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Composition, Size, and Surface Functionalization dependent Optical Properties of Lead Bromide Perovskite Nanocrystals
- Source :
- J. Phys. Chem. Lett. 2020
- Publication Year :
- 2020
-
Abstract
- The photoluminescence (PL), color purity, and stability of lead halide perovskite nanocrystals depend critically on the surface passivation. We present a study on the temperature dependent PL and PL decay dynamics of lead bromide perovskite nanocrystals characterized by different types of A cations, surface ligands, and nanocrystal sizes. Throughout, we observe a single emission peak from cryogenic to ambient temperature. The PL decay dynamics are dominated by the surface passivation, and a post-synthesis ligand exchange with a quaternary ammonium bromide (QAB) results in a more stable passivation over a larger temperature range. The PL intensity is highest from 50K-250K, which indicates that the ligand binding competes with the thermal energy at ambient temperature. Despite the favorable PL dynamics of nanocrystals passivated with QAB ligands (monoexponential PL decay over a large temperature range, increased PL intensity and stability), the surface passivation still needs improvement toward increased emission intensity in nanocrystal films.<br />Comment: 19 pages, 5 figures
- Subjects :
- Physics - Chemical Physics
Subjects
Details
- Database :
- arXiv
- Journal :
- J. Phys. Chem. Lett. 2020
- Publication Type :
- Report
- Accession number :
- edsarx.2004.08310
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1021/acs.jpclett.0c00266