cathode. The ductivity, and electrode polarizations in symmetrical cell based is developed and elec...A cobalt-free perovskite-type Ba0.5Sr0.5A10.1Fe0.9O3-δ （BSAF） chemically studied as solid oxide fuel cell （SOFC） cathode. The ductivity, and electrode polarizations in symmetrical cell based is developed and electro- structures, electrical con- on mixed ion conducting electrolyte were investigated, respectively. The temperature dependence of conductivity of BSAF in air shows a typical semiconductor behavior with positive temperature coefficient up to 450℃ where the conductivity reaches 14.0 S/cm while above this temperature the negative temperature coefficient dominates the total conductivity. Electrochemical charac- terizations show desirable polarization resistance of BSAF cathode in a symmetric cell based on mixed ion conducting electrolyte at 650-700℃, A single SOFC with BSAF cathode shows OCV of 1.0 V and maximum output of 420 mW/cm2 at 700 ℃ with humidified hydrogen fuel and static air oxidant.展开更多
MXenes are emerging two-dimensional(2D)nanomaterials composed of transition metal carbides and/or nitrides and possess unique layered structures with abundant surface functional groups,which enable them with excellent...MXenes are emerging two-dimensional(2D)nanomaterials composed of transition metal carbides and/or nitrides and possess unique layered structures with abundant surface functional groups,which enable them with excellent and tunable properties.MXenes films can be solution-processed in polar solvents and are very suitable for optoelectronic device applications.Especially,Ti_(3)C_(2)T_(x) MXene with the clear advantages of facile synthesis,flexible surface controlling,easily tunable work function,high optical transmittance and excellent conductivity shows great potential for applications in organic/perovskite optoelectronic devices.Therefore,this review briefly introduces the mainstream synthesis methods,optical and electrical properties of MXenes,and comprehensively summarizes the versatile applications of Ti_(3)C_(2)T_(x) MXene in different functional layers(electrode,interface layer and active layer)of organic/perovskite optoelectronic devices including solar cells and light-emitting diodes.Finally,the current application characteristics and the future possibilities of MXenes in organic/perovskite optoelectronic devices are concluded and discussed.展开更多
The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskit...The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskite films.It is meaningful to reduce and passivate the defect states by incorporating additive into the perovskite layer to improve perovskite crystallization.Here an environmental friendly 2D nanomaterial protonated graphitic carbon nitride(p-g-C_(3)N_(4))was successfully synthesized and doped into perovskite layer of carbon-based PSCs.The addition of p-g-C_(3)N_(4)into perovskite precursor solution not only adjusts nucleation and growth rate of methylammonium lead tri-iodide(MAPb I3)crystal for obtaining flat perovskite surface with larger grain size,but also reduces intrinsic defects of perovskite layer.It is found that thep-g-C_(3)N_(4) locates at the perovskite core,and the active groups-NH_(2)/NH_(3)and NH have a hydrogen bond strengthening,which effectively passivates electron traps and enhances the crystal quality of perovskite.As a result,a higher power conversion efficiency of 6.61% is achieved,compared with that doped with g-C_(3)N_(4)(5.93%)and undoped one(4.48%).This work demonstrates a simple method to modify the perovskite film by doping new modified additives and develops a low-cost preparation for carbon-based PSCs.展开更多
Organic-inorganic hybrid perovskites (OHPs) are well-known as light-absorbing materials in solar cells and have recently attracted considerable attention for the applications in resistive switching memory. Previous st...Organic-inorganic hybrid perovskites (OHPs) are well-known as light-absorbing materials in solar cells and have recently attracted considerable attention for the applications in resistive switching memory. Previous studies have shown that ions can migrate to form a conductive channel in perovskites under an external voltage. However, the exact resistance mechanism for Ag or halogens which dominate the resistive behavior is still controversial. Here, we demonstrate a resistive switching memory device based on Ag/FA0.83MA0.17Pb(I0.82Br0.18)3/fluorine doped tin oxide (FTO). The migration of Ag cations and halide anions is demonstrated by energy dispersive X-ray spectroscopy (EDS) after the SET process (positive voltage on Ag). By comparing the I-V behavior of the Au-based devices, it is clear that the conductive channel formed by Ag is the main factor of the switching characteristics for Ag-based devices. Meanwhile, by controlling the appropriate SET voltage, two kinds of resistance characteristics of the analog switch and threshold switch can be realized in the Ag-based device. As a result, it may be possible to implement both data storage and neuromorphic computing in a single device.展开更多
Hybrid organic-inorganic halide perovskite material has been considered as a potential candidate for various optoelectronic applications. However, their high sensitivity to the environment hampers the actual applicati...Hybrid organic-inorganic halide perovskite material has been considered as a potential candidate for various optoelectronic applications. However, their high sensitivity to the environment hampers the actual application.Hence the technology replacing the organic part of the hybrid solar cells needs to be developed. Herein, we fabricated fullyinorganic carbon-based perovskite CsPbBr_3 solar cells via a sequential deposition method with a power conversion efficiency of 2.53% and long-time stability over 20 d under ambient air conditions without any encapsulation. An evolution process from tetragonal CsPb_2Br_5 to CsPb_2Br_5-CsPbBr_3 composites to quasi-cubic CsPbBr_3 was found, which was investigated by scanning electron microscopy, X-ray diffraction spectra, UV-vis absorption spectra and Fourier transform infrared spectroscopy. Detailed evolution process was studied to learn more information about the formation process before10 min. Our results are helpful to the development of inorganic perovskite solar cells and the CsPb_2Br_5 based optoelectronic devices.展开更多
This article presents our experimental studies to unravel the dynamic photovoltaic processes occurring at donor:acceptor(D:A)and electrode:active layer(E:A)interfaces under device-operating conditions by using two uni...This article presents our experimental studies to unravel the dynamic photovoltaic processes occurring at donor:acceptor(D:A)and electrode:active layer(E:A)interfaces under device-operating conditions by using two unique magneto-optical measurements,namely photo-induced capacitance and magnetic field effect measurement.First,we have found that a higher surface polarization of dielectric thin film can decrease the surface charge accumulation at E:A interface.The photo-induced capacitance results indicate that dielectric thin film plays a crucial role in the charge collection in generating photocurrent in organic solar cells.Second,our experimental results from magnetic field effect show that the binding energies of charge transfer(CT)states at D:A interface can be evaluated by using the critical bias required to completely dissociate the CT states.This is the first experimental demonstration that the binding energies of CT states can be measured under deviceoperating conditions.Furthermore,we use our measurement of magnetic field effect to investigate the most popular organic photovoltaic solar cells,organometal halide perovskite photovoltaic devices.The results of magneto-photoluminescence show that the photogenerated electrons and holes are inevitably recombined into electron–hole pairs through a spin-dependent process in the perovskites.Therefore,using spin polarizations can present a new design to control the photovoltaic loss in perovskites-based photovoltaic devices.Also,we found that introducing D:A interface can largely affect the bulk charge dissociation and recombination in perovskite solar cells.This indicates that the interfacial and bulk photovoltaic processes are internally coupled in developing photovoltaic actions in perovskite devices.Clearly,these magneto-optical measurements show a great potential to unravel the deeper photovoltaic processes occurring at D:A and E:A interfaces in both organic bulk-heterojunction and perovskite solar cells under device-operating conditions.展开更多
文摘A cobalt-free perovskite-type Ba0.5Sr0.5A10.1Fe0.9O3-δ （BSAF） chemically studied as solid oxide fuel cell （SOFC） cathode. The ductivity, and electrode polarizations in symmetrical cell based is developed and electro- structures, electrical con- on mixed ion conducting electrolyte were investigated, respectively. The temperature dependence of conductivity of BSAF in air shows a typical semiconductor behavior with positive temperature coefficient up to 450℃ where the conductivity reaches 14.0 S/cm while above this temperature the negative temperature coefficient dominates the total conductivity. Electrochemical charac- terizations show desirable polarization resistance of BSAF cathode in a symmetric cell based on mixed ion conducting electrolyte at 650-700℃, A single SOFC with BSAF cathode shows OCV of 1.0 V and maximum output of 420 mW/cm2 at 700 ℃ with humidified hydrogen fuel and static air oxidant.
基金Projects(52063010,51961010)supported by the National Natural Science Foundation of China。
文摘MXenes are emerging two-dimensional(2D)nanomaterials composed of transition metal carbides and/or nitrides and possess unique layered structures with abundant surface functional groups,which enable them with excellent and tunable properties.MXenes films can be solution-processed in polar solvents and are very suitable for optoelectronic device applications.Especially,Ti_(3)C_(2)T_(x) MXene with the clear advantages of facile synthesis,flexible surface controlling,easily tunable work function,high optical transmittance and excellent conductivity shows great potential for applications in organic/perovskite optoelectronic devices.Therefore,this review briefly introduces the mainstream synthesis methods,optical and electrical properties of MXenes,and comprehensively summarizes the versatile applications of Ti_(3)C_(2)T_(x) MXene in different functional layers(electrode,interface layer and active layer)of organic/perovskite optoelectronic devices including solar cells and light-emitting diodes.Finally,the current application characteristics and the future possibilities of MXenes in organic/perovskite optoelectronic devices are concluded and discussed.
基金supported by the Natural Science Foundation of Liaoning Province(No.20170540086)the Open Fund of the State Key Laboratory of Molecular Reaction Dynamics in Dalian Institute of Chemical Physics,Chinese Academy of Sciences(SKLMRD-K202107,K202216)。
文摘The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskite films.It is meaningful to reduce and passivate the defect states by incorporating additive into the perovskite layer to improve perovskite crystallization.Here an environmental friendly 2D nanomaterial protonated graphitic carbon nitride(p-g-C_(3)N_(4))was successfully synthesized and doped into perovskite layer of carbon-based PSCs.The addition of p-g-C_(3)N_(4)into perovskite precursor solution not only adjusts nucleation and growth rate of methylammonium lead tri-iodide(MAPb I3)crystal for obtaining flat perovskite surface with larger grain size,but also reduces intrinsic defects of perovskite layer.It is found that thep-g-C_(3)N_(4) locates at the perovskite core,and the active groups-NH_(2)/NH_(3)and NH have a hydrogen bond strengthening,which effectively passivates electron traps and enhances the crystal quality of perovskite.As a result,a higher power conversion efficiency of 6.61% is achieved,compared with that doped with g-C_(3)N_(4)(5.93%)and undoped one(4.48%).This work demonstrates a simple method to modify the perovskite film by doping new modified additives and develops a low-cost preparation for carbon-based PSCs.
基金the financial supports from the National Natural Science Foundation of China(51872036,51773025)Dalian Science and Technology Innovation Fund(2018J12GX033)National Key R&D Program of China(2017YFB0405604)
文摘Organic-inorganic hybrid perovskites (OHPs) are well-known as light-absorbing materials in solar cells and have recently attracted considerable attention for the applications in resistive switching memory. Previous studies have shown that ions can migrate to form a conductive channel in perovskites under an external voltage. However, the exact resistance mechanism for Ag or halogens which dominate the resistive behavior is still controversial. Here, we demonstrate a resistive switching memory device based on Ag/FA0.83MA0.17Pb(I0.82Br0.18)3/fluorine doped tin oxide (FTO). The migration of Ag cations and halide anions is demonstrated by energy dispersive X-ray spectroscopy (EDS) after the SET process (positive voltage on Ag). By comparing the I-V behavior of the Au-based devices, it is clear that the conductive channel formed by Ag is the main factor of the switching characteristics for Ag-based devices. Meanwhile, by controlling the appropriate SET voltage, two kinds of resistance characteristics of the analog switch and threshold switch can be realized in the Ag-based device. As a result, it may be possible to implement both data storage and neuromorphic computing in a single device.
基金supported by the National Basic Research Program of China (2016YFA0202400 and 2015CB932200)the National Natural Science Foundation of China (21403247)+2 种基金Distinguished Youth Foundation of Anhui Province (1708085J09)the Fundamental Research Funds for the Central Universities (2017XS079)the Major/Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology (2016FXZY003)
文摘Hybrid organic-inorganic halide perovskite material has been considered as a potential candidate for various optoelectronic applications. However, their high sensitivity to the environment hampers the actual application.Hence the technology replacing the organic part of the hybrid solar cells needs to be developed. Herein, we fabricated fullyinorganic carbon-based perovskite CsPbBr_3 solar cells via a sequential deposition method with a power conversion efficiency of 2.53% and long-time stability over 20 d under ambient air conditions without any encapsulation. An evolution process from tetragonal CsPb_2Br_5 to CsPb_2Br_5-CsPbBr_3 composites to quasi-cubic CsPbBr_3 was found, which was investigated by scanning electron microscopy, X-ray diffraction spectra, UV-vis absorption spectra and Fourier transform infrared spectroscopy. Detailed evolution process was studied to learn more information about the formation process before10 min. Our results are helpful to the development of inorganic perovskite solar cells and the CsPb_2Br_5 based optoelectronic devices.
基金supported by the National Science Foundation of the United States(ECCS-1102011,ECCS-0644945,and CBET-1438181)the support from Sustainable Energy Education and Research Center and Center for Materials Processing at the University of Tennessee+1 种基金This research was partially conducted at the Center for Nanophase Materials Sciences based on user project(CNMS2012-106,CNMS2012-107,CNMS-2012-108),which is sponsored at Oak Ridge National Laboratory by the Division of Scientific User Facilities,U.S.Department of Energythe University of Tennessee also acknowledge the project support from the National Natural Science Foundation of China(21161160445,61077020)
文摘This article presents our experimental studies to unravel the dynamic photovoltaic processes occurring at donor:acceptor(D:A)and electrode:active layer(E:A)interfaces under device-operating conditions by using two unique magneto-optical measurements,namely photo-induced capacitance and magnetic field effect measurement.First,we have found that a higher surface polarization of dielectric thin film can decrease the surface charge accumulation at E:A interface.The photo-induced capacitance results indicate that dielectric thin film plays a crucial role in the charge collection in generating photocurrent in organic solar cells.Second,our experimental results from magnetic field effect show that the binding energies of charge transfer(CT)states at D:A interface can be evaluated by using the critical bias required to completely dissociate the CT states.This is the first experimental demonstration that the binding energies of CT states can be measured under deviceoperating conditions.Furthermore,we use our measurement of magnetic field effect to investigate the most popular organic photovoltaic solar cells,organometal halide perovskite photovoltaic devices.The results of magneto-photoluminescence show that the photogenerated electrons and holes are inevitably recombined into electron–hole pairs through a spin-dependent process in the perovskites.Therefore,using spin polarizations can present a new design to control the photovoltaic loss in perovskites-based photovoltaic devices.Also,we found that introducing D:A interface can largely affect the bulk charge dissociation and recombination in perovskite solar cells.This indicates that the interfacial and bulk photovoltaic processes are internally coupled in developing photovoltaic actions in perovskite devices.Clearly,these magneto-optical measurements show a great potential to unravel the deeper photovoltaic processes occurring at D:A and E:A interfaces in both organic bulk-heterojunction and perovskite solar cells under device-operating conditions.
