Inverted perovskite solar cells(PSCs)have attracted increasing attention in recent years owing to their low-temperature fabrication proces s.However,they suffer from a limited number of electron transport materials av...Inverted perovskite solar cells(PSCs)have attracted increasing attention in recent years owing to their low-temperature fabrication proces s.However,they suffer from a limited number of electron transport materials available with[6,6]-phenyl C61 butyric acid methyl ester(PCBM)to be the most widely studied based on its appropriate energy levels and high electron mobility.The low relative permittivity and aggregation tendency upon illumination of PCBM,however,compromises the solar cell efficiency whereas its modest hydrophobicity negatively impacts on the device stability.Alternative electron transport materials with desired properties and appropriate degree of hydrophobicity are thus desirable for further developments in inverted PSCs.Herein,we synthesize a triethyleneglycol C60 mono-adduct derivative(termed as EPF03)and test it as a novel electron transport material to replace PCBM in inverted PSCs based on a quadruple cation(RbCsMAFA)perovskite.We also compare this derivative with two novel fullerenes decorated with two(EPF01)or one dodecyl(EPF02)long side chains.The latter two fail to perform efficiently in inverted PSCs whereas the former enabled a power conversion efficiency of 18.43%,which represents a 9%improvement compared to the reference device using PCBM(17.21%).The enhanced performance mainly stems from improved electron extraction and reduced recombination enabled by the insertion of the large relative permittivity amongst other properties of EPF03.Furthermore,our results indicate that triethylene glycol side chains can also passivate perovskite trap states,suppress ion migration and enhance photostability and long-term stability of EPF03 based perovskite solar cells.展开更多
基金T.S.and E.R.S acknowledge funding from the DFG in the frame of the SPP2196(project numbers 424156582 and 423660474)G.C.V.and L.P.Z.acknowledge funding provided by the Special Account for Research Grants of the National and Kapodistrian University of Athens(research projects 14872,16294,16598,17168,and 17784)+2 种基金Dr.Eleftherios K.Pefkianakis and Anastasios Misichronis are acknowledged for some initial contributions in the synthesis of the fullerene derivatives.This work was also supported by the research project"HELIOKERAMOs"-MIS 5066858funded by the Operational Programme(EPAnEK)"Competitiveness,Entrepreneurship and Innovation"(NSRF2014-2020)under the special action"lndustrial Materials"and co-financed by Greece and the European Union(European Regional Development Fund).
文摘Inverted perovskite solar cells(PSCs)have attracted increasing attention in recent years owing to their low-temperature fabrication proces s.However,they suffer from a limited number of electron transport materials available with[6,6]-phenyl C61 butyric acid methyl ester(PCBM)to be the most widely studied based on its appropriate energy levels and high electron mobility.The low relative permittivity and aggregation tendency upon illumination of PCBM,however,compromises the solar cell efficiency whereas its modest hydrophobicity negatively impacts on the device stability.Alternative electron transport materials with desired properties and appropriate degree of hydrophobicity are thus desirable for further developments in inverted PSCs.Herein,we synthesize a triethyleneglycol C60 mono-adduct derivative(termed as EPF03)and test it as a novel electron transport material to replace PCBM in inverted PSCs based on a quadruple cation(RbCsMAFA)perovskite.We also compare this derivative with two novel fullerenes decorated with two(EPF01)or one dodecyl(EPF02)long side chains.The latter two fail to perform efficiently in inverted PSCs whereas the former enabled a power conversion efficiency of 18.43%,which represents a 9%improvement compared to the reference device using PCBM(17.21%).The enhanced performance mainly stems from improved electron extraction and reduced recombination enabled by the insertion of the large relative permittivity amongst other properties of EPF03.Furthermore,our results indicate that triethylene glycol side chains can also passivate perovskite trap states,suppress ion migration and enhance photostability and long-term stability of EPF03 based perovskite solar cells.
