title: Neutral and Charged Exciton Fine Structure in Single Lead Halide Perovskite Nanocrystals Revealed by Magneto-optical Spectroscopy.
abstract: Revealing the crystal structure of lead halide perovskite nanocrystals is essential for the optimization of stability of these emerging materials in applications such as solar cells, photodetectors, and light-emitting devices. We use magneto-photoluminescence spectroscopy of individual perovskite CsPbBr3nanocrystals as a unique tool to determine their crystal structure, which imprints distinct signatures in the excitonic sublevels of charge complexes at low temperatures. At zero magnetic field, the identification of two classes of photoluminescence spectra, displaying either two or three sublevels in their exciton fine structure, shows evidence for the existence of two crystalline structures, namely tetragonal D4hand orthorhombic D2hphases. Magnetic field shifts, splitting, and coupling of the sublevels provide a determination of the diamagnetic coefficient and valuable information on the exciton g-factor and its anisotropic character. Moreover, this spectroscopic study reveals the optical properties of charged excitons and allows the extraction of the electron and hole g-factors for perovskite systems.
authors.affiliation: LP2N, Université de Bordeaux , Talence F-33405, France.|LP2N, Institut d'Optique and CNRS , Talence F-33405, France.
authors.forename: Ming
authors.initials: M
authors.lastname: Fu
authors.affiliation: LP2N, Université de Bordeaux , Talence F-33405, France.|LP2N, Institut d'Optique and CNRS , Talence F-33405, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Tamarat
authors.affiliation: Department of Physics and Materials Science and Centre for Functional Photonics (CFP), City University of Hong Kong , 83 Tat Chee Avenue Kowloon, Hong Kong, SAR China.
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.affiliation: Fonctions Optiques pour les Technologies de l'Information, FOTON UMR 6082, CNRS, INSA de Rennes , 35708 Rennes, France.
authors.forename: Jacky
authors.initials: J
authors.lastname: Even
authors.affiliation: Department of Physics and Materials Science and Centre for Functional Photonics (CFP), City University of Hong Kong , 83 Tat Chee Avenue Kowloon, Hong Kong, SAR China.
authors.forename: Andrey L
authors.identifier: 0000-0002-8263-8141
authors.initials: AL
authors.lastname: Rogach
authors.affiliation: LP2N, Université de Bordeaux , Talence F-33405, France.|LP2N, Institut d'Optique and CNRS , Talence F-33405, France.
authors.forename: Brahim
authors.initials: B
authors.lastname: Lounis
keywords: Lead halide perovskite; band-edge fine structure; exciton; magneto-optical spectroscopy; single nanocrystals; trion