A One-Dimensional Broadband Emissive Hybrid Lead Iodide with Face-Sharing PbI₆ Octahedral Chains

Abstract

One-dimensional (1D) organic−inorganic hybrid lead halides with unique core−shell quantum wire structures and splendid photoluminescence properties have been considered one of the most promising high-efficiency broadband emitters. However, studies on the broadband emissions in 1D purely face-shared lead iodide hybrids are still rare so far. Herein, we report on a new 1D lead iodide hybrid, (2cepyH)PbI 3 (2cepy = 1-(2-chloroethyl)pyrrolidine), characterized with face-sharing PbI 6 octahedral chains. Upon UV photoexcitation, this material shows broadband yellow emissions originating from the self-trapped excitons associated with distorted Pb−I lattices on account of the strong exciton−phonon coupling, as proved by variable-temperature emission spectra. Moreover, experimental and calculated results reveal that (2cepyH)PbI 3 is an indirect bandgap semiconductor, the band structures of which are governed by inorganic parts. Our work represents the first broadband emitter based on a 1D face-shared lead iodide hybrid and opens a new way to obtain the novel broadband emission materials.

Molecular engineering of naphthalene spacers in low-dimensional perovskites

“…S7, ESI†) of the (1,5-DAN)PbI 4 , (2,6-DAN)PbI 4 , (1-AN)PbI 3 , and (2-AN)PbI 3 perovskites are 47.5 meV, 72.2 meV, 39.3 meV, and 31.9 meV, respectively. They are close to reported values for low-dimensional halide perovskites such as (ClC 6 H 13 N)PbI 3 ( E a = 48.45 meV) 13 and (C 13 H 16 N 2 )Pb 2 Cl 6 ( E a = 44.76 meV). 16…”

Zero-Dimensional (Piperidinium)2MnBr4: Ring Puckering-Induced Isostructural Transition and Strong Electron–Phonon Coupling-Mediated Self-Trapped Exciton Emission

“…Interest in organic–inorganic hybrid (OIH) metal halides has been burgeoning as they have emerged as a forefront candidate for light-harvesting and optoelectronic applications and possess fascinating multifunctional properties like magnetism, ferroelectricity, and so forth. − These properties are mainly governed by the crystal structure of these compounds. − Especially, the structural dimensionality has a great impact on the photophysical properties . The three-dimensional (3D) hybrid halide perovskites can exhibit long-range carrier transport and low exciton binding energy, hence making them promising materials for solar cells. − However, they demonstrate a narrow emission band resulting from free exciton emission and are not compatible for single-component white-light LED applications. , On the other hand, low-dimensional compounds exhibit broader emission bands and higher photoluminescence quantum yield (PLQY) than 3D compounds. − Among the low-dimensional materials, the zero-dimensional (0D) compounds exhibit the highest quantum yield due to internal quantum confinement, including the broad emission spectrum. , The broadening of emission linewidth has been attributed to self-trapped exciton (STE) emission. , STEs are transient defect species in the excited state resulting from elastic structural distortion in a soft deformable lattice. , STEs are analogous to Frenkel-like excitons or small polarons with a small exciton Bohr radius. , Therefore, charge carrier localization is imperative for STE emission, which is achieved in 0D compounds. , In such a low-dimensional lattice, the photoexcited charge carriers are stabilized by strong electron–phonon coupling . The longitudinal optical phonon scatters the charge carrier by Fröhlich interaction, limiting its mobility and facilitating localization. , Although there is no direct confirmation of STE emission, the large Stokes shift, broad emission spectrum, long lifetimes of photoexcited electrons, soft liquid-like crystalline lattice, and electron–phonon coupling are the signatures of exciton self-trapping …”

Two-Dimensional Organic–Inorganic Hybrid Materials with Dielectric Switching and Photoluminescence Properties

“…Because of the deficiencies in the reported materials, in this work we have synthesized two halide perovskite materials ([BA-PbBr 4 ] (Prv-1) and [MACH-PbI 4 ] (Prv-2)) via halogen substitution (Br → I) and cation replacement (BA → MACH). − Both compounds exhibit a reversible phase transition; in addition, Prv-2 has a photoluminescence effect. Therefore, both compounds are potential dielectric switching and luminescent materials.…”