LED lens prepared through net-shaped quantum dot structure
By adopting a mesh quantum dot structure in LED lenses and combining the thermal injection method to synthesize quantum dot solutions and polymers, the problem of spectral defects of existing LED light sources is solved, and the full spectrum LED light source is realized, protecting human eye health , and saves costs and materials.
Patent Information
- Application Number
- CN202411173554.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-02-14
AI Technical Summary
There is a gap in the spectrum of existing LED light sources, the proportion of blue light is high, and the difference is significant from the natural spectrum, posing a threat to human eye health. The method of improving the spectrum by adding LED chips or phosphors of multiple colors is complex, with high cost and low efficiency. .
LED lenses are prepared using a mesh quantum dot structure, and quantum dot colloidal solution emitting red and green light is synthesized by thermal injection method. After mixing evenly, it is combined with the polymer solution, and cross-linking agent and photosensitizer are added, and cross-linked by ultraviolet lamp irradiation. , quantum dots are embedded in the reticular polymer, and a reticular polymer quantum dot LED lens is prepared.
A full spectrum LED light source is realized, the red spectrum is strengthened, the blue spectrum is weakened, the eye burden is reduced, the vision health is protected, the use of quantum dot film is avoided, materials and costs are saved, and the stability of quantum dots is improved. and service life.
Smart Images
Figure FT_1
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of quantum dots, in particular to an LED lens with a mesh quantum dot structure. Background Art
[0002] LED tubes commonly seen on the market usually use a single-band blue light chip to stimulate one or two phosphors to generate white light. However, the spectrum of this conventional LED has some defects, mainly manifested in a large spectrum gap, a high proportion of blue light, and a significant difference from the natural spectrum, which poses a certain threat to human eye health. Although the LED spectrum can be improved by adding LED chips or phosphors of multiple colors, on the one hand, the effect is minimal, and on the other hand, the process is complex, costly, and inefficient, which significantly increases manufacturing and maintenance costs.
[0003] Quantum dots are nano-scale semiconductors that can emit light. When photoluminescence or electroluminescence is applied, they will emit bright visible light with pure spectral colors. At the same time, quantum dots have quantum size and quantum confinement effects. By simply adjusting the size of the prepared quantum dots, their spectrum can cover all bands from blue light to near infrared. At present, there are two main applications of quantum dots in optoelectronic devices. One is to replace phosphors with quantum dots in LED lamps and directly encapsulate them on blue light LEDs; the other is to directly make quantum dot films and attach expensive water vapor barrier films on the top and bottom. If quantum dots are directly encapsulated on blue light chips, the quantum dots will be kept in a high temperature environment, causing the quantum dots to attenuate and fail, resulting in a reduction in their lifespan; making quantum dot films is far away from the LED chip source, but it increases the manufacturing cost. LED lenses are used to control and optimize the light output elements of LED light sources. They improve the efficiency of light utilization and lighting effects by focusing, diffusing or changing the direction of light.
[0004] Therefore, it is necessary to use a new quantum dot technology combined with LED lens technology to achieve a full-spectrum LED light source and achieve the effect of healthy lighting. Summary of the invention
[0005] In order to solve the deficiencies of the prior art, the present invention proposes an LED lens made of a mesh quantum dot structure to realize a full-spectrum LED light source and achieve a healthy lighting effect.
[0006] The technical problem to be solved by the present invention is achieved through the following technical solutions: A network quantum dot structure is used to prepare an LED lens, and the specific preparation steps include: S1: synthesize quantum dot colloidal solutions emitting red and green light bands by hot injection method and mix them evenly in a certain proportion; S2: dissolving a polymer used as a lens material in an organic solvent to obtain a polymer solution, then adding the mixed quantum dot colloid solution to the polymer solution, heating and stirring to obtain a quantum dot polymer solution; S3: adding a small amount of cross-linking agent and a trace amount of photosensitizer to the quantum dot polymer solution in turn, heating and stirring evenly to obtain the final solution; S4: The final solution is injected into the lens mold. Under the irradiation of ultraviolet light, the polymer and the cross-linking agent are cross-linked under the catalysis of the photosensitizer, and the quantum dots are embedded in the network polymer, which is then cured to prepare a network polymer quantum dot LED lens.
[0007] In the present invention, the quantum dot colloidal solution synthesis process comprises the following steps: S1-1: preparing quantum dot materials, organic solvents, and surfactants, adding the organic solvents and surfactants into a reaction container, heating at a constant temperature and stirring to obtain a uniform reaction solution; S1-2: Injecting quantum dot materials into the reaction container in a certain proportion, keeping a constant temperature during injection, and keeping it for a certain time to allow the reaction to be complete; S1-3: After the reaction is completed, the mixture is cooled to room temperature to obtain a crude colloidal solution; S1-4: Centrifuge, wash, and disperse the crude colloidal solution to remove impurities and unreacted substances to obtain a quantum dot colloidal solution.
[0008] In the present invention, the raw materials required for the preparation process, according to the final solution, the mass fraction of the quantum dot material is 1-10%, the mass fraction of the lens material is 80-90%, the mass fraction of the cross-linking agent is 0.5-5%, the mass fraction of the photosensitizer is 0.05-1%, and the mass fraction of the organic solvent is 5-10%.
[0009] In the present invention, in the quantum dot colloidal solution, the molar ratio of quantum dots emitting red light band and green light band is 1:0-0:1, preferably 1:8-1:1.
[0010] Furthermore, the quantum dot material is II-VI quantum dots (for example: CdSe / ZnS, CdSe / CdS quantum dots, etc.), III-V quantum dots (for example: InP, GaAs quantum dots, etc.), perovskite quantum dots (for example: CsPbX3, CH3NH2Pb2X3 quantum dots, etc.), or the single-core nanoparticles of the above materials are coated with one or more layers including but not limited to CdS, ZnO, ZnS, ZnSe, ZnTe or any one or a combination of at least two of the alloy materials.
[0011] In the present invention, the organic solvent is one of chloroform, toluene, chlorobenzene, alkanes, olefins, aromatic hydrocarbons, alcohols, ethyl acetate, halogenated alkanes, halogenated olefins, halogenated aromatic hydrocarbons, diol derivatives, and ketones.
[0012] In the present invention, the lens material is one of polycarbonate (PC), polypropylene (PP), polymethyl methacrylate (PMMA), polysiloxane polymer, and polyalkylene oxide polymer.
[0013] In the present invention, the crosslinking agent is a mixture of one or more of propylene diamine, trimethylol propane, polyols, benzoyl peroxide, p-toluenesulfonic acid, acrylates, styrene, and zinc oxide.
[0014] In the present invention, the photosensitizer is one of hydrogen abstraction photosensitizers such as benzophenone and 2,4-dihydroxybenzophenone, or one of cleavage photosensitizers such as 2-hydroxy-2-methyl-1-phenylpropanone and 1-hydroxycyclohexylphenyl ketone, or one of cationic photosensitizers such as diazonium salts and diaryliodonium salts, or a mixture of at least two of the above three categories.
[0015] Based on the above preparation process, the obtained mesh quantum dot LED lens is used for LED light source, which can improve the spectrum, strengthen the red light spectrum in the full spectrum, weaken the blue light spectrum, reduce the burden on the eyes, and protect vision health.
[0016] Compared with the prior art, this application has the following advantages: (1) This application can improve the spectrum, strengthen the red spectrum in the full spectrum, weaken the blue spectrum, effectively reduce the burden on the eyes, protect eyesight, and achieve the effect of healthy lighting; (2) This application avoids the use of quantum dot film, greatly saving materials and costs; (3) The present application can keep quantum dots away from heat sources, thereby improving the stability of quantum dots and extending the service life of quantum dots.
[0017] Therefore, the present invention has novel concept and ingenious design, which effectively improves the stability of quantum dots of LED lenses, prolongs service life, saves materials and costs, and achieves the effect of healthy lighting. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a schematic diagram of the mesh quantum dot LED lens produced by the present invention.
[0019] In the figure: quantum dot LED lens 1, quantum dots 2, cross-linking agent 3, polymer 4. DETAILED DESCRIPTION
[0020] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. Example
[0021] A network quantum dot structure is used to prepare an LED lens, and the specific preparation steps include: S1: Prepare stock solutions of 0.5 M indium oleate (In(OA)3), 0.5 M zinc oleate (Zn(OA)2), 0.5 M cadmium oleate (Cd(OA)2), 2 M TOPSe (trioctylphosphine selenide), and 2 M TOPS (trioctylphosphine sulfide) as precursors; S2: Preparation of red quantum dots (CdSe / Cd x Zn 1-x Se / ZnSeyS 1-y QD): 0.2 mmol of Cd(OA)2 and 10 mL of ODE were added to a flask, degassed under vacuum at 110 °C, and backfilled with argon; after heating to 300 °C, 0.1 mmol of TOPSe was quickly injected into the flask to form a CdSe core (r = 1.5 nm); Cd(OA)2 (0.3 mmol) and TOPSe (0.3 mmol) precursors were injected at high temperature to obtain a larger CdSe core (r = 2.5 nm), thereby forming a red luminescent element; in order to increase the Cd x Zn 1-x Se layer was coated on the CdSe core, and 10 mmol Zn(OA)2 was injected at high temperature, followed by 2 mmol Cd(OA)2 and 8 mmol TOPSe gradually injected over 2 hours. y S 1-y For the outer shell, 20 mmol Zn(OA)2 was added to the flask at high temperature, and then 6.2 mmol TOPSe and 9.1 mmol TOPS were added dropwise for 3 hours; after cooling to room temperature, the obtained quantum dot solution was purified by repeated precipitation / redispersion method (acetone / toluene), and diluted with toluene to obtain a red quantum dot colloidal solution; S3: Preparation of green quantum dots (CdSe / Cd x Zn 1-x Se / ZnSe y S 1-y QDs: Synthesized in the same way as S2, but with a smaller CdSe core (r = 2.0 nm), CdxZn QDs were grown on the CdSe core by gradually injecting 0.1 mmol Cd(OA)2 and 3.8 mmol TOPSe after injecting 5.5 mmol Zn(OA)2 precursor.1-x Se shell; one hour after the shell growth, the reaction flask was heated to 320 ° C to induce cation mutual diffusion, and the reaction temperature was maintained until the emission wavelength moved to the green region; after the synthesized green luminescent quantum dot solution was cooled to room temperature, it was repeatedly purified by precipitation / redispersion method (acetone / toluene) and diluted with toluene to obtain a green quantum dot colloidal solution; S4: mixing the two quantum dot colloidal solutions prepared in S2 and S3 in a molar ratio of 1:8-1:1; S5: dissolving the lens material polymer polymethyl methacrylate in a toluene solvent to obtain a polymer solution, then adding the uniformly mixed quantum dot colloid solution to the polymer solution, heating and stirring to obtain a quantum dot polymer solution; S6: adding a small amount of cross-linking agent propylene diamine and a trace amount of photosensitizer benzophenone to the quantum dot polymer solution in turn, heating and stirring evenly to obtain a final solution, wherein the mass fraction of quantum dots is 1-10%, the mass fraction of lens material polymer polymethyl methacrylate is 85-92%, the mass fraction of cross-linking agent propylene diamine is 0.5-5%, the mass fraction of photosensitizer benzophenone is 0.05-1%, and the mass fraction of organic solvent toluene is 5-10%; S7: The final solution is injected into the lens mold. Under ultraviolet light, the polymer and the cross-linking agent are cross-linked under the catalysis of the photosensitizer, and the quantum dots are embedded in the network polymer, which is then cured to prepare a network polymer quantum dot LED lens.
[0022] In the LED lens made by the above process, the quantum dot luminescent material can absorb short-wavelength light and convert it into longer-wavelength light, resulting in a better proportion of blue light being converted into red light, weakening the output of blue light and increasing the output of red light, thereby improving the spectrum and achieving healthy lighting. In addition, the quantum dots in the LED lens structure are away from heat sources, which can improve the stability of the quantum dots, extend the life of the quantum dots, and thus extend the service life of the LED lens. Example
[0023] An LED light source, such as Figure 1 As shown, it includes a quantum dot LED lens 1, which is a mesh polymer quantum dot LED lens prepared in Example 1, and is hemispherical in shape with a hollow interior and an open side. The LED lens 1 is cross-linked by a polymer 4 and a cross-linking agent 3 under the catalysis of a photosensitizer, and the quantum dots 2 are embedded in the mesh polymer 4 and are obtained through curing.
Claims
1. A network quantum dot structure for preparing LED lens, characterized in that: The specific preparation steps include: S1: synthesize quantum dot colloidal solutions emitting red and green light bands by hot injection method and mix them evenly in a certain proportion; S2: dissolving a polymer used as a lens material in an organic solvent to obtain a polymer solution, then adding the mixed quantum dot colloid solution to the polymer solution, heating and stirring to obtain a quantum dot polymer solution; S3: adding a small amount of cross-linking agent and a trace amount of photosensitizer to the quantum dot polymer solution in turn, heating and stirring evenly to obtain the final solution; S4: The final solution is injected into the lens mold. Under the irradiation of ultraviolet light, the polymer and the cross-linking agent are cross-linked under the catalysis of the photosensitizer, and the quantum dots are embedded in the network polymer, which is then cured to prepare a network polymer quantum dot LED lens.
2. The LED lens according to claim 1, characterized in that: The quantum dot colloidal solution synthesis process comprises the following steps: S1-1: preparing quantum dot materials, organic solvents, and surfactants, adding the organic solvents and surfactants into a reaction container, heating at a constant temperature and stirring to obtain a uniform reaction solution; S1-2: Injecting quantum dot materials into the reaction container in a certain proportion, keeping a constant temperature during injection, and keeping it for a certain time to allow the reaction to be complete; S1-3: After the reaction is completed, the mixture is cooled to room temperature to obtain a crude colloidal solution; S1-4: Centrifuge, wash, and disperse the crude colloidal solution to remove impurities and unreacted substances to obtain a quantum dot colloidal solution.
3. The LED lens according to claim 1, characterized in that: The raw materials required for the preparation process, according to the final solution, include 1-10% by mass of quantum dot material, 85-92% by mass of lens material, 0.5-5% by mass of crosslinking agent, 0.05-1% by mass of photosensitizer, and 5-10% by mass of organic solvent.
4. The LED lens according to claim 1, characterized in that: In the quantum dot colloidal solution, the molar ratio of quantum dots emitting red light band and green light band is 1:0-0:1, preferably 1:8-1:
1.
5. The LED lens according to claim 1, characterized in that: The quantum dot material is II-VI quantum dots or III-V quantum dots or perovskite quantum dots, or the single-core nanoparticles of the above materials are coated with one or more layers of coating materials, and the coating material is any one of CdS, ZnO, ZnS, ZnSe, ZnTe or alloy materials or a combination of at least two thereof.
6. The LED lens according to claim 1, characterized in that: The organic solvent is one of chloroform, toluene, chlorobenzene, alkanes, olefins, aromatic hydrocarbons, alcohols, ethyl acetate, halogenated alkanes, halogenated olefins, halogenated aromatic hydrocarbons, diol derivatives, and ketones.
7. The LED lens according to claim 1, characterized in that: The lens material is one of polycarbonate, polypropylene, polymethyl methacrylate, polysiloxane polymer and polyalkylene oxide polymer.
8. The LED lens according to claim 1, characterized in that: The crosslinking agent is a mixture of one or more of propylene diamine, trimethylol propane, polyols, benzoyl peroxide, p-toluenesulfonic acid, acrylates, styrene and zinc oxide.
9. The LED lens according to claim 1, characterized in that: The photosensitizer is one of hydrogen abstraction photosensitizers such as benzophenone and 2,4-dihydroxybenzophenone, or one of cleavage photosensitizers such as 2-hydroxy-2-methyl-1-phenylpropanone and 1-hydroxycyclohexylphenyl ketone, or one of cationic photosensitizers such as diazonium salts and diaryliodonium salts, or a mixture of at least two of the above three categories.
10. An LED lens as claimed in any one of claims 1 to 9, used for an LED light source.