https://doi.org/10.1051/epjconf/202328705009
Exciton fine structure of a single highly anisotropic CsPbBr3 nanocrystal
1 Institut des NanoSciences de Paris, CNRS UMR 7588, Sorbonne Université, F-75005 Paris, France ;
2 LR01ES15 Laboratoire de Physique des Matériaux: Structure et Propriétés, Faculté des Sciences de Bizerte, Université de Carthage, Bizerte 7021, Tunisia ;
* Corresponding author: chamarro@insp.jussieu.fr
Published online: 18 October 2023
We measured the photoluminescence (PL) of single CsPbBr3 nanocrystals (NCs) that have a highly anisotropic shape and orthorhombic crystal phase. As the thickness of these NCs is much more smaller than the other two dimensions, they are also called nanoplatelets (NPLs). We obtain PL spectra characterized by doublets separated in energy by about 2 meV in average and showing orthogonal and linearly polarized polar lines. We identified these doublets as the two bright-exciton states of the exciton fine structure contained in the plane of the NPLs. By a comparison between theory and experiments, we were able to obtain fundamental parameters as tetragonal and orthorhombic crystal field. We measured and analysed the time-resolved PL evolution as a function of temperature of small ensemble of NPLs. We thus succeed at framing the experimental value of the bright-dark exciton splitting (5-7meV) that is slightly smaller than the theoretical value.
© The Authors, published by EDP Sciences, 2023
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