FAPbI</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> and FA(Mn:Pb)I</span><sub><span style="...FAPbI</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> and FA(Mn:Pb)I</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> perovskite films were prepared and evaluated</span></span><span style="font-family:""><span style="font-family:Verdana;"> through steady and transient absorption spectroscopy. According to the analysis using Elliot’s model, there were no considerable differences except for the absorption intensity between FAPbI</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> and FA(Mn:Pb)I</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> perovskite films: the value of the optical gap (</span><i><span style="font-family:Verdana;">E</span><sub><span style="font-family:Verdana;">g</span></sub></i><span style="font-family:Verdana;">) and the position of exciton resonance (</span><i><span style="font-family:Verdana;">E</span><sub><span style="font-family:Verdana;">0</span></sub></i><span style="font-family:Verdana;">) were the same. </span><span style="font-family:Verdana;">The femtosecond transient absorption showed biexponential relaxation</span><span style="font-family:Verdana;"> properties of the charge carriers, suggesting that biexcitons are more easily generated in FA(Mn:Pb)I</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> than FAPbI</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> perovskite. The generation of biexcitons in FA(Mn:Pb)I</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> was also confirmed by the photon pump fluence dependence. Moreover, we were able to estimate the average number of absorbed photons </span><i><span style="font-family:Verdana;"><N></span></i><span style="font-family:Verdana;"> directly from the photon pump power dependence without needing any further experimental measurements such as photoluminescence. Our findings may offer a new way of understanding photoinduced carrier dynamics in perovskite manganites.展开更多
Formamidinium lead triiodide(HC(NH2)2PbI3 or FAPbI3)is a promising light absorber for high-efficiency perovskite solar cells because of its superior light absorption range and thermal stability to CH3NH3PbI3(MAPbI3).U...Formamidinium lead triiodide(HC(NH2)2PbI3 or FAPbI3)is a promising light absorber for high-efficiency perovskite solar cells because of its superior light absorption range and thermal stability to CH3NH3PbI3(MAPbI3).Unfortunately,it is difficult to fabricate high-quality FAPbI3 thin films to surpass the MAPbI3-based cells due to easily forming unwanted but more stable yellow d-phase and thus requiring high annealing-temperature for wanted photovoltaic-active black a-phase.Herein,we reported a novel low-temperature fabrication of highly crystallized a-FAPbI3 film exhibiting uniaxial-oriented nature with large grain sizes up to 2 lm.First-principles energetic calculations predicted that this novel deposition should be ascribed to the formation of a high-energy metastable two-dimensional(2D)intermediate of MAFAPbI3 Cl followed by a spontaneous conversion to a-FAPbI3.The ions exchange reaction during this MAFAPbI3 Cl-FAPbI3 conversion account for the perovskite film uniaxial-oriented grown along the(111)direction.This large-grain and uniaxial-oriented grown a-FAPbI3 based solar cells exhibited an efficiency up to 20.4%accompanying with low density-voltage(J-V)hysteresis and high stability.展开更多
Two-dimensional(2D) lead halide perovskite materials are emerging as one of promising light-absorbing materials in perovskite solar cells(PSCs), which show outstanding stability and defect passivation. Unfortunately, ...Two-dimensional(2D) lead halide perovskite materials are emerging as one of promising light-absorbing materials in perovskite solar cells(PSCs), which show outstanding stability and defect passivation. Unfortunately, the power conversion efficiency(PCE) of those stable 2D PSCs is still far behind that of 3D PSCs. Herein, we reported a simple in-situ growth technique for the ethylenediamine lead iodide(EDAPbI4) layer on the top of formamidinium lead iodide(FAPbI3) layer. The rationally designed layered architecture of2D-3 D perovskite film could improve the PCE of the PSCs. In addition, benefiting from the high moisture resistance and inhibited ion migration of EDAPbI4 layer, the 2D-3D-based devices showed obviously enhanced long-term stability,keeping the initial PCE value for 200 h and 90% of its initial PCE even after 500 h.展开更多
文摘FAPbI</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> and FA(Mn:Pb)I</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> perovskite films were prepared and evaluated</span></span><span style="font-family:""><span style="font-family:Verdana;"> through steady and transient absorption spectroscopy. According to the analysis using Elliot’s model, there were no considerable differences except for the absorption intensity between FAPbI</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> and FA(Mn:Pb)I</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> perovskite films: the value of the optical gap (</span><i><span style="font-family:Verdana;">E</span><sub><span style="font-family:Verdana;">g</span></sub></i><span style="font-family:Verdana;">) and the position of exciton resonance (</span><i><span style="font-family:Verdana;">E</span><sub><span style="font-family:Verdana;">0</span></sub></i><span style="font-family:Verdana;">) were the same. </span><span style="font-family:Verdana;">The femtosecond transient absorption showed biexponential relaxation</span><span style="font-family:Verdana;"> properties of the charge carriers, suggesting that biexcitons are more easily generated in FA(Mn:Pb)I</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> than FAPbI</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> perovskite. The generation of biexcitons in FA(Mn:Pb)I</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> was also confirmed by the photon pump fluence dependence. Moreover, we were able to estimate the average number of absorbed photons </span><i><span style="font-family:Verdana;"><N></span></i><span style="font-family:Verdana;"> directly from the photon pump power dependence without needing any further experimental measurements such as photoluminescence. Our findings may offer a new way of understanding photoinduced carrier dynamics in perovskite manganites.
基金the support of the National Natural Science Foundation of China(21777096,51861145101)the support of the National Natural Science Foundation of China(61722403,11674121)+3 种基金Huoyingdong Grant(151046)the National Key Research and Development Program of China(2016YFB0201204)the support of The Initiative Postdocs Supporting Program(BX20180185)China Postdoctoral Science Foundation(2018M640387)
文摘Formamidinium lead triiodide(HC(NH2)2PbI3 or FAPbI3)is a promising light absorber for high-efficiency perovskite solar cells because of its superior light absorption range and thermal stability to CH3NH3PbI3(MAPbI3).Unfortunately,it is difficult to fabricate high-quality FAPbI3 thin films to surpass the MAPbI3-based cells due to easily forming unwanted but more stable yellow d-phase and thus requiring high annealing-temperature for wanted photovoltaic-active black a-phase.Herein,we reported a novel low-temperature fabrication of highly crystallized a-FAPbI3 film exhibiting uniaxial-oriented nature with large grain sizes up to 2 lm.First-principles energetic calculations predicted that this novel deposition should be ascribed to the formation of a high-energy metastable two-dimensional(2D)intermediate of MAFAPbI3 Cl followed by a spontaneous conversion to a-FAPbI3.The ions exchange reaction during this MAFAPbI3 Cl-FAPbI3 conversion account for the perovskite film uniaxial-oriented grown along the(111)direction.This large-grain and uniaxial-oriented grown a-FAPbI3 based solar cells exhibited an efficiency up to 20.4%accompanying with low density-voltage(J-V)hysteresis and high stability.
基金supported by the National Key Research and Development Program of China (2016YFA0202400)the 111 Project (B16016)+2 种基金the National Natural Science Foundation of China (51572080, 51702096 and U1705256)the Fundamental Research Funds for the Central Universities (2018ZD07, 2017MS021 and 2019MS027)the Double Top Construction Program of North China Electric Power University (XM1805314)
文摘Two-dimensional(2D) lead halide perovskite materials are emerging as one of promising light-absorbing materials in perovskite solar cells(PSCs), which show outstanding stability and defect passivation. Unfortunately, the power conversion efficiency(PCE) of those stable 2D PSCs is still far behind that of 3D PSCs. Herein, we reported a simple in-situ growth technique for the ethylenediamine lead iodide(EDAPbI4) layer on the top of formamidinium lead iodide(FAPbI3) layer. The rationally designed layered architecture of2D-3 D perovskite film could improve the PCE of the PSCs. In addition, benefiting from the high moisture resistance and inhibited ion migration of EDAPbI4 layer, the 2D-3D-based devices showed obviously enhanced long-term stability,keeping the initial PCE value for 200 h and 90% of its initial PCE even after 500 h.
