While serious stability issues impede the commercialization of perovskite solar cells(PSCs),two-dime nsional(2D)perovskites based on fluorinated bulky cations have emerged as more intrinsically stable materials.Howeve...While serious stability issues impede the commercialization of perovskite solar cells(PSCs),two-dime nsional(2D)perovskites based on fluorinated bulky cations have emerged as more intrinsically stable materials.However,the influence of fluorination degree of the bulky aromatic cation on the per-formance of resulting PSCs has not been scrutinized.Here,2D perovskites(FxPEA)_(2)PbI_(4)(x=1,2,3,5)are grown in situ on the surface of the three-dime nsion al(3D)perovskite and dem on strate effective passivation of the surface defects of 3D perovskite.The power conversion efficiency(PCE)of the optimized devices were boosted from 20.75%for the control device to 21.09%,22.06%,22.74%and 21.86%for 2D/3D devices treated with 4-fluorophenethylamine iodide,3,5-difluorophenylethylamine iodide,2,4,5-trifluoroethylphenylethylamine iodide,and 1,2,3,4,5-pentafluorophenylethylamine iodide,respectively.We firstly reported two unexplored RP-type layered perovskites with F_(2)PEAI and F_(3)PEAI as bulky cations.The combined experimental and theoretical analysis revealed the reasons behind the various morphology,device performances,dynamic behavior,and humidity stability.The best performing F_(5)PEAI-treated device retaining 95.0%of its initial PCE under ambient atmosphere(with RH of 60%±5%)without encapsulation for 300 h storage.This work provides useful guidance for selecting fluorinated bulky cations with different molecular electronic properties,which will play an essential role in further improving the performance/stability of PSCs for the sake of further commercialization.展开更多
The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase tr...The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase transition and defects-induced non-ideal interfacial recombination, which significantly induces energy loss and hinders the improvement of device performance. Herein, we employed 4-fluorophenylmethylammonium iodide(F-PMAI) to modulate surface structure and energy level alignment of the FA-based perovskite films. The superior optoelectronic films were obtained with reduced trap density, pure α-phase FAPbI_(3) and favorable energy band bending. The lifetime of photogenerated charge carriers increased from 489.3 ns to 1010.6 ns, and a more “p-type” perovskite film was obtained by the post-treatment with F-PMAI. Following this strategy, we demonstrated an improved power conversion efficiency of 22.59% for the FA-based PSCs with an open-circuit voltage loss of 399 m V.展开更多
Hole transporting materials(HTMs)play an unparalleled role in heightening the stability and photovoltaic performance of perovskite solar cells(PSCs).The organic small molecule spiro-OMeTAD is frequently utilized for H...Hole transporting materials(HTMs)play an unparalleled role in heightening the stability and photovoltaic performance of perovskite solar cells(PSCs).The organic small molecule spiro-OMeTAD is frequently utilized for HTM in PSCs.However,the raw spiro-OMeTAD without dopant would be harmful to the development of highly efficient PSCs,due to its unsatisfied hole mobility and conductivity.Therefore,we introduce an inorganic dopant(chromium trioxide,CrO_(3))into the lithium-salt doped spiro-OMeTAD.Because of the exclamatory oxidizability of CrO_(3),it can accelerate the oxidation of spiro-OMeTAD and thereby enhancing the hole mobility of HTM.The introduction of CrO_(3) not only substantially decreases the density of defects,but also adjusts spiro-OMeTAD energy band,and thus effectively suppresses the hysteresis and improving stability of PSCs.In the end,we obtained a power conversion efficiency(PCE)as high as 22.6%after doping CrO_(3) in spiro-OMeTAD.The facile,low cost and outstanding photovoltaic performance render CrO_(3) an excellent dopant for HTMs in PSCs.展开更多
基金financial support from the National Natural Science Foundation of China (Grant No. 21975260)the financial support from the National Natural Science Foundation of China (Grant No. 22078241).
文摘While serious stability issues impede the commercialization of perovskite solar cells(PSCs),two-dime nsional(2D)perovskites based on fluorinated bulky cations have emerged as more intrinsically stable materials.However,the influence of fluorination degree of the bulky aromatic cation on the per-formance of resulting PSCs has not been scrutinized.Here,2D perovskites(FxPEA)_(2)PbI_(4)(x=1,2,3,5)are grown in situ on the surface of the three-dime nsion al(3D)perovskite and dem on strate effective passivation of the surface defects of 3D perovskite.The power conversion efficiency(PCE)of the optimized devices were boosted from 20.75%for the control device to 21.09%,22.06%,22.74%and 21.86%for 2D/3D devices treated with 4-fluorophenethylamine iodide,3,5-difluorophenylethylamine iodide,2,4,5-trifluoroethylphenylethylamine iodide,and 1,2,3,4,5-pentafluorophenylethylamine iodide,respectively.We firstly reported two unexplored RP-type layered perovskites with F_(2)PEAI and F_(3)PEAI as bulky cations.The combined experimental and theoretical analysis revealed the reasons behind the various morphology,device performances,dynamic behavior,and humidity stability.The best performing F_(5)PEAI-treated device retaining 95.0%of its initial PCE under ambient atmosphere(with RH of 60%±5%)without encapsulation for 300 h storage.This work provides useful guidance for selecting fluorinated bulky cations with different molecular electronic properties,which will play an essential role in further improving the performance/stability of PSCs for the sake of further commercialization.
基金funded by the National Natural Science Foundation of China(62004165)the China Postdoctoral Science Foundation(2020M670036)+2 种基金the Natural Science Foundation of Shaanxi Province,China(2020JQ195)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-007,2020GXLH-Z-025)the Fundamental Research Funds for the Central Universities。
文摘The vast majority of high-performance perovskite solar cells(PSCs) are based on a formamidinium lead iodide(FAPbI_(3))-dominant composition. Nevertheless, the FA-based perovskite films suffer from undesirable phase transition and defects-induced non-ideal interfacial recombination, which significantly induces energy loss and hinders the improvement of device performance. Herein, we employed 4-fluorophenylmethylammonium iodide(F-PMAI) to modulate surface structure and energy level alignment of the FA-based perovskite films. The superior optoelectronic films were obtained with reduced trap density, pure α-phase FAPbI_(3) and favorable energy band bending. The lifetime of photogenerated charge carriers increased from 489.3 ns to 1010.6 ns, and a more “p-type” perovskite film was obtained by the post-treatment with F-PMAI. Following this strategy, we demonstrated an improved power conversion efficiency of 22.59% for the FA-based PSCs with an open-circuit voltage loss of 399 m V.
基金jointly supported by the National Natural Science Foundation of China(Nos.51972123,U1705256,61804058,21771066)the Promotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University(ZQN-706)the Cultivation Program for Postgraduate in Scientific Research Innovation Ability of Huaqiao University(No.19011081020)。
文摘Hole transporting materials(HTMs)play an unparalleled role in heightening the stability and photovoltaic performance of perovskite solar cells(PSCs).The organic small molecule spiro-OMeTAD is frequently utilized for HTM in PSCs.However,the raw spiro-OMeTAD without dopant would be harmful to the development of highly efficient PSCs,due to its unsatisfied hole mobility and conductivity.Therefore,we introduce an inorganic dopant(chromium trioxide,CrO_(3))into the lithium-salt doped spiro-OMeTAD.Because of the exclamatory oxidizability of CrO_(3),it can accelerate the oxidation of spiro-OMeTAD and thereby enhancing the hole mobility of HTM.The introduction of CrO_(3) not only substantially decreases the density of defects,but also adjusts spiro-OMeTAD energy band,and thus effectively suppresses the hysteresis and improving stability of PSCs.In the end,we obtained a power conversion efficiency(PCE)as high as 22.6%after doping CrO_(3) in spiro-OMeTAD.The facile,low cost and outstanding photovoltaic performance render CrO_(3) an excellent dopant for HTMs in PSCs.
