22.8%-Efficient single-crystal mixed-cation inverted perovskite solar cells with a near-optimal bandgap

Abdullah Yousef Alsalloum, Bekir Turedi, Khulud M. Almasabi, Xiaopeng Zheng, Rounak Naphade, Samuel D. Stranks, Omar F. Mohammed, Osman Bakr

Research output: Contribution to journalArticlepeer-review

141 Scopus citations


Expanding the near-infrared (NIR) response of perovskite materials to approach the ideal bandgap range (1.1-1.4 eV) for single-junction solar cells is an attractive step to unleash the full potential of perovskite solar cells (PSCs). However, polycrystalline formamidinium lead triiodide (FAPbI3)-based absorbers, used in record-efficiency PSCs, currently offer the smallest bandgap that can be achieved for lead-halide perovskite thin films (>100 meV larger than the optimal bandgap). Here, we uncover that utilizing a mixed-cation single-crystal absorber layer (FA0.6MA0.4PbI3) is capable of redshifting the external quantum efficiency (EQE) band edge past that of FAPbI3 polycrystalline solar cells by about 50 meV-only 60 meV larger than that of the top-performing photovoltaic material, GaAs-leading to EQE-verified short-circuit current densities exceeding 26 mA cm-2 without sacrificing the open-circuit voltage (VOC), and therefore, yielding power conversion efficiencies of up to 22.8%. These figures of merit not only set a new record for SC-PSCs and are among the highest reported for inverted-structured-PSCs, but also offer an avenue for lead halide PSCs to advance their performance toward their theoretical Shockley-Queisser Limit potential. This journal is
Original languageEnglish (US)
Pages (from-to)2263-2268
Number of pages6
JournalEnergy and Environmental Science
Issue number4
StatePublished - 2021

Bibliographical note

KAUST Repository Item: Exported on 2021-05-07
Acknowledgements: We acknowledge the use of KAUST Core Lab and KAUST Solar Center facilities. S.D.S acknowledges the Royal Society and Tata Group (UF150033).


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