Broadband white light emission from one-dimensional zigzag edge-sharing perovskite

Abstract

Low dimensional organic–inorganic halide perovskites have gained a great deal of attention due to their augmented performance in optoelectronic applications, such as solid-state lighting and display. Such compounds consist of a layered structure, such as a multiquantum well structure, where the broadband white-light emission has been observed from diverse metal halide structures. Their broadband emission is ascribed to the self-trapped excitons (STE), which are generated from a deformable structure due to the strong electron-phono coupling. The intensity of the broadband emission is improved by lowing the dimensionality to a 1D perovskite due to the enhanced STE. Herein, we report zigzag edge-sharing 1D perovskites, (4-(aminomethyl)pyridinium)PbBr₄ (C₆H₁₀N₂²⁺ = AMP²⁺), and (AMP)PbCl₄, which are intrinsic deformative structures due to a zigzag connected PbBr₆ (or PbCl₆) octahedra. Through single crystal X-ray diffraction, we have identified the local lattice distortion from the octahedral environmental of Pb²⁺ in the inorganic sheet. The temperature dependent photoluminescence data indicate that the unusual broadband emission in zigzag edge sharing (AMP)PbBr₄ and (AMP)PbCl₄ perovskites is attributed to an intrinsic bulk property, in which photogenerated carriers cause the lattice distortion through electron–phonon coupling. When comparing two compounds, (AMP)PbCl₄ gives more remarkable efficient white-light emission than (AMP)PbBr₄, because the inorganic structure of (AMP)PbCl₄ is a much larger distortion than that of (AMP)PbBr₄, which results in a high color rendering index of 90.21. These established results allow us to systematically design white-light emitting materials from 1D perovskites by fine-tuning their crystal structures.