A high-fluorescence quantum yield Sb 3+ : method for preparing a perovskite Cs2NaInCl6

Abstract

The application discloses a high-fluorescence-quantum-yield Sb 3+ :Cs2NaInCl6 perovskite preparation method belongs to the technical field of inorganic luminescent material preparation. First, cesium chloride, sodium chloride, indium chloride and antimony chloride are mixed and ground, the obtained powder is placed in a vacuum drying box and is treated at 60-300 DEG C for 0.5-2h, a mixture of oleylamine and oleic acid is added, and grinding is continuously performed until the solution becomes uniform, a hydrochloric acid solution with pH=3.2 is added to the product, and after uniform grinding, DOPC is immediately added to the product, and it is observed that the blue fluorescence of the product is strengthened, thereby obtaining high-purity and high-fluorescence-efficiency Sb 3+ :Cs3TbCl6NCs inorganic perovskite. The application realizes Sb doping through mechanical grinding for the first time 3+ :Preparation of Cs2NaInCl6 NCs, and the fluorescence efficiency of the Cs2NaInCl6 NCs is obviously enhanced through post-processing, thereby being Sb 3+ :Application of Cs2NaInCl6 in photoelectricity provides a good prospect.

Description

Technical Field

[0001] This invention belongs to the field of inorganic luminescent material preparation technology, specifically relating to a method for preparing Sb with high fluorescence quantum efficiency. 3+ A novel approach to Cs2NaInCl6 all-inorganic perovskite nanomaterials. Background Technology

[0002] Lead halide perovskites have become star materials in the optoelectronic field due to their narrow full width at half maximum (FWHM), high fluorescence quantum efficiency, and tunable bandgap. However, their application in optoelectronics is limited by poor structural stability and the toxicity of the heavy metal lead (Pb). In recent years, many scientists have attempted to replace highly toxic lead with other environmentally friendly elements of the same valence state (such as tin and germanium) while maintaining their excellent optoelectronic properties. However, Sn... 2+ and Ge 2+ Its stability is also relatively poor, which is not conducive to its further development in the optoelectronic field. Bilayer perovskites, due to their broad metal element selectivity and stable structure, have become one of the most promising non-lead perovskite candidates.

[0003] Despite the widespread interest in bilayer perovskites, their inherent structure leads to transition-forbidden conditions, resulting in very low fluorescence quantum efficiency (PLQY). Currently, inducing Jahn-Teller distortion in the soft lattice octahedrons of perovskites upon excitation, thereby generating self-confined exciton (STE) emission, is one of the most effective strategies for tuning the band structure and fluorescence properties of bilayer perovskites. Importantly, such bilayer perovskites can serve as excellent host materials for various optical dopants. In the past two years, various isovalent substitutions have been achieved in bilayer perovskites to enhance PLQY. In Cs₂NaInCl₆... ， Especially large trivalent f-electron dopants or s-electron dopants, such as Bi 3+ or Sb 3+ It can replace In in octahedral networks 3+ Sb is introduced at the B site of Cs2NaInCl6. 3+ This breakthrough overcomes the parity-even forbidden transition, not only solving the instability and toxicity of lead-based perovskites but also improving their fluorescence efficiency and environmental friendliness. This makes them more competitive in future applications such as solar cells, photodetectors, and especially lighting and displays.

[0004] Therefore, the synthesis method of Sb-doped Cs₂NaInCl₆ bilayer perovskite nanomaterials has attracted widespread attention from scientists. Furthermore, this perovskite emits a dazzling blue light under ultraviolet excitation, which has broad application prospects in the scarce field of blue photons and optoelectronics. The Zhuang group synthesized Cs₂NaInCl₆ NCs using a high-temperature hydrothermal method. Cs(OAc), Na(OAc), In(OAc)₃, and Sb(OAc)₃ were mixed in a composition ratio of 2:1:0.45:0.05 and added to a flask along with oleylamine, oleic acid, and octadecene. The mixture was heated at 120°C. ◦ Vigorously stir under vacuum for 30 minutes at C, then introduce N2 and heat at 120°C. ◦ Keep the reaction mixture at C for 5-10 minutes until the white powder dissolves, then heat the reaction system to 177°C. ◦ C, finally inject TMSCl. After reacting for 30 seconds, cool the mixture in a water bath; PLQY is 36.9%. Zhou's group used a hot-injection method to place a mixture of cesium acetate, anhydrous sodium acetate, and Sb oleic acid precursor, hydrated acetic acid, oleic acid, and oleic acid in a three-necked round flask at a molar ratio of 2:1. Octadene was added, and the mixture was degassed at 120°C for 1 h. Then, tri-n-octylphosphine was injected under a N2 atmosphere. The resulting Sb 3+ The PLQY of Cs2NaInCl6 NCs reached 39.1%.

[0005] Although the above synthesis method can synthesize Sb 3+ The synthesis method yields Cs₂NaInCl₆NCs, but it is complex, requires organic solvents, is time-consuming, and necessitates prolonged heating at high temperatures, resulting in high energy consumption and hindering large-scale production, thus limiting its application in the optoelectronic field. This synthesis method requires further improvement and innovation.

[0006] Therefore, how to achieve a green, environmentally friendly, and pollution-free preparation method for Sb that can also efficiently synthesize and improve fluorescence quantum efficiency is a key challenge. 3 + The new method for Cs2NaInCl6NCs is of great significance for the large-scale production and application of this inorganic perovskite nanomaterial. Summary of the Invention

[0007] The technical problem to be solved by this invention is to overcome the problems existing in the prior art and provide a new method for synthesizing doped Sb with high optical properties that is simple to operate, time-saving, and can be synthesized in large quantities at room temperature and pressure. 3+ : Cs2NaInCl6 perovskite.

[0008] The technical problem of this invention is solved by the following technical solution:

[0009] A high fluorescence quantum efficiency Sb 3+The preparation method of Cs2NaInCl6 perovskite involves first mixing and grinding cesium chloride, sodium chloride, indium chloride, and antimony chloride in a molar ratio of 2:1:0.9:0.1. The mixture gradually becomes denser and adheres to the agate wall as it transitions from a loose white powder. With prolonged grinding, the white powder becomes loose again, at which point grinding is stopped. When irradiated with a 302nm ultraviolet lamp, the product exhibits blue fluorescence. The resulting powder is then placed in a vacuum drying oven at 60-300°C. ◦ Heat treatment at C for 0.5-2 hours, followed by the addition of a mixture of oleylamine and oleic acid. The amount used is 800-950 μl of the oleylamine-oleic acid mixture per 1 mmol of cesium chloride, with a volume ratio of oleylamine to oleic acid of 5:1. Grinding continues until the solution becomes homogeneous. Then, hydrochloric acid solution at pH 3.2 is added to the product, with a amount of 0.4-1.5 ml of hydrochloric acid per 1 mmol of cesium chloride. After further grinding until homogeneous, DOPC (1,2-dioleoyl-sn-glycerol-3-phosphocholine, >99%) is immediately added, with a amount of 5-10 ml of DOPC per 1 mmol of cesium chloride. An increase in the blue fluorescence of the product is observed, indicating the yield of high-purity, high-fluorescence-efficiency Sb. 3+ : Cs2NaInCl6 perovskite.

[0010] In a high fluorescence quantum efficiency Sb of the present invention 3+ In the preparation method of Cs2NaInCl6 perovskite, in order to better improve the fluorescence efficiency of the product, the vacuum heat treatment is preferably carried out at 180°C. ◦ Processing at C for 0.5 hours.

[0011] In a high fluorescence quantum efficiency Sb of the present invention 3+ In the preparation method of Cs2NaInCl6 perovskite, in order to better promote the synthesis of nanoparticles, it is preferable to use a mixture of 900 μl of oleylamine oleic acid per 1 mmol of cesium chloride.

[0012] In a high fluorescence quantum efficiency Sb of the present invention 3+ In the preparation method of Cs2NaInCl6 perovskite, in order to better improve the fluorescence efficiency of the product and accelerate the reaction time, the amount of hydrochloric acid solution with pH=3.2 is 0.4 ml of hydrochloric acid solution per 1 mmol of cesium chloride.

[0013] In a high fluorescence quantum efficiency Sb of the present invention 3+ In the preparation method of Cs2NaInCl6 perovskite, in order to further improve the stability and size uniformity of the product, DOPC is added to obtain high-quality quantum dots. The preferred amount of DOPC is 1 mmol of cesium chloride and 5 ml of DOPC.

[0014] Beneficial effects:

[0015] This invention is the first to achieve Sb doping through mechanical polishing. 3+ The preparation of Cs2NaInCl6NCs was carried out, and its fluorescence efficiency was significantly enhanced through post-treatment, making it suitable for Sb 3+ Cs₂NaInCl₆ shows promising potential for applications in optoelectronics. Under excitation with a 302 nm UV lamp, the product emits bright blue fluorescence, consistent with the fluorescence spectrum. This simple and efficient method was used to synthesize Sb. 3+ : Cs2NaInCl6NCs.

[0016] In summary, this invention has the advantages of simple method, easy operation, low energy consumption, and efficient synthesis of Sb. 3+ The high fluorescence efficiency of Cs2NaInCl6NCs inorganic perovskites is of great significance. Attached Figure Description

[0017] Figure 1 It is the doped Sb prepared in Example 1 3+ Solid-state absorption spectrum of Cs2NaInCl6NCs perovskite material.

[0018] Figure 2 It is the doped Sb prepared in Example 1 3+ Solid-state fluorescence emission spectrum of Cs2NaInCl6NCs perovskite material.

[0019] Figure 3 It is the doped Sb prepared in Example 1 3+ Solid-state XRD pattern of Cs2NaInCl6NCs perovskite material.

[0020] Figure 4 It is the doped Sb prepared in Example 1 3+ Photograph of Cs2NaInCl6NCs perovskite material under 302nm ultraviolet light. Detailed Implementation

[0021] Example 1:

[0022] 1 mmol cesium chloride, 0.5 mmol sodium chloride, 0.45 mmol indium chloride, 0.05 mmol antimony chloride, and 25 agate balls with a diameter of 6 mm were placed in a 25 ml agate jar. The ball mill was set to an AC frequency of 35 Hz and a rotation speed of 1050 rad / min for mechanical grinding for 2 hours. The mixture gradually changed from a loose white powder to a denser powder that adhered to the agate wall. As the grinding time increased, the white powder became loose again. At this point, grinding was stopped, and the resulting product was dried in a vacuum oven at 180°C. ◦Heat treatment at C for 0.5 h was followed immediately by the addition of 150 μl of oleylamine and 750 μl of oleic acid to the resulting product to obtain Sb-doped material. 3+ The Cs₂NaInCl₆ NCs inorganic perovskite was irradiated with a 302nm UV lamp, and the product emitted blue fluorescence. Subsequently, 0.4ml of hydrochloric acid solution (pH 3.2) was added to the product, and grinding continued until the product became homogeneous. Immediately afterwards, 10ml of DOPC was added, and irradiation with a 302nm UV lamp resulted in a significant increase in fluorescence intensity. Solid-state absorption analysis and fluorescence emission tests were performed on the product, and its absorption spectrum is shown below. Figure 1 As shown; fluorescence emission spectrum as shown Figure 2 As shown. The XRD pattern of the product is as follows. Figure 3 As shown, by Figure 3 As can be seen, this embodiment successfully prepared Sb-doped Cs₂NaInCl₆ inorganic perovskite. The product emitted bright blue fluorescence upon excitation under ultraviolet light (302 nm), as shown in the image. Figure 4 As shown. The ball mill used was a QM-3SP04 planetary ball mill. Its fluorescence quantum efficiency was 53.1%.

[0023] Example 2:

[0024] The heat treatment temperature in Example 1 was changed from 180... ◦ C becomes 60 respectively ◦ C, 240 ◦ C, 300 ◦ C. With other conditions unchanged, the fluorescence quantum efficiencies of the products treated at different drying temperatures were measured to be 42.3%, 47.5%, and 44.1%, respectively. Therefore, the heat treatment temperature is 180°C. ◦ C is optimal.

[0025] Example 3:

[0026] Keeping the oleylamine-oleic acid ratio of 1:5 unchanged in Example 1, the total volume of the two was changed from 900 μl to 800 μl, 850 μl, and 950 μl respectively. The fluorescence efficiencies of the products were measured to be 44.1%, 47.2%, and 42.1% respectively. Therefore, the optimal volume of oleylamine-oleic acid is 900 μl.

[0027] Example 4:

[0028] The amount of hydrochloric acid solution used in Example 1 was changed from 0.4 ml to 0.2 ml, 0.6 ml, and 0.8 ml, respectively, while other conditions remained unchanged. The fluorescence quantum efficiencies of the products treated at different drying temperatures were measured to be 42.1%, 52.3%, and 47.5%, respectively. Therefore, the amount of hydrochloric acid solution added was 0.4 ml, which was the optimal amount.

[0029] Example 5:

[0030] The amount of DOPC in Example 1 was changed from 5 ml to 2.5 ml, 7.5 ml, and 10 ml, respectively, while other conditions remained unchanged. The fluorescence quantum efficiencies of the products treated at different cooling temperatures were measured to be 42.6%, 42.9%, and 40.8%, respectively. Therefore, the optimal amount of DOPC added was 5 ml.

[0031] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A high fluorescence quantum efficiency Sb 3+ The preparation method of Cs₂NaInCl₆ perovskite involves first mixing and grinding cesium chloride, sodium chloride, indium chloride, and antimony chloride in a molar ratio of 2:1:0.9:0.

1. The mixture gradually transforms from a loose white powder into a denser powder that adheres to the agate wall. With prolonged grinding, the white powder becomes loose again, at which point grinding is stopped. Upon irradiation with a 302nm ultraviolet lamp, the product exhibits blue fluorescence. The resulting powder is then heat-treated in a vacuum drying oven at 60-300℃ for 0.5 seconds. After grinding for 2 hours, a mixture of oleylamine and oleic acid was added, at a volume ratio of 800-950 μl of the mixture per 1 mmol of cesium chloride (oleylamine:oleic acid volume ratio 5:1). Grinding continued until the solution became homogeneous. Then, hydrochloric acid solution at pH 3.2 was added, at a volume of 0.4-1.5 ml per 1 mmol of cesium chloride. After grinding was complete, DOPC was immediately added, at a volume of 5-10 ml per 1 mmol of cesium chloride. Irradiation under a 302 nm UV lamp at this point showed a significant increase in fluorescence intensity, indicating the yield of high-purity, high-fluorescence-efficiency Sb. 3+ : Cs2NaInCl6 perovskite.

2. A high fluorescence quantum efficiency Sb according to claim 1 3+ A method for preparing Cs2NaInCl6 perovskite, characterized in that, The vacuum heat treatment mentioned is at 180°C. ◦ Processing at C for 0.5 hours.

3. A high fluorescence quantum efficiency Sb according to claim 1 3+ A method for preparing Cs2NaInCl6 perovskite, characterized in that, Use a mixture of 900 μl of oleylamine and oleic acid per 1 mmol of cesium chloride.

4. A high fluorescence quantum efficiency Sb according to claim 1 3+ A method for preparing Cs2NaInCl6 perovskite, characterized in that, The amount of hydrochloric acid solution with pH=3.2 used is 0.4 ml of hydrochloric acid solution per 1 mmol of cesium chloride.

5. A high fluorescence quantum efficiency Sb according to claim 1 3+ A method for preparing Cs2NaInCl6 perovskite, characterized in that, The dosage of DOPC is 5 ml for every 1 mmol of cesium chloride.

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