Efficient Photoluminescence of Manganese-Doped Two-Dimensional Chiral Alloyed Perovskites

Abstract

In this work, we introduced chiral cations into the achiral two-position layered perovskite system for the first time to form an alloyed system that still retains a clear layered structure. In addition, in order to explore the potential photoelectric properties of the alloyed system, manganese ions were doped into the alloyed system. The XRD pattern shows that the steady-state absorption and emission spectra of the alloyed system have a large structural distance, while the doped manganese system exhibits a two-color photoluminescence phenomenon. In addition, combined with time-resolved fluorescence and testing, the photoluminescence characteristics and ultralong lifetime of Mn-doped samples were further characterized. The exciton band structure of the lead halide perovskite framework can be adjusted through this design strategy. Mn2+ ions can form characteristic energy levels in the host system and then energy transfer of excitons occurs, which is of great significance for the development of new functional and high-efficiency photoluminescent materials.

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

“…In addition, their group also obtained a hybrid perovskite, (2-methyl-1,5-diaminopentane)­PbBr 4 ; although it had highly efficient white-light emission, the PLQY was only about 3%. In addition, Zhao’s group reported a manganese-doped two-dimensional chiral alloyed perovskite (containing (PEA) 2 PbBr 4 ), which exhibited a photoluminescent color transition from blue to pink (achieving a change in the light color). However, the photoluminescence quantum yield had a certain loss.…”

Solvent Modulation of Chiral Perovskite Films Enables High Circularly Polarized Luminescence Performance from Chiral Perovskite/Quantum Dot Composites

“…It can be verified that all samples show full coverage and a dense film morphology on the substrate with the absence of pinholes, and they all exhibit unique rotating flower-like surfaces. The grain size of the chiral perovskite samples is significantly enlarged after solvent modulation, increasing from an average value of 21 μm for the pristine sample ( R -DMF) to 37 μm for R -DMSO and 57 μm for R -NMP for the modified films, indicating an improved crystallinity of chiral perovskite films induced by the solvent modulation strategy . This is reasonable because NMP has the largest steric hindrance, which can delay intermolecular interactions between the solvent and the perovskite material and help promote a more stable nucleation environment, so it may provide more sufficient time for the perovskite grains to grow …”

“…All composite samples exhibited a PL peak position at around 625 nm in the steady-state PL spectra, which comes from the luminescent property of CdSe/ZnS red QDs, as shown in Figure S1. The chiral perovskite/QD samples show a little lower intensity than the pure QD sample, implying that a charge carrier transfer occurred at the interface between the chiral perovskite films and the QD layer, which has been proven by ultrafast dynamics analysis from other literature. , As shown in Figure c, the samples exhibit a high degree of PL quenching compared with the pristine QD film. The values of fitted PL lifetimes through a biexponential fit (Table S1) decrease from 18.87 ns (QD sample) to less than 10 ns (9.06 ns for R -DMF/QDs, 7.42 ns for R -DMSO/QDs, and 7.32 ns for R -NMP/QDs), manifesting a superior charge carrier-transfer efficiency from the chiral perovskite film to the QD layer regardless of which solvent was used in the chiral perovskite precursor solution.…”

“…The grain size of the chiral perovskite samples is significantly enlarged after solvent modulation, increasing from an average value of 21 μm for the pristine sample (R-DMF) to 37 μm for R-DMSO and 57 μm for R-NMP for the modified films, indicating an improved crystallinity of chiral perovskite films induced by the solvent modulation strategy. 38 This is reasonable because NMP has the largest steric hindrance, which can delay intermolecular interactions between the solvent and the perovskite material and help promote a more stable nucleation environment, so it may provide more sufficient time for the perovskite grains to grow. 39 GIWAXS measurements were carried out to investigate the crystallization and orientation of chiral perovskite samples before and after solvent modulation.…”

A New Look at the Structure and Thermal Behavior of Polyvinylidene Fluoride–Camphor Mixtures

“…That is why it would be more correct to characterize the states in domains II and III as “macroscopically homogeneous” and “macroscopically inhomogeneous” instead of “single-phase” and “two-phase”. The absence of a true equilibrium state in semicrystalline polymers hinders the application of higher characterization methods reported for the complex organic [ 71 ] and inorganic [ 72 , 73 ] systems exhibiting crystallinity.…”