Stable and Intense Violet-Emitting CsPbCl<sub>3</sub> Nanocrystals for Light-Emitting Diodes: Directly Obtained by L-Type Surface Passivation

Das, Somnath; Hossain, Modasser; Samanta, Anunay

doi:10.1021/acsanm.3c00371

Cited by 8 publications

(3 citation statements)

References 45 publications

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“…The final absolute PLQY was found to be exceptionally high (96 ± 5%). It is reasonable to suppose that the low ligand density allowed the passivation of the NC surface with L-type ligands (OLAm), thus limiting the nonradiative exciton recombination and improving the PL efficiency. , In fact, we observed a monoexponential PL decay (τ AV = 3.1 ± 0.2 ns, Table S1), probably resulting from the annihilation of the faster nonradiative recombination due to the OLAm copassivation of the NC surface (Figure E). Importantly, probably due to steric impediments, the amine excess does not impair the adhesion of the OPDA ligand via its proton abstraction, thus preserving the colloidal integrity of OPDA-CsPbBr 3 NCs in these conditions.…”

Section: Resultsmentioning

confidence: 86%

Surface-Engineered Cesium Lead Bromide Perovskite Nanocrystals for Enabling Photoreduction Activity

Conelli,

Matuhina,

Dibenedetto

et al. 2024

ACS Appl. Mater. Interfaces

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In recent years, colloidal lead halide perovskite (LHP) nanocrystals (NCs) have exhibited such intriguing light absorption properties to be contemplated as promising candidates for photocatalytic conversions. However, for effective photocatalysis, the light harvesting system needs to be stable under the reaction conditions propaedeutic to a specific transformation. Unlike photoinduced oxidative reaction pathways, photoreductions with LHP NCs are challenging due to their scarce compatibility with common hole scavengers like amines and alcohols. In this contribution, it is investigated the potential of CsPbBr 3 NCs protected by a suitably engineered bidentate ligand for the photoreduction of quinone species. Using an in situ approach for the construction of the passivating agent and a halide excess environment, quantum-confined nanocubes (average edge length = 6.0 ± 0.8 nm) are obtained with a low ligand density (1.73 ligand/nm 2 ) at the NC surface. The bifunctional adhesion of the engineered ligand boosts the colloidal stability of the corresponding NCs, preserving their optical properties also in the presence of an amine excess. Despite their relatively short exciton lifetime (τ AV = 3.7 ± 0.2 ns), these NCs show an efficient fluorescence quenching in the presence of the selected electron accepting quinones (1,4-naphthoquinone, 9,10phenanthrenequinone, and 9,10-anthraquinone). All of these aspects demonstrate the suitability of the NCs for an efficient photoreduction of 1,4-naphthoquinone to 1,4-dihydroxynaphthalene in the presence of triethylamine as a hole scavenger. This chemical transformation is impracticable with conventionally passivated LHP NCs, thereby highlighting the potential of the surface functionalization in this class of nanomaterials for exploring new photoinduced reactivities.

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Section: Resultsmentioning

confidence: 86%

Surface-Engineered Cesium Lead Bromide Perovskite Nanocrystals for Enabling Photoreduction Activity

Conelli,

Matuhina,

Dibenedetto

et al. 2024

ACS Appl. Mater. Interfaces

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“…C–X bond activation represents a specific and intriguing area of photocatalytic organic transformation. ,,− Recent research has demonstrated the ability to activate C–X bonds in alkyl halides via photoassisted anion exchange reactions using perovskites. ,, This light-controlled approach offers significant advantages, allowing for the reaction to be carried out under ambient conditions with near-perfect conversion. This paves the way for exciting possibilities beyond photocatalysis, extending to the potential use of perovskite NCs in light-emitting diodes for display technologies. − …”

Section: Introductionmentioning

confidence: 99%

Metal Halide Perovskite Nanocrystals for C–X Activation: Role of Halide Vacancies

Singh,

Sahu,

Mittal

et al. 2024

ACS Appl. Nano Mater.

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Metal halide perovskite nanocrystals (NCs) possess immense potential in photocatalysis. However, deciphering the intricate surface chemistry that governs these catalytic processes remains a challenge. This study investigates C−X bond activation with CsPbBr 3 NCs, focusing on elucidating the role of dynamic molecular domains in dictating catalytic activity. By manipulating surface interactions through ligand dynamics, we identify halide vacancies as critical sites for C−X bond activation. A systematic exploration of different ligand types reveals varying kinetics of C−X exchange, with oleyl amine-capped CsPbBr 3 NCs demonstrating the highest reactivity. Temperature-dependent photoluminescence measurements corroborate these findings, highlighting the influence of ligand dynamics on surface interactions. Additionally, postsynthetic treatments, such as lead oleate modification, which leads to an increase in the density of active sites (halide vacancies), significantly enhance catalytic performance. Conversely, SOBr 2 treatment, which repairs surface bromide vacancies, results in almost completely suppressed catalytic activity. So, by engineering surface environments, we demonstrate significant improvement in the catalytic performance of metal halide perovskite NCs, offering valuable insights for future development.

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“…This may find exciting applications in fabricating violet LEDs (<435 nm). Violet LEDs suffer from weak luminescence due to reduced lattice stability, a wider band gap, and the formation of a high density of deep trap states due to chloride vacancies. − As a result, they are less prominent commercially than red and green LEDs . Our approach can perhaps bypass the standard hot injection technique for synthesizing CsPbCl 3 NCs, omitting the need for a hazardous TOP ( n -trioctylphosphine) ligand to solubilize PbCl 2 .…”

Section: Introductionmentioning

confidence: 99%

CsPbBr₃ Nanocrystals as Efficient Photocatalysts for Dehydrohalogenation: Toward Environmentally Friendly Trichloroethylene Synthesis

Singh,

Choudhary,

Govind Rao

2023

ACS Appl. Mater. Interfaces

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The demand for a benign alternative to energy-intensive industrial chemical transformations is critical. Lead halide perovskites have emerged as promising candidates due to their unique optoelectronic properties, including high absorption coefficients in the visible region, tunable band gaps, and long charge carrier-diffusion lengths. In this study, we present a model reaction to showcase the photocatalytic utility of perovskite nanocrystals (NCs). Specifically, we demonstrate the synthesis of trichloroethylene (TCEt) from 1,1,2,2-tetrachloroethane (TCE) using CsPbBr 3 NCs under white light illumination. The band-edge positions of the NCs and the redox potential of TCE enable efficient electron transfer for C−Cl bond activation. Furthermore, while ensuring operational stability, CsPbBr 3 NCs undergo lightcontrolled modification, leading to the formation of mixed-halide perovskite (CsPbBr x Cl 3−x ) NCs during the reaction. This procedure yields a mixed-halide perovskite that maintains stability while containing the desired halide content. Additionally, the reaction produces HBr as a byproduct, serving as a self-cleaning technique to eliminate excess Br − ions from the solution. Ultimately, we achieve nearly 100% conversion of CsPbBr 3 to pure CsPbCl 3 NCs, with a full width at half-maximum of approximately 11.2 nm. Our clean and efficient approach to synthesizing TCEt using perovskite NCs provides interesting insights into violet light-emitting diode (LED) fabrication and color patterning. This study highlights the promising potential of perovskite materials for sustainable chemical transformations and optoelectronic applications.

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Stable and Intense Violet-Emitting CsPbCl₃ Nanocrystals for Light-Emitting Diodes: Directly Obtained by L-Type Surface Passivation

Cited by 8 publications

References 45 publications

Surface-Engineered Cesium Lead Bromide Perovskite Nanocrystals for Enabling Photoreduction Activity

Surface-Engineered Cesium Lead Bromide Perovskite Nanocrystals for Enabling Photoreduction Activity

Metal Halide Perovskite Nanocrystals for C–X Activation: Role of Halide Vacancies

CsPbBr₃ Nanocrystals as Efficient Photocatalysts for Dehydrohalogenation: Toward Environmentally Friendly Trichloroethylene Synthesis

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Stable and Intense Violet-Emitting CsPbCl3 Nanocrystals for Light-Emitting Diodes: Directly Obtained by L-Type Surface Passivation

Cited by 8 publications

References 45 publications

Surface-Engineered Cesium Lead Bromide Perovskite Nanocrystals for Enabling Photoreduction Activity

Surface-Engineered Cesium Lead Bromide Perovskite Nanocrystals for Enabling Photoreduction Activity

Metal Halide Perovskite Nanocrystals for C–X Activation: Role of Halide Vacancies

CsPbBr3 Nanocrystals as Efficient Photocatalysts for Dehydrohalogenation: Toward Environmentally Friendly Trichloroethylene Synthesis

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Product

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Stable and Intense Violet-Emitting CsPbCl₃ Nanocrystals for Light-Emitting Diodes: Directly Obtained by L-Type Surface Passivation

CsPbBr₃ Nanocrystals as Efficient Photocatalysts for Dehydrohalogenation: Toward Environmentally Friendly Trichloroethylene Synthesis