Ligand-assisted Reprecipitation Research Articles

Understanding the ligand-assisted reprecipitation of CsPbBr3 nanocrystals via high-throughput robotic synthesis approach

•High-throughput automated experimental workflow for LARP-PNC synthesis is employed •Effects of chemical and processing parameters on PNC functionalities are explored •SHAP, a machine learning method, assesses the impact of synthesis parameters •Ligand diffusion during reaction determines the functionalities of PNCs Inorganic cesium lead bromide (CsPbBr3) perovskite nanocrystals (PNCs) have shown promise in optoelectronic applications. A simpler method of synthesizing high-quality PNCs is the ligand-assisted reprecipitation (LARP) method, but it is susceptible to instability. This study used a high-throughput automated experimental platform to explore the growth behaviors and colloidal stability of LARP-synthesized PNCs. The influence of ligands on particle growth and functionalities was systematically explored using two distinctive acid-base pairs. The study found that short-chain ligands cannot make functional PNCs with the desired sizes and shapes, whereas long-chain ligands provide homogeneous and stable PNCs. The study also found that excessive amines or polar antisolvents can cause PNCs to transform into a Cs-rich non-perovskite structure with poorer emission functionalities and larger size distributions. The diffusion of ligands in a reaction system is crucial in determining the structures and functionalities of the PNCs. This study provides detailed guidance on synthesis routes for desired PNCs. Inorganic cesium lead bromide (CsPbBr3) perovskite nanocrystals (PNCs) have shown promise in optoelectronic applications. A simpler method of synthesizing high-quality PNCs is the ligand-assisted reprecipitation (LARP) method, but it is susceptible to instability. This study used a high-throughput automated experimental platform to explore the growth behaviors and colloidal stability of LARP-synthesized PNCs. The influence of ligands on particle growth and functionalities was systematically explored using two distinctive acid-base pairs. The study found that short-chain ligands cannot make functional PNCs with the desired sizes and shapes, whereas long-chain ligands provide homogeneous and stable PNCs. The study also found that excessive amines or polar antisolvents can cause PNCs to transform into a Cs-rich non-perovskite structure with poorer emission functionalities and larger size distributions. The diffusion of ligands in a reaction system is crucial in determining the structures and functionalities of the PNCs. This study provides detailed guidance on synthesis routes for desired PNCs.

Lead-Free Cs3Bi2Br9 Perovskite Quantum Dots for Detection of Heavy Metal Cu2+ Ions in Seawater

Seawater pollution caused by heavy metal ions is a growing concern among the public. Perovskite quantum dots (PeQDs) are ideal probes for detecting metal ions due to their exceptional sensing characteristics, including remarkable sensitivity, low detection limit, and good selectivity. However, traditional lead-based PeQDs exhibit drawbacks related to lead toxicity and poor water stability. Herein, lead-free halide PeQDs Cs3Bi2Br9 were synthesized using Bi3+ instead of Pb2+ via the ligand-assisted reprecipitation method. The luminescence performance of the precursor is analyzed with respect to the reaction conditions. The results reveal that the optimal reaction temperature is 80 °C, the ideal octylamine dosage is 35 μL, and the most effective reaction time is 10 min. Photoluminescence spectra of Cs3Bi2Br9 are analyzed at various temperatures and demonstrate that fluorescence intensity decreases as temperature increases. The value of the exciton binding energy (Eb) is determined to be 88.6 meV. Cs3Bi2Br9 PeQDs synthesized under the optimum reaction conditions are utilized as fluorescent probes to detect copper ions in seawater. Results from experiments demonstrate that the presence of copper ions markedly quenched the photoluminescence of Cs3Bi2Br9 owing to the effective transfer of electrons from Cs3Bi2Br9 to Cu2+. A strong linear correlation between the degree of quenching and the contents of Cu2+ is observed. Cs3Bi2Br9 PeQDs demonstrate a sensitivity and detection limit of 1.21 μM−1 and 98.3 nM, respectively. Furthermore, this probe exhibits good photostability, water stability, and selectivity for copper ions, thereby indicating its potential for detecting marine heavy metal contaminants.

Controlled synthesis and photoluminescence study of blue-emitting Cs3Bi2Br9 nanocrystals prepared by the ligand-assisted reprecipitation (LARP) method

Cs3Bi2Br9 perovskite nanocrystals (PNCs) offer promising light-emitting properties due to a tunable bandgap, excellent luminescence, and low-cost fabrication. Multiple synthesis methods to produce Cs3Bi2Br9 have been investigated in recent years, with discrepancies in their reported photoluminescent properties, and low quantum yields. In this study, the ligand-assisted reprecipitation (LARP) method was adopted to synthesize Cs3Bi2Br9 PNCs using dimethyl sulfoxide and chloroform as the solvent and anti-solvent, respectively. LARP provided a simple approach to produce Cs3Bi2Br9 PNCs with the freedom to vary parameters such as temperature, solvents, and ligands. The use of dimethyl sulfoxide allowed for the rapid dissolution of the precursors, thereby decreasing the fabrication time, while chloroform resulted in a high product yield. The synthesis temperature was demonstrated as a significant parameter that influenced the direct and indirect bandgap nature of the PNCs. Oleylamine and oleic acid were used as ligands in the LARP synthesis. By varying the concentration of oleic acid, the bandgap of the Cs3Bi2Br9 NCs changed from 3.85 eV to 3.29 eV. Oleic acid concentration demonstrated influence over the crystal structure of the Cs3Bi2Br9 NCs. The photoluminescence quantum yield (PLQY) of the optimum PNCs was 62%.

Environment friendly lead-free Cs3Sb2Br9 perovskite: Wide measure range, high sensitivity, and rapid sensing response for high-performance humidity sensor

Due to the superiority of easy manufacture, low cost, coupled with super optoelectronic attributes, the metal halide perovskites have appeared as an emerging class of semiconductors owning their considerable potential for assorted utilization in humidity sensors. Nevertheless, the toxicity problem along with inherent instability of lead (Pb) halide perovskites is grimly impeding the large-scale manufacturing as well as commercialization. Herein, lead-free Cs3Sb2Br9 perovskites were successfully synthesized using a modified ligand-assisted reprecipitation approach and the humidity sensing properties relevant for humidity sensor applications were investigated. The as-fabricated Cs3Sb2Br9 humidity sensors display a super-high impedance variation of more than 105, and the testing range can be extended to a very low humidity (2% relative humidity, RH). The value of hysteresis is as low as 2.9%, and the response/recovery time is discovered to reach ∼0.9/3 s from 11% to 95% RH, which owns a large potential in the detection of the real-time moisture. Moreover, the Cs3Sb2Br9 humidity sensor boasts good reversibility and a remarkable level of stability. Our results demonstrate the potential for lead-free Cs3Sb2Br9 perovskites in a real-time and high-performance humidity sensor.

Lead-Free, Luminescent Perovskite Nanocrystals Obtained through Ambient Condition Synthesis.

Heterovalently substituting toxic lead is an increasingly popular design strategy to obtain environmentally sustainable variants of the exciting material class of halide perovskites. Perovskite nanocrystals (NCs) obtained through solution-based methods exhibit exceedingly high optical quality. Unfortunately, most of these synthesis routes still require reaction under inert gas and at very high temperatures. Herein a novel synthesis routine for lead-free double perovskite (LFDP) NCs is presented. An approach based upon the hot injection and ligand-assisted reprecipitation (LARP) methods to achieve a low-temperature and ambient atmosphere-based synthesis for manganese-doped Cs2 NaBiCl6 NCs is presented. Mn incorporation is critical for the otherwise non-emissive material, with a 9:1 Bi:Mn precursor ratio maximizing the bright orange photoluminescence (PL) and quantum yield (QY). Higher synthesis temperatures slightly increase the material's performance, yet NCs synthesized at room temperature are still emissive, highlighting the versatility of the synthetic approach. While the material's indirect bandgap limits its appeal for optoelectronics, this feature could benefit photocatalysis due to longer carrier lifetimes. Moreover, the developed synthesis is facile and can rapidly be adapted to other more viable material compositions and up-scaled to realize applications directly.

Room-temperature synthesis of lead-free copper(I)-antimony(III)-based double perovskite nanocrystals

In the field of perovskite solar cells, explorations of new lead-free all-inorganic perovskite materials are of great interest to address the instability and toxicity issues of lead-based hybrid perovskites. Recently, copper-antimony-based double perovskite materials have been reported with ideal band gaps, which possess great potential as absorbers for photovoltaic applications. Here, we synthesize Cs2CuSbCl6 double perovskite nanocrystals (DPNCs) at ambient conditions by a facile and fast synthesis method, namely, a modified ligand-assisted reprecipitation method. We choose methanol as a solvent for precursor salts as it is less toxic and easily removed in contrast to widely used dimethylformamide. Our computational structure search shows that the Cs2CuSbCl6 structure containing alternating [CuCl6]5− and [SbCl6]3− octahedral units is a metastable phase that is 30 meV/atom higher in energy compared to the ground state structure with [CuCl3]2− and [SbCl6]3− polyhedra. However, this metastable Cs2CuSbCl6 double perovskite structure can be stabilized through solution-based nanocrystal synthesis. Using an anion-exchange method, Cs2CuSbBr6 DPNCs are obtained for the first time, featuring a narrow bandgap of 0.9 eV. Finally, taking advantage of the solution processability of DPNCs, smooth and dense Cs2CuSbCl6 and Cs2CuSbBr6 DPNC films are successfully fabricated.

Highly stable multi-encapsulated red-emitting cesium lead halide nanocrystals for efficient copper ion detection and imaging in live cells

Recently, cesium lead halide (CsPbX3: X = Cl, Br, I) perovskite nanocrystals (NCs) have shown potentiality in the detection of different heavy metal ions and bioimaging applications for their smaller particle size, tunable emission spectra, high luminescent intensity, narrow emission spectra, multiphoton absorption property, etc. CsPbBr3 NCs are explored extensively in bioimaging applications for their comparatively higher stability in water. A longer wavelength excitation light source is recommended due to less scattering of light results in deeper penetration in living cells. However, imaging in live cells with red-emitting perovskite NCs is not suitable because of their poor structural stability, low emission intensity, and complex synthesis process. To tackle these issues, we introduce a specific halide exchange to the NCs and then multi-encapsulation shelling techniques that eventually improve the structural and environmental stability of the red-emitting NCs. Here, we synthesized Zn-doped CsPbBr3 NCs via the ligand-assisted reprecipitation (LARP) synthesis method in an open atmosphere. Then the highly luminescent red emitting CsPbBrxI3−x NCs with Zn doping were grown via the exchange of halide ions from pre-synthesized Zn-doped CsPbBr3 NCs to maintain the stable perovskite crystal structure in the nanoscale regime. Such NCs were further encapsulated with different shelling materials and then compared their photophysical properties. Among them, n-isopropyl acrylamide passivated Zn-doped CsPbBrxI3−x/SiO2/polyvinylpyrrolidone core/shell/shell NCs showed the highest stability against water and UV-irradiation. These NCs efficiently detect Cu2+-ions in water and achieved a detection limit of around 9.68 µM. The NCs were also tested for their compatibility as a fluorescent probe for live cell imaging using mammalian Chinese Hamster Ovary cells. As a proof-of-principle, we demonstrate both the efficient uptake and biocompatibility of the perovskite NCs. This work provides insight for expanding research activities on red-emitting perovskite NCs by developing a new strategy to improve the stability of the NCs, which is beneficial for both cost-effective bioimaging applications and heavy metal ion detection in water.

Hybrid Organic–Inorganic Perovskite Superstructures for Ultrapure Green Emissions

All inorganic CsPbBr3 superstructures (SSs) have attracted much research interest due to their unique photophysical properties, such as their large emission red-shifts and super-radiant burst emissions. These properties are of particular interest in displays, lasers and photodetectors. Currently, the best-performing perovskite optoelectronic devices incorporate organic cations (methylammonium (MA), formamidinium (FA)), however, hybrid organic-inorganic perovskite SSs have not yet been investigated. This work is the first to report on the synthesis and photophysical characterization of APbBr3 (A = MA, FA, Cs) perovskite SSs using a facile ligand-assisted reprecipitation method. At higher concentrations, the hybrid organic-inorganic MA/FAPbBr3 nanocrystals self-assemble into SSs and produce red-shifted ultrapure green emissions, meeting the requirement of Rec. 2020 displays. We hope that this work will be seminal in advancing the exploration of perovskite SSs using mixed cation groups to further improve their optoelectronic applications.

Structural Study of Paraffin-Stabilized Methylammonium Lead Bromide Magic-Sized Clusters

Metal halide perovskites, such as methylammonium lead bromide, have recently attracted considerable attention due to their interesting and useful photoelectric properties. Here, two types of methylammonium lead bromide magic-sized clusters (MSCs), passivated with oleylamine and oleic acid, were synthesized using ligand-assisted reprecipitation (LARP) and heated LARP (HLARP) methods. The optical properties of these MSCs were characterized using UV–vis electronic absorption and photoluminescence (PL) spectroscopies. The HLARP synthesis resulted in a two-fold increase in the PL quantum yield of the MSCs to 76%. The stability of the MSCs was tested using time-dependent PL spectroscopy. LARP MSCs in solution degraded completely after 14 days under ambient conditions, while HLARP MSCs lasted for 26 days. To stabilize them, the MSCs were added to a non-coordinating matrix, paraffin. Both MSCs showed significantly improved resistance to water with the addition of paraffin. Solid LARP MSCs lost all luminescence with and without the addition of paraffin by about 3 h. Solid HLARP MSCs without paraffin started to aggregate after 3 h, but paraffin stabilized HLARP MSC films were stable for 8 days. This improved stability in solid state form allowed for accurate, nonaggregated analysis using Raman spectroscopy, X-ray diffraction, and transmission electron microscopy. Raman spectroscopy revealed that the HLARP MSCs show an additional peak at 147 cm–1 compared to LARP MSCs, which is attributed to methylammonium. X-ray diffraction and transmission electron microscopy confirm that MSCs have a quasi-crystalline orthorhombic structure.

Lead-Free Halide Perovskite Cs2AgBiBr6/Bismuthene Composites for Improved CH4 Production in Photocatalytic CO2 Reduction.

CO2 photocatalytic conversion into value-added fuels through solar energy is a promising way of storing renewable energy while simultaneously reducing the concentration of CO2 in the atmosphere. Lead-based halide perovskites have recently shown great potential in various applications such as solar cells, optoelectronics, and photocatalysis. Even though they show high performance, the high toxicity of Pb2+ along with poor stability under ambient conditions restrains the application of these materials in photocatalysis. In this respect, we developed an in situ assembly strategy to fabricate the lead-free double perovskite Cs2AgBiBr6 on a 2D bismuthene nanosheet prepared by a ligand-assisted reprecipitation method for a liquid-phase CO2 photocatalytic reduction reaction. The composite improved the production and selectivity of the eight-electron CH4 pathway compared with the two-electron CO pathway, storing more of the light energy harvested by the photocatalyst. The Cs2AgBiBr6/bismuthene composite shows a photocatalytic activity of 1.49(±0.16) μmol g-1 h-1 CH4, 0.67(±0.14) μmol g-1 h-1 CO, and 0.75(±0.20) μmol g-1 h-1 H2, with a CH4 selectivity of 81(±1)% on an electron basis with 1 sun. The improved performance is attributed to the enhanced charge separation and suppressed electron-hole recombination due to good interfacial contact between the perovskite and bismuthene promoted by the synthesis method.

Room temperature synthesis of lead-free FASnI3 perovskite nanocrystals with improved stability by SnF2 additive

Tin halide perovskites are among the candidates for replacing lead-based ones for less toxicity and comparable optical properties. However, stability remains a challenge due to the easier oxidation of Sn2+ than Pb2+. Here, for the first time, we applied the ligand-assisted reprecipitation method to synthesize CH(NH2)2SnI3 (FASnI3) orthorhombic perovskite nanocrystals with an average diameter of 7.7 nm and a photoluminescence emission at 825 ± 2 nm (1.5 eV). The influence of synthesis parameters, including precursor solvent, precipitation media, temperature, and time on optical properties of nanocrystals, was studied. By incorporating SnF2, the stability of the nanocrystals was improved, and the oxidation from FASnI3 to FA2SnI6 was significantly delayed, which was quantitively demonstrated and confirmed by observing the characteristic diffraction peaks of the perovskite phase using x-ray diffraction at various exposure time to air. The addition of SnF2 is optimized to be 6%. The FASnI3 nanocrystals stayed stable for at least 265 days under N2 storage at room temperature and relative humidity of 20%.

高稳定性铋基钙钛矿纳米晶的可控合成: 结构和光物 理性质

Recently, cesium bismuth halide perovskites have emerged as potential substitutes to their counterparts, cesium lead halide perovskites, owing to their low toxicity. However, the photophysics of cesium-bismuth halides nanocrystals (NCs) have not yet been fully rationalized because their structures remain highly debated. The ultraviolet-visible (UV-vis) absorption along with other photophysical properties such as the nature and lifetime of the excited states vary considerably across the previous reports. Here, we successfully synthesize pure Cs3BiBr6 and Cs3Bi2Br9 NCs via a modified hot-injection method, where the structure can be easily controlled by tuning the reaction temperature. The UV-vis absorption spectrum of the pure Cs3Bi2Br9 NCs features two characteristic peaks originating from the absorption of the first exciton and second exciton, respectively, which ultimately clarifies the debate in the previous reports. Using femtosecond transient absorption spectroscopy, we systematically investigate the excited state dynamics of the Cs3Bi2Br9 NCs and reveal that the photoexcited carriers undergo a self-trapping process within 3 ps after excitation. More intriguingly, the Cs3Bi2Br9 NCs prepared by this method show much better photostability than those prepared by the ligand-assisted reprecipitation process. Photodetectors based on these Cs3Bi2Br9 NCs show a sensitive light response, demonstrating the definite potential for breakthrough optoelectronic applications.

Chirality in luminescent Cs3Cu2Br5 microcrystals produced via ligand-assisted reprecipitation.

Herein we report new chiral luminescent Cs3Cu2Br5 needle-like microcrystals and the analysis of their optical properties and the effect of the ligand structure on the transfer of chirality.

Quantum Label of Organic Acid Ligands-Determined CsPbBr3 Perovskite Magic-Sized Clusters

A strategy for synthesizing stable, pure, and excellent luminescent perovskite magic-sized clusters (PMSCs) by optimizing ligands is proposed. The optimal ligand pair was selected from methylphosphonic acid (MPA), valeric acid (VA), and butanesulfonic acid (BA) ligands in conjunction with ethylenediamine (EDA), respectively. Through ligand-assisted reprecipitation (LAPR) method, MPA–EDA CsPbBr3 PMSCs with high photoluminescence quantum yield (PLQY) of up to [Formula: see text]72% and excellent stability were optimized. By the density of states (DOS) analysis, the differences in luminescence properties were explored to originate from Pb(6s)–Br(4p) hybridization, and the hypothesis of constructing quantum maps of functional materials based on valence electron orbital hybridization was proposed. The above results provide a reliable experimental and theoretical direction for the future application of quantum label PMSCs in the field of optoelectronic devices.

LARP-assisted synthesis of CsBi3I10 perovskite for efficient lead-free solar cells.

Bismuth-based perovskites are an important class of materials in the fabrication of lead-free perovskite solar cells. Bi-based Cs3Bi2I9 and CsBi3I10 perovskites are getting much attention due to their appropriate bandgap values of 2.05 eV and 1.77 eV, respectively. However, the device optimisation process plays a key role in controlling the film quality and the performance of perovskite solar cells. Hence, a new strategy to improve crystallization as well as the thin film quality is equally important to develop efficient perovskite solar cells. Herein, an attempt was made to prepare the Bi-based Cs3Bi2I9 and CsBi3I10 perovskites via the ligand-assisted re-precipitation approach (LARP). The physical, structural, and optical properties were investigated on perovskite films deposited by the solution process for solar cell applications. Cs3Bi2I9 and CsBi3I10-based perovskite-based solar cells were fabricated using the device architecture of ITO/NiO x /perovskite layer/PC61BM/BCP/Ag. The device fabricated with CsBi3I10 showed the best power conversion efficiency (PCE) of 2.3% with an improved fill factor (FF) of 69%, V OC of 0.79 V, and J SC of 4.2 mA cm-2 compared to the Cs3Bi2I9-based device which showed a PCE of 0.7% with a FF of 47%, V OC of 0.62 V and J SC of 2.4 mA cm-2.

Precursor silanization assisted synthesis and optical tuning of dual-phase perovskite nanocrystals embedded in silica matrix with high environmental stability.

Ligand-assisted re-precipitation (LARP) is one of the most practicing techniques for synthesizing colloidal nanocrystals (NCs). But due to its fast reaction kinetics, it offers limited synthesis control. In the present study, we report a novel, precursor silanization-based room temperature technique unveiling slow crystallization of Cs4PbBr6/CsPbBr3 dual-phase nanocrystals (DPNCs) protected with a dense silica cloud-like matrix. Unlike conventional LARP, we can observe the tuneable optical bandgap of the DPNCs as a function of reaction time because of the slow reaction kinetics. The as-synthesized DPNCs exhibit a high photoluminescence quantum yield (PLQY) of 76% with ultrahigh stability while retaining∼100% of their initial PLQY in an ambient environment with a relative humidity of 55% for more than 1year. DPNCs demonstrates ambient photostability of 560h, and water stability of 25days. This interesting precursor silanization technique developed here can be extended for the synthesis of other nanomaterials.

Stability and spectroscopic analysis of CsPbBr3 quantum dots modified with 2-n-octyl-1-dodecanol.

Due to their excellent optical and electrical properties, all-inorganic metal halide perovskite CsPbBr3 quantum dots (QDs) have become one of the most promising materials in the field of optoelectronics during recent years. However, the stability of CsPbBr3 QDs limits their practical application and further development to a certain extent. In order to improve their stability, CsPbBr3 QDs were modified with 2-n-octyl-1-dodecanol for the first time in this paper. The 2-n-octyl-1-dodecanol-modified CsPbBr3 QDs were prepared by the ligand-assisted reprecipitation (LARP) method at room temperature in an air environment. Then the stability of the samples was tested at different temperatures and humidity. When the humidity was 80%, the photoluminescence (PL) intensity of both unmodified and modified CsPbBr3 QDs increased to different degrees because the appropriate amount of water changed the crystallization environment. The PL intensity of the modified QDs increased, and the peak positions were basically not shifted, proving that they did not agglomerate. Thermal stability test results showed that the PL intensity of the 2-n-octyl-1-dodecanol-modified QDs could still maintain 65% of the original intensity at 90 °C, which is 4.6 times that of the unmodified CsPbBr3 QDs. Experimental results show that the stability of CsPbBr3 QDs is significantly improved after 2-n-octyl-1-dodecanol modification, which demonstrates the excellent surface passivation of CsPbBr3 QDs by 2-n-octyl-1-dodecanol.

Molecular insights into the growth and time evolution of surface states of CsPbBr3 nanoparticles synthesized using a scalable room temperature approach

Room temperature ligand-assisted reprecipitation syntheses of CsPbBr3 nanoparticles (NPs) under open air conditions and with non-polar solvents have recently emerged as viable strategies for large-scale production of highly emissive NPs.

An improved ligand-assisted reprecipitation method to synthesize aqueous-phase CsPbBr3 perovskite nanocrystals and investigate their electrochemiluminescence behavior.

We propose a novel ligand-assisted reprecipitation method to synthesize aqueous-phase CsPbBr3 nanocrystals, the fluorescence intensity of which remained at 51% after 120 h. As a multifunctional additive, cesium trifluoroacetate (Cs-TFA) can improve the surface adsorption energy and induce nanocrystals to show significant anodic electrochemiluminescence (ECL) and stable cathodic ECL performances.

Orange LED and cell fluorescence imaging of Mn2+ doped CsPbCl3 water-soluble nanocrystals with improved stability and optimized luminescence

Water-soluble Mn2+ doped CsPbCl3 nanocrystals coating by 6-aminocaproic acid (ACA) ligand were prepared by a simple ligand assisted reprecipitation method at room temperature. The CsPbCl3:Mn2+/ACA nanocrystals were almost cubic phase and had mean size of about 10 nm. Due to the coating and passivation of ACA, the CsPbCl3:Mn2+/ACA nanocrystals retained the initial fluorescence intensity of 20% after being dispersed in deionized water for 20 days. The orange LED device based on CsPbCl3:Mn2+/ACA nanocrystals were prepared with excellent luminescence properties. In the cytotoxicity test, even if the MCF-7 cells were cultured for 24 h at the concentration of CsPbCl3:Mn2+/ACA nanocrystals as high as 160 μg·ml−1, the cell survival rate was still 70%. Confocal fluorescent cell imaging results showed that the nanocrystals had remarkable fluorescent cell imaging effect even after 24 h. The synthesized CsPbCl3:Mn2+/ACA nanocrystals have nice water solubility, good water stability, low cytotoxicity and highly luminescence properties, and have great application potential in the field of orange LED and fluorescent probes.