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Saponification Precipitation Method of CsPbBr3 Nanocrystals with Blue-Green Tunable Emission
摘要： We report on a new synthesis process for halide perovskite nanoplatelets and nanoplates that switches the production process of the cesium precursor from a fatty acid/cesium salt reaction to a cesium base/fatty acid ester reaction, thus enabling the reaction to occur in ambient conditions in minutes instead of hours. The saponification precipitation process reported here, as a result, does not require a vacuum oven or inert reaction environment in obtaining the cesium precursor, or any part of the reaction. Furthermore, the process creates a hygroscopic byproduct that results in a self-drying synthesis. The obtained perovskite nanocrystals exhibit a blue-green tunable emission that occurs via quantum confinement effect, phase, and morphology change. The consequence of these physical processes is that the band gap is highly tunable with temperature and the resulting nanocrystals show remarkable optical properties, while greatly simplifying the production of halide perovskite nanoplatelets and nanoplates.
关键词： Blue-Green Tunable Emission,Saponification Precipitation Method,Hybrid Materials,Magnetic,CsPbBr3 Nanocrystals,Plasmonics,Optical
更新于2025-11-19 16:46:39
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Light-induced effects on crystal size and photo-stability of colloidal CsPbBr<sub>3</sub> perovskite nanocrystals
摘要： CsPbBr3 perovskite nanocrystals (PNCs) have been synthesized using the hot injection method. The CsPbBr3 PNCs exhibit a high photoluminescence quantum yield (PLQY) of 73%. A comprehensive study of UV light interaction with the CsPbBr3 PNCs was performed. SEM images, photoluminescence spectra, X-Ray Diffraction and PLQY measurements were obtained for different time of UV exposure. The exposure to UV light modifies the crystal size (from 10X10 nm to 12X95 nm) and morphology (change from nanocubic to nanorods form). The XRD spectra show a change from tetragonal to cubic crystalline structure. In addition, the interaction of UV light modifies the optical properties of the PNCs by varying the photoluminescence. The material remains stable for a period of 1 hour, however, with exposure to UV light, the PNCs show a decrement in QY from 73.3% to 46.6% after 30 days. These results indicate that light-induce variation in morphological and photo-stability of CsPbBr3 PNCs.
关键词： luminescence,photostability,CsPbBr3 nanocrystals,morphological study
更新于2025-09-23 15:23:52
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Highly stable all-inorganic CsPbBr <sub/>3</sub> nanocrystals film encapsulated with alumina by plasma-enhanced atomic layer deposition
摘要： All-inorganic CsPbBr3 nanocrystals (NCs) have been considered as promising candidates for many optoelectronic applications. However, their perspectives are primarily impeded by the material instability arising from the labile surface and ionic nature of CsPbBr3 NCs. Hence it is high desired to obtain robust CsPbBr3 NCs film for practical applications. Herein, we deposited Al2O3 on NCs film surface for film stabilization by plasma-enhanced atomic layer deposition. The dense Al2O3 film can yield an excellent encapsulation effect, leading to a dramatically improved stability of CsPbBr3 NCs film. This work not only provides a superior technique for NCs film coating but also contributes to address the stability issue of CsPbBr3 NCs.
关键词： PEALD,Encapsulation,Inorganic Materials,Stability,CsPbBr3 Nanocrystals
更新于2025-09-23 15:22:29
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Enhancing the performance of LARP-synthesized CsPbBr <sub/>3</sub> nanocrystal LEDs by employing a dual hole injection layer
摘要： Lead halide perovskites have been considered promising materials for optoelectronic applications owing to their superior properties. CsPbBr3 nanocrystals (NCs) with a narrow particle size distribution and a narrow emission spectrum are synthesized by ligand-assisted re-precipitation (LARP), a low-cost and facile process. In inverted CsPbBr3 NC LEDs, a dual hole injection layer (HIL) of 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN)/MoO3 is introduced to enhance hole injection and transport, because HAT-CN can extract electrons easily from the hole transport layer and leave a large number of holes there. The current and power efficiencies of the optimized device with a dual HIL are 1.5- and 1.8-fold higher than those of the single HIL device. It is believed that the dual HAT-CN/MoO3 HIL effectively promotes hole injection and has promise for application in many other devices.
关键词： Ligand-assisted re-precipitation,Optoelectronic applications,Lead halide perovskites,CsPbBr3 nanocrystals,Dual hole injection layer,HAT-CN/MoO3
更新于2025-09-23 15:21:01
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Facile method for the preparation of high-performance photodetectors with a GQDs/perovskite bilayer heterostructure
摘要： A high-performance nitrogen doped graphene quantum dots (GQDs)/all-inorganic (CsPbBr3) perovskite nanocrystals (NCs) heterostructure photodetector was fabricated on a quartz substrate, using the low cost spin coating technique followed by hot plate annealing. The GQDs/CsPbBr3 NCs heterostructure photodetector exhibits a high overall performance with a photoresponsivity of 0.24 AW?1, on/off ratio of 7.2 × 104, and specific detectivity of up to 2.5 × 1012 Jones. The on/off ratio of the hybrid device was improved by almost ten orders of magnitude, and the photoresponsivity was enhanced almost three times compared to the single layer perovskite NCs photodetector. The performance enhancement of the hybrid device was due to its highly efficient carrier separation at the GQDs/CsPbBr3 NCs interface. This results from the coupling of the GQDs layer, which efficiently extracts and transports the photogenerated carriers, with the CsPbBr3 NCs layer, which has a large absorption coefficient and high quantum efficiency. The interfacial charge transfer from the CsPbBr3 NCs to the GQDs layer was demonstrated by the quenching in the photoluminescence (PL) spectra, and the fast-average decay time in the time-resolved photoluminescence (Trpl) spectra of the hybrid photodetector. Moreover, the performance-enhancement mechanism of the hybrid GQDs/CsPbBr3 photodetector was elucidated by analyzing the band alignment of the GQDs and CsPbBr3 under laser illumination.
关键词： Carrier separation,Charge transfer,CsPbBr3 nanocrystals,Photodetectors,Graphene quantum dots
更新于2025-09-12 10:27:22
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Femtosecond-Laser-Induced Precipitation of CsPbBr3 Perovskite Nanocrystals in Glasses for Solar Spectral Conversion
摘要： Inorganic perovskite quantum dots (QDs) and nanocrystals (NCs) have attracted much attention in recent years because of their high photoluminescence quantum yield (PL QY), narrow full width at half maximum, and wide tunability cross the whole visible range. In this work, space- and size-controlled precipitation of CsPbBr3 perovskite NCs was realized through femtosecond laser direct writing method. Precipitation of CsPbBr3 NCs in glasses was confirmed by the energy dispersive spectroscopy, transmission electron microscope analysis and photoluminescence (PL). Growth of CsPbBr3 perovskite NCs in glass was modulated by fs laser irradiation parameters such as repetition rate, pulse energy, and scanning rate, and PL in the range spanning from blue to green was achieved. With well-designed arrangement of CsPbBr3 NCs and the reduction of self-absorption emission, solar concentrator fabricated by fs laser irradiation can realize the spectral conversion and enhance the quantum efficiency of solar cells.
关键词： Glass,All-inorganic perovskite,Spectral conversion,Solar concentrator,Femtosecond laser,Photoluminescence,CsPbBr3,Nanocrystals
更新于2025-09-12 10:27:22
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Solvent-Assisted Tuning the Size and Shape of CsPbBr3 Nanocrystals via Re-Dispersion Process at Ambient Condition
摘要： All-inorganic CsPbBr3 perovskite nanocrystals are emerging as a new class of semiconductors with outstanding optoelectronic properties and great potential for various applications, such as, lasing, photon detection, photovoltaics etc. This article provides the effect of solvents on the re-precipitation of CsPbBr3 perovskite at room temperature. The results observed for CsPbBr3 perovskite in various anti-solvent showed various cubes (nano to micro size), self-assembly of nanocubes and nanorods. In addition, all the various size (nano to micro), self-assembly of nanocubes and shape-controlled nanorods exhibited band-gap tuning at the green light region. The corresponding microscopy (FE-SEM and HR-TEM) images and photoluminescence quantum yield as well as lifetime decay are presented. To the best of our literature knowledge this is the first report on various solvent assisted studies on CsPbBr3 perovskite nanocrystals.
关键词： CsPbBr3 Nanocrystals,nanocubes,effect of solvents,lifetime decay,nanorods,self-assembly
更新于2025-09-10 09:29:36