Tellurium-doped zirconium-based halide perovskite materials with white light emission and their synthesis and applications

Abstract

The present invention discloses a tellurium-doped zirconium-based halide perovskite material with white light emission, a preparation method thereof, and an application thereof. The chemical formula of the perovskite material with white light emission is (Cs 1‑ x Rb x )2Zr 1‑y Te y Cl6, where 0 ≤ x ≤ 1, 0

Description

Technical Field

[0001] The invention belongs to the field of lighting and display, and in particular relates to a tellurium-doped zirconium-based halide perovskite material with white light emission, and its synthesis and application. Background Art

[0002] Nearly 20% of the world's electricity is consumed for lighting, and more efficient lighting technology can achieve large-scale energy conservation and emission reduction. However, it remains a challenge to effectively create the high-quality white light required for indoor lighting. In order to accurately represent colors, the lighting source must provide photons of all energies visible to our eyes. Such a wide range of emission is difficult to achieve from a single material. Currently commercial white light emitting diodes (LEDs) are mainly made of red, green and blue LED arrays or blue LEDs with phosphor coatings, which makes them highly dependent on blue LED wafers (such as GaN) grown by epitaxial technology, thus increasing the production cost to a certain extent. When the device is illuminated, the blue light component is too much, which may damage the retina. In addition, most phosphors contain non-renewable rare earth elements, and their mining and refining processes have adverse effects on the environment. Therefore, it is necessary to develop environmentally friendly and efficient single-component white light materials and use them in electroluminescent diodes to achieve green lighting. Summary of the invention

[0003] The purpose of the present invention is to provide a tellurium-doped zirconium-based halide perovskite material with white light emission and a preparation method thereof. The perovskite material with white light emission is simple to prepare, environmentally friendly and non-toxic, has stable performance and high luminous efficiency, and is expected to be used in optoelectronic devices such as light-emitting diodes.

[0004] A tellurium-doped zirconium-based halide perovskite material with white light emission, synthesis and application thereof, wherein the chemical formula of the material is (Cs 1-x R x )2Zr 1-y Te y Cl6(0≤x≤1,0 <y≤0.5%)。

[0005] Preferably, 0≤x≤0.2, 0.2%≤y≤0.4%.

[0006] Optionally, the tellurium-doped zirconium-based halide perovskite material with white light emission has a cubic structure with a unit cell side length of

[0007] Optionally, the excitation wavelength of the tellurium-doped zirconium-based halide perovskite material with white light emission is 240 to 260 nm;

[0008] The emission wavelength of the material is 380-750nm.

[0009] The tellurium-doped zirconium-based halide perovskite material provided by this application can emit broadband white light under ultraviolet light excitation in the range of 240-260 nm.

[0010] Optionally, the tellurium-doped zirconium-based halide perovskite material with white light emission is a single-component white light material.

[0011] A preparation method of a tellurium-doped zirconium-based halide perovskite material with white light emission as described above, characterized in that the method at least includes:

[0012] Reacting raw materials containing cesium source, rubidium source, zirconium source, tellurium source, and chlorine source in a hydrothermal autoclave;

[0013] The dosages of the cesium source, rubidium source, zirconium source, tellurium source, and chlorine source satisfy the molar ratios of the respective elements in the chemical formula.

[0014] Optionally, the cesium source is at least one of cesium chloride and cesium carbonate;

[0015] The rubidium source is at least one of rubidium chloride and rubidium carbonate;

[0016] The zirconium source is at least one of zirconium chloride, zirconium carbonate, zirconium hydroxide, and zirconium acetate;

[0017] The tellurium source is at least one of tellurium chloride and tellurium oxide;

[0018] The chlorine source is hydrochloric acid.

[0019] As a preferred embodiment of this application, the steps for preparing the tellurium-doped zirconium-based halide perovskite material with white light emission include:

[0020] (1) According to the chemical formula of (Cs 1-x Rb x )2Zr 1-y Te y Cl6(0≤x≤1, 0<y≤1%), put CsCl, ZrCl4, and TeCl4 into a hydrothermal autoclave according to the required stoichiometric ratio, and add hydrochloric acid with a mass fraction of 5%-37% to make the concentration of CsCl 0.01-1 mol / L.

[0021] (2) Place the hydrothermal autoclave in an electrothermal blast drying oven and heat it at 120°C-180°C for 8-24 hours. Then cool it to room temperature (20-30°C) at a cooling rate of 5-10°C / h.

[0022] (3) Take out the product obtained in step (2). Filter it by suction, rinse it with methanol, ethanol, and acetonitrile, and place the product in a vacuum oven at 50°C-70°C for 12-24 hours.

[0023] Optionally, the mass fraction of the hydrochloric acid is 5-37%.

[0024] Optionally, the concentration of the cesium ions in the raw material is 0.01 to 1 mol / L.

[0025] Optionally, the reaction conditions are: reaction temperature 120°C to 180°C, reaction time 8 to 24 hours; cooling to room temperature (20-30°C) at a cooling rate of 5-10°C / h.

[0026] The tellurium-doped zirconium-based halide perovskite material with white light emission prepared by the present invention has excellent optical properties and good stability, and is expected to be used as a luminescent material in the fields of lighting, display, photoelectric detection, lasers, scintillators, medical imaging, etc.

[0027] Beneficial effects: The tellurium-doped zirconium-based halide perovskite material with white light emission and its preparation method provided by the present invention have an emission spectrum of 380-750nm, can achieve single-component white light emission, and a luminescence quantum yield of up to 79.3%. The perovskite material is simple to prepare, environmentally friendly and non-toxic, has stable performance, and high luminescence efficiency, and has good application prospects in the optoelectronic field. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the XRD diffraction spectrum of Te-doped Cs2ZrCl6 prepared in Example 1.

[0029] Figure 2 This is the fluorescence spectrum of Te-doped Cs2ZrCl6 prepared in Example 1-3. DETAILED DESCRIPTION

[0030] In the following examples, the raw materials used were from:

[0031] CsCl, 99.999%, Alfa Aesar; Cs2CO3, 99.9%, Alfa Aesar; RbCl, 99%, Alfa Aesar; Rb2CO3, 99.975%, Alfa Aesar; ZrCl4, 99.95%, Strem Chemicals; Zr(CO3)2, 99.9%, HWRK Chem; Zr(OH)4, 97%, Aladdin; Zr(CH3COO)4, Accela, ≥95%; TeCl4, 99.9%, AlfaAesar; TeO2, 99.9995%, Alfa Aesar; Hydrochloric acid, 36.5wt.%, Sinopharm Group.

[0032] In the present application, the XRD spectrum is obtained by PANalytical Empyrean X-ray powder diffractometer, and the emission spectrum is obtained by Edinburgh Instruments FLS 1000 spectrometer.

[0033] Example 1

[0034] Put 1346.8mg of cesium chloride (x=0), 932.4mg of zirconium chloride and 2.2mg of tellurium chloride (y=0.2%) into a 100ml hydrothermal kettle, and add 30ml of hydrochloric acid (36.5wt.%). Place the hydrothermal kettle in an electric blast drying oven and heat at 160℃ for 12 hours. Then cool to room temperature at a cooling rate of 5℃ / h. Filter the obtained product and rinse it with methanol, ethanol and acetonitrile in turn. Then put the product into a vacuum oven at 60℃ for 24 hours to obtain the final sample. After irradiation with 254nm ultraviolet light, the sample emits a strong warm white light with an emission spectrum range of 380-750nm and a quantum yield of about 79.4%. The powder XRD diffraction pattern of Te-doped Cs2ZrCl6 prepared in Example 1 is shown in Figure 1 , the material has a cubic crystal structure with a unit cell side length of The room temperature emission spectrum of Te-doped Cs2ZrCl6 prepared in Example 1 is shown in Figure 2 The chemical formula of the material is Cs2Zr 0.998 Te 0.002 Cl6;

[0035] After the Te-doped Cs2ZrCl6 sample prepared in Example 1 was stored in air for five months, the powder XRD and emission spectrum did not change significantly, indicating that the material has excellent stability.

[0036] Example 2

[0037] 1303.3 mg of cesium carbonate (x=0), 932.4 mg of zirconium chloride and 1.9 mg of tellurium chloride (y=0.18%) were placed in a 100 ml hydrothermal kettle, and 20 ml of hydrochloric acid (36.5 wt.%) was added. The hydrothermal kettle was placed in an electric blast drying oven and heated at 150°C for 14 hours. Then the temperature was cooled to room temperature at a cooling rate of 6°C / h. The obtained product was filtered and rinsed with methanol, ethanol and acetonitrile, and then the product was placed in a vacuum oven at 65°C for 20 hours to obtain the final sample. After irradiation with 254 nm ultraviolet light, the sample emitted a strong warm white light, the emission spectrum range was 380-750 nm, and the quantum yield was about 78.2%.

[0038] The room temperature emission spectrum of Te-doped Cs2ZrCl6 prepared in Example 2 is shown in Figure 2 , the material has a cubic crystal structure with a unit cell side length of The chemical formula of the material is Cs2Zr 0.9982 Te 0.0018 Cl6.

[0039] Example 3

[0040] 1346.8 mg of cesium chloride (x=0), 845.0 mg of zirconium carbonate and 1.3 mg of tellurium chloride (y=0.12%) were placed in a 100 ml hydrothermal kettle, and 30 ml of hydrochloric acid (36.5 wt.%) was added. The hydrothermal kettle was placed in an electric blast drying oven and heated at 140°C for 16 hours. Then the temperature was cooled to room temperature at a cooling rate of 7°C / h. The obtained product was filtered and rinsed with methanol, ethanol and acetonitrile, and then the product was placed in a vacuum oven at 60°C for 24 hours to obtain the final sample. After irradiation with 254 nm ultraviolet light, the sample emitted a strong warm white light, the emission spectrum range was 380-750 nm, and the quantum yield was about 77.5%.

[0041] The room temperature emission spectrum of Te-doped Cs2ZrCl6 prepared in Example 3 is shown in Figure 2 , the material has a cubic crystal structure with a unit cell side length of The chemical formula of the material is Cs2Zr 0.9988 Te 0.0012 Cl6.

[0042] Example 4

[0043] 1178.5 mg of cesium chloride, 120.9 mg of rubidium chloride (x=0.14), 932.4 mg of zirconium chloride and 2.2 mg of tellurium chloride (y=0.2%) were placed in a 100 ml hydrothermal kettle, and 35 ml of hydrochloric acid (36.5 wt.%) was added. The hydrothermal kettle was placed in an electric blast drying oven and heated at 160°C for 12 hours. Then the temperature was cooled to room temperature at a cooling rate of 9°C / h. The obtained product was filtered and rinsed with methanol, ethanol and acetonitrile, and then the product was placed in a vacuum oven at 60°C for 24 hours to obtain the final sample. After irradiation with 254 nm ultraviolet light, the sample emitted a strong warm white light, the emission spectrum range was 380-750 nm, and the quantum yield was about 79.2%.

[0044] Example 4 Preparation of Te doped (Cs 1-x R x )2ZrCl6 has a cubic crystal structure with a unit cell side length of The chemical formula of the material is (Cs 0.86 R 0.14 )2Zr 0.998 Te 0.002 Cl6.

[0045] Example 5

[0046] 977.5 mg of cesium carbonate, 230.9 mg of rubidium carbonate (x = 0.33), 932.4 mg of zirconium chloride and 1.3 mg of tellurium dioxide (y = 0.2%) were placed in a 100 ml hydrothermal kettle, and 30 ml of hydrochloric acid (36.5 wt.%) was added. The hydrothermal kettle was placed in an electric blast drying oven and heated at 150 ° C for 15 hours. Then the temperature was cooled to room temperature at a cooling rate of 5 ° C / h. The obtained product was filtered and rinsed with methanol, ethanol and acetonitrile, and then the product was placed in a vacuum oven at 60 ° C for 24 hours to obtain the final sample. After irradiation with 254 nm ultraviolet light, the sample emitted a strong warm white light, the emission spectrum range was 380-750 nm, and the quantum yield was about 75.8%.

[0047] Example 5 Preparation of Te doped (Cs 1-x R x )2ZrCl6 has a cubic crystal structure with a unit cell side length of The chemical formula of the material is (Cs 0.67 R 0.33 )2Zr 0.998 Te 0.002 Cl6.

[0048] Example 6

[0049] 977.5 mg of cesium carbonate, 241.8 mg of rubidium chloride (x=0.33), 845.0 mg of zirconium carbonate and 2.7 mg of tellurium chloride (y=0.25%) were placed in a 100 ml hydrothermal kettle, and 40 ml of hydrochloric acid (36.5 wt.%) was added. The hydrothermal kettle was placed in an electric blast drying oven and heated at 160°C for 11 hours. Then the temperature was cooled to room temperature at a cooling rate of 7°C / h. The obtained product was filtered and rinsed with methanol, ethanol and acetonitrile, and then the product was placed in a vacuum oven at 60°C for 24 hours to obtain the final sample. After irradiation with 254 nm ultraviolet light, the sample emitted a strong warm white light, the emission spectrum range was 380-750 nm, and the quantum yield was about 74.9%.

[0050] Example 6 Preparation of Te doped (Cs 1-x R x )2ZrCl6 has a cubic crystal structure with a unit cell side length of The chemical formula of the material is (Cs 0.67 R 0.33 )2Zr 0.9975 Te 0.0025 Cl6.

[0051] Example 7

[0052] 1346.8 mg of cesium chloride (x=0), 637.0 mg of zirconium hydroxide and 2.0 mg of tellurium chloride (y=0.19%) were placed in a 100 ml hydrothermal kettle, and 35 ml of hydrochloric acid (36.5 wt.%) was added. The hydrothermal kettle was placed in an electric blast drying oven and heated at 160°C for 12 hours. Then the temperature was cooled to room temperature at a cooling rate of 8°C / h. The obtained product was filtered and rinsed with methanol, ethanol and acetonitrile, and then the product was placed in a vacuum oven at 65°C for 24 hours to obtain the final sample. After irradiation with 254 nm ultraviolet light, the sample emitted a strong warm white light, the emission spectrum range was 380-750 nm, and the quantum yield was about 75.8%.

[0053] The Te-doped Cs2ZrCl6 prepared in Example 7 has a cubic crystal structure with a unit cell side length of The chemical formula of the material is Cs2Zr 0.9981 Te 0.0019 Cl6.

[0054] Example 8

[0055] 1303.3 mg of cesium carbonate (x=0), 845.0 mg of zirconium carbonate and 1.0 mg of tellurium dioxide (y=0.16%) were placed in a 100 ml hydrothermal kettle, and 30 ml of hydrochloric acid (36.5 wt.%) was added. The hydrothermal kettle was placed in an electric blast drying oven and heated at 140°C for 14 hours. Then the temperature was lowered to room temperature at a cooling rate of 10°C / h. The obtained product was filtered and rinsed with methanol, ethanol and acetonitrile, and then the product was placed in a vacuum oven at 65°C for 20 hours to obtain the final sample. After irradiation with 254 nm ultraviolet light, the sample emitted a strong warm white light, the emission spectrum range was 380-750 nm, and the quantum yield was about 78.7%.

[0056] The Te-doped Cs2ZrCl6 prepared in Example 8 has a cubic crystal structure with a unit cell side length of The chemical formula of the material is Cs2Zr 0.9984 Te 0.0016 Cl6.

[0057] The embodiments described above are only preferred solutions of the present invention and are only used to illustrate the present invention rather than to limit the scope of the present invention. Any technical solutions obtained by equivalent replacement or equivalent transformation shall fall within the protection scope of the present invention.

Claims

1. A method for synthesizing a tellurium-doped zirconium-based halide perovskite material with white light emission, characterized in that: The chemical formula of the material is (Cs 1-x R x )2Zr 1-y Te y Cl6, where 0≤x≤1, 0 <y<0.5%; The perovskite material has a cubic structure with a unit cell side length of 10.4-10.5 Å; The material can emit white light under the excitation of ultraviolet light with an excitation wavelength of 240-260 nm, and the emission spectrum ranges from 380 to 750 nm; The chemical formula of the tellurium-doped zirconium-based halide perovskite material with white light emission is prepared by reacting one or two of a cesium source and a rubidium source containing the required elements, and raw materials of a zirconium source, a tellurium source, and a chlorine source according to the required element stoichiometric ratio; The cesium source is at least one or two of cesium chloride and cesium carbonate; The rubidium source is at least one or two of rubidium chloride and rubidium carbonate; The zirconium source is at least one or more of zirconium chloride, zirconium carbonate, zirconium hydroxide and zirconium acetate; The tellurium source is at least one or two of tellurium chloride and tellurium oxide; The chlorine source is hydrochloric acid; The specific steps include: (1) According to (Cs 1-x Rb x )2Zr 1-y Te y Cl6 where 0 ≤ x ≤ 1 and 0 < y < 0.5%, put one or two of a cesium source and a rubidium source, a zirconium source, and a tellurium source into a hydrothermal autoclave according to the required stoichiometric ratio, add hydrochloric acid with a mass fraction of 5% - 37% so that the concentration of cesium ions is 0.01 - 1 mol / L; (2) Place the hydrothermal kettle in an electric blast drying oven and heat at 120°C to 180°C for 8 to 24 hours; then cool down to 20 to 30°C at a cooling rate of 5 to 10°C / h; (3) Take out the product obtained in step (2); filter it, rinse it with methanol, ethanol and acetonitrile in sequence, and place the product in a vacuum oven at 50°C to 70°C for 12 to 24 hours.

2. The synthesis method according to claim 1, characterized in that The chemical formula of the material is (Cs 1-x R x )2Zr 1- y Te y Cl6, where 0≤x≤0.2, 0.2%≤y≤0.4%.

3. Application of the material obtained by the synthesis method according to claim 1, characterized in that: The material can be used as a luminescent material in the fields of lighting, display, photoelectric detection, laser, scintillator or medical imaging.

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