Is there a polaron signature in angle-resolved photoemission of CsPbBr₃?
Creators
- 1. Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
- 2. Institut für Physik und Astronomie, Universita ̈t Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany
- 3. Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Ju ̈lich and JARA, 52425, Jülich Germany
- 4. Institute of Energy and Climate Research IEK-5 Photovoltaics, Forschungszentrum Ju ̈lich, 52425 Juelich, Germany
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Description
The formation of large polarons has been proposed as reason for the high defect tolerance, low mobility, low charge carrier trapping and low nonradiative recombination rates of lead halide perovskites. Recently, direct evidence for large-polaron formation has been reported from a 50% effective mass enhancement in angle-resolved photoemission of CsPbBr₃ over theory for the orthorhombic structure. We present in-depth band dispersion measurements of CsPbBr₃ and GW calculations which lead to almost identical effective masses at the valence band maximum of 0.203+/-0.016 m₀ in experiment and 0.217 m₀ in orthorhombic theory. We argue that the effective mass can be explained solely on the basis of electron-electron correlation and large polaron formation cannot be concluded from photoemission data.
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References
Journal reference (Paper where the data is discussed) M Sajedi, M Krivenkov, D Marchenko, J Sánchez-Barriga, A K. Chandran, A Varykhalov, E D. L. Rienks, I Aguilera, S Blügel, O Rader, arXiv(2022), doi: 10.48550/ARXIV.2203.15070