Ionic organic high-temperature phosphorescent material as well as preparation method and application thereof
By preparing ionic organic high-temperature phosphorescent materials through doping, the problem of easy quenching of organic phosphorescent materials at high temperatures is solved, achieving a highly efficient LED flicker elimination effect and possessing low-cost and highly efficient visual health protection capabilities.
Patent Information
- Application Number
- CN202511612272.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-05
- Publication Date
- 2026-03-10
AI Technical Summary
Existing organic phosphorescent materials are prone to quenching at high temperatures, leading to severe LED flickering and affecting visual health. Current technologies are unable to effectively solve this problem.
Ionic organic high-temperature phosphorescent materials are prepared by doping. By using a specific ratio of host and guest materials, high-density ionic bonds are formed, which suppresses lattice expansion and molecular thermal motion, and achieves afterglow characteristics with single exponential decay. The materials can maintain high-efficiency phosphorescence performance at high temperatures.
It achieves extremely low afterglow intensity decay at high temperatures, high phosphorescence efficiency, effectively suppresses LED flicker, reduces visual fatigue and the risk of eye damage, and the material preparation is simple and low cost.
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Figure CN121628619A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of preparation and application of ionic organic phosphorescent materials, specifically relating to an ionic organic high-temperature phosphorescent material, its preparation method and application, to achieve high-temperature phosphorescence and to eliminate LED flicker. Background Technology
[0002] Lighting is a core technological means for humanity to overcome the limitations of natural light, supporting not only efficient nighttime life and industrial production but also directly impacting visual health. Currently, light-emitting diode (LED) lighting remains the mainstream technology. It is well known that because LED devices are DC-powered, they may flicker when powered by AC. The AC voltage alternates periodically at a frequency of 50 Hz, causing LEDs to flicker with a period of 10 ms. This phenomenon can easily lead to visual fatigue, headaches, and even eye damage. Current solutions to LED flicker primarily focus on optimizing the driving circuit. Typical technical approaches include using high-frequency pulse width modulation (PWM) dimming, linear constant current driving, and adding capacitor filtering modules. However, these methods have significant limitations, such as high power consumption, high cost, poor compatibility, and suboptimal performance.
[0003] Against this backdrop, afterglow technology, with its core logic of "brightness decay compensation," has become an ideal technological paradigm for solving the LED flicker problem. Typically, afterglow can be generated by inorganic long-afterglow materials, long-afterglow luminescent (LPL) materials, and organic phosphorescent materials. In terms of decay characteristics, inorganic long-afterglow materials and LPL materials follow a power-law decay law. Its most notable characteristic is a rapid decay rate of afterglow intensity; in contrast, organic phosphorescent materials follow an exponential decay law, resulting in a more gradual decrease in afterglow intensity. To achieve efficient LED flicker elimination, afterglow compensation needs to meet the requirement of a small decrease in afterglow intensity within 20 ms. Therefore, organic phosphorescent materials have become ideal afterglow materials for solving the LED flicker problem.
[0004] Currently, organic phosphorescent materials have attracted much attention due to their broad application prospects in fields such as information encryption, anti-counterfeiting, bioimaging, and photodynamic therapy. These materials are characterized by long lifetimes and high efficiency, and can achieve broad-spectrum tuning from blue to red light, demonstrating enormous practical application potential. The steeper the slope of the lifetime decay curve of an organic phosphorescent material, the smaller the intensity drop within 20 ms; that is, Δ... I 20 ms ( I 1 / IThe larger the value (0), the better the flicker suppression effect. It is worth noting that the heat generated during LED operation significantly intensifies molecular motion, leading to enhanced nonradiative transitions of triplet excitons and ultimately causing phosphorescence quenching. Simultaneously, thermally driven lattice expansion induces molecular configuration distortion, causing a sharp decline in phosphorescence performance. This thermal quenching phenomenon not only limits the application of organic phosphorescent materials in high-temperature environments but also reduces their flicker suppression capability in LEDs, severely hindering their integrated application in advanced optoelectronic devices. Summary of the Invention
[0005] The purpose of this invention is to provide an ionic organic high-temperature phosphorescent material, which relates to important properties such as the afterglow intensity attenuation range, phosphorescence efficiency, afterglow emission color adjustment, and high temperature resistance.
[0006] Another objective of this invention is to provide a method for preparing the ionic organic high-temperature phosphorescent material.
[0007] Another objective of this invention is to provide the application of this material in LED flicker elimination.
[0008] To promote the widespread application of organic phosphorescent materials in daily life, this invention designs and prepares a series of high-efficiency, long-life ionic organic high-temperature phosphorescent materials. The objective of this invention is achieved through the following methods: An ionic organic high-temperature phosphorescent material is prepared by doping a guest material and a host material at a molar ratio of 0.5%. The host and guest materials each possess the following general formula structures:
[0009] Both the host and guest materials have two parts: anion and cation. Among them, the cation M + NH4 + NO2 + pyridine ion, pyrazine ion, piperazine ion, pyrimidine ion, pyrrole ion, imidazole ion and other polyatomic cations or Li + Na + K + Rb + Cs + Monovalent alkali metal ions or Be 2+ Mg 2+ Ca 2+ Divalent alkaline earth metal ions.
[0010] Anions are aromatic carboxylic acids, boric acids, sulfonic acids, or phosphoric acids that have the following structures, formed by the removal of one or more protons:
[0011] In the above figure, for each molecule, the substituents R1-R n (R) n The substituents with the highest numbers are -COOH, -B(OH)2, -SO3H, -H, -F, -Cl, -Br, -I, -CF3, -CN, -NO2, -NH2, -N(CH3)2, C=O, or alkyl chains, alkoxy chains, ether chains, and other organic groups. R1-R n There must be two or more -COOH, -B(OH)2, or -SO3H in the sample. X and Y can be atoms such as C, Si, N, P, As, O, S, Se, and Te.
[0012] If necessary, substituents R can be present on atoms X and Y. X R Y These can be -H, alkyl chains, etc.
[0013] The properties of the aforementioned ionic organic high-temperature phosphorescent material are as follows: the afterglow decay curve of this doped material follows an exponential decay law and is a single exponential decay; the afterglow intensity decreases very little within 20 ms, reaching the second level; the afterglow intensity remains at 90% within 20 ms after the material is excited; the phosphorescence efficiency of the material reaches 87%; and the material can withstand 640°C. o C does not decompose, 300 o C still exhibits phosphorescence.
[0014] The high density of ionic bonds and the matching structure between the host and guest in the doped material play an important role in suppressing lattice expansion, molecular thermal motion and molecular decomposition, thereby effectively suppressing the thermal quenching of triplet excitons and achieving high-temperature phosphorescence.
[0015] The preparation method of the above-mentioned ionic organic high-temperature phosphorescent material is as follows: Aromatic carboxylic acids, boric acids, sulfonic acids, or phosphoric acids with substituted carbocyclic or heterocyclic forms are mixed with hydroxides of alkali metals and alkaline earth metals and dissolved in water (acid-base reaction). Then, some water is evaporated, and finally the mixture is heated to 140°C. o C. Rapidly evaporate moisture at high temperature to obtain the desired ionic salt white powder (see attached image). Figure 1 For example, doped materials are prepared using terephthalic acid, naphthalenetetracarboxylic acid, and sodium hydroxide solution. The host terephthalic acid molecule has the first structure shown in the figure, where R1, R2, R4, R5 = HR3, and R6 = -COOH; the guest naphthalenetetracarboxylic acid molecule has the second structure shown in the figure, where R2, R3, R6, R7 = H, and R1, R4, R5, R8 = -COOH; while the cation M... + = Na + .
[0016] The preferred main material is sodium terephthalate, and the preferred guest material is sodium naphthalenetetracarboxylate.
[0017] The remaining materials are obtained by reacting substituted carbocyclic or heterocyclic aromatic carboxylic acids, boric acids, sulfonic acids or phosphoric acids with hydroxides of alkali metals and alkaline earth metals.
[0018] This invention characterized the ion crystal arrangement of the host and guest atoms using powder X-ray diffraction and single-crystal X-ray diffraction (see...). Figure 2 The photophysical properties of this series of organic high-temperature phosphorescent materials were studied in detail through fluorescence and phosphorescence high-temperature variable-temperature spectroscopy, as well as measurements of phosphorescence lifetime and efficiency. By changing different cations, the molecular packing distance and π-π overlap area in the host and guest molecules were altered, thereby regulating the packing mode of the luminescent groups in the organic salts and achieving rational control of the high-temperature phosphorescence properties (see...). Figure 3 ).
[0019] The flicker index of the treated LED devices was tested using AC power, and the light intensity data of both untreated and treated LED devices were recorded over time. The untreated LED devices, lacking afterglow compensation, exhibited significant fluctuations in light intensity. Notably, after treatment with ion-type organic high-temperature phosphorescent materials, the flickering of the LED devices was significantly reduced, with the flicker index (PF) decreasing to 11.3% (Appendix 5). Even after prolonged operation and heat generation, the treated devices maintained an invisible flicker, and after disconnecting the AC power, they exhibited a bright yellow afterglow for approximately 6 seconds. (Appendix) Figure 5 ).
[0020] Compared with the prior art, the present invention has the following advantages: This invention not only features a simple preparation method and inexpensive raw materials, but also produces ionic materials with high-temperature phosphorescent properties, demonstrating significant application potential. Furthermore, these ionic organic high-temperature phosphorescent materials can be used in LED flicker elimination, reducing visual fatigue, headaches, and even potential eye damage caused by flicker. Attached Figure Description
[0021] Figure 1 Preparation process of ionic high-temperature phosphorescent materials Figure 2 Schematic diagram of the crystal arrangement of the host material (sodium terephthalate) and the guest material (sodium naphthalenetetracarboxylate). Figure 3 High-temperature variable-temperature phosphorescence spectrum of TN-K, an ionic high-temperature phosphorescent material Figure 4 Afterglow intensity decay curve of TN-Na ionic high-temperature phosphorescent material Figure 5 Demonstration of LED luminous intensity and LED flicker elimination based on TN-Na materials Figure 6Demonstration of LED luminous intensity and LED flicker elimination based on TR materials Figure 7 Demonstration of LED luminous intensity and LED flicker elimination based on TN-K material Figure 8 Demonstration of LED luminous intensity and LED flicker elimination based on TB material Figure 9 Demonstration of LED luminous intensity and LED flicker elimination based on BN material Figure 10 Demonstration of LED luminous intensity and LED flicker elimination based on CN materials Figure 11 Demonstration of LED luminous intensity and LED flicker elimination based on FN material Figure 12 Demonstration of LED luminous intensity and LED flicker elimination based on TY material Figure 13 Demonstration of LED luminous intensity and LED flicker elimination based on BY materials Figure 14 Demonstration of LED luminous intensity and LED flicker elimination based on FY material Detailed Implementation
[0022] The present invention will be further described below with reference to specific embodiments. Example 1:
[0023] Synthesis process of ionic high-temperature phosphorescent materials: 165.2 mg (0.995 mmol) of terephthalic acid and 1.52 mg (0.005 mmol) of naphthalenetetracarboxylic acid were weighed into a 10 mL centrifuge tube. 5 mL of 0.4 mol / L NaOH solution was added, and the mixture was sonicated until the terephthalic acid and naphthalenetetracarboxylic acid were completely dissolved. The centrifuge tube was then placed in a 50°C oil bath to evaporate some of the water. The remaining solution was then placed in a 140°C oil bath. o In a C-type oven, the sample was rapidly dried to completely remove moisture, ultimately yielding a white powder sample TN-Na (synthesis process illustrated in Figure 1). Figure 1 The molecular arrangement of its main structure and guest structure is shown in the appendix. Figure 2 The host and guest molecules are arranged in a layer-by-layer molecular and ion structure, with well-matched distances between layers. This ensures that the guest molecules can be well incorporated into the host structure, ultimately achieving a high-efficiency, high-temperature-resistant organic phosphorescent material. Its phosphorescence efficiency reaches 87.3%, and the material can withstand temperatures up to 640°C. o C does not decompose, 200 o C still has an afterglow that lasts for 1 second. Example 2:
[0024] Weigh 165.2 mg (0.995 mmol) of terephthalic acid and 1.52 mg (0.005 mmol) of naphthalenetetracarboxylic acid into a 10 mL centrifuge tube, and sonicate until the terephthalic acid and naphthalenetetracarboxylic acid are completely dissolved. Prepare the potassium terephthalate and potassium naphthalenetetracarboxylic acid doped material TN-K as a white solid powder using the method described in Example 1. By changing the type of counterion, the high-temperature luminescence properties of the phosphorescent material were improved. The high-temperature variable-temperature phosphorescence spectrum of this white solid powder is shown in the appendix. Figure 3 , in 300 o Phosphorescence emission still occurs above C, and in this state, the phosphorescence lifetime exceeds 70 ms. Example 3:
[0025] LED flicker elimination application: The afterglow intensity attenuation of the material in Example 1 of this invention is shown in the appendix. Figure 4 Its afterglow retention intensity reached 90.0% in 20 ms. Based on its excellent afterglow retention intensity and high temperature resistance, this ionic organic high-temperature phosphorescent material was uniformly mixed with epoxy resin at a mass ratio of 1:20 to prepare a high-temperature phosphorescent composite material, which was then applied to LED flicker elimination. To evaluate its light intensity compensation effect, the flicker index of the treated LED device was tested using an AC power supply, and the light intensity data of the untreated and treated LED devices were recorded over time. The untreated LED device showed significant fluctuations in light intensity due to the lack of afterglow compensation; notably, after treatment with the ionic organic high-temperature phosphorescent material, the flicker phenomenon of the LED device was significantly reduced, and its flicker index (… PF The figure dropped to 11.3% (with appendix). Figure 5 Even after prolonged operation and the generation of heat, the treated device can still maintain an invisible flickering state, and after the AC power is disconnected, the LED device can display a bright yellow afterglow for about 6 seconds. Example 4:
[0026] Based on the preparation method of the high-temperature phosphorescent composite material in Example 3, Rhodamine B was added during the preparation process. The ionic organic high-temperature phosphorescent material, Rhodamine B, and epoxy resin were uniformly mixed in a mass ratio of 10:1:200 to prepare a long-afterglow composite material TR with energy transfer characteristics. This composite material was then applied to LED flicker elimination, achieving a white LED emission color (see attached). Figure 6 Testing the flicker index of this LED device revealed that its... PF The value is only 15.7% (attached) Figure 6 It still has a good flicker elimination effect. Example 5:
[0027] Based on material TN-K from Example 2, a composite material of this material and epoxy resin was prepared using the method and proportions of Example 3, and applied to LED flicker elimination. Testing the flicker index of this LED device revealed that its... PF The value is 58.0% (see attached image). Figure 7 ). Example 6:
[0028] Weigh 165.2 mg (0.995 mmol) of terephthalic acid and 1.21 mg (0.005 mmol) of biphenyl phthalate, and measure 5 mL of 0.4 mol / L NaOH solution into a 10 mL centrifuge tube. Sonicate until the terephthalic acid and biphenyl phthalate are completely dissolved. Prepare the sodium terephthalate and sodium biphenyl phthalate doped material TB using the method in Example 1. Using the method and proportions of Example 3, prepare a composite material of this material and epoxy resin, and apply it to LED flicker elimination. Testing the flicker index of this LED device revealed that its... PF The value is 95.5% (see attached image). Figure 8 ). Example 7:
[0029] Weigh 166.3 mg (0.995 mmol) of p-pyridinedicarboxylic acid and 1.52 mg (0.005 mmol) of naphthalenetetracarboxylic acid, and measure 5 mL of 0.4 mol / L NaOH solution into a 10 mL centrifuge tube. Sonicate until the p-pyridinedicarboxylic acid and naphthalenetetracarboxylic acid are completely dissolved. Prepare the doped material BN of sodium p-pyridinedicarboxylic acid and sodium naphthalenetetracarboxylic acid using the method in Example 1. Using the method and proportions of Example 3, prepare a composite material of this material and epoxy resin, and apply it to LED flicker elimination. Testing the flicker index of this LED device revealed that its... PF The value is 87.1% (see attached image). Figure 9 ). Example 8:
[0030] Weigh 179.3 mg (0.995 mmol) of 2-methylterephthalic acid and 1.52 mg (0.005 mmol) of naphthalenetetracarboxylic acid, and measure 5 mL of 0.4 mol / L NaOH solution into a 10 mL centrifuge tube. Sonicate until the 2-methylterephthalic acid and naphthalenetetracarboxylic acid are completely dissolved. Prepare the doped material CN of sodium 2-methylterephthalate and sodium naphthalenetetracarboxylic acid using the method in Example 1. Using the method and proportions of Example 3, prepare a composite material of this material and epoxy resin, and apply it to LED flicker elimination. Testing the flicker index of this LED device revealed that its… PF The value is 91.1% (see attached image). Figure 10 ). Example 9:
[0031] Weigh 183.2 mg (0.995 mmol) of 2-fluoroterephthalic acid and 1.52 mg (0.005 mmol) of naphthalenetetracarboxylic acid, and measure 5 mL of 0.4 mol / L NaOH solution into a 10 mL centrifuge tube. Sonicate until the 2-fluoroterephthalic acid and naphthalenetetracarboxylic acid are completely dissolved. Prepare the doped material FN of sodium 2-fluoroterephthalate and sodium naphthalenetetracarboxylic acid using the method in Example 1. Using the method and proportions of Example 3, prepare a composite material of this material and epoxy resin, and apply it to LED flicker elimination. Testing the flicker index of this LED device revealed that its... PF The value is 78.6% (see attached) Figure 11 ). Example 10:
[0032] 165.2 mg (0.995 mmol) of terephthalic acid and 2.38 mg (0.005 mmol) of phthalic acid were weighed and 5 mL of 0.4 mol / L KOH solution was added to a 10 mL centrifuge tube. The mixture was sonicated until the terephthalic acid and phthalic acid were completely dissolved. A doped material TY, consisting of sodium terephthalate and sodium phthalic acid, was prepared using the method described in Example 1. Using the method and proportions of Example 3, a composite material of this material and epoxy resin was prepared and applied to LED flicker elimination. Testing the flicker index of this LED device revealed that its… PF The value is 94.4% (see attached image). Figure 12 ). Example 11:
[0033] Weigh 166.3 mg (0.995 mmol) of p-pyridinedicarboxylic acid and 2.38 mg (0.005 mmol) of phenylenetetracarboxylic acid into a 10 mL centrifuge tube, and sonicate until the p-pyridinedicarboxylic acid and phenylenetetracarboxylic acid are completely dissolved. Prepare the doped material BY of sodium p-pyridinedicarboxylic acid and sodium phenylenetetracarboxylic acid using the method in Example 1. Using the method and proportions of Example 3, prepare a composite material of this material and epoxy resin, and apply it to LED flicker elimination. Testing the flicker index of this LED device revealed that its... PF The value is 95.4% (see attached image). Figure 13 ). Example 12:
[0034] Weigh p-fluorobenzoic acid (139.4 mg, 0.995 mmol) and benzoic acid (2.38 mg, 0.005 mmol), and measure 2.5 mL of 0.4 mol / L KOH solution into a 10 mL centrifuge tube. Sonicate until the p-fluorobenzoic acid and benzoic acid are completely dissolved. Prepare the doped material FY of sodium p-fluorobenzoate and sodium benzoic acid using the method in Example 1. Using the method and proportions of Example 3, prepare a composite material of this material and epoxy resin, and apply it to LED flicker elimination. Testing the flicker index of this LED device revealed that its... PF The value is 97.4% (see attached image). Figure 14 ).
[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the technical solution of the present invention, based on the technical essence of the present invention, shall still fall within the protection scope of the technical solution of the present invention.
Claims
1. An ionic organic high temperature phosphor material, characterized in that The material is prepared by doping the guest and host materials in a molar ratio of 0.5%; the host and guest materials have the following general structures respectively: , Both the host and guest materials have anionic and cationic parts; wherein the cation M + is a polyatomic cation NH4 + , NO2 + , a pyridinium ion, a pyrazinium ion, a piperazinium ion, a pyrimidinium ion, a pyrrolinium ion, an imidazolium ion or a monovalent alkali metal ion Li + , Na + , K + , Rb + , Cs + or a divalent alkaline earth metal ion Be 2+ , Mg 2+ , Ca 2 + ; The anion is one of the aromatic carboxylic acid, boronic acid, sulfonic acid or phosphoric acid root negative ions formed by removing one or more protons from the substituted carbon ring or heterocyclic aromatic carboxylic acid, boronic acid, sulfonic acid or phosphoric acid with the following structure: , wherein for each molecule in the above figure, R n is a substituent R1~R n is a substituent R1~R n is selected from -COOH, -B(OH)2, -SO3H, -H, -F, -Cl, -Br, -I, -CF3, -CN, -NO2, -NH2, -N(CH3)2, C=O, or one of the organic groups alkyl chain, alkoxy chain, ether chain; and two or more of the substituents R1~R n must be -COOH, -B(OH)2, or -SO3H; X, Y are C, Si, N, P, As, O, S, Se.
2. The ionically organic high temperature phosphorescent material according to claim 1, characterized in that The guest is naphthalene tetracarboxylic acid, the host is terephthalic acid; wherein R1, R2, R4, R5 = H, R3, R6 = -COOH; the guest naphthalene tetracarboxylic acid molecular structure R2, R3, R6, R7 = H, R1, R4, R5, R8 = -COOH; and the cation M + = Na + .
3. The ionically organic thermophosphorescent material according to claim 1, characterized in that R1-R4 are substituents of the aromatic carboxylic acid corresponding to the anion in the host and guest structure n with the exception of the carboxylate -COOH, borate -B(OH)2, sulfonate -SO3H and phosphate -PO3H2, the remaining substituents are selected as -H.
4. The ionic organic high temperature phosphorescent material according to claim 1, wherein the material preparation is characterized in that the material preparation method is mixing the guest and the host at a molar ratio of 0.5%, preparing a solution by one-step aqueous reaction with hydroxides of alkali metals and alkaline earth metals, and then rapidly drying the solution at 140 °C. o C.
5. Use of the ion-type organic high-temperature phosphorescent material of claim 1 in LED stroboscopic elimination.