Tandem solar cells offer a pathway beyond the Shockley-Queisser limit of single-junction devices.Among these,all-perovskite tandems are especially appealing for their low cost and facile fabrication.However,non-radiat...Tandem solar cells offer a pathway beyond the Shockley-Queisser limit of single-junction devices.Among these,all-perovskite tandems are especially appealing for their low cost and facile fabrication.However,non-radiative recombination at the interfaces between perovskite absorbers and chargetransport layers continues to impede their translation from theoretical potential to experimental realization.Here,we develop a molecular-design strategy for dual interface engineering of the perovskite photoactive layer,addressing the vertical inhomogeneity inherent to solution-processed films.We demonstrate that the efficacy of surface modification hinges on matching the alkylchain length of diammonium cations to the local lattice dimensions of each sub-cell.By applying tailored alkyl diammonium salts to both the top and bottom interfaces,we achieve dramatic reductions in non-radiative loss,lowered interfacial energy barriers,and suppressed vacancy formation.As a result,the power conversion efficiencies(PCEs)of single-junction cells improved from 16.7%to 20.5%for the high-bandgap sub-cell and from 18.9%to 22.4%for the low-bandgap sub-cell.Integration into a monolithic tandem architecture yields a PCE of 27.5%,and the device retains 90%of its initial performance under maximum-power-point operation(AM 1.5G,100 mW cm^(-2))at room temperature in ambient air for over 500 h.This work establishes a clear,structureguided paradigm for interface passivation in perovskite tandems,unlocking both high efficiency and operational durability.展开更多
基金Funding information National Research Foundation of Korea(NRF),Grant/Award Number:RS-2024-00350701Technology Innovation Program Development Program funded by the Ministry of Trade,Industry&Energy(MOTIE),Grant/Award Number:RS-2023-00265858。
文摘Tandem solar cells offer a pathway beyond the Shockley-Queisser limit of single-junction devices.Among these,all-perovskite tandems are especially appealing for their low cost and facile fabrication.However,non-radiative recombination at the interfaces between perovskite absorbers and chargetransport layers continues to impede their translation from theoretical potential to experimental realization.Here,we develop a molecular-design strategy for dual interface engineering of the perovskite photoactive layer,addressing the vertical inhomogeneity inherent to solution-processed films.We demonstrate that the efficacy of surface modification hinges on matching the alkylchain length of diammonium cations to the local lattice dimensions of each sub-cell.By applying tailored alkyl diammonium salts to both the top and bottom interfaces,we achieve dramatic reductions in non-radiative loss,lowered interfacial energy barriers,and suppressed vacancy formation.As a result,the power conversion efficiencies(PCEs)of single-junction cells improved from 16.7%to 20.5%for the high-bandgap sub-cell and from 18.9%to 22.4%for the low-bandgap sub-cell.Integration into a monolithic tandem architecture yields a PCE of 27.5%,and the device retains 90%of its initial performance under maximum-power-point operation(AM 1.5G,100 mW cm^(-2))at room temperature in ambient air for over 500 h.This work establishes a clear,structureguided paradigm for interface passivation in perovskite tandems,unlocking both high efficiency and operational durability.
