Martin Stolterfoht, Pietro Caprioglio, Christian Michael Wolff, Jose A. Marquez, Joleik Nordmann, Shanshan Zhang, Daniel Rothhardt, Ulrich Hörmann, Yohai Amir, Alex Redinger, Lukas Kegelmann, Fengshuo Zu, Steve Albrecht, Norbert Koch, Thomas Kirchartz, Michael Saliba, Thomas Unold, Dieter Neher
- Charge transport layers (CTLs) are key components of diffusion controlled perovskite solar cells, however, they can induce additional non-radiative recombination pathways which limit the open circuit voltage (V-OC) of the cell. In order to realize the full thermodynamic potential of the perovskite absorber, both the electron and hole transport layer (ETL/HTL) need to be as selective as possible. By measuring the photoluminescence yield of perovskite/CTL heterojunctions, we quantify the non-radiative interfacial recombination currents in pin- and nip-type cells including high efficiency devices (21.4%). Our study comprises a wide range of commonly used CTLs, including various hole-transporting polymers, spiro-OMeTAD, metal oxides and fullerenes. We find that all studied CTLs limit the V-OC by inducing an additional non-radiative recombination current that is in most cases substantially larger than the loss in the neat perovskite and that the least-selective interface sets the upper limit for the V-OC of the device. Importantly, theCharge transport layers (CTLs) are key components of diffusion controlled perovskite solar cells, however, they can induce additional non-radiative recombination pathways which limit the open circuit voltage (V-OC) of the cell. In order to realize the full thermodynamic potential of the perovskite absorber, both the electron and hole transport layer (ETL/HTL) need to be as selective as possible. By measuring the photoluminescence yield of perovskite/CTL heterojunctions, we quantify the non-radiative interfacial recombination currents in pin- and nip-type cells including high efficiency devices (21.4%). Our study comprises a wide range of commonly used CTLs, including various hole-transporting polymers, spiro-OMeTAD, metal oxides and fullerenes. We find that all studied CTLs limit the V-OC by inducing an additional non-radiative recombination current that is in most cases substantially larger than the loss in the neat perovskite and that the least-selective interface sets the upper limit for the V-OC of the device. Importantly, the V-OC equals the internal quasi-Fermi level splitting (QFLS) in the absorber layer only in high efficiency cells, while in poor performing devices, the V-OC is substantially lower than the QFLS. Using ultraviolet photoelectron spectroscopy and differential charging capacitance experiments we show that this is due to an energy level mis-alignment at the p-interface. The findings are corroborated by rigorous device simulations which outline important considerations to maximize the V-OC. This work highlights that the challenge to suppress non-radiative recombination losses in perovskite cells on their way to the radiative limit lies in proper energy level alignment and in suppression of defect recombination at the interfaces.…
MetadatenAuthor details: | Martin StolterfohtORCiDGND, Pietro CaprioglioORCiDGND, Christian Michael WolffORCiDGND, Jose A. MarquezORCiD, Joleik Nordmann, Shanshan Zhang, Daniel RothhardtORCiD, Ulrich HörmannORCiDGND, Yohai Amir, Alex RedingerORCiD, Lukas Kegelmann, Fengshuo Zu, Steve Albrecht, Norbert KochORCiD, Thomas KirchartzORCiD, Michael SalibaORCiD, Thomas UnoldORCiD, Dieter NeherORCiDGND |
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DOI: | https://doi.org/10.1039/c9ee02020a |
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ISSN: | 1754-5692 |
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ISSN: | 1754-5706 |
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Title of parent work (English): | Energy & environmental science |
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Publisher: | Royal Society of Chemistry |
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Place of publishing: | Cambridge |
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Publication type: | Article |
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Language: | English |
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Year of first publication: | 2019 |
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Publication year: | 2019 |
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Release date: | 2020/11/26 |
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Volume: | 12 |
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Issue: | 9 |
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Number of pages: | 11 |
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First page: | 2778 |
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Last Page: | 2788 |
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Funding institution: | HyPerCells (a joint graduate school of the Potsdam University); Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)German Research Foundation (DFG) [182087777 - SFB 951]; HyPerCells (HZB) |
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Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
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DDC classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
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Peer review: | Referiert |
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Publishing method: | Open Access / Green Open-Access |
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