Cesium lead iodide(CsPbI_(3)) perovskite has gained great attention in the photovoltaic(PV) community because of its unique optoelectronic properties, good chemical stability and appropriate bandgap for sunlight harve...Cesium lead iodide(CsPbI_(3)) perovskite has gained great attention in the photovoltaic(PV) community because of its unique optoelectronic properties, good chemical stability and appropriate bandgap for sunlight harvesting applications. However, compared to solar cells fabricated from organic-inorganic hybrid perovskites, the commercialization of devices based on all-inorganic CsPbI_(3) perovskites still faces many challenges regarding PV performance and long-term stability. In this work, we discovered that tetrabutylammonium bromide(TBABr) post-treatment to CsPbI_(3) perovskite films could achieve synergistic stabilization with both TBA+cation intercalation and Br-doping. Such TBA^(+) cation intercalation leads to onedimensional capping with TBAPb I3 perovskite formed in situ, while the Br-induced crystal secondary growth helps effectively passivate the defects of CsPbI_(3) perovskite, thus enhancing the stability. In addition, the incorporation of TBABr can improve energy-level alignment and reduce interfacial charge recombination loss for better device performance. Finally, the highly stable TBABr-treated CsPbI_(3)-based perovskite solar cells show reproducible photovoltaic performance with a champion efficiency up to 19.04%, while retaining 90% of the initial efficiency after 500 h storage without encapsulation.展开更多
FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method...FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method for surface passivation of FA-Cs perovskite layer in devices.However,it is still controversial whether the PEAI post-treatment would form two-dimensional(2D)perovskite PEA_(2)PbI_(4) capping layer or just result in PEA+terminated surface.Here in this work,the function of PEAI post-treatment on FA-Cs mixed-cation perovskite FA_(1-x)Cs_(x)PbI_(3)(x=0.1–0.9)with varied Cs contents is elucidated.With increased Cs content,the FA-Cs perovskite shows higher resistance to the cation exchange between FA+and PEA+.This Cs-content-dependent cation exchange results in the different PEAI reaction preferences with FA-Cs mixed-cation perovskites.Furthermore,higher Cs content with stronger resistance to cation exchange reaction leads to a wider processing window for post-treatment and defect passivation,which is beneficial for the fabrication of large-scale photovoltaic devices.展开更多
Perovskite solar cells(PSCs)have undergone a dramatic increase in laboratory-scale effi ciency to more than 25%,which is comparable to Si-based single-junction solar cell effi ciency.However,the effi ciency of PSCs dr...Perovskite solar cells(PSCs)have undergone a dramatic increase in laboratory-scale effi ciency to more than 25%,which is comparable to Si-based single-junction solar cell effi ciency.However,the effi ciency of PSCs drops from laboratory-scale to large-scale perovskite solar modules(PSMs)because of the poor quality of perovskite fi lms,and the increased resistance of large-area PSMs obstructs practical PSC applications.An in-depth understanding of the fabricating processes is vital for precisely controlling the quality of large-area perovskite fi lms,and a suitable structural design for PSMs plays an impor-tant role in minimizing energy loss.In this review,we discuss several solution-based deposition techniques for large-area perovskite fi lms and the eff ects of operating conditions on the fi lms.Furthermore,diff erent structural designs for PSMs are presented,including the processing technologies and device architectures.展开更多
Light-emitting diodes(LEDs)based on perovskites show great potential in lighting and display applications.However,although perovskite films with high photoluminescence quantum efficiencies are commonly achieved,the ef...Light-emitting diodes(LEDs)based on perovskites show great potential in lighting and display applications.However,although perovskite films with high photoluminescence quantum efficiencies are commonly achieved,the efficiencies of perovskite LEDs are largely limited by the low light out-coupling efficiency.Here,we show that high-efficiency perovskite LEDs with a high external quantum efficiency of 20.2% and an ultrahigh radiant exitance up to 114.9mWcm^(−2) can be achieved by employing the microcavity effect to enhance light extraction.The enhanced microcavity effect and light outcoupling efficiency are confirmed by the study of angle-dependent emission profiles.Our results show that both the optical and electrical properties of the device need to be optimized to achieve high-performance perovskite LEDs.展开更多
Recent works showed that high efficient perovskite light-emitting diodes can be achieved from solution-processed,self-organized multiple quantum wells(MQWs)with an energy cascade.We investigate how the mixing of QWs w...Recent works showed that high efficient perovskite light-emitting diodes can be achieved from solution-processed,self-organized multiple quantum wells(MQWs)with an energy cascade.We investigate how the mixing of QWs with different band gaps can affect the perovskite LED device performance.We find that the annealing process can significantly affect the constitution of the MQWs films,where the dominant phase can evolve from large band gap QWs to small band gap QWs.The optimal constitution for LED application lies in a transition point of small-n QWs dominant phase to large-n QWs dominant phase,when the MQW film presents highest photoluminescence while still remains uniform film morphology.展开更多
The efficiency and stability of typical three-dimensional(3D)MAPbI_(3)perovskite-based solar cells are highly restricted,due to the weak interaction between methylammonium(MA^(+))and[PbI 6]4-octahedra in the 3D struct...The efficiency and stability of typical three-dimensional(3D)MAPbI_(3)perovskite-based solar cells are highly restricted,due to the weak interaction between methylammonium(MA^(+))and[PbI 6]4-octahedra in the 3D structure,which can cause the ion migration and the related defects.Here,we found that the in situ-grown perovskitoid TEAPbI_(3)layer on 3D MAPbI_(3)can inhibit the MA^(+)migration in a polar solvent,thus enhancing the thermal and moisture stability of perovskite films.The crystal structure and orientation of TEAPbI_(3)are reported for the first time by single crystal and synchrotron radiation analysis.The ultra-thin perovskitoid layer can reduce the trap states and accelerate photo-carrier diffusion in perovskite solar cells,as confirmed by ultra-fast spectroscopy.The power conversion efficiency of TEAPbI_(3)-MAPbI_(3)based solar cells increases from 18.87%to 21.79%with enhanced stability.This work suggests that passivation and stabilization by in situ-grown perovskitoid can be a promising strategy for efficient and stable perovskite solar cells.展开更多
Low-bandgap formamidinium-cesium(FA-Cs)perovskites of FA_(1-x)CsxPbI_(3)(x<0:1)are promising candidates for efficient and robust perovskite solar cells,but their black-phase crystallization is very sensitive to ann...Low-bandgap formamidinium-cesium(FA-Cs)perovskites of FA_(1-x)CsxPbI_(3)(x<0:1)are promising candidates for efficient and robust perovskite solar cells,but their black-phase crystallization is very sensitive to annealing temperature.Unfortunately,the low heat conductivity of the glass substrate builds up a temperature gradient within from bottom to top and makes the initial annealing temperature of the perovskite film lower than the black-phase crystallization point(~150℃).Herein,we take advantage of such temperature gradient for the diffusional growth of high-quality FA-Cs perovskites by introducing a thermally unstable MA^(+)cation,which would firstly formα-phase FA-MA-Cs mixed perovskites with low formation energy at the hot bottom of the perovskite films in the early annealing stage.The natural gradient annealing temperature and the thermally unstable MA^(+)cation then lead to the bottom-to-top diffusional growth of highly orientatedα-phase FA-Cs perovskite,which exhibits 10-fold of enhanced crystallinity and reduced trap density(~3:85×10^(15) cm^(−3)).Eventually,such FA-Cs perovskite films were fabricated into stable solar cell devices with champion efficiency up to 23.11%,among the highest efficiency of MA-free perovskite solar cells.展开更多
基金support from the National Natural Science Foundation of China (Grant Nos. 22025505, 51861145101,21777096)the Program of Shanghai Academic/Technology Research Leader (Grant No. 20XD1422200)+1 种基金the Key Laboratory of Resource Chemistry,Ministry of Education (Grant No.KLRC_ME2003)support from the Energy Materials and Surface Sciences Unit of the Okinawa Institute of Science and Technology Graduate University。
文摘Cesium lead iodide(CsPbI_(3)) perovskite has gained great attention in the photovoltaic(PV) community because of its unique optoelectronic properties, good chemical stability and appropriate bandgap for sunlight harvesting applications. However, compared to solar cells fabricated from organic-inorganic hybrid perovskites, the commercialization of devices based on all-inorganic CsPbI_(3) perovskites still faces many challenges regarding PV performance and long-term stability. In this work, we discovered that tetrabutylammonium bromide(TBABr) post-treatment to CsPbI_(3) perovskite films could achieve synergistic stabilization with both TBA+cation intercalation and Br-doping. Such TBA^(+) cation intercalation leads to onedimensional capping with TBAPb I3 perovskite formed in situ, while the Br-induced crystal secondary growth helps effectively passivate the defects of CsPbI_(3) perovskite, thus enhancing the stability. In addition, the incorporation of TBABr can improve energy-level alignment and reduce interfacial charge recombination loss for better device performance. Finally, the highly stable TBABr-treated CsPbI_(3)-based perovskite solar cells show reproducible photovoltaic performance with a champion efficiency up to 19.04%, while retaining 90% of the initial efficiency after 500 h storage without encapsulation.
基金supported by the National Key Research and Development Program of China(2017YFE0127100)the National Natural Science Foundation of China(NSFC,Grant 22025505)+1 种基金the Program of Shanghai Academic Technology Research Leader(Grant 20XD1422200)the Key Laboratory of Resource Chemistry,Ministry of Education(KLRC_ME2003)。
文摘FA-Cs mixed-cation perovskite has been reported as a promising candidate for obtaining highly efficient and stable photovoltaic devices.Phenylethylamine iodide(PEAI)post-treatment is a widely used and effective method for surface passivation of FA-Cs perovskite layer in devices.However,it is still controversial whether the PEAI post-treatment would form two-dimensional(2D)perovskite PEA_(2)PbI_(4) capping layer or just result in PEA+terminated surface.Here in this work,the function of PEAI post-treatment on FA-Cs mixed-cation perovskite FA_(1-x)Cs_(x)PbI_(3)(x=0.1–0.9)with varied Cs contents is elucidated.With increased Cs content,the FA-Cs perovskite shows higher resistance to the cation exchange between FA+and PEA+.This Cs-content-dependent cation exchange results in the different PEAI reaction preferences with FA-Cs mixed-cation perovskites.Furthermore,higher Cs content with stronger resistance to cation exchange reaction leads to a wider processing window for post-treatment and defect passivation,which is beneficial for the fabrication of large-scale photovoltaic devices.
基金supported by the National Key Research and Development Program of China(No.2017YFE0127100)the National Natural Science Foundation of China(No.22025505)the Program of Shanghai Academic/Technology Research Leader(No.20XD1422200).
文摘Perovskite solar cells(PSCs)have undergone a dramatic increase in laboratory-scale effi ciency to more than 25%,which is comparable to Si-based single-junction solar cell effi ciency.However,the effi ciency of PSCs drops from laboratory-scale to large-scale perovskite solar modules(PSMs)because of the poor quality of perovskite fi lms,and the increased resistance of large-area PSMs obstructs practical PSC applications.An in-depth understanding of the fabricating processes is vital for precisely controlling the quality of large-area perovskite fi lms,and a suitable structural design for PSMs plays an impor-tant role in minimizing energy loss.In this review,we discuss several solution-based deposition techniques for large-area perovskite fi lms and the eff ects of operating conditions on the fi lms.Furthermore,diff erent structural designs for PSMs are presented,including the processing technologies and device architectures.
基金This work was supported by the National Natural Science Foundation of China(22025505,22220102002,and 22209111)Program of Shanghai Academic/Technology Research Leader(20XD1422200).
基金financially supported by the Major Research Plan of the National Natural Science Foundation of China(91733302)the National Natural Science Foundation of China(11804156,51972171,61935017,61725502,61875084,and 61974066)+2 种基金the National Key Research and Development Program of China(2018YFB0406704)the Natural Science Foundation of Jiangsu Province,China(BK20180085)the Synergetic Innovation Center for Organic Electronics and Information Displays.
文摘Light-emitting diodes(LEDs)based on perovskites show great potential in lighting and display applications.However,although perovskite films with high photoluminescence quantum efficiencies are commonly achieved,the efficiencies of perovskite LEDs are largely limited by the low light out-coupling efficiency.Here,we show that high-efficiency perovskite LEDs with a high external quantum efficiency of 20.2% and an ultrahigh radiant exitance up to 114.9mWcm^(−2) can be achieved by employing the microcavity effect to enhance light extraction.The enhanced microcavity effect and light outcoupling efficiency are confirmed by the study of angle-dependent emission profiles.Our results show that both the optical and electrical properties of the device need to be optimized to achieve high-performance perovskite LEDs.
基金This work is financially supported by the Major Research Plan of the National Natural Science Foundation of China(91733302)the National Basic Research Program of China-Fundamental Studies of Perovskite Solar Cells(2015CB932200)+5 种基金National Key Research and Development Program of China(2017YFB0404501)the Natural Science Foundation of Jiangsu Province,China(BK20140952,BK20150043,BK20170991)the National Natural Science Foundation of China(11474164,61634001,51703094)the Joint Research Program between China and European Union(2016YFE0112000)the National Science Fund for Distinguished Young Scholars(61725502)the Synergetic Innovation Center for Organic Electronics and Information Displays.
文摘Recent works showed that high efficient perovskite light-emitting diodes can be achieved from solution-processed,self-organized multiple quantum wells(MQWs)with an energy cascade.We investigate how the mixing of QWs with different band gaps can affect the perovskite LED device performance.We find that the annealing process can significantly affect the constitution of the MQWs films,where the dominant phase can evolve from large band gap QWs to small band gap QWs.The optimal constitution for LED application lies in a transition point of small-n QWs dominant phase to large-n QWs dominant phase,when the MQW film presents highest photoluminescence while still remains uniform film morphology.
基金This work was supported by the NSFC(Grant 51861145101,21777096,22025505)Program of Shanghai Academic Technology Research Leader(Grant 20XD1422200)+1 种基金Cultivating fund of Frontiers Science Center for Transformative Molecules(2019PT02)China Postdoctoral Science Foundation(2020M671110).
文摘The efficiency and stability of typical three-dimensional(3D)MAPbI_(3)perovskite-based solar cells are highly restricted,due to the weak interaction between methylammonium(MA^(+))and[PbI 6]4-octahedra in the 3D structure,which can cause the ion migration and the related defects.Here,we found that the in situ-grown perovskitoid TEAPbI_(3)layer on 3D MAPbI_(3)can inhibit the MA^(+)migration in a polar solvent,thus enhancing the thermal and moisture stability of perovskite films.The crystal structure and orientation of TEAPbI_(3)are reported for the first time by single crystal and synchrotron radiation analysis.The ultra-thin perovskitoid layer can reduce the trap states and accelerate photo-carrier diffusion in perovskite solar cells,as confirmed by ultra-fast spectroscopy.The power conversion efficiency of TEAPbI_(3)-MAPbI_(3)based solar cells increases from 18.87%to 21.79%with enhanced stability.This work suggests that passivation and stabilization by in situ-grown perovskitoid can be a promising strategy for efficient and stable perovskite solar cells.
基金support of the NSFC(Grant Nos.22025505 and 21777096)Program of Shanghai Academic/-Technology Research Leader(Grant No.20XD1422200)+2 种基金Cultivating fund of Frontiers Science Center for Transformative Molecules(2019PT02)TZ acknowledges the support of the Initiative Postdocs Supporting Program(Grant No.BX20180185)China Postdoctoral Science Foundation(Grant No.2018M640387)。
文摘Low-bandgap formamidinium-cesium(FA-Cs)perovskites of FA_(1-x)CsxPbI_(3)(x<0:1)are promising candidates for efficient and robust perovskite solar cells,but their black-phase crystallization is very sensitive to annealing temperature.Unfortunately,the low heat conductivity of the glass substrate builds up a temperature gradient within from bottom to top and makes the initial annealing temperature of the perovskite film lower than the black-phase crystallization point(~150℃).Herein,we take advantage of such temperature gradient for the diffusional growth of high-quality FA-Cs perovskites by introducing a thermally unstable MA^(+)cation,which would firstly formα-phase FA-MA-Cs mixed perovskites with low formation energy at the hot bottom of the perovskite films in the early annealing stage.The natural gradient annealing temperature and the thermally unstable MA^(+)cation then lead to the bottom-to-top diffusional growth of highly orientatedα-phase FA-Cs perovskite,which exhibits 10-fold of enhanced crystallinity and reduced trap density(~3:85×10^(15) cm^(−3)).Eventually,such FA-Cs perovskite films were fabricated into stable solar cell devices with champion efficiency up to 23.11%,among the highest efficiency of MA-free perovskite solar cells.
