Strong circularly polarized luminescence from quantum dots/2D chiral perovskites composites

Wang, Qingqian; Zhu, Hongmei; Chen, Wei; Hao, Junjie; Wang, Zhaojin; Tang, Jun; Yang, Yingguo; Sun, Xiao Wei; Wu, Dan; Wang, Kai

doi:10.1007/s12274-023-5380-0

Cited by 12 publications

(9 citation statements)

References 35 publications

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“…To verify this, the energy landscapes of chiral perovskites were calculated from the results of UPS measurements and Tauc plots of absorption spectra (Figure S13). 55 Thus, we can further affirm that charge carriers could be transferred from perovskites to combine in the QD layer through experimental data. However, when the chiral perovskite film and QD layer are separated with glass, as illustrated in Figure 5a, a small part of excitation light would still pass through the QD layer and reach the chiral perovskite film since the QD layer was virtually very thin (about several tens of nanometers) in our experiments.…”

Section: ■ Results and Discussionmentioning

confidence: 53%

“…The valence bands and conductive bands are −5.87 and −3.48 eV for R -DMF, −5.88 and −3.49 eV for R -DMSO, and −5.84 and −3.44 eV for R -NMP. The valence bands and conductive bands are −6.50 and −4.40 eV for red CdSe/Zns QDs . Thus, we can further affirm that charge carriers could be transferred from perovskites to combine in the QD layer through experimental data.…”

Section: Resultsmentioning

confidence: 97%

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

Zhu

Wang

Sun

et al. 2023

ACS Appl. Mater. Interfaces

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Materials with circularly polarized luminescence (CPL) activity are promising in many chiroptoelectronics fields, such as for biological probes, asymmetric photosynthesis, information storage, spintronic devices, and so on. Promoting the value of the dissymmetry factor (g lum) for the CPL-active materials based on chiral perovskite draws increasing attention since a higher g lum value indicates better CPL. In this work, we find that, after being treated with a facile solvent modulation strategy, the chirality of 2D chiral perovskite films has been enhanced a lot, which we attribute to an increased lattice distortion degree. By forming chiral perovskite/quantum dot (QD) composites, the CPL-active material is successfully obtained. The calculated maximum |g lum| of these composites increased over 4 times after solvent modulation treatment (1.53 × 10–3 for the pristine sample of R-DMF and 6.91 × 10–3 for R-NMP) at room temperature. Moreover, the enhancement of the CPL intensity is ascribed to two aspects: one is the generation and transportation of spin-polarized charge carriers from chiral perovskite films to combine in the QD layer, and the other is the solvent modulation strategy to enlarge the lattice distortion of chiral perovskite films. This facile route provides an effective way to construct CPL-active materials. More importantly, this kind of composite material (chiral perovskite film/QD layer) can be easily applied for fabricating circularly polarized light-emitting diode devices for electroluminescence.

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Section: ■ Results and Discussionmentioning

confidence: 53%

Section: Resultsmentioning

confidence: 97%

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

Zhu

Wang

Sun

et al. 2023

ACS Appl. Mater. Interfaces

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“…[ 37 ] We put R‐ MBA 2 PbI 4 as represent since the energy band difference between R‐ MBA 2 PbI 4 and S‐ MBA 2 PbI 4 is little. [ 30 ] We choose CdSe/ZnS QDs as light emitter because the QDs are dispersed in a nonpolar solvent octane which does not dissolve the chiral perovskites. Besides, the energy band of chiral perovskites suits well in this device structure while stable and efficient red CdSe QLEDs are routinely obtained.…”

Section: Spin‐qled Fabrication Characterization and Simulationmentioning

confidence: 99%

“…In our previous study, the QDs/chiral perovskites thin film exhibited CPL asymmetry factor ( g lum ) of 9.06 × 10 −3 . [ 30 ] Since the spin injection of chiral perovskites are significantly effective, we believe QDs/chiral perovskites thin film could be promising in spin‐QLED. Here, in this work, we apply 2D chiral perovskites as spin injection layer and CdSe/ZnS quantum dots (QDs, TEM images shown in Figure S1, Supporting Information) as active layer to construct spin‐QLED.…”

Section: Introductionmentioning

confidence: 99%

Spin Quantum Dot Light‐Emitting Diodes Enabled by 2D Chiral Perovskite with Spin‐Dependent Carrier Transport

Wang,

Zhu,

Tan

et al. 2023

Advanced Materials

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Chiral‐induced spin selectivity (CISS) effect provides innovative approach to spintronics and quantum‐based devices for chiral materials. Different from the conventional ferromagnetic devices, the application of CISS effect is potential to operate under room temperature and zero applied magnetic field. Low dimensional chiral perovskites by introducing chiral amines are beginning to show significant CISS effect for spin injection, but research on chiral perovskites is still in its infancy, especially on spin‐light emitting diode (spin‐LED) construction. Here we report the spin‐QLEDs enabled by two‐dimensional (2D) chiral perovskites as CISS layer for spin‐dependent carrier injection and CdSe/ZnS quantum dots (QDs) as light emitting layer. The regulation pattern of the chirality and thickness of chiral perovskites, which affects the circularly polarized electroluminescence (CP‐EL) emission of spin‐QLED, has been discovered. Notably, the spin injection polarization of 2D chiral perovskites is higher than 80% and the CP‐EL asymmetric factor (gCP‐EL) achieves up to 1.6 × 10−2. Consequently, this work opens up a new and effective approach for high‐performance spin‐LEDs.This article is protected by copyright. All rights reserved

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“…Taking the chiral perovskite ( R / S -MBA) 2 PbI 4 (MBA = α-methylbenzylamine cation) as an example, the reported CD spectra vary from different studies. For example, the CD spectra of the powder sample dispersed in the KBr pellet all exhibit no signal. , For the film sample, the CD signals in the deep UV region are not shown or only have a pair of mirror peaks in the band-gap edge region, ,,− and some of them also do not show the Cotton effect. ,, Even the results from the same research group are incompatible, which means that the sample state dramatically affects the CD spectra. Lacking comparison from different sample states poses challenges to understanding the artifacts originating from the interaction between the sample and circularly polarized light.…”

Section: Introductionmentioning

confidence: 99%

Unveiling Chiral Perovskite CD Signal Scaling: Discerning Authentic and Counterfeit Signals through Sample-State Analysis

Han,

Wang,

Jin

et al. 2023

Anal. Chem.

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Circular dichroism (CD) spectroscopy is a well-known and powerful technique widely used for distinguishing chiral enantiomers based on their differential absorbance of the right and left circularly polarized light. With the increasing demand for solid-state chiral optics, CD spectroscopy has been extended to elucidate the chirality of solid-state samples beyond the traditional solution state. However, due to the sample preparation differential, the CD spectra of the same compound measured by different researchers may not be mutually consistent. In this study, we employ solution, powder, thin-film, and single-crystal samples to explore the challenges associated with CD measurements and distinguish between genuine and fake signals.Rational fabrication of the solid-state samples can effectively minimize the macroscopic anisotropic nature of the samples and thereby mitigate the influence of linear dichroism (LD) and linear birefringence (LB) effects, which arise from anisotropy-induced differences in the absorbances and refractive indices. The local anisotropic and overall isotropic features of the high-quality thin-film sample achieve an optically isotropic state, which exhibits superior CD signal repeatability at the front and back sides at different angles by rotating the sample along the light path. In addition, sample thickness-induced CD signal overload and absorption saturation pose more severe challenges than the LBLD-induced amplified CD signal but are rarely focused on. The CD signal overload in the deep UV region leads to the presence of fake signals, while absorption saturation results in a complete loss of the CD signal. These findings help obtain accurate CD signals by a wellfabricated optically isotropic sample to avoid LDLB and optimize the sample thickness to avoid fake signals and no signals.

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Strong circularly polarized luminescence from quantum dots/2D chiral perovskites composites

Cited by 12 publications

References 35 publications

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

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

Spin Quantum Dot Light‐Emitting Diodes Enabled by 2D Chiral Perovskite with Spin‐Dependent Carrier Transport

Unveiling Chiral Perovskite CD Signal Scaling: Discerning Authentic and Counterfeit Signals through Sample-State Analysis

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