Regulating surface potential maximizes voltage in all-perovskite tandems

Hao Chen, Aidan Maxwell, Chongwen Li, Sam Teale, Bin Chen, Tong Zhu, Esma Ugur, George Harrison, Luke Grater, Junke Wang, Zaiwei Wang, Lewei Zeng, So Min Park, Lei Chen, Peter Serles, Rasha Abbas Awni, Biwas Subedi, Xiaopeng Zheng, Chuanxiao Xiao, Nikolas J. PodrazaTobin Filleter, Cheng Liu, Yi Yang, Joseph M. Luther, Stefaan De Wolf, Mercouri G. Kanatzidis, Yanfa Yan*, Edward H. Sargent*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

170 Scopus citations


The open-circuit voltage (VOC) deficit in perovskite solar cells is greater in wide-bandgap (over 1.7 eV) cells than in perovskites of roughly 1.5 eV (refs. 1,2). Quasi-Fermi-level-splitting measurements show VOC-limiting recombination at the electron-transport-layer contact3–5. This, we find, stems from inhomogeneous surface potential and poor perovskite–electron transport layer energetic alignment. Common monoammonium surface treatments fail to address this; as an alternative, we introduce diammonium molecules to modify perovskite surface states and achieve a more uniform spatial distribution of surface potential. Using 1,3-propane diammonium, quasi-Fermi-level splitting increases by 90 meV, enabling 1.79 eV perovskite solar cells with a certified 1.33 V VOC and over 19% power conversion efficiency (PCE). Incorporating this layer into a monolithic all-perovskite tandem, we report a record VOC of 2.19 V (89% of the detailed balance VOC limit) and over 27% PCE (26.3% certified quasi-steady state). These tandems retained more than 86% of their initial PCE after 500 h of operation.

Original languageEnglish (US)
Pages (from-to)676-681
Number of pages6
Issue number7945
StatePublished - Jan 26 2023

ASJC Scopus subject areas

  • General


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