Deep Exciton Self-Trapping Cu-Based Perovskite Nanocrystals for Optoelectronic Applications

Herein, we demonstrate a facile ligand-mediated hot injection strategy for manipulating the growth of Cs3Cu2Br5 nanocrystals to systematically control their morphology and properties. The use of ligands with different chain lengths (C6, C9, and C18) resulted in different morphologies. All of the nanocrystals exhibited large band gaps, and their optical absorption spectra depended on their morphology. Furthermore, we demonstrated that the photoluminescence of the nanocrystals can be modulated by replacing the halogen atom Br with I or Cl. The electronegativity of the halogen atom was correlated with the excitonic effect and structural deformation in the nanocrystal.