Design and preparation method of down-conversion illumination gain agricultural glass

Abstract

The invention provides a design and preparation method of down-conversion illumination gain agricultural glass, and belongs to the field of novel agricultural functional materials. Aiming at the contradiction between spectrum mismatch of a traditional greenhouse material and photovoltaic agricultural light transmission-power generation, a zero-dimensional perovskite material (A4BX6) and quantum dot collaborative system is innovatively adopted, and efficient light quality regulation and control are achieved through a sandwich structure. The glass can convert ultraviolet light with the wavelength of 300-400 nm into visible light with the wavelength of 400-700 nm, green light with the wavelength of 515-565 nm is subjected to 90% capture and then converted into red light with the wavelength of 600-700 nm, the quantum efficiency reaches 85% or above, and the photosynthetically active radiation gain is 40%. The photon capture efficiency is optimized by innovatively adopting gradient concentration design. Compared with a traditional material, the material has the functions of spectrum adaptation optimization and light-electricity cooperation, and no splashing risk exists during crushing. The system is suitable for modern agricultural greenhouses, can shorten the crop cycle and improve the yield, retains the spectrum required by photovoltaic power generation, and achieves the dual purposes of light energy gradient utilization and energy self-supply.

Description

Technical Field

[0001] The present invention belongs to the field of new agricultural functional materials, and relates to a preparation method of laminated glass, in particular to a design and preparation method of a down-conversion light-enhanced agricultural glass. Through the design of down-conversion light, the present invention converts ultraviolet light in the solar spectrum into visible light or captures green light that has little impact on crop growth and converts it into red light required by most plants, realizing the enhancement of photosynthetically active radiation, thereby shortening the crop growth cycle, increasing crop yields, and achieving gradient utilization of light energy. The present invention is applicable to modern agricultural greenhouse covering materials, taking into account the growth requirements of crops and the function of energy self-supply. Background Art

[0002] Traditional agricultural greenhouses generally use ordinary glass or plastic films as covering materials, and there is a significant mismatch between their spectral transmission characteristics and the photosynthesis requirements of crops. The ultraviolet light band in the solar spectrum cannot be effectively utilized by most crops and may even induce plant damage. At the same time, the development of photovoltaic agriculture is limited by the inherent contradiction between light transmittance and power generation efficiency - the high absorption of visible light by traditional photovoltaic modules seriously weakens the available light intensity for crops, while transparent photovoltaic materials are difficult to achieve gradient utilization of spectral resources due to their single-function design.

[0003] Although spectral conversion technology can theoretically improve the light energy utilization efficiency through light quality regulation, the existing materials have insufficient stability in outdoor environments. Conventional materials are prone to performance degradation after long-term outdoor exposure and are difficult to meet the stringent requirements of agricultural facilities for material lifespan. In addition, the lack of collaborative design with photovoltaic power generation systems makes it difficult to meet the dual demands of modern agriculture for intelligent regulation of the light environment and energy self-supply. With the large-scale development of protected agriculture, the development of new agricultural functional materials with optimized spectral adaptation, photo-electricity co-conversion, and long-term stability has become an urgent direction for industrial upgrading.

[0004] Based on this, the present invention proposes a down-conversion light-enhanced agricultural glass, which breaks through the above technical bottlenecks through the down-conversion effect of zero-dimensional perovskite materials and the sandwich encapsulation process, realizing efficient, stable, and safe regulation of the agricultural light environment. Summary of the Invention

[0005] Traditional agricultural greenhouses mostly use ordinary glass or transparent plastics as covering materials, but there is a significant mismatch between their spectral transmission characteristics and the photosynthesis requirements of crops. Ultraviolet light cannot be effectively utilized by crops and may even cause photo-oxidative damage; in photovoltaic agriculture, the high absorption of visible light by traditional photovoltaic glass leads to a prominent contradiction between light transmittance and power generation efficiency, seriously restricting the light intensity requirements of crops.

[0006] Aiming at the problems existing in the prior art, the present invention provides a design and preparation method for a down-conversion light-enhanced agricultural glass. The down-conversion light-enhanced agricultural glass prepared by the preparation method has high transparency, high safety factor, simple preparation process, and is green and environmentally friendly.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] 1. A design and preparation method for a down-conversion light-enhanced agricultural glass, characterized in that the method comprises:

[0009] (1) Coating a solution containing a down-conversion material on the surface of a substrate to obtain a down-conversion material layer;

[0010] (2) Spreading a polymer film on the surface of the material obtained in step (1), and covering another glass substrate above the polymer film to form a sandwich structure;

[0011] (3) Thermally pressing and encapsulating the sandwich structure obtained in step (2) in a vacuum or normal pressure environment to obtain the down-conversion light-enhanced agricultural glass.

[0012] 2. The preparation method according to claim 1, characterized in that the down-conversion material in step (1) is a zero-dimensional perovskite material A 4 BX 6 , a rare earth luminescent material, an organic luminescent material, a metal complex luminescent material, an organic-inorganic hybrid luminescent material, an inorganic quantum dot luminescent material, or a combination of one or more thereof;

[0013] Among them, in the zero-dimensional perovskite material A 4 BX 6 A is selected from at least one of Ar-CH 2 NH 3 + , Ar-CH 2 CH 2 NH 3 + or Ar-CH 2 CH 2 CH 2 CH 2 NH 3 + (Ar is an aryl group), B is selected from at least one of Pb 2+ , Sn 2+ or Ge 2+ , and X is selected from at least one of I - , Br - , Cl - or F -At least one of them; in the down-conversion functional layer, quantum dot materials (such as CdSe / ZnS) can capture more than 90% of the 515 - 565 nm green light that has little impact on crop growth and convert it into red light of 600 - 700 nm required by most plants with a quantum efficiency of more than 85%; while the zero-dimensional perovskite material A 4 BX 6 can convert 300 - 400 nm ultraviolet light into 400 - 700 nm visible light. The above light conversion increases the photosynthetically active radiation by nearly 40%, thereby shortening the crop growth cycle and increasing crop yields.

[0014] 3. The preparation method according to claim 1, wherein the concentration of the solution in step (1) is 0.2 - 1.5 mol / L.

[0015] 4. The preparation method according to claim 1, wherein the thickness of the down-conversion functional layer in step (1) is 50 nm - 1 μm.

[0016] 5. The preparation method according to claim 1, wherein the glass substrate in step (1) includes any one or several of various glass substrates, plexiglass substrates, or polymer substrates, with a light transmittance ≥ 90% and a thickness of 2 - 5 mm.

[0017] 6. The preparation method according to claim 1, wherein the polymer film in step (2) is polyvinyl butyral (PVB) or ethylene-vinyl acetate copolymer (EVA);

[0018] Preferably, the other substrate in step (2) includes any one or several of various glass substrates, plexiglass substrates, or polymer substrates, with a light transmittance ≥ 90% and a thickness of 2 - 5 mm.

[0019] 7. The preparation method according to any one of claims 1 - 6, wherein the refractive index of the down-conversion material is greater than the refractive indices of the glass substrate and the polymer film to achieve an optical waveguide effect.

[0020] 8. The preparation method according to claim 1, wherein the encapsulating material in step (3) comprises one or more of polyvinyl butyral PVB, ethylene-vinyl acetate EVA, polyolefin elastomer POE, polyurethane PU, and fused glass powder; with a thickness of 0.1 - 10 mm.

[0021] 9. The preparation method according to any one of claims 1 - 8, wherein the visible light transmittance of the down-conversion light gain agricultural glass is ≥ 85%, the ultraviolet light conversion efficiency is ≥ 15%, and the performance attenuation after 12 months of outdoor weather resistance testing is < 5%.

[0022] 10. The preparation method according to any one of claims 1-5, characterized in that the hot pressing temperature in step (3) is 70-170 °C;

[0023] Preferably, the pressure of the lower hot pressing in step (3) is 0.1-1 MPa.

[0024] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0025] (1) The down-conversion light-enhanced agricultural glass prepared by the design and preparation method of the down-conversion light-enhanced agricultural glass provided by the present invention converts green light and ultraviolet light with low plant utilization rate into light required for photosynthesis through the spectral conversion layer. When used in a photovoltaic agricultural greenhouse, part of the visible light can also be retained for photovoltaic power generation, realizing the double utilization of one beam of light;

[0026] (2) The laminated glass device prepared by the design and preparation method of the down-conversion light-enhanced agricultural glass provided by the present invention realizes a photon capture gradient through the gradient concentration design of the down-conversion material, thereby optimizing the absorption efficiency of light with different wavelengths;

[0027] (3) The laminated glass device prepared by the design and preparation method of the down-conversion light-enhanced agricultural glass provided by the present invention has long-term stability. The sandwich structure isolates water and oxygen to ensure durability, and there is no glass splashing when broken, ensuring personal safety through the buffer protection layer. Description of the Drawings

[0028] Figure 1 is a schematic diagram of the sandwich structure of the down-conversion light-enhanced agricultural glass;

[0029] where 1 - substrate, 2 - polymer film, 3 - down-conversion material;

[0030] Figure 2 is the excitation, absorption and emission spectra of the down-conversion light-enhanced agricultural glass;

[0031] Figure 3 is the spectral diagram of the quantum dot material in the functional layer absorbing green light and converting it into red light.

[0032] The present invention will be further described in detail below. However, the following examples are merely simple examples of the present invention and do not represent or limit the scope of the patent protection of the present invention. The scope of protection of the present invention shall be subject to the claims. Detailed Embodiments

[0033] The technical solutions of the present invention will be further described below in conjunction with the drawings and through specific embodiments.

[0034] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0035] Example 1

[0036] This example provides a method for preparing a down-conversion light-gain agricultural glass, and the method includes:

[0037] (1) Spin-coat a benzylamine tin bromide perovskite solution (A 4 BX 6 , A = benzylamino, B = Sn 2+ , X = Br - , with a concentration of 0.8 mol / L and a solvent of DMF) on the surface of a substrate (light transmittance 92%, thickness 3 mm). The spin-coating speed is 2000 rpm and the time is 20 seconds. Subsequently, anneal at 90°C for 10 minutes to form a down-conversion functional layer with a thickness of about 500 nm;

[0038] (2) Cover the functional layer with an EVA film (thickness 50 μm), stack another soda-lime glass substrate, and perform vacuum hot pressing at 150°C and 0.8 MPa for 20 minutes;

[0039] (3) Seal the edges with polyurethane to complete the sandwich encapsulation, and finally obtain the down-conversion light-gain agricultural glass.

[0040] Example 2

[0041] (1) Spin-coat a benzylethylamine tin bromide perovskite solution (A 4 BX 6 , A = benzylamino, B = Sn 2+ , X = Br - , with a concentration of 0.8 mol / L and a solvent of DMF) on the surface of a substrate (light transmittance 92%, thickness 3 mm). The spin-coating speed is 1500 rpm and the time is 25 seconds. Subsequently, anneal at 80°C for 15 minutes to form a down-conversion functional layer with a thickness of about 600 nm;

[0042] (2) Cover the functional layer with a PVB film (thickness 60 μm), stack another soda-lime glass substrate, and perform vacuum hot pressing at 160°C and 0.7 MPa for 30 minutes;

[0043] (3) Seal the edges with polyurethane to complete the sandwich encapsulation, and finally obtain the down-conversion light-gain agricultural glass.

Claims

1. A design and preparation method of down-conversion light gain agricultural glass, characterized in that: The method comprises: (1) coating a solution containing a down-conversion material on a surface of a substrate to obtain a down-conversion material layer; (2) spreading a polymer film on the surface of the material obtained in step (1), and covering the polymer film with another glass substrate to form a sandwich structure; (3) The sandwich structure obtained in step (2) is heat-pressed and packaged in a vacuum or normal pressure environment to obtain down-conversion light gain agricultural glass.

2. The preparation method according to claim 1, characterized in that: The down-conversion material in step (1) is one or more combinations of zero-dimensional perovskite material A4BX6, rare earth luminescent material, organic luminescent material, metal complex luminescent material, organic-inorganic hybrid luminescent material, and inorganic quantum dot luminescent material; Among them, A in the zero-dimensional perovskite material A4BX6 is selected from Ar-CH2NH3 + 、Ar-CH2CH2NH3 + or Ar-CH2CH2CH2CH2NH3 + At least one of (Ar is an aromatic group), B is selected from Pb 2+ Sn 2+ Or Ge 2+ At least one of, X is selected from I - Br - , Cl - or F - At least one of the following: quantum dot materials (such as CdSe / ZnS) in the down-conversion functional layer can achieve >90% capture of 515-565nm green light, which has little effect on crop growth, and convert it into 600-700nm red light required by most plants with a quantum efficiency of >85%; and zero-dimensional perovskite material A4BX6 can convert 300-400nm ultraviolet light into 400-700nm visible light. The above light conversion increases the photosynthetic active radiation gain by nearly 40%, thereby shortening the crop growth cycle and increasing crop yield.

3. The preparation method according to claim 1, characterized in that: The concentration of the solution in step (1) is 0.2-1.5 mol / L.

4. The preparation method according to claim 1, characterized in that: In step (1), the thickness of the down-conversion functional layer is said to be 50 nm-1 μm.

5. The preparation method according to claim 1, characterized in that: The glass substrate in step (1) includes any one or more of various glass substrates, organic glass substrates, or polymer substrates, with a light transmittance of ≥90% and a thickness of 2-5 mm.

6. The preparation method according to claim 1, characterized in that: The polymer film in step (2) is polyvinyl butyral (PVB) or ethylene-vinyl acetate copolymer (EVA); Preferably, the other substrate in step (2) comprises any one or more of various glass substrates, organic glass substrates, or polymer substrates, with a light transmittance of ≥90% and a thickness of 2-5 mm.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The refractive index of the down conversion material is greater than that of the glass substrate and the polymer film to achieve an optical waveguide effect.

8. The preparation method according to claim 1, characterized in that: The packaging material in step (3) comprises one or more of polyvinyl butyral PVB, polyethylene vinyl acetate EVA, polyolefin elastomer POE, polyurethane PU, and molten glass powder; and the thickness is 0.1-10 mm.

9. The preparation method according to any one of claims 1 to 8, characterized in that: The down-conversion illumination gain agricultural glass has a visible light transmittance of ≥85%, an ultraviolet light conversion efficiency of ≥15%, and a performance attenuation of <5% after 12 months of outdoor weather resistance testing.

10. The preparation method according to any one of claims 1 to 5, characterized in that: The hot pressing temperature in step (3) is 70-170°C; preferably, the hot pressing pressure in step (3) is 0.1-1 MPa.

Images