| 1. |
- Gao, Zhaoju, et al.
(author)
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Short-chain ligand achieves ultra-stable CsPbX3 perovskite quantum dots for white light-emitting diodes
- 2024
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In: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 124:4
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Journal article (peer-reviewed)abstract
- All-inorganic perovskite quantum dots (PeQDs) have aroused great research interest in white light-emitting diodes (WLED) due to their excellent optoelectronic properties, but the poor stability, caused by dynamically binding long-chain capping ligands, hinders their future practical applications. To address this issue, here, we exploit short-chain butyric acid (BA) to replace long-chain oleic acid (OA) as capping ligand of CsPbX3 PeQDs by a hot-injection method. The addition of BA not only makes the morphology of CsPbBr3 PeQDs uniform and improves the crystallinity but also effectively suppresses nonradiative recombination, achieving a near unit photoluminescence quantum yield of 96%. The BA capped CsPbBr3 PeQDs exhibit high stability up to 180 d stored in ambient environment and also significantly improved resistance against polar solvent, ultra-violet lamp irradiation, and heat, which is rationalized by the strong binding capacity and shortened distance of BA to the PeQDs through ab initio calculations. Furthermore, by combining green-emission CsPbBr3 and red-emission CsPbBr0.8I2.2 PeQDs with blue GaN chip, we achieved WLEDs with excellent luminous properties, showing their great potential in practical application of wide-color-gamut display and lighting.
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| 2. |
- Pan, Zhangcheng, et al.
(author)
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Highly stable CsPbI3 perovskite quantum dots enabled by single SiO2 coating toward down-conversion light-emitting diodes
- 2023
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In: Applied Sciences. - : MDPI. - 2076-3417. ; 13:13
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Journal article (peer-reviewed)abstract
- All-inorganic CsPbI3 perovskite quantum dots (PeQDs) have sparked widespread research due to their excellent optoelectronic properties and facile synthesis. However, attaining highly stable CsPbI3 perovskite quantum dots (PeQDs) against heat and polar solvents still remains a challenge and hinders any further practical application. Here, by exploiting (3-aminopropyl) triethoxysilane (APTES) as the sole silica (SiO2) precursor, we report a one-step in situ synthesis of single SiO2-coated CsPbI3 (SiO2-CsPbI3) PeQDs, namely that one SiO2 particle only contains one CsPbI3 PeQD particle. The obtained SiO2-CsPbI3 PeQDs are cubic in shape, have a more uniform size distribution, and possess narrow emission, with near unit photoluminescence quantum yields of up to 97.5%. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the formation of SiO2 through the hydrolysis of APTES on the CsPbI3 PeQDs surface. Furthermore, they have a significantly improved stability against storage, heat, and ethanol. By combining purple-emission GaN light-emitting diodes, the SiO2-CsPbI3 PeQDs were successfully employed as down-conversion emitters and exhibited considerable enhanced luminous performance and excellent stability, demonstrating their promising future in the practical application of solid-state lighting fields.
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| 3. |
- Zhu, Xiaolin, et al.
(author)
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Capping ligand engineering enables stable CsPbBr3 perovskite quantum dots toward white-light-emitting diodes
- 2023
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 62:23, s. 9190-9198
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Journal article (peer-reviewed)abstract
- All-inorganic perovskite quantum dots (PeQDs) have sparked extensive research focus on white-light-emitting diodes (WLEDs), but stability and photoluminescence efficiency issues are still remain obstacles impeding their practical application. Here, we reported a facile one-step method to synthesize CsPbBr3 PeQDs at room temperature using branched didodecyldimethylammonium fluoride (DDAF) and short-chain-length octanoic acid as capping ligands. The obtained CsPbBr3 PeQDs have a near-unity photoluminescence quantum yield of 97% due to the effective passivation of DDAF. More importantly, they exhibit much improved stability against air, heat, and polar solvents, maintaining >70% of initial PL intensity. Making use of these excellent optoelectronic properties, WLEDs based on CsPbBr3 PeQDs, CsPbBr1.2I1.8 PeQDs, and blue LEDs were fabricated, which show a color gamut of 122.7% of the National Television System Committee standard, a luminous efficacy of 17.1 lm/W, with a color temperature of 5890 K, and CIE coordinates of (0.32, 0.35). These results indicate that the CsPbBr3 PeQDs have great practical potential in wide-color-gamut displays.
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