1. |
- Cai, Weidong, et al.
(author)
-
Multicolor light emission and multifunctional applications in double perovskite-Cs 2 NaInCl 6 by Cu + /Sb 3+co-doping
- 2024
-
In: Chemical Engineering Journal. - : ELSEVIER SCIENCE SA. - 1385-8947 .- 1873-3212. ; 489
-
Journal article (peer-reviewed)abstract
- Halide double perovskites managed by metal doping approach can exhibit dual emission colors, which have been considered as promising multicolor luminescent materials. However, an independent and stable emission at yellow region is missing owing to limited doping candidates, hindering the further commercialization of multicolor luminescence applications in double perovskites. In this work, we successfully obtain stable multicolor emission with PLQE (photoluminescence quantum yield) as high as 78% through developing the CuI doping strategy in Sb-Cs2NaInCl6. By introducing a high CuI feed ratio in airtight autoclave to compete the oxidization effect, the oxidization of CuI into CuII (detrimental factor for high PLQE due to serious quenching effect) is largely suppressed. With changing the CuI feed ratio, at least four distinct emission colors ranging from blue, purple, pink to yellow can be realized via changing the excitation wavelength. Depending on tunable multicolor emission, we further demonstrate the promise of our co-doped double perovskites in anti-counterfeiting technology and multicolor lighting devices. Our results open the way for enriching the optical applications of double perovskites based on multicolor emission.
|
|
2. |
- Cai, Weidong, et al.
(author)
-
Multicolor light emission in manganese-based metal halide composites
- 2022
-
In: Applied Physics Reviews. - : AIP Publishing. - 1931-9401. ; 9:4
-
Journal article (peer-reviewed)abstract
- Manganese-based organic-inorganic metal halide composites have been considered as promising candidates for lead-free emitters. However, in spite of their excellent luminescence properties in green and red regions, blue emission-a critical component for white light generation-from pristine manganese-based composites is currently missing. In this work, we successfully achieve blue luminescence center in manganese-based composites through selecting specific organic component methylbenzylamine (MBA). Our approach is fundamentally different from green and red emission in manganese-based composites, which result from manganese-halide frameworks. The coexistence of different luminescence centers in our manganese-based composites is confirmed by photoluminescence (PL) and photoluminescence excitation (PLE) results. As a result of different photoluminescence excitation responses of different emission centers, the resulting emission color can be tuned with selecting different excitation wavelengths. Specifically, a white light emission can be obtained with Commission Internationale de leclairage coordinates of (0.33, 0.35) upon the 330 nm excitation. We further demonstrate the promise of our manganese-based composites in the anti-counterfeiting technology and multicolor lighting. Our results provide a novel strategy for full-spectral emission in manganese-based organic-inorganic metal halide composites and lay a solid foundation for a range of new applications. (C) 2022 Author(s).
|
|
3. |
- Guo, Na, et al.
(author)
-
Enhancing Emission and Stability in Na-Doped Cs3Cu2I5 Nanocrystals
- 2024
-
In: Nanomaterials. - : MDPI. - 2079-4991. ; 14:13
-
Journal article (peer-reviewed)abstract
- Lead-free Cs3Cu2I5 metal halides have garnered significant attention recently due to their non-toxic properties and deep-blue emission. However, their relatively low photoluminescence quantum efficiency and poor stability have limited their applications. In this work, sodium iodide (NaI) is used to facilitate the synthesis of Cs3Cu2I5 nanocrystals (NCs), demonstrating improved photoluminescence intensity, photoluminescence quantum yield, and stability. Systematic optoelectronic characterizations confirm that Na+ is successfully incorporated into the Cs3Cu2I5 lattice without altering its crystal structure. The improved Photoluminescence Quantum Yield (PLQY) and stability are attributed to the strengthened chemical bonding, which effectively suppresses vacancy defects in the lattice. Additionally, light-emitting diodes (LEDs) based on 10% NaI-doped Cs3Cu2I5 NCs were assembled, emitting vibrant blue light with a maximum radiant intensity of 82 lux and Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of (0.15, 0.1). This work opens new possibilities for commercial lighting display applications.
|
|
4. |
- Wang, Hao, et al.
(author)
-
In-situ growth of low-dimensional perovskite-based insular nanocrystals for highly efficient light emitting diodes
- 2023
-
In: Light. - : SPRINGERNATURE. - 2095-5545 .- 2047-7538. ; 12:1
-
Journal article (peer-reviewed)abstract
- Regulation of perovskite growth plays a critical role in the development of high-performance optoelectronic devices. However, judicious control of the grain growth for perovskite light emitting diodes is elusive due to its multiple requirements in terms of morphology, composition, and defect. Herein, we demonstrate a supramolecular dynamic coordination strategy to regulate perovskite crystallization. The combined use of crown ether and sodium trifluoroacetate can coordinate with A site and B site cations in ABX(3) perovskite, respectively. The formation of supramolecular structure retard perovskite nucleation, while the transformation of supramolecular intermediate structure enables the release of components for slow perovskite growth. This judicious control enables a segmented growth, inducing the growth of insular nanocrystal consist of low-dimensional structure. Light emitting diode based on this perovskite film eventually brings a peak external quantum efficiency up to 23.9%, ranking among the highest efficiency achieved. The homogeneous nano-island structure also enables high-efficiency large area (1 cm(2)) device up to 21.6%, and a record high value of 13.6% for highly semi-transparent ones.
|
|