Method for improving surface lattice resonance quality factor of two-dimensional gold nanoparticle array on quartz glass substrate

Abstract

The invention discloses a method for improving surface lattice resonance quality factors of a two-dimensional gold nanoparticle array on a quartz glass substrate, which comprises the following steps of: firstly, carrying out ultrasonic cleaning on the quartz glass substrate, and self-assembling a single-layer colloidal crystal template at an air-water interface by utilizing PS (polystyrene) nanospheres on a clean and dry glass slide; the method comprises the following steps: transferring a single-layer ordered PS ball array onto a quartz plate to form a single-layer densely-arranged PS ball colloidal crystal template, and preparing a two-dimensional ordered gold nanoparticle array on a quartz glass substrate by utilizing a PS ball self-assembly process and a high-temperature annealing method; on the basis, chemical etching post-treatment is carried out on the array structure by utilizing a KI solution, so that the SLR quality factor of the array is remarkably improved by reducing the size of the gold nanoparticles under the condition that the array period value and the orderliness of the two-dimensional gold nanoparticle array are kept unchanged.

Description

Technical Field

[0001] The present invention relates to a micro-nano photonics technology, and in particular to a method for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate. Background Art

[0002] For metal plasmon nanostructures, achieving local field enhancement and improving the resonance quality factor (Q value) is extremely important for their applications in fluorescence enhancement, nanolasers, sensing detection, and nonlinear optics. When metal nanoparticles are arranged in a one-dimensional or two-dimensional periodic array, the local surface plasmon oscillation (LSPR) mode of the nanoparticles and the diffraction mode interaction between the arrays are coupled to produce a collective response of lattice resonance, called surface lattice resonance (SLR). Compared with the LSPR of a single metal nanostructure (Q value is usually less than 10), the SLR supported by the two-dimensional metal nanostructure array benefits from the coupling of the diffraction mode within the array plane, so it can effectively suppress the radiation loss of a single metal nanostructure, thereby achieving greater local field enhancement and higher Q value. In addition, by adjusting the structure and material parameters of the metal nanoparticle array (such as metal composition, size, shape, arrangement position, etc.), the SLR spectrum of the metal nanoarray structure can be controlled over a wide wavelength range.

[0003] Since the first experimental observation of SLRs in two-dimensional metal nanostructure arrays, achieving high-Q SLRs has been a hot topic for researchers both domestically and internationally. Top-down fabrication methods such as electron beam lithography, focused ion beam etching, and nanoimprint lithography enable the fabrication of two-dimensional metal nanostructure arrays through high-precision patterning of metals or metal films.

[0004] However, these methods generally have problems such as expensive equipment, low output efficiency, or complex template preparation. In comparison, the use of polystyrene (PS) nanosphere self-assembly process to prepare colloidal crystal templates, combined with metal film deposition and high-temperature annealing post-processing technology, is generally considered to be a method for preparing two-dimensional gold nanoarray structures with the advantages of low processing cost and high output efficiency. However, the two-dimensional gold nanoparticle arrays currently prepared using this method have difficulty in obtaining high-Q SLRs in both uniform and non-uniform refractive index environments. This is mainly due to the large size of the gold nanoparticles, which makes it difficult to achieve strong coupling conditions between the LSPR mode and the diffraction mode between the arrays.

[0005] Generally speaking, when the array period is fixed, as the size of the gold nanoparticles decreases, the SLR spectrum of the resulting two-dimensional plasmon array will narrow, resulting in a significant improvement in the resonant Q value. Since the size of the gold nanoparticles depends on the thickness of the gold film deposited on the PS nanospheres, reducing the thickness of the gold film can reduce the size of the gold nanoparticles. However, this method of reducing the size of the nanoparticles is limited, because when the thickness of the gold film is small, the thickness gradient difference of the gold film is correspondingly reduced, which will be detrimental to the formation of a regular and ordered gold nanoparticle array. Therefore, in the two-dimensional gold nanoparticle arrays directly obtained using this preparation method, it is difficult to reduce the particle diameter to around 100nm or even smaller.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate, so as to solve the above-mentioned technical problems existing in the prior art.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] The method of the present invention for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate comprises the steps of:

[0010] (1) First, ultrasonically clean the quartz glass substrate and prepare a PS ball liquid with a diameter of 500-600 nm. After the substrate is cleaned and dried, it is ready for use.

[0011] (2) PS nanospheres were self-assembled at the air-water interface on a clean and dry glass slide to form a monolayer colloidal crystal template, which was then transferred onto the water surface;

[0012] (3) The cleaned quartz glass substrate is tilted into water and then slowly lifted up to transfer the ordered monolayer PS sphere array to the quartz plate. After natural drying, a monolayer of densely packed PS sphere colloidal crystal template is formed on the quartz plate.

[0013] (4) Depositing a gold film on a single-layer close-packed PS sphere colloidal crystal template using thermal evaporation or magnetron sputtering, with a gold film thickness of 15-40 nm;

[0014] (5) placing the quartz glass substrate after the gold film deposition in a muffle furnace for high-temperature annealing, preferably at a temperature of 1060° C. and for 150 minutes, to obtain a two-dimensional ordered gold nanoparticle array on the quartz glass substrate;

[0015] (6) Using potassium iodide (KI) solution as a reaction reagent, the two-dimensional gold nanoparticle array prepared by the annealing process is chemically etched. The chemical reaction process involved is as follows:

[0016] 4KI+O2+2H2O→2I2+4KOH (1)

[0017] 2Au+I2→2AuI (2)

[0018] AuI+KI→KAuI2 (3)

[0019] 2KOH+SiO2→K2SiO3+H2O (4)

[0020] This step can reduce the size of gold nanoparticles without changing the periodic and orderly arrangement of gold nanoparticles, thereby improving the quality factor of the array SLR.

[0021] In step (6), the chemical etching process is as follows:

[0022] (6-1) KI solution was prepared by dissolving 99.5% pure KI powder in ultrapure water in a beaker and ultrasonically shaking for 5 minutes to mix thoroughly.

[0023] (6-2) placing the two-dimensional gold nanoparticle array prepared by the annealing process into a KI solution for chemical etching;

[0024] (6-3) After the gold nanoparticle array reacted in the KI solution for a certain period of time, the sample was taken out and rinsed with ultrapure water, and then structural characterization and spectral measurement analysis were performed respectively.

[0025] Compared with the existing technology, the method provided by the present invention for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate is based on the preparation of the gold nanoparticle array by PS sphere self-assembly and high-temperature annealing method, combined with a chemical etching post-treatment process, thereby improving the SLR quality factor of the gold nanoparticle array on the quartz glass substrate and achieving a high-Q value SLR. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the preparation process of a two-dimensional gold nanoparticle array using quartz glass as a substrate according to an embodiment of the present invention;

[0027] Figure 2 This is a flow chart of the preparation of a high-Q gold nanoparticle array based on a chemical etching post-treatment process according to an embodiment of the present invention;

[0028] Figure 3 This is an SEM image of the two-dimensional gold nanoparticle array structure prepared by high-temperature annealing method when the PS ball diameter is 500 nm and the gold film deposition time is 50 s in an embodiment of the present invention;

[0029] Figure 4 The SEM images of the gold nanoparticle arrays obtained under different etching conditions in the examples of the present invention are shown, where (a) is the etching reaction for 25 hours under natural backlight and semi-sealed conditions, and (b) is the etching reaction for 15 hours under weak light and unsealed conditions;

[0030] Figure 5 The extinction spectra of samples etched with KI solution (2 g KI dissolved in 18 g ultrapure water) for (a) 24 h and (b) 48 h were measured in different refractive index environments, where the chemical etching process was under natural backlight and semi-sealed conditions.

[0031] Figure 6 This is the extinction spectrum of the two-dimensional gold nanoparticle array sample of the embodiment of the present invention after being etched with KI solution (2g KI dissolved in 18g ultrapure water) for 8.5h measured in different refractive index environments, wherein the chemical etching process is under weak light and unsealed conditions. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. It is obvious that the described embodiments are only some of the embodiments of the present invention, not all of them, and do not constitute a limitation of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] First, the following terms may be used in this article:

[0034] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y includes both “X” or “Y” and “X and Y”.

[0035] The terms "include," "comprises," "contains," "has," or other similar expressions should be interpreted as non-exclusive. For example, "including certain technical features (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products, or manufactured articles, etc.) should be interpreted as including not only the technical features explicitly listed, but also other technical features known in the art that are not explicitly listed.

[0036] The term "consisting of" excludes any technical features not explicitly listed. If used in a claim, this term renders the claim closed, excluding any technical features other than those explicitly listed, except for conventional impurities associated with them. If this term appears only in a clause of a claim, it limits only the elements explicitly listed in that clause; elements listed in other clauses are not excluded from the claim as a whole.

[0037] The contents not described in detail in the examples of the present invention belong to the prior art known to those skilled in the art. If specific conditions are not specified in the examples of the present invention, the methods are carried out according to conventional conditions in the art or the conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments used in the examples of the present invention are not specified, they are all conventional products that can be purchased commercially.

[0038] The method of the present invention for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate comprises the steps of:

[0039] (1) First, ultrasonically clean the quartz glass substrate and prepare a PS ball liquid with a diameter of 500-600 nm. After the substrate is cleaned and dried, it is ready for use.

[0040] (2) PS nanospheres were self-assembled at the air-water interface on a clean and dry glass slide to form a monolayer colloidal crystal template, which was then transferred onto the water surface;

[0041] (3) The cleaned quartz glass substrate is tilted into water and then slowly lifted up to transfer the ordered monolayer PS sphere array to the quartz plate. After natural drying, a monolayer of densely packed PS sphere colloidal crystal template is formed on the quartz plate.

[0042] (4) Depositing a gold film on a single-layer close-packed PS sphere colloidal crystal template using thermal evaporation or magnetron sputtering, with a gold film thickness of 15-40 nm;

[0043] (5) placing the quartz glass substrate after the gold film deposition in a muffle furnace for high-temperature annealing, preferably at a temperature of 1060° C. and for 150 minutes, to obtain a two-dimensional ordered gold nanoparticle array on the quartz glass substrate;

[0044] (6) Using potassium iodide (KI) solution as a reaction reagent, the two-dimensional gold nanoparticle array prepared by the annealing process is chemically etched. The chemical reaction process involved is as follows:

[0045] 4KI+O2+2H2O→2I2+4KOH (1)

[0046] 2Au+I2→2AuI (2)

[0047] AuI+KI→KAuI2 (3)

[0048] 2KOH+SiO2→K2SiO3+H2O (4)

[0049] This step can reduce the size of gold nanoparticles without changing the periodic and orderly arrangement of gold nanoparticles, thereby improving the quality factor of the array SLR.

[0050] In step (6), the chemical etching process is as follows:

[0051] (6-1) KI solution was prepared by dissolving 99.5% pure KI powder in ultrapure water in a beaker and ultrasonically shaking for 5 minutes to mix thoroughly.

[0052] (6-2) placing the two-dimensional gold nanoparticle array prepared by the annealing process into a KI solution for chemical etching;

[0053] (6-3) After the gold nanoparticle array reacted in the KI solution for a certain period of time, the sample was taken out and rinsed with ultrapure water, and then structural characterization and spectral measurement analysis were performed respectively.

[0054] In the step (6-2):

[0055] The chemical etching reaction process is carried out in any of the following oxygen atmospheres:

[0056] The first is a semi-sealed state: the beaker mouth is sealed with Parafilm sealing film, and then the oxygen input is controlled by punching holes in the sealing film;

[0057] The second is the unsealed state: the mouth of the beaker is not sealed, leaving it open to the air to allow sufficient oxygen input.

[0058] The beaker in the semi-sealed state is placed in the laboratory under natural shade lighting conditions, which can avoid sunlight but not avoid indoor lighting, which is called natural backlight conditions;

[0059] The beaker in the unsealed state is placed in a dark box with the door open, which can avoid exposure to sunlight and indoor lighting, which is called low-light conditions.

[0060] In summary, the method for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate according to an embodiment of the present invention first utilizes a PS sphere self-assembly process and a high-temperature annealing method to prepare a two-dimensional ordered gold nanoparticle array on a quartz glass substrate. Furthermore, a chemical etching post-treatment process is utilized to significantly improve the SLR quality factor of the array by reducing the gold nanoparticle size while maintaining the array period and order.

[0061] In order to more clearly demonstrate the technical solutions and technical effects provided by the present invention, the embodiments of the present invention are described in detail below with reference to specific embodiments.

[0062] like Figure 1 The figure shows a schematic diagram of the preparation process of a two-dimensional gold nanoparticle array based on quartz glass. The specific preparation process is as follows:

[0063] (1) First, ultrasonically clean the quartz glass substrate and prepare a PS ball liquid with a diameter of 500-600 nm. After the substrate is cleaned and dried, it is ready for use.

[0064] (2) PS nanospheres were self-assembled at the air-water interface on a clean and dry glass slide to form a monolayer colloidal crystal template, which was then transferred onto the water surface;

[0065] (3) The cleaned quartz glass substrate is tilted into water and then slowly lifted up to transfer the ordered monolayer PS sphere array to the quartz plate. After natural drying, a monolayer of densely packed PS sphere colloidal crystal template (such as Figure 1 a);

[0066] (4) Thermal evaporation or magnetron sputtering is used to deposit a gold film on a single layer of closely packed PS sphere colloidal crystal template, with a gold film thickness of 15-40 nm (e.g. Figure 1 b);

[0067] (5) The quartz glass substrate after gold film deposition is placed in a muffle furnace for high-temperature annealing. The preferred annealing temperature is 1060°C and the annealing time is 150 minutes. Finally, a two-dimensional ordered gold nanoparticle array (such as Figure 1 c).

[0068] In order to reduce the size of gold nanoparticles while maintaining the periodic and orderly arrangement of gold nanoparticles, potassium iodide (KI) solution was used as a reaction reagent to chemically etch the two-dimensional gold nanoparticle array sample prepared by the annealing process. The chemical reaction process involved is as follows:

[0069] 4KI+O2+2H2O→2I2+4KOH (1)

[0070] 2Au+I2→2AuI (2)

[0071] AuI+KI→KAuI2 (3)

[0072] 2KOH+SiO2→K2SiO3+H2O (4)

[0073] As can be seen from formulas (1)-(3), a KI solution undergoes a chemical reaction in an oxygen atmosphere to produce elemental I2 and KOH. The mixture of I2 and KI is an excellent gold etchant. This is mainly because I2 and gold react to form AuI, and the chemical reaction between AuI and KI promotes the etching of gold by I2. In addition, KOH, which is generated by the reaction of KI solution with oxygen, is a strong base that reacts with SiO2 (as shown in formula (4)), thereby also producing an etching effect on the quartz glass substrate. In particular, because gold is a good catalyst, the etching reaction rate at the quartz glass substrate in contact with the gold nanoparticles will be significantly higher than the reaction rate at locations where no gold nanoparticles are distributed. This difference in reaction rate at different locations will cause the gold nanoparticles to gradually sink into the quartz glass substrate, thereby affecting the refractive index environment around the gold nanoparticles and the diffraction coupling between the arrays, ultimately changing the resonant spectral response of the gold nanoparticle array.

[0074] According to the above-mentioned chemical etching reaction principle, based on the two-dimensional gold nanoparticle array prepared by high-temperature annealing method, the quality factor of the array SLR can be improved by using a chemical etching post-treatment process.

[0075] Figure 2 The figure shows a flow chart for preparing a high-Q gold nanoparticle array based on a post-chemical etching process. The specific preparation process is as follows: (1) To prepare a KI solution of a certain concentration, 99.5% pure KI powder is dissolved in ultrapure water in a beaker and ultrasonically vibrated for 5 minutes to mix evenly; (2) The two-dimensional gold nanoparticle array sample prepared by the annealing process is placed in the KI solution for chemical etching. On the one hand, since the amount of I2 and KOH generated is related to the amount of oxygen entering the beaker, which affects the reaction rate, the etching reaction process can be carried out in two oxygen atmospheres: one is to seal the beaker mouth with Parafilm sealing film, and then control the oxygen input by punching holes in the sealing film; the other is to leave the beaker mouth unsealed and expose it to the air to allow sufficient oxygen input. For convenience of description, the former is called a semi-sealed state and the latter is called an unsealed state. On the other hand, the generation reaction of I2 and KOH is also affected by light conditions. A bright light environment will accelerate the reaction rate of the KI solution. In order to balance the effects of oxygen atmosphere and light conditions on the reaction rate, the semi-sealed beaker was placed in the laboratory under natural shade conditions, which could avoid sunlight but not indoor lighting (called natural backlight conditions); the unsealed beaker was placed in a dark box with the door open (to facilitate oxygen entry), which could avoid sunlight and indoor lighting at the same time (called weak light conditions); (3) After the gold nanoparticle array sample reacted in the KI solution for a certain period of time, the sample was taken out and rinsed with ultrapure water, and then structural characterization and spectral measurement analysis were performed respectively.

[0076] Compared with the prior art, the technical solution of the present invention has the following technical effects or advantages:

[0077] (1) Compared with top-down preparation methods such as electron beam lithography, focused ion beam etching and nanoimprint lithography, the present invention has the advantages of low processing cost and high output efficiency when used to prepare high-Q two-dimensional gold nanoarray structures.

[0078] (2) Compared with the existing two-dimensional gold nanoparticle arrays prepared by PS nanosphere self-assembly and high-temperature annealing, the two-dimensional gold nanoparticle arrays prepared by the method described in the present invention have a narrower SLR spectral response. The resonant Q value obtained in a uniform refractive index environment can reach 24.4, which is more than 2.5 times the Q value obtained by the nanoarray without any chemical etching treatment (about 9.6).

[0079] The following describes in more detail a method for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate, described in the present invention, with reference to the accompanying drawings and three examples. It should be noted that the following three specific examples are intended only to illustrate the present invention and are not intended to limit it. Any modifications and improvements based on the technical principles described herein are considered within the scope of protection of the present invention.

[0080] In the following three specific examples, the preparation conditions of the two-dimensional gold nanoparticle array samples used before the chemical etching reaction were the same, namely: PS balls with a diameter of 500 nm were used to construct a two-dimensional colloidal crystal template on a quartz glass substrate, and then a gold film was deposited by magnetron sputtering for 50 seconds (current 30 mA), and finally annealed at a high temperature of 1060°C for 150 minutes to form an ordered two-dimensional gold nanoparticle array. The SEM image of its structure is shown in FIG. Figure 3 shown.

[0081] Example 1:

[0082] Figure 4 (a) Shows the etching results after a gold nanoparticle array was placed in a KI solution (2g potassium iodide dissolved in 18ml ultrapure water) and etched for 25 hours under natural backlight and semi-enclosed conditions. The gold nanoparticles decrease in size and become trapped in the quartz glass pits at the center of their lattice, while maintaining their orderly hexagonal periodic arrangement.

[0083] According to the chemical reaction formula (4.1), when the potassium iodide content increases and the amount of oxygen participating in the reaction increases, the amount of I2 element and KOH generated also increases accordingly, which will accelerate the etching rate of gold nanoparticles and quartz glass substrate. Figure 4(b) shows the etching results after exposing the gold nanoparticle array to a KI solution (4g potassium iodide dissolved in 36ml ultrapure water) and allowing the etching reaction to proceed for 15 hours under weak light and unsealed conditions. It can be seen that while the processing time was halved, the gold nanoparticles still achieved the same reduction in size and entrapment in the quartz glass.

[0084] Example 2:

[0085] The two-dimensional gold nanoparticle array samples prepared by the annealing method were placed in a prepared KI solution (2g KI dissolved in 18g ultrapure water), and then chemically etched for different times to obtain array samples with new structural morphology. The chemical etching reaction process was carried out under natural backlight and semi-sealed conditions. When the array samples etched with KI solution for different lengths of time were placed in different air, water and glycerol refractive index environments (refractive index of 1, 1.333 and 1.474, respectively), the resonance spectrum response results were measured as shown in Figure 2. Figure 5 shown.

[0086] Depend on Figure 5 (a) It can be seen that when the etching time is 24h, the Q value of the array SLR in the air environment is about 15.8, which is significantly higher than the Q value of the sample without KI solution etching (about 12.5). However, when the array cover layer is water and glycerol solution, although it is closer to a uniform refractive index environment, the array SLR spectrum does not narrow further. In contrast, Figure 5 (b) As can be seen, when the etching time is increased to 48h, the SLR peak of the array in the air environment is significantly weakened and accompanied by a blue shift in the central wavelength and spectral broadening, indicating that the gold nanoparticle size is now sufficiently small. When the array sample at this time is placed in the refractive index environment of water and glycerol, its SLR spectrum is significantly narrowed. The Q value of the SLR peak generated in the water environment (approximately 19.2) is more than doubled that in the air environment (approximately 9.4); when the covering layer is changed to glycerol, which is closer to a uniform refractive index environment, the SLR peak width is further narrowed, and the corresponding Q value is as high as 21.5, which is comparable to the Q value measurement results obtained by directly growing ordered gold nanoparticle arrays on substrates reported in the literature.

[0087] Depend on Figure 5 The results shown in (b) show that when the size of the gold nanoparticles etched by the KI solution is reduced to a certain extent, their LSPR mode and the array diffraction mode will be strongly coupled in a uniform refractive index environment, thereby achieving a significant improvement in the SLR quality factor.

[0088] Example 3:

[0089] In order to shorten the etching processing time, the etching reaction process is carried out under weak light and unsealed conditions. Under these conditions, the etching reaction speed will be significantly increased due to the presence of sufficient oxygen to participate in the etching reaction.

[0090] Figure 6 The extinction spectrum of the gold nanoparticle array obtained by etching for only 8.5 hours under near-uniform refractive index conditions (with a glycerol cover layer) is shown. The Q value of the SLR peak is as high as 24.4, even higher than that of the gold nanoparticle array obtained by etching for only 8.5 hours under near-uniform refractive index conditions (with a glycerol cover layer). Figure 5 The Q value obtained after 48 hours of etching (b) is over 2.5 times the Q value of the nanoarray obtained without any chemical etching (approximately 9.6). This shows that compared to the influence of lighting conditions, oxygen flux has a more direct and significant impact on the etching reaction rate. If the etching reaction process can be carried out under precisely controlled temperature, lighting, and oxygen conditions, and by optimizing the etching reaction conditions, SLRs with even higher Q values can be achieved.

[0091] The main innovations of this patent are:

[0092] The two-dimensional gold nanoparticle array previously prepared by annealing method was chemically etched with KI solution, which significantly improved the array SLR quality factor by reducing the size of the gold nanoparticles while maintaining the array period and order.

[0093] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art.

Claims

1. A method for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate, characterized in that: Including steps: (1) First, ultrasonically clean the quartz glass substrate and prepare a PS ball liquid with a diameter of 500-600 nm. After the substrate is cleaned and dried, it is ready for use. (2) PS nanospheres were self-assembled at the air-water interface on a clean and dry glass slide to form a monolayer colloidal crystal template, which was then transferred onto the water surface; (3) The cleaned quartz glass substrate is tilted into water and then slowly lifted up to transfer the ordered monolayer PS sphere array to the quartz plate. After natural drying, a monolayer of densely packed PS sphere colloidal crystal template is formed on the quartz plate. (4) Depositing a gold film on a single-layer close-packed PS sphere colloidal crystal template using thermal evaporation or magnetron sputtering, with a gold film thickness of 15-40 nm; (5) placing the quartz glass substrate after the gold film deposition in a muffle furnace for high-temperature annealing, preferably at a temperature of 1060° C. and for 150 minutes, to obtain a two-dimensional ordered gold nanoparticle array on the quartz glass substrate; (6) Using potassium iodide (KI) solution as a reaction reagent, the two-dimensional gold nanoparticle array prepared by the annealing process is chemically etched. The chemical reaction process involved is as follows: 4KI+O2+2H2O→2I2+4KOH (1) 2Au+I2→2AuI (2) AuI+KI→KAuI2 (3) 2KOH+SiO2→K2SiO3+H2O (4) This step can reduce the size of gold nanoparticles without changing the periodic and orderly arrangement of gold nanoparticles, thereby improving the quality factor of the array SLR. In step (6), the chemical etching process is as follows: (6-1) KI solution was prepared by dissolving 99.5% pure KI powder in ultrapure water in a beaker and ultrasonically shaking for 5 minutes to mix thoroughly. (6-2) placing the two-dimensional gold nanoparticle array prepared by the annealing process into a KI solution for chemical etching; (6-3) After the gold nanoparticle array reacted in the KI solution for a certain period of time, the sample was taken out and rinsed with ultrapure water, and then structural characterization and spectral measurement analysis were performed respectively.

2. The method for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate according to claim 1, characterized in that: In the step (6-2): The chemical etching reaction process is carried out in any of the following oxygen atmospheres: The first is a semi-sealed state: the beaker mouth is sealed with Parafilm sealing film, and then the oxygen input is controlled by punching holes in the sealing film; The second is the unsealed state: the mouth of the beaker is not sealed, leaving it open to the air to allow sufficient oxygen input.

3. The method for improving the surface lattice resonance quality factor of a two-dimensional gold nanoparticle array on a quartz glass substrate according to claim 2, characterized in that: The beaker in the semi-sealed state is placed in the laboratory under natural shade lighting conditions, which can avoid sunlight but not avoid indoor lighting, which is called natural backlight conditions; The beaker in the unsealed state is placed in a dark box with the door open, which can avoid exposure to sunlight and indoor lighting, which is called low-light conditions.

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