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Brightening of Dark States in CsPbBr 3 Quantum Dots Caused by Light‐Induced Magnetism
Author(s) -
Lohmann SvenHendrik,
Cai Tong,
Morrow Darien J.,
Chen Ou,
Ma Xuedan
Publication year - 2021
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202101527
Subject(s) - quantum dot , magnetism , photoexcitation , ground state , zeeman effect , perovskite (structure) , condensed matter physics , materials science , optoelectronics , magnetic field , physics , chemistry , atomic physics , excited state , quantum mechanics , crystallography
Lead halide perovskite quantum dots (QDs) have shown great potential for optoelectronic and quantum photonic applications. Although controversy remains about the electronic fine structures of bulk perovskites due to the strong spin‐orbit coupling affecting the conduction bands, compelling evidence indicates that the ground states of perovskite QDs remain dark, limiting their applications in optoelectronic devices. Here, it is demonstrated that photoexcitation can induce large intrinsic magnetic fields in Mn‐doped CsPbBr 3 perovskite QDs. Equivalent to applying an external magnetic field, the light‐induced field causes giant Zeeman splitting to the bright triplet states and brightens the dark singlet ground state, thus effectively rendering a partially bright ground state in the doped QDs. These findings here may contribute to the understanding of the electronic fine structures in perovskite QDs and demonstrate a potential approach for creating semiconductor nanostructures that can serve as bright light sources.