Mn-based metal halide fluorescent solar concentrating device and preparation method thereof

Abstract

The present invention discloses a Mn-based metal halide fluorescent solar concentrator device and its preparation method. The method first involves mixing benzyltrimethylammonium bromide, MnBr2, and water in an air atmosphere, stirring to clarify, and then filtering. PEO is then added and thoroughly stirred to dissolve to form a precursor solution. Finally, the precursor solution is applied by blade coating followed by spin coating to form a light-absorbing layer. The thickness of the light-absorbing layer is controlled by regulating the spin coating rate. By selecting the appropriate PEO additive, using a hybrid Mn-based metal halide as a precursor, and employing a solution method of blade coating followed by spin coating, the present invention achieves the preparation of a photovoltaic concentrator with high transparency, high light conversion efficiency, and high edge emission efficiency, without the need for organic solvents or external processing.

Description

Technical Field

[0001] The invention belongs to the field of organic and inorganic metal halide fluorescent solar concentrators and relates to a Mn-based metal halide fluorescent solar concentrator device and a preparation method thereof. Background Art

[0002] A fluorescent solar concentrator (LSC) is an optical device that can convert large-area sunlight into high-quantum-efficiency fluorescence and achieve edge light convergence. It can be used as a large-area sunlight collector for photovoltaic cells. The LSC consists of a piece of transparent material (such as glass or plastic) impregnated or coated with a high-emission fluorophore. After absorbing sunlight that strikes a large surface area of ​​the flat plate, the LSC fluorophore re-emitted lower-energy photons, which are guided by total internal reflection to the edge of the device, where they are collected by solar cells. Compared with traditional focusing and reflective concentrating technologies, LSC concentrating technology can not only absorb scattered light, but is also not affected by the incident angle of sunlight. Therefore, there is no need to configure a solar tracking device, which can effectively reduce the cost of concentrating.

[0003] If LSCs cost significantly less than solar cells of the same area and their light conversion efficiency is sufficiently high, their application could significantly reduce the cost of solar power generation. LSCs also offer the flexibility and translucency to enable new devices such as solar windows or photovoltaic windows. For example, they could be installed on roofs, exterior walls, and other building surfaces to serve as large-scale solar collectors, transforming currently passive building facades into power generation units.

[0004] Despite their significant advantages in concentrated photovoltaics (CPV), LSCs have yet to achieve widespread application due to a lack of suitable fluorophores. While organic dyes offer high quantum yields, they suffer from poor stability and a narrow solar absorption range. While conventional colloidal quantum dots (QDs) can improve the absorption range and stability, they still suffer from reabsorption losses. Furthermore, these QDs lack advantages in synthesis cost and environmental friendliness, making them unsuitable for industrial, large-scale synthesis.

[0005] In recent years, organic-inorganic hybrid metal halide materials have attracted much attention as another type of organometallic chromophore. Due to their excellent properties such as low toxicity, structural diversity, optical tunability and high quantum yield, they have broad application prospects in the replacement of quantum dot materials. The Sun Chun research group reported a non-toxic, highly luminescent (PEA) 4Cu4I4 ink based on copper (I)-halide hybrid clusters (ACS Appl. Mater. Interfaces, 2021, 13, 56348-56357), with a quantum yield (QY) of more than 68%, and the prepared LSC device has an internal quantum efficiency of up to 44.1%. This is the first report of the application of an organometallic halide system in the field of LSC, but this system still has disadvantages such as poor transparency of the concentrator device, low quantum yield and high cost. Summary of the Invention

[0006] The object of the present invention is to provide a Mn-based metal halide fluorescent solar concentrator device with high light transmittance and extremely low cost, and a preparation method thereof.

[0007] The technical solutions for achieving the purpose of the present invention are as follows:

[0008] A method for preparing a Mn-based metal halide fluorescent solar concentrator device comprises the following steps:

[0009] (1) In an air atmosphere, MnBr2, benzyltrimethylammonium bromide, and water are mixed at a molar ratio of benzyltrimethylammonium bromide to MnBr2 of 2:1, stirred thoroughly at room temperature, and filtered to remove impurities to obtain a transparent and clear mixed solution;

[0010] (2) adding polyethylene oxide (PEO) to the mixed solution of step (1) under air atmosphere and stirring thoroughly at room temperature to obtain a viscous translucent solution;

[0011] (3) The translucent solution obtained in step (2) is sequentially applied to a clean and hydrophobic transparent glass surface to prepare a fluorescent layer by scraping and spin coating. The spin coating process is carried out at an acceleration of 1000 r / min and a rotation speed of 1000 to 3000 rpm for 20 seconds, and then annealed at 80° C. for 2 hours to obtain a fluorescent solar concentrator device.

[0012] Preferably, in step (1), the Mn 2+ The concentration is 1 to 3 mol / L, more preferably 2 mol / L.

[0013] Preferably, in step (2), the mass fraction of PEO in the total mass of PEO, MnBr2 and benzyltrimethylammonium bromide is 4 wt%, and the molecular weight of PEO is 300,000.

[0014] Preferably, in step (2), the stirring time is more than 24 hours.

[0015] Preferably, in step (3), the transparent glass is electronic grade white glass.

[0016] Preferably, in step (3), the transparent glass with a clean and hydrophobic surface is subjected to the following treatment: the transparent glass is ultrasonically cleaned in clean water, deionized water, acetone and isopropyl alcohol for 15 minutes each, then blown dry with nitrogen, and then subjected to ultraviolet light irradiation for 20 minutes for hydrophobic treatment.

[0017] Preferably, in step (3), the coating thickness is greater than 500 μm, and the coating area completely covers the glass surface.

[0018] Preferably, in step (3), the rotation speed is 2000 rpm.

[0019] Compared with the prior art, the present invention has the following significant advantages:

[0020] 1) The present invention is prepared in an air environment at low temperature and normal pressure throughout the entire process, the process is simple and efficient, and large-area devices can be easily prepared;

[0021] 2) The reagents used in the present invention are extremely environmentally friendly and inexpensive, with costs far lower than those of existing technologies. From the perspective of process and cost, the present invention is highly suitable for industrial large-scale preparation;

[0022] 3) The concentrating device prepared by the present invention has an ultraviolet-visible light conversion efficiency of 73% and an effective edge emission efficiency of more than 50%, and has a very good light transmittance (~70%). BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the transmittance curve of the concentrator in Example 1.

[0024] Figure 2 This is a comparison curve of the effective and surface escape quantum yields of the concentrator edge in Example 1.

[0025] Figure 3 The photocurrent test involves the AM1.5G solar spectrum diagram and the perovskite cell EQE and concentrator absorption layer spectral band combination diagram.

[0026] Figure 4 This is a comparison curve of the photocurrent density of the perovskite cell in Example 1 with and without a fluorescent concentrator.

[0027] Figure 5 This is the transmittance curve of the concentrator in Example 2.

[0028] Figure 6 This is a comparison curve of the effective and surface escape quantum yields of the concentrator edge in Example 2.

[0029] Figure 7This is a comparison curve of the photocurrent density of the perovskite cell in Example 2 with and without a fluorescent concentrator.

[0030] Figure 8 This is the transmittance curve of the concentrator in Example 3.

[0031] Figure 9 This is a comparison curve of the effective and surface escape quantum yields of the concentrator edge in Example 3.

[0032] Figure 10 This is a comparison curve of the photocurrent density of the perovskite cell in Example 3 with and without a fluorescent concentrator.

[0033] Figure 11 This is a comparison curve of the effective and surface escape quantum yields of the concentrator edge in comparative example 2. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0035] The photovoltaic devices involved in the following comparative examples and embodiments are MAPbI3 solar cells, and the device external quantum efficiency (EQE) is as follows: Figure 3 As shown. The concentrator used in the test measures 1 cm long, 1 cm wide, and 0.2 cm high (thickness); the solar cell's active operating area is 1 cm long and 0.2 cm wide. Before testing, three sides of the concentrator's length x height are covered with tin foil, leaving one side's length x height and the upper and lower sides' length x width completely exposed. The exposed length x height surface of the concentrator is aligned perfectly with the solar cell's active operating area, and the concentrator and cell are secured together using tape as described above. The secured device's length x height surface, covered with the light-absorbing layer, is then placed directly opposite the light exit window of a solar simulator 10 cm away. The solar cell is connected to an external source meter (model: 2400). During testing, a standard AM1.5G simulated sunlight is emitted from the light source and directed directly onto the concentrator. The solar cell receives the light signal incident on the active area after conversion by the concentrator and converts it into an electrical signal. The electrical signal is collected and processed by the source meter to obtain the photocurrent density value of the photovoltaic module, thus completing the test.

[0036] Example 1

[0037] The preparation method of a Mn-based metal halide fluorescent solar concentrator device specifically comprises the following steps:

[0038] (1) An electronic grade white glass sheet was ultrasonically cleaned in clean water, deionized water, acetone, and isopropyl alcohol for 15 min each. A nitrogen gun was used to gently sweep the glass sheet to dry it. The glass sheet was irradiated with UV light for 20 min before use.

[0039] (2) In an air atmosphere, benzyltrimethylammonium bromide, MnBr2 and deionized water were mixed at a molar ratio of 2:1 to form Mn 2+ The mixed solution with a concentration of 2 mol / L was stirred thoroughly at room temperature and filtered to remove impurities to obtain a transparent and clear mixed solution;

[0040] (3) Add 4 wt% PEO to the transparent mixed solution and stir at room temperature for more than 24 h to obtain a viscous translucent solution.

[0041] (4) A 500 μm thick translucent solution was scraped onto the treated glass sheet. The scraped glass sheet was spin-coated at an acceleration of 1000 r / min and a rotation speed of 1000 rpm for 20 seconds, and then annealed at 80°C for 2 hours to obtain a fluorescent solar concentrator device.

[0042] The transmission curve of the fluorescent solar concentrator prepared in Example 1 is as follows: Figure 1 As shown, its effective edge emission efficiency is as follows Figure 2 As shown. The device transmittance is maintained at around 60%, the photoluminescence quantum yield is 93%, the edge effective quantum yield is 52%, and the device edge emission efficiency is 56%. Figure 4 , the photocurrent density ratio of perovskite solar cells with and without concentrators is 0.63.

[0043] Example 2

[0044] This embodiment is basically the same as embodiment 1, with the only difference being that in step (4): the coated glass sheet is spin-coated at an acceleration of 1000 r / min and a rotation speed of 2000 rpm for 20 seconds.

[0045] The transmission curve of the fluorescent solar concentrator prepared in Example 2 is as follows: Figure 5 As shown, its effective edge emission efficiency is as follows Figure 6 As shown. The device transmittance is maintained at around 70%, the photoluminescence quantum yield is 73%, the edge effective quantum yield is 45%, and the device edge emission efficiency is 62%. Figure 7 , the photocurrent density ratio of perovskite solar cells with and without concentrators is 0.66.

[0046] Example 3

[0047] This embodiment is basically the same as embodiment 1, with the only difference being that in step (4): the coated glass sheet is spin-coated at an acceleration of 1000 r / min and a rotation speed of 3000 rpm for 20 s.

[0048] The transmission curve of the fluorescent solar concentrator prepared in Example 3 is as follows: Figure 8As shown, its effective edge emission efficiency is as follows Figure 9 As shown. The device transmittance is maintained at around 80%, the photoluminescence quantum yield is 59%, the edge effective quantum yield is 42%, and the device edge emission efficiency is 71%. Figure 10 , the photocurrent density ratio of perovskite solar cells with and without concentrators is 0.40.

[0049] Comparative Example 1

[0050] This comparative example is basically the same as Example 1, except that step (3) is not performed.

[0051] The film quality of the light-absorbing layer of the fluorescent solar concentrator prepared in Comparative Example 1 was poor. Due to the high surface energy of deionized water, the solution shrank and coalesced into droplets in some areas after being doctor-bladed and spin-coated onto the glass. After annealing, the light-absorbing layer on the concentrator device did not completely cover the glass surface, and the thickness varied significantly across different areas of the surface.

[0052] Comparative Example 2

[0053] This comparative example is substantially the same as Example 3, except that tetramethylammonium bromide is used in place of benzyltrimethylammonium bromide in step (2).

[0054] The effective edge emission efficiency of the fluorescent solar concentrator prepared in Comparative Example 2 is as follows: Figure 11 The photoluminescence quantum yield is 58%, the edge effective quantum yield is 17%, and the device edge emission efficiency is 36%. These results indicate that the quantum yield and edge emission efficiency of the concentrator using tetramethylammonium bromide as an organic ligand are lower than those of the concentrator using benzyltrimethylammonium bromide as a coordination ligand.

Claims

1. A method for preparing a Mn-based metal halide fluorescent solar concentrator device, characterized in that: The steps include: (1) In an air atmosphere, MnBr2, benzyltrimethylammonium bromide, and water are mixed at a molar ratio of benzyltrimethylammonium bromide to MnBr2 of 2:1, stirred thoroughly at room temperature, and filtered to remove impurities to obtain a transparent and clear mixed solution; (2) Adding PEO to the mixed solution of step (1) under air atmosphere, stirring thoroughly at room temperature to obtain a viscous translucent solution; (3) The translucent solution obtained in step (2) is sequentially applied to a clean and hydrophobic transparent glass surface to prepare a fluorescent layer by scraping and spin coating. The spin coating process is carried out at an acceleration of 1000 r / min and a rotation speed of 1000 to 3000 rpm for 20 seconds, and then annealed at 80° C. for 2 hours to obtain a fluorescent solar concentrator device.

2. The preparation method according to claim 1, characterized in that In step (1), Mn in the mixed solution 2+ The concentration is 1~3mol / L.

3. The preparation method according to claim 1, characterized in that In step (1), Mn in the mixed solution 2+ The concentration is 2mol / L.

4. The preparation method according to claim 1, characterized in that In step (2), the mass fraction of PEO in the total mass of PEO, MnBr2 and benzyltrimethylammonium bromide is 4 wt%, and the molecular weight of PEO is 300,000.

5. The preparation method according to claim 1, characterized in that In step (2), the stirring time is more than 24 hours.

6. The preparation method according to claim 1, characterized in that In step (3), the transparent glass is electronic grade white glass.

7. The preparation method according to claim 1, characterized in that In step (3), the transparent glass with a clean and hydrophobic surface is subjected to the following treatment: the transparent glass is ultrasonically cleaned in clean water, deionized water, acetone and isopropyl alcohol for 15 minutes each, then blown dry with nitrogen, and then subjected to ultraviolet light irradiation for 20 minutes for hydrophobic treatment.

8. The preparation method according to claim 1, characterized in that In step (3), the coating thickness is greater than 500 μm, and the coating area completely covers the glass surface.

9. The preparation method according to claim 1, characterized in that In step (3), the rotation speed is 2000 rpm.

10. A fluorescent solar concentrator device prepared according to the preparation method according to any one of claims 1 to 9.

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