Abstract
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 language | American English |
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Pages (from-to) | 676-681 |
Number of pages | 6 |
Journal | Nature |
Volume | 613 |
Issue number | 7945 |
DOIs | |
State | Published - 2023 |
Bibliographical note
Publisher Copyright:© 2022, The Author(s), under exclusive licence to Springer Nature Limited.
NREL Publication Number
- NREL/JA-5900-83296
Keywords
- all perovskite tandem
- electronic properties
- perovskite solar cell
- photonic devices