19 research outputs found
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Highly Stable Luminous "snakes" from CsPbX3 Perovskite Nanocrystals Anchored on Amine-Coated Silica Nanowires
CsPbX3 (X = Cl, Br, and I) perovskite nanocrystals (NCs) are known for their exceptional optoelectronic properties, yet the material's instability toward polar solvents, heat, or UV irradiation greatly limits its further applications. Herein, an efficient in situ growing strategy has been developed to give highly stable perovskite NC composites (abbreviated CsPbX3@CA-SiO2) by anchoring CsPbX3 NCs onto silica nanowires (NWs), which effectively depresses the optical degradation of their photoluminescence (PL) and enhances stability. The preparation of surface-functionalized serpentine silica NWs is realized by a sol-gel process involving hydrolysis of a mixture of tetraethyl orthosilicate (TEOS), 3-aminopropyltriethoxysilane (APTES), and trimethoxy(octadecyl)silane (TMODS) in a water/oil emulsion. The serpentine NWs are formed via an anisotropic growth with lengths up to 8 ÎŒm. The free amino groups are employed as surface ligands for growing perovskite NCs, yielding distributed monodisperse NCs (âŒ8 nm) around the NW matrix. The emission wavelength is tunable by simple variation of the halide compositions (CsPbX3, X = Cl, Br, or I), and the composites demonstrate a high photoluminescence quantum yield (PLQY 32-69%). Additionally, we have demonstrated the composites CsPbX3@CA-SiO2 can be self-woven to form a porous 3D hierarchical NWs membrane, giving rise to a superhydrophobic surface with hierarchical micro/nano structural features. The resulting composites exhibit high stability toward water, heat, and UV irradiation. This work elucidates an effective strategy to incorporate perovskite nanocrystals onto functional matrices as multifunctional stable light sources
Tunable Anisotropic Photon Emission from Self-Organized CsPbBr<inf>3</inf>Perovskite Nanocrystals
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Stable luminous nanocomposites of CsPbX 3 perovskite nanocrystals anchored on silica for multicolor anti-counterfeit ink and white-LEDs
Inorganic perovskite (CsPbX 3 , X = Cl, Br and I) nanocrystals (NCs) have received great attention for their fascinating optoelectronic properties. However, their potential applications are primarily limited by the instability arising from their mobile ionic nature. Herein, we demonstrate extremely stable CsPbX 3 nanocomposites (denoted as CsPbX 3 @CA-SiO 2 ) using a facile and effective templated synthetic strategy, by the in situ anchoring of CsPbX 3 NCs onto octadecyl-/propylamine-capped silica particles (SiO 2 NPs). The two-step synthesis involves first the preparation of amino-group-capped silica NPs from a mixed 3-aminopropyltriethoxysilane (APTES) and trimethoxy(octadecyl)silane (TMODS) precursor, which were utilized to induce the nucleation and growth of CsPbX 3 nanocrystals to produce CsPbX 3 @CA-SiO 2 composites with monodispersed CsPbX 3 NCs (âŒ6 nm). The emission wavelength of the resulting composite can be tuned between 400 nm and 650 nm by controlling the halide composition, while maintaining a high photoluminescence quantum yield (PLQY = 76%). The as-fabricated composites exhibited remarkable photostability and water stability, both uncommon in these materials. The CsPbX 3 @CA-SiO 2 composite can also be used to create an anti-counterfeit ink and down-converting white light emitting diode (WLED). This work provides a valuable approach for the production of future optoelectronic devices, catalysts and sensors based on perovskite NCs
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Improved Stability and Exciton Diffusion of Self-Assembled 2D Lattices of Inorganic Perovskite Nanocrystals by Atomic Layer Deposition
Colloidal inorganic perovskite nanocrystals (PNCs) are solution-processable optoelectronic materials whose emission can be easily tuned via both size and composition while maintaining high photoluminescence quantum yield. Despite their relative defect tolerance, they suffer from photoinduced damage and degradation under ambient conditions. The lack of long-term stability is addressed by investigating how a â3 nm transparent ceramic coating applied onto a thin layer of close-packed PNCs via atomic layer deposition (ALD) affects the exciton mobility across the PNCs. Samples coated via both thermal and plasma ALD are compared, as well as an uncoated one. Exciton diffusion measurements yield a record value for all samples, up to λD = 480 ± 24 nm, one order of magnitude larger than the previously reported values for chalcogenide quantum dots and more than two times larger than what was previously found for the PNCs. Moreover, the ALD-coated samples show stable photoluminescence intensity and energy over 1 year time span. The measurement approach allows for discerning minimal variations in the local luminescence and qualitatively correlating them to the samplesâ morphology. Hence, it is shown that PNCs coated with an ultrathin ALD film become a very versatile optoelectronic material that can be employed in devices beyond proof of principle
Improved Stability and Exciton Diffusion of Self-Assembled 2D Lattices of Inorganic Perovskite Nanocrystals by Atomic Layer Deposition
Colloidal inorganic perovskite nanocrystals (PNCs) are solution-processable optoelectronic materials whose emission can be easily tuned via both size and composition while maintaining high photoluminescence quantum yield. Despite their relative defect tolerance, they suffer from photoinduced damage and degradation under ambient conditions. The lack of long-term stability is addressed by investigating how a â3 nm transparent ceramic coating applied onto a thin layer of close-packed PNCs via atomic layer deposition (ALD) affects the exciton mobility across the PNCs. Samples coated via both thermal and plasma ALD are compared, as well as an uncoated one. Exciton diffusion measurements yield a record value for all samples, up to λD = 480 ± 24 nm, one order of magnitude larger than the previously reported values for chalcogenide quantum dots and more than two times larger than what was previously found for the PNCs. Moreover, the ALD-coated samples show stable photoluminescence intensity and energy over 1 year time span. The measurement approach allows for discerning minimal variations in the local luminescence and qualitatively correlating them to the samplesâ morphology. Hence, it is shown that PNCs coated with an ultrathin ALD film become a very versatile optoelectronic material that can be employed in devices beyond proof of principle