J. Phys. Chem. Lett. 2020, 11, 8, 2934–2940. https://pubs.acs.org/doi/10.1021/acs.jpclett.0c00578.

Organic–inorganic hybrid perovskites have aroused intense research interest because of their excellent physical performance and potential for use in optoelectronic field. Herein, we report two new 2D hybrid lead bromides, (C₇H₁₈N₂)PbBr₄ [C₇H₁₈N₂ is 1,7-diaminoheptane] and (C₉H₂₂N₂)PbBr₄ [C₉H₂₂N₂ is 1,9-diaminononane], both of which possess ⟨100⟩-oriented inorganic layers consisting of corner-sharing octahedra. The optical bandgaps are experimentally determined to be 2.76 eV for (C₇H₁₈N₂)PbBr₄ and 2.78 eV for (C₉H₂₂N₂)PbBr₄. Upon 390 nm excitation, (C₇H₁₈N₂)PbBr₄ exhibits white-light emission centered at 600 nm, and (C₉H₂₂N₂)PbBr₄ exhibits red-light emission centered at 620 nm. These broad photoluminescent spectra originate from the synergistic emission of free excitons (FEs) and self-trapped excitons (STEs). This work provides a strategy for realizing single-component white-light emission and efficient red-light emission in two-dimensional perovskites, demonstrating the vast application prospects of 2D perovskites in photoelectric devices.