In-situ growth of light-induced quantum dots coupled with defects of filling elements and applications

Abstract

The application relates to a light-induced in-situ growth method for coupling defects of filling elements and application, relates to the technical field of defect detection of optical elements, and solves the problems of poor selectivity, low resolution and low sensitivity of the defect detection of the material in-situ grown by heat induction on the optical elements in the prior art. The application selects and fills CsPbBr3 quantum dot precursors in the defect area on the surface of the element, and induces in-situ growth of the quantum dot precursors at the defect position under irradiation of a specific light source, so that a significant local light-thermal effect is generated at the defect position. The application effectively makes up for the problem of insufficient positioning selectivity of the traditional heat-induced method in the defect area by using the selective growth mechanism, can realize high-sensitivity, high-selectivity and high-spatial-resolution positioning detection of the micro defects of the optical element, can be applied to defect positioning of the optical element, and provides a new technical approach for defect visualization characterization and high-precision positioning.

Description

Technical Field

[0001] This invention relates to the field of optical element defect detection technology, specifically to a method and application of photoinduced quantum dot in-situ growth for coupling and filling element defects. Background Technology

[0002] In the field of optical manufacturing, optical components, as core parts of laser systems, imaging systems, and precision measuring devices, directly determine the overall performance and lifespan of the system through their surface and internal quality. However, during processing and long-term service, various defects such as pitting, scratches, and dents inevitably occur on the surface or inside of optical components. These defects not only damage the surface morphology and structural integrity of the components but also induce effects such as scattering, diffraction, and localized absorption during beam transmission, thereby significantly reducing the system's transmittance, focusing performance, and damage resistance threshold. Therefore, achieving accurate detection and characterization of defects in optical components is of great significance for ensuring the stability and reliability of high-end optical systems.

[0003] In existing technologies, conventional morphology detection methods (such as optical microscopy and scanning electron microscopy) can visually reflect the morphology of defects, but their resolution, field of view, and sensitivity are limited, making it difficult to meet the requirements for rapid localization and high-precision analysis of defects on large-aperture optical components. Especially in the detection of complex defect distributions or submicron-scale defects, these methods often exhibit insufficient sensitivity or low operational efficiency. In contrast, photothermal detection methods, relying on the local absorption of light and thermal accumulation effects in the defect region, possess the advantages of being non-contact, non-destructive, and highly efficient. By monitoring changes in the thermal field distribution, the location and distribution characteristics of defects can be accurately revealed without affecting the performance of the component. However, existing photothermal detection technologies still suffer from spatial resolution limitations due to the diameter of the test spot, making it difficult to achieve high-sensitivity detection of nanometer or submicron-scale defects. Furthermore, some detection schemes have long testing cycles and high equipment costs, hindering their widespread application in large-scale production and online inspection.

[0004] To overcome the shortcomings of the aforementioned detection methods, emerging nanomaterials have been gradually introduced into the field of optical component defect detection. Among them, quantum dots, with their size-dependent band structure and strong fluorescence emission characteristics, have attracted widespread attention. Quantum dots exhibit highly sensitive optical responses to minute energy perturbations or environmental changes, thus being considered a class of highly promising defect detection marker materials. Traditional in-situ growth methods for quantum dots mainly rely on thermal induction mechanisms, i.e., forming a macroscopic thermal field by heating the entire optical component, causing ions in the precursor solution to migrate and nucleate and grow under the influence of thermal driving force. Although the thermally induced in-situ growth method of quantum dots has achieved quantum dot deposition to a certain extent, it still has significant limitations. For example, the thermal induction forms a global thermal field, making it difficult to achieve precise temperature control within a local area. This results in random nucleation and distribution of quantum dots across the entire component surface, lacking selectivity for specific defect regions. Furthermore, the macroscopic thermal field often introduces additional thermal stress and structural perturbations, thereby affecting the overall performance of the optical component. Moreover, this process is highly dependent on energy consumption and process conditions, making it difficult to simultaneously meet the requirements of high precision and high efficiency.

[0005] Therefore, how to achieve the directional growth or selective labeling of quantum dots at defect sites and break through the resolution and selectivity limitations of traditional thermally induced methods has become a core problem that needs to be solved in current optical component defect detection technology. Summary of the Invention

[0006] To address the shortcomings of existing thermally induced in-situ material growth techniques for defect detection in optical components, such as poor selectivity, low resolution, and low sensitivity, this invention proposes a photo-induced quantum dot in-situ growth method and application for coupling and filling component defects. The technical solution of this invention is as follows:

[0007] A method for in-situ photoinduced quantum dot growth coupled to fill element defects includes the following preparation steps:

[0008] S1: Cesium bromide / N,N-dimethylformamide (CsBr / DMF) solution and polymethyl methacrylate / N,N-dimethylformamide (PMMA / DMF) solution are mixed, heated and stirred to obtain a cesium bromide / polymethyl methacrylate (CsBr / PMMA) solution; lead bromide / N,N-dimethylformamide (PbBr2 / DMF) solution is added, heated and stirred to obtain a CsPbBr3 precursor solution; the CsPbBr3 precursor solution is preheated and kept at a constant temperature.

[0009] S2: Spin-coat the CsPbBr3 precursor solution onto the pretreated defective element surface to obtain a CsPbBr3 / PMMA wet film; irradiate the CsPbBr3 / PMMA wet film with a light source to complete the in-situ growth of photoinduced quantum dots that directly couple and fill the defects of the tested element.

[0010] Further, the CsBr / DMF solution in S1 is obtained by mixing and stirring cesium bromide (CsBr) powder and N,N-dimethylformamide (DMF), heating, and filtering; the heating temperature is 50~80℃, the stirring speed is 1000~1500rpm, and the stirring is carried out overnight; the filtration is performed using a 0.22 μm needle filter.

[0011] Further, the PMMA / DMF solution in S1 is obtained by mixing, heating and stirring polymethyl methacrylate (PMMA) and DMF under nitrogen atmosphere; the heating temperature is 100~120℃, the stirring speed is 1500~1800 rpm, and the stirring time is 1~2 h.

[0012] Further, the PbBr2 / DMF solution in S1 is obtained by mixing and stirring lead bromide (PbBr2) powder and DMF, heating, and filtering; the heating temperature is 50~80℃, the stirring speed is 1000~1500 rpm, and stirring is carried out overnight; the filtration is carried out using a 0.22 μm needle filter.

[0013] Furthermore, in S1, the mixing volume ratio of the CsBr / DMF solution and the PMMA / DMF solution is 3:40; the heating temperature in the heating and stirring process is 80~100 ℃, the stirring speed is 1500~1800 rpm, and the stirring time is 10~12 h.

[0014] Further, in S1, the molar ratio of CsBr to PbBr2 in the CsPbBr3 precursor solution is 2:3; the CsPbBr3 precursor solution is preheated to a temperature of 70~100 ℃; and the holding time is 5~10 min.

[0015] Further, the defective element in S2 is any one of silicon carbide, single crystal silicon, sapphire, or fused silica; the pretreatment step of the defective element is to first perform ultrasonic cleaning, and then perform plasma cleaning; the solvent for ultrasonic cleaning is water, anhydrous ethanol, isopropanol, or acetone, the frequency of ultrasonic cleaning is 40 kHz, and the time of ultrasonic cleaning is 5~10 min; the power of plasma cleaning is 80~100 W, and the cleaning time is 3~5 min.

[0016] Furthermore, the spin coating speed in S2 is 1000~3000 rpm, and the spin coating time is 20~40 s.

[0017] Furthermore, the irradiation source in S2 is a semiconductor laser or LED light source with a center wavelength of 400~1050 nm; the power of the light source is 10~200 mW, and the focusing diameter of the light spot is 50~200 μm.

[0018] An application of the above-mentioned photoinduced quantum dot in-situ growth method for coupling and filling element defects is characterized in that it is applied to defect localization of optical elements.

[0019] Compared with existing technologies, this invention solves the problems of poor selectivity, low resolution, and low sensitivity in the detection of defects in optical components using thermally induced in-situ grown materials. Specifically, the beneficial effects are as follows:

[0020] 1. Achieving Highly Selective Defect Localization: This invention achieves high-precision defect localization of optical components based on a photo-induced in-situ growth method of CsPbBr3 quantum dots that directly couples and fills defects in the tested component. By selectively filling the defect region on the component surface with quantum dot precursors and inducing in-situ growth at the defect location under specific light source illumination, a significant localized photothermal effect is generated at the defect site. The non-defect region, lacking band traps and photothermal accumulation, hardly undergoes crystallization. This results in a significantly higher temperature in the defect region (125.86℃) compared to the non-defect region (58.08℃), with the electric field mainly distributed in the defect region, reaching a maximum field strength of 0.99 V / m. Furthermore, stable and well-defined fluorescent markers can form in the defect region. This selective growth mechanism effectively overcomes the insufficient selectivity of traditional thermally induced methods for defect localization, enabling highly sensitive, selective, and spatially resolved localization and detection of microscopic defects in optical components. This provides a new technical approach for defect visualization characterization and high-precision localization.

[0021] 2. Quantum Dot-Assisted Defect Localization: This invention uses CsPbBr3 quantum dots as defect localization markers, fully leveraging the unique advantages of CsPbBr3 quantum dots in terms of size controllability, high fluorescence efficiency, and good coupling with the substrate surface. Selective coupling is achieved between CsPbBr3 quantum dots and defect regions on the surface of optical components. Combined with a light source of specific wavelength, pulse energy, and time-domain modulated light, the surface of the component under test is scanned and excited, efficiently inducing in-situ growth of quantum dots at defect locations, forming stable and well-defined fluorescence signals. This method enables high-throughput detection and defect localization of complex optical components, providing a feasible technical solution for quantum dot-assisted defect analysis and industrial applications in optical components. Attached Figure Description

[0022] Figure 1 A simulation model diagram of the thermal induction of a defective component;

[0023] Figure 2This is a temperature field distribution diagram of fused silica under thermal induction;

[0024] Figure 3 A simulation model diagram of the photoinduced defective component;

[0025] Figure 4 This is a temperature field distribution diagram of fused silica under photoinduced conditions;

[0026] Figure 5 This is a diagram showing the electric field distribution of fused silica under photoinduced conditions.

[0027] Figure 6 The fluorescence spectrum of photoinduced CsPbBr3 quantum dots;

[0028] Figure 7 This is a fluorescence image of the photoinduced in-situ growth of CsPbBr3 quantum dots on a defective element. Detailed Implementation

[0029] To make the technical solutions of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the following embodiments are only used to better understand the technical solutions of the present invention and should not be construed as limiting the present invention.

[0030] Example 1.

[0031] S1: In a glove box under nitrogen atmosphere, mix 1 g PMMA and 3 mL DMF. Place the mixture on a heating plate and heat and stir. The heating plate temperature is 100 ℃ and the rotation speed is 2000 rpm. Heat and stir for 1 h until a transparent solution is formed, i.e. PMMA / DMF solution.

[0032] S2: In a glove box under nitrogen atmosphere, 1.267 g of PbBr2 and 0.514 g of CsBr powder were placed in two 40 mL glass bottles, and 4 mL of DMF was added to each bottle. The two solutions were heated and stirred on a heating plate at 50 °C and 2000 rpm overnight. After filtering the two solutions through a 0.22 μm syringe filter, CsBr / DMF solution and PbBr2 / DMF solution were obtained, respectively.

[0033] S3: Add 300 μL of CsBr / DMF solution to 4 mL of PMMA / DMF solution. Place the mixture on a heating plate, adjust the temperature of the heating plate to 100 ℃, and heat and stir at 2000 rpm for 10 h to obtain a CsBr / PMMA solution. Then add 200 μL of PbBr2 / DMF solution and continue to heat and stir at 100 ℃ and 1600 rpm for 10 h to obtain a CsPbBr3 precursor solution.

[0034] S4: The CsPbBr3 precursor solution was preheated to 100 °C in a constant temperature oil bath and kept at that temperature for 10 min to pretreat the fused silica element: first, it was ultrasonically cleaned with deionized water (frequency 40 kHz, time 15 min) to remove the particulate matter attached to the surface, then ultrasonically cleaned with anhydrous ethanol and isopropanol for 10 min each to remove organic contaminants, and finally dried with a nitrogen gun (flow rate 0.5 L / min); it was then placed in a plasma cleaner (power 100 W, oxygen atmosphere, pressure 50 Pa) for 5 min to further increase the surface hydroxyl density to enhance the adhesion to the subsequent wet film; the treated fused silica element was immediately fixed on a spin coater, the precursor solution was added, and the spin coater was used at 2000 rpm for 30 s to obtain a CsPbBr3 / PMMA wet film;

[0035] S5: Using an LED light source with a center wavelength of 808 nm, the power of the light source was gradually adjusted to 50 mW and maintained for 3 min before irradiating the CsPbBr3 / PMMA wet film for 5 min with a spot diameter of 50 μm to complete the photoinduced in-situ growth of CsPbBr3 quantum dots that directly couple and fill the defects in fused silica.

[0036] Example 2.

[0037] The difference between this embodiment and Embodiment 1 is that, in S4: the CsPbBr3 precursor solution is placed in a constant temperature oil bath and preheated to 100 °C and kept at that temperature for 10 min to pretreat the monocrystalline silicon device: first, it is ultrasonically cleaned with deionized water (frequency 40 kHz, time 10 min) to remove the particulate matter attached to the surface, and then ultrasonically cleaned with anhydrous ethanol and isopropanol for 5 min each to remove organic contaminants. Finally, it is dried with a nitrogen gun (flow rate 0.5 L / min); it is then placed in a plasma cleaner (power 100 W, oxygen atmosphere, pressure 50 Pa) for 2 min to further increase the surface hydroxyl density to enhance the adhesion to the subsequent wet film; the treated monocrystalline silicon device is immediately fixed on a spin coater, the precursor solution is added, and the spin coater is used at a speed of 2500 rpm for 20 s to obtain a CsPbBr3 / PMMA wet film.

[0038] The remaining preparation steps and conditions are exactly the same as in Example 1, completing the in-situ photoinduced quantum dot growth that directly couples CsPbBr3 quantum dots to fill defects in single-crystal silicon.

[0039] Example 3.

[0040] The difference between this embodiment and embodiment 1 is that, in S5: a laser light source with a wavelength of 1050 nm and a laser power of 20 mW is used, and the CsPbBr3 / PMMA wet film is irradiated after the power is kept stable for 5 min. The irradiation time is 2 min and the spot diameter is 200 μm.

[0041] The remaining preparation steps and conditions were exactly the same as in Example 1, completing the in-situ growth of CsPbBr3 quantum dots directly coupled to fill the defects in fused silica.

[0042] Example 4.

[0043] The difference between this embodiment and Embodiment 1 is that, in S5: a laser light source with a wavelength of 808 nm and a laser power of 2 W is used, and the CsPbBr3 / PMMA wet film is irradiated after the power is kept stable for 2 min. The irradiation time is 30 s and the spot diameter is 100 μm.

[0044] The remaining preparation steps and conditions were exactly the same as in Example 1, completing the in-situ growth of CsPbBr3 quantum dots directly coupled to fill the defects in fused silica.

[0045] Comparative Example 1.

[0046] The difference between this comparative example and Example 1 is that in step S5, the CsPbBr3 / PMMA wet film is heated at a temperature of 100°C for 2 minutes to complete the thermally induced in-situ growth of CsPbBr3 quantum dots from fused silica defects.

[0047] The light absorption and heat absorption characteristics of the simulated fused silica surface micro-nano damage obtained in Example 1 and Comparative Example 1 were calculated using FDTD and COMSOL finite element analysis. Figure 1 This is a simulation model of a thermally induced defective component. The simulated optical component is a cuboid measuring 10 μm × 10 μm × 3 μm. The defect crack width is 800 nm, the length is 1000 nm, and the depth is 800 nm. Figure 2The figures show the temperature field distribution of fused silica under thermal induction in Comparative Example 1, where (a) is the temperature field distribution of the xoy surface of the fused silica and (b) is the temperature field distribution of the yoz surface. As can be seen from the figures, when the heat source temperature is set to 100 ℃ and its radiation area is 10 μm × 10 μm, complete and uniform heat source coverage can be achieved on the surface of the optical element. According to the theory of heat conduction, heat flow is hindered when it encounters surface defects (such as air inclusions) during transmission, leading to a decrease in the thermal conductivity of the defect area, resulting in a local temperature rise and forming a "temperature hotspot". The temperature of the defect area is 99.2 ℃, while the temperature of the non-defect area is 98.4 ℃, with a difference of only 0.8 ℃. This indicates that under thermal induction conditions, the temperature rise difference between the surface defect and non-defect areas is relatively small, and the defect has no significant impact on the overall temperature field distribution.

[0048] like Figure 3 The image shows a simulation model of a defective component induced by light. Figure 4 The figures show the temperature field distribution of fused silica under light-induced conditions in Example 1, where (a) is the temperature field distribution of the xoy plane of the fused silica, and (b) is the temperature field distribution of the yoz plane of the fused silica. As can be seen from the figures, the temperature of the defect area on the fused silica surface gradually increases with light irradiation, reaching 125.86℃, significantly higher than the temperature of the non-defect area (58.08℃). This is because when the light source irradiates the defect area on the component surface, its surface morphology differs from the surrounding area, causing significant scattering and reflection of the incident light, resulting in localized concentration of light energy in the defect area. Simultaneously, because the phase of the light wave changes abruptly when passing through the defect, interference occurs in the beam, forming a standing wave effect between the incident and reflected waves in the defect area, resulting in an increase in local electric field intensity, such as... Figure 5 The figure shows the electric field distribution of fused silica under light in Example 1. (a) is the electric field distribution of the xoy plane of fused silica, and (b) is the electric field distribution of the yoz plane of fused silica. It can be seen from the figure that the electric field distribution is most concentrated at the defects on the surface of the optical element, with the maximum field strength reaching 0.99 V / m, which is significantly higher than that in the defect-free area.

[0049] like Figure 6The fluorescence spectrum of the photoinduced CsPbBr3 quantum dots in Example 1 further characterizes the in-situ growth effect of quantum dots in the defect region. As shown in the figure, the fluorescence peak is located at 519 nm with a full width at half maximum (FWHM) of 18 nm. This peak position highly coincides with the characteristic emission peak (515-525 nm) of pure-phase CsPbBr3 quantum dots, proving that well-crystallized CsPbBr3 quantum dots were successfully synthesized during photoinduced growth. Furthermore, the narrow FWHM of 18 nm is much lower than the typical FWHM (usually >30 nm) exhibited by disordered quantum dots, indicating that the quantum dots formed in the defect region have a highly uniform particle size distribution and excellent crystallinity.

[0050] like Figure 7 This image shows the fluorescence of the photoinduced in-situ growth of CsPbBr3 quantum dots on the surface of coupled defect fused silica, as described in Example 1. The image clearly shows that the fluorescence signal of the quantum dots is highly concentrated in the defect region, while almost no significant fluorescence emission is observed in the non-defect region. This result demonstrates that the photoinduced process can effectively utilize the localized photothermal effect at the defect site to achieve selective in-situ growth of quantum dots in the target region. This is completely different from the traditional thermally induced method of crystallization across the entire device surface. The photoinduced in-situ growth method provided in this application exhibits stronger spatial selectivity and higher imaging contrast in the defect region, thus providing a new technical approach for defect visualization and high-precision localization.

[0051] In summary, this invention achieves high-precision localization of defects in optical components based on a photo-induced in-situ growth method of CsPbBr3 quantum dots. By using a selective growth mechanism, it effectively compensates for the lack of selectivity in defect localization of traditional thermally induced methods. This invention enables high-sensitivity, high-selectivity, and high-spatial-resolution localization and detection of microscopic defects in optical components, providing a feasible technical solution for defect visualization characterization and quantum dot-assisted defect analysis and industrial applications of optical components.

[0052] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for in-situ growth of light-induced quantum dots coupled to defects of a filling element, characterized in that, The preparation steps include: S1: mixing cesium bromide / N,N-dimethylformamide solution and polymethyl methacrylate / N,N-dimethylformamide solution, heating and stirring to obtain a cesium bromide / polymethyl methacrylate solution; adding a lead bromide / N,N-dimethylformamide solution, heating and stirring to obtain a CsPbBr3 precursor solution; preheating the CsPbBr3 precursor solution; S2: spin coating the CsPbBr3 precursor solution onto the surface of the pretreated defective element to obtain a CsPbBr3 / polymethyl methacrylate wet film; using a light source to irradiate the CsPbBr3 / polymethyl methacrylate wet film to complete the light-induced in-situ growth of quantum dots for filling the defects of the measured element; The defective element is any one of silicon carbide, monocrystalline silicon, sapphire or fused quartz; The irradiation light source is a semiconductor laser or an LED light source with a central wavelength of 400-1050 nm; the light source power is 10-200 mW, and the light source spot focusing diameter is 50-200 μm.

2. The method of claim 1, wherein the method is performed in-situ. In S1, the cesium bromide / N,N-dimethylformamide solution is obtained by mixing and stirring cesium bromide powder and N,N-dimethylformamide, heating, and filtering; the heating temperature is 50-80℃, the stirring speed is 1000-1500 rpm, and the stirring is overnight; the filtering is performed using a 0.22 μm needle filter.

3. The method of claim 1, wherein the method is performed in-situ. In S1, the polymethyl methacrylate / N,N-dimethylformamide solution is obtained by mixing and heating polymethyl methacrylate and N,N-dimethylformamide under a nitrogen environment and stirring; the heating temperature is 100-120℃, the stirring speed is 1500-1800 rpm, and the stirring time is 1-2 h.

4. The method of claim 1, wherein the method is performed in-situ. In S1, the lead bromide / N,N-dimethylformamide solution is obtained by mixing and stirring lead bromide powder and N,N-dimethylformamide, heating, and filtering; the heating temperature is 50-80℃, the stirring speed is 1000-1500 rpm, and the stirring is overnight; the filtering is performed using a 0.22 μm needle filter.

5. The method of claim 1, wherein the method is performed in-situ. In S1, the mixing volume ratio of the cesium bromide / N,N-dimethylformamide solution and the polymethyl methacrylate / N,N-dimethylformamide solution is 3:40; the heating temperature in the heating and stirring is 80-100℃, the stirring speed is 1500-1800 rpm, and the stirring time is 10-12 h.

6. The method of claim 1, wherein the method is performed in-situ. In S1, the molar ratio of cesium bromide and lead bromide in the CsPbBr3 precursor solution is 2:3; the preheating of the CsPbBr3 precursor solution is preheating to a temperature of 70-100℃; and the holding time is 5-10 min.

7. The method of claim 1, wherein the method is performed in-situ. The pre-treatment step of the defect element in S2 is ultrasonic cleaning followed by plasma cleaning; the solvent of the ultrasonic cleaning is water, anhydrous ethanol, isopropanol or acetone, the frequency of the ultrasonic cleaning is 40 kHz, the time of the ultrasonic cleaning is 5-10 min; the power of the plasma cleaning is 80-100 W, and the time of the plasma cleaning is 3-5 min.

8. The method of claim 1, wherein the method is performed in-situ. The rotation speed of the spin coating in S2 is 1000-3000 rpm, and the time of the spin coating is 20-40 s.

9. Use of a method of in situ growth of photoluminescent quantum dots coupled to defects of a filler element according to any one of claims 1 to 8, characterized in that, The application is applied to defect positioning of optical elements.

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