Zero-dimensional organic-inorganic hybrid halide perovskite green light material for white light LED and preparation method of zero-dimensional organic-inorganic hybrid halide perovskite green light material

Abstract

The invention relates to a zero-dimensional organic-inorganic hybrid halide perovskite green light material for a white light LED and a preparation method of the zero-dimensional organic-inorganic hybrid halide perovskite green light material. The chemical composition of the material is C6H14N2ZnCl4 doped with Mn < 2 + >. According to the invention, the novel 0-dimensional organic-inorganic hybrid halide perovskite crystal is prepared by adopting a hydrothermal method. The crystal does not emit light, but generates bright green light at 535nm after being doped with Mn < 2 + >, the light is derived from d-d transition of tetrahedral coordination Mn < 2 + >, and the maximum quantum yield can reach 70%. The white light LED prepared from the material has good performance, the correlated color temperature is 6003K, and the color rendering index is 79. In addition, the material can also be used in the field of security and anti-counterfeiting. The preparation method disclosed by the invention is simple, low in cost and environment-friendly, the product has excellent photophysical properties and high yield, and a novel green luminescent material is provided for the field of white light LEDs.

Description

Technical Field

[0001] The present invention relates to the field of organic-inorganic hybrid materials, and particularly to a zero-dimensional organic-inorganic hybrid halide perovskite green light material for white light LEDs and a preparation method thereof, which can be applied to fields such as lighting, security anti-counterfeiting, etc. Background Art

[0002] In recent years, organic-inorganic hybrid metal halide perovskites have become a research hotspot in the optoelectronic field due to their excellent optoelectronic properties (such as high absorption coefficient, tunable bandgap, and high carrier mobility) (Literature 1: J. Am. Chem. Soc. 2020, 142, 10112). These materials show great potential in fields such as solar cells, LEDs, and lasers (Literature 2: Science 2015, 348, 1234). However, traditional commercial phosphors such as YAG:Ce 3+ Although widely used in white light LEDs, their color rendering index is low (<75), and the red light component is insufficient, resulting in a cold lighting color and poor color rendering ability (Literature 3: Adv. Mater. 2018, 30, 1802486). In addition, the synthesis of YAG:Ce 3+ requires high-temperature solid-state reaction (>1500 °C), with high energy consumption and easy introduction of impurities (Literature 4: Chem. Mater. 2017, 29, 5264).

[0003] On the other hand, although lead-based perovskite materials (such as MAPbBr3) have high quantum efficiency, the toxicity of lead limits their practical applications (Literature 5: Nat. Photonics 2016, 10, 699), and their stability is poor, being easily affected by humidity, light, and thermal degradation (Literature 6: ACS Energy Lett. 2018, 3, 641). To address these problems, researchers have attempted to develop lead-free perovskite materials (such as Sn 2+ , Bi 3+ -based materials), but their luminous efficiency is generally lower than that of the lead-based system (Literature 7: Angew. Chem. Int. Ed. 2019, 58, 7268).

[0004] In recent years, zero-dimensional perovskites have attracted attention due to their quantum confinement effect and high-efficiency luminescence characteristics (Literature 8: Nat. Commun. 2019, 10, 5164). For example, materials such as C4H 12 N2SnBr4 achieve high-efficiency luminescence through self-trapped exciton emission, but they contain heavy metals and have harsh synthesis conditions (Literature 9: J. Mater. Chem. C 2021, 9, 2345). In addition, the manganese doping strategy has been proven to effectively regulate the luminescence properties of materials. For example, Mn 2+Orange to green luminescence is achieved through d-d transitions in Zn-based halides (Literature 10: Adv. Opt. Mater. 2020, 8, 1901723), but its application in zero-dimensional perovskites has been rarely reported.

[0005] In summary, developing a lead-free green light material with simple process, environmental friendliness and high quantum efficiency is a key challenge to promote the development of white light LEDs and anti-counterfeiting technologies. In this invention, by designing the zero-dimensional organic-inorganic hybrid perovskite C6H 14 N2ZnCl4:Mn 2+ , combining hydrothermal synthesis and manganese doping strategy, high-efficiency green luminescence (quantum yield 70%) and low toxicity are achieved, providing an innovative solution to the above problems. Summary of the Invention

[0006] Purpose of the Invention:

[0007] The purpose of this invention is to provide a zero-dimensional organic-inorganic hybrid halide perovskite green light material for white light LEDs and its preparation method, to solve the problems existing in existing phosphors, and to meet the requirements of high-performance fluorescent materials in fields such as lighting and security anti-counterfeiting.

[0008] Technical Solution:

[0009] Material Composition: The zero-dimensional organic-inorganic hybrid halide perovskite green light material of this invention has the composition of C6H 14 N2ZnCl4 doped with Mn 2+ . By precisely controlling the doping concentration of Mn 2+ , the material produces bright green luminescence at 535 nm, and the quantum yield of the doped sample can reach up to 70%.

[0010] Preparation Method: The material is prepared by a simple hydrothermal method. The specific steps are as follows: First, the raw materials containing C6H 12 N2, ZnCl2 and MnCl2 (added according to doping requirements) are mixed in a specific molar ratio, and an appropriate amount of concentrated hydrochloric acid solution is added and stirred evenly to form a reaction solution. Then the reaction solution is transferred to a reaction kettle and reacted at a certain temperature for a certain time. After the reaction is completed, it is naturally cooled to room temperature, and after post-treatment steps such as filtration, washing and drying, the target product is obtained.

[0011] Advantageous Effects:

[0012] Simple preparation process: The hydrothermal method is easy to operate, the reaction conditions are mild, no complex equipment and special environment are required, which is conducive to large-scale industrial production.

[0013] Excellent optical properties: Doped with Mn 2+The resulting material emits bright light at 535 nm with a high quantum yield. When used to prepare white LEDs, the correlated color temperature is 6003 K and the color rendering index is 79, providing a high-quality lighting source.

[0014] Wide application prospects: The material performs excellently in security anti-counterfeiting. Relevant anti-counterfeiting application patterns can be customized, and its anti-counterfeiting function is realized by utilizing its bright luminescence characteristics, expanding the application fields of the material.

[0015] Technical solution Description of the drawings

[0016] Figure 1 : C6H 14 N2ZnCl4:Mn 2+ XRD pattern of the C6H

[0017] Figure 2 : C6H 14 N2ZnCl4:Mn 2+ Excitation spectrum of the C6H

[0018] Figure 3 : C6H 14 N2ZnCl4:Mn 2+ Emission spectrum of the C6H

[0019] Figure 4 : C6H 14 N2ZnCl4:Mn 2+ Emission spectrum of the white LED prepared from the C6H Detailed implementation manners

[0020] The present invention will be further described below in conjunction with embodiments and the drawings, but the scope claimed by the present invention is not limited to the scope shown in the embodiments.

[0021] Example 1

[0022] Mix C6H 12 N2, ZnCl2 and MnCl2 in a molar ratio of 1:1:0.01, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 120 °C for 5 hours. After the reaction, cool it naturally to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain the green light-emitting material of C6H 14 N2ZnCl4 doped with Mn 2+ . This material produces bright green luminescence at 535 nm, and the quantum yield is 65%. As Figure 1As shown, the crystals obtained from the product were detected using an XRD powder diffractometer (Bruker D8 Advance), and the XRD of the transparent crystals of the product was consistent with the fitting diagram of the high-energy ray single crystal. The luminescence properties of the product were detected using a fluorescence spectrometer (HORIBA Jobin Yvon Inc. Fluoromax-4). As Figure 2 shown, the excitation spectrum of the product in this example has a strong broadband absorption peak in the long-wavelength region of 250 - 450 nm, and can effectively absorb the light emitted by violet and blue LEDs. As Figure 3 shown, it emits green light at 535 nm, and both its excitation and emission originate from the d-d transition of Mn 2+ . As Figure 4 shown, the product of this example of the present invention was mixed with the red phosphor K2SiF6:Mn 4+ , and then encapsulated in a 460 nm chip, successfully achieving white light emission. The corresponding CIE coordinates were (0.33, 0.36), the CRI was 79, and the CCT was 6003K. This result proves the potential of the product of this example of the present invention as a WLED phosphor material.

[0023] Example 2

[0024] C6H 12 N2, ZnCl2, and MnCl2 were mixed in a molar ratio of 1:1:0.02, added to 4 mL of concentrated hydrochloric acid, and stirred evenly. The mixed solution was placed in a hydrothermal reaction kettle and reacted at 120 °C for 6 hours. After the reaction, it was naturally cooled to room temperature, the precipitate was collected, washed with deionized water and ethanol, and dried to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 66%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those of Example 1.

[0025] Example 3

[0026] C6H 12 N2, ZnCl2, and MnCl2 were mixed in a molar ratio of 1:1:0.03, added to 4 mL of concentrated hydrochloric acid, and stirred evenly. The mixed solution was placed in a hydrothermal reaction kettle and reacted at 120 °C for 7 hours. After the reaction, it was naturally cooled to room temperature, the precipitate was collected, washed with deionized water and ethanol, and dried to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 67%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those of Example 1.

[0027] Example 4

[0028] Mix C6H 12 N2, ZnCl2 and MnCl2 in a molar ratio of 1:1:0.04, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 120 °C for 8 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 68%. The XRD pattern, fluorescence spectrum and packaged white LED spectrum of the product in this example are basically similar to those in Example 1.

[0029] Example 5

[0030] Mix C6H 12 N2, ZnCl2 and MnCl2 in a molar ratio of 1:1:0.05, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 140 °C for 5 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 70%. The XRD pattern, fluorescence spectrum and packaged white LED spectrum of the product in this example are basically similar to those in Example 1.

[0031] Example 6

[0032] Mix C6H 12 N2, ZnCl2 and MnCl2 in a molar ratio of 1:1:0.06, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 140 °C for 6 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 69%. The XRD pattern, fluorescence spectrum and packaged white LED spectrum of the product in this example are basically similar to those in Example 1.

[0033] Example 7

[0034] Mix C6H 12N2, ZnCl2, and MnCl2 were mixed in a molar ratio of 1:1:0.07 and added to 4 mL of concentrated hydrochloric acid, and stirred evenly. The mixed solution was placed in a hydrothermal reaction kettle and reacted at 140 °C for 7 hours. After the reaction, it was naturally cooled to room temperature, the precipitate was collected, washed with deionized water and ethanol, and dried to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 68%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those in Example 1.

[0035] Example 8

[0036] C6H 12 N2, ZnCl2, and MnCl2 were mixed in a molar ratio of 1:1:0.08 and added to 4 mL of concentrated hydrochloric acid, and stirred evenly. The mixed solution was placed in a hydrothermal reaction kettle and reacted at 140 °C for 8 hours. After the reaction, it was naturally cooled to room temperature, the precipitate was collected, washed with deionized water and ethanol, and dried to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 67%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those in Example 1.

[0037] Example 9

[0038] C6H 12 N2, ZnCl2, and MnCl2 were mixed in a molar ratio of 1:1:0.09 and added to 4 mL of concentrated hydrochloric acid, and stirred evenly. The mixed solution was placed in a hydrothermal reaction kettle and reacted at 160 °C for 5 hours. After the reaction, it was naturally cooled to room temperature, the precipitate was collected, washed with deionized water and ethanol, and dried to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 66%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those in Example 1.

[0039] Example 10

[0040] C6H 12 N2, ZnCl2, and MnCl2 were mixed in a molar ratio of 1:1:0.1 and added to 4 mL of concentrated hydrochloric acid, and stirred evenly. The mixed solution was placed in a hydrothermal reaction kettle and reacted at 160 °C for 6 hours. After the reaction, it was naturally cooled to room temperature, the precipitate was collected, washed with deionized water and ethanol, and dried to obtain C6H 14Mn-doped N2ZnCl4 2+ green light-emitting material. This material produces bright green luminescence at 535 nm with a quantum yield of 65%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product of this example are basically similar to those of Example 1. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product of this example are basically similar to those of Example 1.

[0041] Example 11

[0042] Mix C6H 12 N2, ZnCl2, and MnCl2 in a molar ratio of 1:1:0.01, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 160 °C for 7 hours. After the reaction is completed, cool it naturally to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 Mn-doped N2ZnCl4 2+ green light-emitting material. This material produces bright green luminescence at 535 nm with a quantum yield of 64%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product of this example are basically similar to those of Example 1.

[0043] Example 12

[0044] Mix C6H 12 N2, ZnCl2, and MnCl2 in a molar ratio of 1:1:0.02, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 160 °C for 8 hours. After the reaction is completed, cool it naturally to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 Mn-doped N2ZnCl4 2+ green light-emitting material. This material produces bright green luminescence at 535 nm with a quantum yield of 63%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product of this example are basically similar to those of Example 1.

[0045] Example 13

[0046] Mix C6H 12 N2, ZnCl2, and MnCl2 in a molar ratio of 1:1:0.03, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 180 °C for 5 hours. After the reaction is completed, cool it naturally to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 Mn-doped N2ZnCl4 2+Green light material. This material produces bright green luminescence at 535 nm with a quantum yield of 62%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those of Example 1.

[0047] Example 14

[0048] Mix C6H 12 N2, ZnCl2, and MnCl2 in a molar ratio of 1:1:0.04, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 180 °C for 6 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ Green light material. This material produces bright green luminescence at 535 nm with a quantum yield of 61%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those of Example 1.

[0049] Example 15

[0050] Mix C6H 12 N2, ZnCl2, and MnCl2 in a molar ratio of 1:1:0.05, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 180 °C for 7 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ Green light material. This material produces bright green luminescence at 535 nm with a quantum yield of 60%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those of Example 1.

[0051] Example 16

[0052] Mix C6H 12 N2, ZnCl2, and MnCl2 in a molar ratio of 1:1:0.06, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 180 °C for 8 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ Green light material. This material produces bright green luminescence at 535 nm with a quantum yield of 59%. The XRD pattern, fluorescence spectrum, and encapsulated white LED spectrum of the product in this example are basically similar to those of Example 1.

[0053] Example 17

[0054] Mix C6H 12 N2, ZnCl2 and MnCl2 in a molar ratio of 1:1:0.07, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 150 °C for 5 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 58%. The XRD pattern, fluorescence spectrum and encapsulated white LED spectrum of the product in this example are basically similar to those in Example 1.

[0055] Example 18

[0056] Mix C6H 12 N2, ZnCl2 and MnCl2 in a molar ratio of 1:1:0.08, add them to 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 150 °C for 6 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 57%. The XRD pattern, fluorescence spectrum and encapsulated white LED spectrum of the product in this example are basically similar to those in Example 1.

[0057] Example 19

[0058] Mix C6H 12 N2, ZnCl2 and MnCl2 in a molar ratio of 1:1:0.09, add 4 mL of concentrated hydrochloric acid, and stir evenly. Place the mixed solution in a hydrothermal reaction kettle and react at 150 °C for 7 hours. After the reaction is completed, naturally cool it to room temperature, collect the precipitate, wash it with deionized water and ethanol, and dry it to obtain C6H 14 N2ZnCl4 doped with Mn 2+ green light material. This material produces bright green luminescence at 535 nm, and the quantum yield is 56%. The XRD pattern, fluorescence spectrum and encapsulated white LED spectrum of the product in this example are basically similar to those in Example 1.

[0059] Example 20

[0060] Mix C6H 12N2, ZnCl2 and MnCl2 are mixed in a molar ratio of 1:1:0.1 and added to 4 mL of concentrated hydrochloric acid, and stirred evenly. The mixed solution is placed in a hydrothermal reaction kettle and reacted at 150 °C for 8 hours. After the reaction is completed, it is naturally cooled to room temperature, the precipitate is collected, washed with deionized water and ethanol, and dried to obtain C6H 14 Mn-doped N2ZnCl4 2+ green light-emitting material. This material produces bright green luminescence at 535 nm, and the quantum yield is 55%. The XRD pattern, fluorescence spectrum and encapsulated white LED spectrum of the product in this example are basically similar to those in Example 1.

[0061] Through the above 20 examples, the effects of different doping concentrations, reaction temperatures and reaction times on the luminescence properties of the C6H 14 Mn-doped N2ZnCl4 2+ green light-emitting material can be systematically studied, providing an experimental basis for optimizing the preparation conditions.

Claims

1. A zero-dimensional organic-inorganic hybrid halide perovskite green light material for white light LED, characterized in that: The material is C6H 14 N2ZnCl4 doped with Mn 2+ of compounds.

2. The material according to claim 1, characterized in that: The Mn 2+ The doping concentration is 0.1-5mol%.

3. The material according to claim 1, characterized in that: The material is prepared by a hydrothermal method, and the hydrothermal reaction time is 5-8 hours.

4. The material according to claim 1, characterized in that: The material has bright green luminescence at 535 nm. Its quantum yield is 60%-70%.

5. A method for preparing the material according to claim 1, characterized in that The following steps are involved: a) C6H 14 N2ZnCl4 powder and Mn 2+ Salt solution mixing; b) conducting a hydrothermal reaction in deionized water at a temperature of 120-180° C. for 5-8 hours; c) cooling to room temperature after the reaction is completed, filtering and washing the product; d) drying the product to obtain the zero-dimensional organic-inorganic hybrid halide perovskite green light material.

6. The method according to claim 5, characterized in that: The Mn2 + The salt is manganese nitrate or manganese chloride.

7. The method according to claim 5, characterized in that: The hydrothermal reaction temperature is 120-180°C.

8. The material according to claim 1 has relevant applications in the field of white light LED or security and anti-counterfeiting.

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