A white light phosphor based on copper-iodine organic hybrid cluster, a preparation method and application thereof

Abstract

The application provides a white light phosphor powder based on copper-iodine organic hybrid clusters and a preparation method thereof, and has a structure shown in formula I. The structure of the white light phosphor powder in the application is that Cu4I4 is used as an inorganic core, and copper atoms are coordinated with nitrogen and phosphorus atoms on ligands to form a stable and unique cluster structure. The light emitting mechanism of the cluster is charge transfer from the inorganic core to the ligand, and the simple core and the ligand cooperate with each other to form degenerate emission energy levels, so that white light emission with double wide peaks from 400 to 800 nm is realized. The light emitting quantum yield reaches 97.8%. The material also exhibits excellent stability, and the thermal decomposition temperature is as high as 265 DEG C. The material also has low thermal quenching, and still maintains more than 80% of the original light emitting quantum yield under the condition of 240 DEG C. The application also provides an application of the white light phosphor powder based on copper-iodine organic hybrid clusters. The white light phosphor powder is applied to the field of solid state lighting, and has significant advantages and application prospects.

Description

Technical Field

[0001] This invention belongs to the field of solid-state lighting luminescent materials technology, and particularly relates to a white phosphor based on copper-iodine organic hybrid clusters, its preparation method and application. Background Technology

[0002] The development of solid-state lighting has significantly reduced energy consumption in lighting applications. Currently, white light lighting, obtained by combining light-emitting diodes (LEDs) and phosphors, has largely replaced energy-consuming traditional lighting technologies such as incandescent lamps and mercury vapor lamps.

[0003] White light produced by LEDs and phosphors falls into two categories. One, currently the most common, combines blue LEDs with yellow phosphors. While this composite produces high luminous efficiency, it suffers from a poor color rendering index, difficulty in color temperature adjustment, and poor spectral coverage. In particular, it suffers from insufficient cyan and red light components, and the gradual decay of the blue LED chip during operation also affects the quality of the white light. The other type uses ultraviolet LEDs to excite red, green, and blue phosphors to produce white light. In this case, the decay of the ultraviolet LED chip has virtually no impact on the white light spectrum, and the resulting white light exhibits good spectral coverage. However, multi-component phosphors suffer from reabsorption issues, and the inconsistent decay patterns of these components cause spectral changes during use, resulting in poor durability. Therefore, developing single-component white light phosphors is essential to address these issues.

[0004] Currently, the most widely used phosphors are based on rare-earth metals. Commercially available white LEDs use cerium-doped yttrium aluminum garnet phosphors. While rare-earth phosphors possess good luminous efficiency and stability, their synthesis is complex, requiring high temperature and pressure, and they exhibit significant thermal quenching. Organic phosphors, on the other hand, suffer from poor thermal stability. Therefore, there is a need to explore new phosphor materials for application in the vast solid-state lighting market. Summary of the Invention

[0005] The purpose of this invention is to provide a white phosphor based on copper-iodine organic hybrid clusters, its preparation method and application. The white phosphor of this invention has excellent thermal stability, low thermal quenching, high efficiency luminescence properties, good spectral coverage and simple synthesis method, which meets the requirements of an ideal single-component white phosphor and has broad application prospects in the field of solid-state lighting.

[0006] This invention provides a white phosphor based on copper-iodine organic hybrid clusters, having the structure shown in Formula I:

[0007]

[0008] This invention provides a method for preparing white phosphor based on copper-iodine organic hybrid clusters as described above, comprising the following steps:

[0009] A) Cuprous iodide was reacted with 4-tert-butyl-2-diphenylphosphine in a solvent, and a white precipitate powder was obtained by solid-liquid separation.

[0010] B) The white precipitated powder is washed and dried to obtain white phosphorescent powder with the structure of Formula I.

[0011] Preferably, the 4-tert-butyl-2-diphenylphosphine is prepared according to the following steps:

[0012] Under a protective atmosphere, 2-chloro-4-tert-butylpyridine, diphenylphosphine, and trifluoromethanesulfonic acid were dissolved in an organic solvent and reacted. The reaction was quenched, extracted, washed, dried, and purified to obtain 4-tert-butyl-2-diphenylphosphine.

[0013] Preferably, the molar ratio of 2-chloro-4-tert-butylpyridine, diphenylphosphine and trifluoromethanesulfonic acid is 1:(1.2-1.3):1.

[0014] Preferably, the reaction temperature of 2-chloro-4-tert-butylpyridine, diphenylphosphine and trifluoromethanesulfonic acid is 120-140°C, and the reaction time is 8-24 hours.

[0015] Preferably, the molar ratio of cuprous iodide to 4-tert-butyl-2-diphenylphosphine is (1.9-2.2):1.

[0016] Preferably, the reaction temperature in step A) is 20–30°C, and the reaction time is 40–50 hours.

[0017] Preferably, in step A), centrifugation is used to separate the reaction products into solid and liquid components; the centrifugation speed is 5500-6500 rpm.

[0018] This invention provides the application of white phosphor based on copper-iodine organic hybrid clusters in the field of solid-state lighting, as described above.

[0019] Preferably, the white phosphor based on copper-iodine organic hybrid clusters is excited by deep blue light and / or ultraviolet light and has a double-wide emission peak covering 400-800 nm.

[0020] This invention provides a white phosphor based on a copper-iodine organic hybrid cluster, having the structure shown in Formula I. The white phosphor's structure uses Cu₄I₄ as the inorganic core, with copper atoms coordinating with nitrogen and phosphorus atoms on the ligands to form a stable and unique cluster structure. The luminescence mechanism of this cluster involves charge transfer from the inorganic core to the ligands. The inorganic core and ligands interact to form degenerate emission levels, achieving double-broad-peak white light emission from 400 to 800 nm. The luminescence quantum yield reaches 97.8%. This material also exhibits excellent stability, with a thermal decomposition temperature as high as 265℃. It also possesses low thermal quenching properties, maintaining over 80% of its original luminescence quantum yield even at 240℃. As a white phosphor, it has significant advantages and promising application prospects in solid-state lighting. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 The 1H NMR spectrum of the ligand 4-tert-butyl-2-diphenylphosphine provided in Example 1 of this invention;

[0023] Figure 2 C prepared in Example 1 42 H 44 A comparison of Cu4I4N2P2 phosphorescent powder under natural light (left) and ultraviolet light (right);

[0024] Figure 3 C prepared in Example 1 42 H 44 Excitation and emission spectra of Cu4I4N2P2 phosphorescent powder;

[0025] Figure 4 C prepared in Example 1 42 H 44 Luminescence quantum efficiency of Cu4I4N2P2 phosphor under excitation light of different wavelengths;

[0026] Figure 5 C prepared in Example 1 42 H 44 Comparison of Cu4I4N2P2 phosphorescent powder and single-crystal simulated XRD;

[0027] Figure 6 C prepared in Example 1 42 H 44Thermogravimetric curve of Cu4I4N2P2 phosphorescent powder under nitrogen atmosphere;

[0028] Figure 7 C prepared in Example 1 42 H 44 The change in luminescence intensity of Cu4I4N2P2 phosphorescent powder under heating cycle conditions of 20-240℃;

[0029] Figure 8 C prepared in Example 1 42 H 44 Changes in the emission spectrum of Cu4I4N2P2 phosphorescent powder during heating at 200℃ for 300 minutes;

[0030] Figure 9 C prepared in Example 1 42 H 44 The application of Cu4I4N2P2 phosphorescent powder as a luminescent powder in long-term white light illumination. Detailed Implementation

[0031] This invention provides a white phosphor based on copper-iodine organic hybrid clusters, having the structure shown in Formula I:

[0032]

[0033] This invention also provides a method for preparing the white phosphor based on copper-iodine organic hybrid clusters as described above, comprising the following steps:

[0034] A) Cuprous iodide was reacted with 4-tert-butyl-2-diphenylphosphine in a solvent, and a white precipitate powder was obtained by solid-liquid separation.

[0035] B) The white precipitated powder is washed and dried to obtain white phosphorescent powder with the structure of Formula I.

[0036] The present invention first prepares the organic ligand 4-tert-butyl-2-diphenylphosphine according to the following steps:

[0037] Under a protective atmosphere, 2-chloro-4-tert-butylpyridine, diphenylphosphine, and trifluoromethanesulfonic acid were dissolved in an organic solvent and reacted. The reaction was quenched, extracted, washed, dried, and purified to obtain 4-tert-butyl-2-diphenylphosphine.

[0038] In this invention, the protective atmosphere is preferably nitrogen, and the organic solvent is preferably chlorobenzene.

[0039] The molar ratio of 2-chloro-4-tert-butylpyridine, diphenylphosphine and trifluoromethanesulfonic acid is preferably 1:(1.2-1.3):1, more preferably 1:1.2:1.

[0040] In this invention, the reaction temperature of 2-chloro-4-tert-butylpyridine, diphenylphosphine and trifluoromethanesulfonic acid is preferably 120-140°C, more preferably 125-135°C; the reaction time is preferably 8-24 hours, more preferably 12-18 hours.

[0041] In this invention, the reaction is preferably quenched using a saturated sodium carbonate aqueous solution, and the reaction product is extracted and washed sequentially with dichloromethane and sodium chloride solution. The washed organic phase is dried, evaporated, and purified by silica gel column chromatography to obtain 4-tert-butyl-2-diphenylphosphine.

[0042] In this invention, the drying, rotary drying and silica gel column purification are all conventional post-processing methods in the art, and will not be described in detail here.

[0043] After obtaining 4-tert-butyl-2-diphenylphosphine, the present invention reacts the organic ligand with cuprous iodide in a solvent under stirring at room temperature.

[0044] In this invention, the molar ratio of cuprous iodide to 4-tert-butyl-2-diphenylphosphine is preferably (1.9-2.2):1, more preferably (2.0-2.1):1; the solvent is preferably dichloromethane.

[0045] In this invention, the reaction temperature is preferably 20-30°C, more preferably 25-30°C; the reaction time is preferably 40-50 hours, more preferably 45-48 hours; and the reaction is preferably carried out under stirring conditions.

[0046] After the reaction is complete, the present invention preferably performs solid-liquid separation on the reaction product, preferably by centrifugation to separate the white precipitate in the reaction product, and then washes and dries the white precipitate to obtain white phosphor based on copper-iodine organic hybrid clusters.

[0047] In this invention, the centrifugation speed is preferably 5500-6500 rpm, more preferably 6000 rpm. This invention preferably uses diethyl ether to wash the white precipitate.

[0048] In this invention, the drying temperature is preferably 35-45°C, more preferably 40°C; the drying time is preferably 20-30 hours, more preferably 24-26 hours.

[0049] The present invention also provides an application of the white phosphor based on copper-iodine organic hybrid clusters described above in the field of solid-state lighting.

[0050] In this invention, the white phosphor based on copper-iodine organic hybrid clusters is excited by deep blue light and / or ultraviolet light, and has a double-wide emission peak covering 400-800 nm, with a luminescence quantum yield of 97.8%.

[0051] This invention provides a white phosphor based on a copper-iodine organic hybrid cluster, having the structure shown in Formula I. The white phosphor's structure uses Cu₄I₄ as the inorganic core, with copper atoms coordinating with nitrogen and phosphorus atoms on the ligands to form a stable and unique cluster structure. The luminescence mechanism of this cluster involves charge transfer from the inorganic core to the ligands. The inorganic core and ligands interact to form degenerate emission levels, achieving double-broad-peak white light emission from 400 to 800 nm. The luminescence quantum yield reaches 97.8%. This material also exhibits excellent stability, with a thermal decomposition temperature as high as 265℃. It also possesses low thermal quenching properties, maintaining over 80% of its original luminescence quantum yield even at 240℃. As a white phosphor, it has significant advantages and promising application prospects in solid-state lighting.

[0052] To further illustrate the present invention, the following describes in detail, in conjunction with embodiments, a white phosphor based on copper-iodine organic hybrid clusters, its preparation method and application, but this should not be construed as limiting the scope of protection of the present invention.

[0053] In the following examples, C was prepared 42 H 44 The raw materials and solvents for Cu4I4N2P2 phosphorescent powder include: cuprous iodide (Annegi, 99.999%), potassium iodide (Sinopharm Chemical Reagent Co., Ltd., analytical grade), 2-chloro-4-tert-butylpyridine (Bide, 97%), diphenylphosphine (Maclean, 95%), trifluoromethanesulfonic acid (Annegi, 99%), acetonitrile (Sinopharm Chemical Reagent Co., Ltd., analytical grade), diethyl ether (Sinopharm Chemical Reagent Co., Ltd., analytical grade), chloroform (Sinopharm Chemical Reagent Co., Ltd., analytical grade), and chlorobenzene (Sinopharm Chemical Reagent Co., Ltd., analytical grade).

[0054] Example 1

[0055] (1) Synthesis of ligand 4-tert-butyl-2-diphenylphosphine

[0056] 20 mmol of 2-chloro-4-tert-butylpyridine was added to a 100 mL Shrek tube, nitrogen was introduced, 45 mL of chlorobenzene, 4.4 mL of diphenylphosphine, and 1.6 mL of trifluoromethanesulfonic acid were added, the tube was sealed, and the reaction was stirred at 130 °C overnight. The reaction was quenched, extracted and washed, the organic phase was dried, evaporated to dryness, and purified by silica gel column chromatography to obtain the product 4-tert-butyl-2-diphenylphosphine.

[0057] The 1H NMR spectrum of the ligand 4-tert-butyl-2-diphenylphosphinopyridine provided in this embodiment of the invention was determined using a Burker AVAVCE III HD 400 nuclear magnetic resonance spectrometer (UMR spectrometer). The solvent was deuterated chloroform. The results are as follows: Figure 1 As shown, this indicates that the obtained ligand has high purity.

[0058] (2)C 42 H 44 Preparation of Cu4I4N2P2 phosphorescent powder

[0059] 1 mmol of ligand 2-chloro-4-tert-butylpyridine and 2 mmol of cuprous iodide were dissolved in 5 mL of dichloromethane and stirred thoroughly for 48 hours. The mixture was then centrifuged to obtain a white powder precipitate. The precipitate was washed with diethyl ether and finally dried in an oven at 40 °C for 24 hours to obtain product C. 42 H 44 Cu4I4N2P2 phosphorescent powder.

[0060] The C prepared in this embodiment 42 H 44 The comparison images of Cu4I4N2P2 phosphorescent powder under natural light and ultraviolet light are shown below. Figure 2 As shown.

[0061] The C0 prepared in this example was measured using a Hamamatsu absolute quantum efficiency fluorescence spectrometer and a C13923-01 temperature controller. 42 H 44 The emission spectrum of Cu4I4N2P2 phosphor and its variation at different temperatures are shown in the following figures: emission and excitation spectra. Figure 3 As shown, the luminescence quantum efficiency of phosphors under different wavelengths of excitation light is as follows: Figure 4 As shown.

[0062] The C prepared in this example was analyzed using an X-ray diffractometer (X-PERTPRO powder X-ray diffractometer). 42 H 44 X-ray diffraction (XRD) of Cu4I4N2P2 phosphor was performed, and the resulting XRD pattern was compared with the simulated XRD pattern from a single crystal. Figure 5 As shown, the prepared C 42 H 44 Cu4I4N2P2 phosphorescent powder has high purity.

[0063] The C20 prepared in this embodiment was analyzed using a thermogravimetric analyzer (Q5000IR thermal gravimetric analyzer). 42 H 44The thermal decomposition temperature of Cu4I4N2P2 phosphorescent powder was tested, and it reached as high as 265℃. The thermogravimetric analysis chart is shown below. Figure 6 As shown. This luminescent material, when cyclically heated in air to 240°C, retains over 80% of its original luminescence quantum yield. Upon returning to 20°C from the high temperature, it also recovers to its original luminescence quantum yield. Figure 7 As shown. When the luminescent material is heated to 200℃ for 300 minutes, its emission spectrum shows no significant change, as... Figure 8 As shown, this luminescent material exhibits excellent thermal stability and low thermal quenching resistance.

[0064] In this embodiment, C 42 H 44 Cu4I4N2P2 phosphor was coated onto a 390nm wavelength ultraviolet LED chip for testing the chip's efficiency and stability. The results are as follows: Figure 9 As shown, by Figure 9 It can be seen that after 1000 hours of operation, the efficiency of the phosphorescent device constructed in this invention decreased from 63.4392 Lm / W to 56.0344 Lm / W.

[0065] (3)C 42 H 44 Crystallographic data analysis of Cu4I4N2P2 luminescent material

[0066] A 1 mL solution of 0.5 mmol cuprous iodide and 1 g / mL potassium iodide was placed at the bottom. Acetonitrile was slowly poured into the cuprous iodide and potassium iodide solution. A chloroform solution of 4-tert-butyl-2-diphenylphosphinopyridine was then slowly poured onto the acetonitrile layer. The middle layer was acetonitrile, and the top layer was a chloroform solution of 0.25 mmol 4-tert-butyl-2-diphenylphosphinopyridine. The mixture was allowed to stand at room temperature for evaporation to obtain C. 42 H 44 Cu4I4N2P2 single crystal.

[0067] The C20 prepared in this example was analyzed at 300 K using a four-circle single-crystal diffraction spectrometer (Rigaku Oxford diffraction Gemini S Ultradiffractometer). 42 H 44 The crystallographic data obtained from the measurement of a single crystal of Cu4I4N2P2 luminescent material are shown in Table 1. It can be seen that the copper-iodine luminescent cluster belongs to the triclinic crystal system. Detailed information on the unit cell and predicted properties such as density are shown in Table 1.

[0068] Table 1. C prepared in Example 1 42 H 44 Crystallographic data of Cu4I4N2P2 luminescent material

[0069]

[0070]

[0071] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Application of white phosphors based on copper-iodine organic hybrid clusters in the field of white solid-state lighting; The white phosphor based on copper-iodine organic hybrid clusters is excited by deep blue light and / or ultraviolet light, and has a wide white light emission peak covering 400-800 nm. The white phosphor based on copper-iodine organic hybrid clusters has the structure shown in Formula I:

2. The application as described in claim 1, wherein the method for preparing the white phosphor based on copper-iodine organic hybrid clusters comprises the following steps: A) Cuprous iodide was reacted with 4-tert-butyl-2-diphenylphosphine in a solvent, and a white precipitate powder was obtained by solid-liquid separation. B) The white precipitated powder is washed and dried to obtain white phosphorescent powder with the structure of Formula I.

3. The application according to claim 2, characterized in that, The 4-tert-butyl-2-diphenylphosphine was prepared according to the following steps: Under a protective atmosphere, 2-chloro-4-tert-butylpyridine, diphenylphosphine, and trifluoromethanesulfonic acid were dissolved in an organic solvent and reacted. The reaction was quenched, extracted, washed, dried, and purified to obtain 4-tert-butyl-2-diphenylphosphine.

4. The application according to claim 3, characterized in that, The molar ratio of 2-chloro-4-tert-butylpyridine, diphenylphosphine and trifluoromethanesulfonic acid is 1:(1.2-1.3):

1.

5. The application according to claim 4, characterized in that, The reaction temperature of 2-chloro-4-tert-butylpyridine, diphenylphosphine and trifluoromethanesulfonic acid is 120-140°C, and the reaction time is 8-24 hours.

6. The application according to claim 2, characterized in that, The molar ratio of cuprous iodide to 4-tert-butyl-2-diphenylphosphine is (1.9–2.2):

1.

7. The application according to claim 6, characterized in that, The reaction temperature in step A) is 20–30°C, and the reaction time is 40–50 hours.

8. The application according to claim 2, characterized in that, In step A), centrifugation is used to separate the reaction products into solid and liquid components; the centrifugation speed is 5500-6500 rpm.

Images