Field Effect Passivation in Perovskite Solar Cells by a LiF Interlayer
| Autor: | Dorothee Menzel, Amran Al‐Ashouri, Alvaro Tejada, Igal Levine, Jorge Andrés Guerra, Bernd Rech, Steve Albrecht, Lars Korte |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
500 Naturwissenschaften und Mathematik
C 60 energy level alignment photoemission spectroscopy Renewable Energy Sustainability and the Environment solar cells halide perovskites passivation interlayers General Materials Science 600 Technik Technologie defects C60 defects energy level alignment halide perovskites passivation interlayers photoemission spectroscopy solar cells |
| DOI: | 10.14279/depositonce-16852 |
| Popis: | The fullerene C60 is commonly applied as the electron transport layer in high‐efficiency metal halide perovskite solar cells and has been found to limit their open circuit voltage. Through ultra‐sensitive near‐UV photoelectron spectroscopy in constant final state mode (CFSYS), with an unusually high probing depth of 5–10 nm, the perovskite/C60 interface energetics and defect formation is investigated. It is demonstrated how to consistently determine the energy level alignment by CFSYS and avoid misinterpretations by accounting for the measurement‐induced surface photovoltage in photoactive layer stacks. The energetic offset between the perovskite valence band maximum and the C60 HOMO‐edge is directly determined to be 0.55 eV. Furthermore, the voltage enhancement upon the incorporation of a LiF interlayer at the interface can be attributed to originate from a mild dipole effect and probably the presence of fixed charges, both reducing the hole concentration in the vicinity of the perovskite/C60 interface. This yields a field effect passivation, which overcompensates the observed enhanced defect density in the first monolayers of C60. |
| Databáze: | OpenAIRE |
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