Method for collecting and generating electricity by ion-modified perovskite quantum dot film

Abstract

The application provides a method for collecting and generating electricity by ion-modified perovskite quantum dot film, and relates to the field of building integrated photovoltaics. By introducing calcium ions into the crystal lattice of perovskite quantum dots, local lattice distortion is triggered, and the strength of the chemical bond inside the perovskite quantum dots is significantly enhanced, thereby producing a phonon hardening phenomenon, reducing lattice thermal vibration, and significantly improving the thermal stability of the perovskite quantum dots, successfully realizing a solar light collector with high optical conversion efficiency and long-term environmental stability. The application provides a manufacturing and practical application scheme of a high-efficiency and low-cost perovskite solar light collector, aiming to realize efficient utilization of solar energy, and has important significance for realizing sustainable development of human society.

Description

Technical Field

[0001] This invention belongs to the field of building-integrated photovoltaics, specifically relating to a method for preparing a high-efficiency and stable solar collector using ion-modified perovskite quantum dot thin films. Background Technology

[0002] Solar energy, as a green and clean energy source, plays a crucial role in achieving sustainable development and the "dual carbon" goal by converting it into electricity using photovoltaic technology. Currently, monocrystalline silicon solar cells dominate the market, but they suffer from high cost, complex processes, and low solar radiation density. Therefore, fluorescent solar energy concentrators have been proposed, which can focus sunlight onto a small-area photovoltaic cell to achieve efficient photoelectric conversion. These concentrators are mainly composed of an optical waveguide medium and a fluorescent material. Perovskite, as a highly efficient fluorescent material, has great potential in solar energy concentrator applications. However, it is prone to fluorescence thermal quenching at high temperatures, severely limiting the practical application of perovskite solar energy concentrators. In this invention, we developed a calcium ion-modified perovskite quantum dot thin film to prepare a highly efficient and stable perovskite solar energy concentrator. The introduction of calcium ions enhances the strength of the internal chemical bonds of the perovskite quantum dots, producing a phonon blue shift, making the crystal structure more stable; at the same time, it can effectively passivate defects in the band gap, reduce lattice distortion, and weaken the electron-phonon coupling strength. This lattice stiffening, driven by both bond enhancement and defect elimination, effectively suppresses thermal vibrations, ultimately significantly improving the material's thermal stability. Therefore, we believe that ion modification strategies play a crucial role in enhancing the thermal stability of perovskite materials and provide a new pathway for the application of perovskite solar concentrators. Summary of the Invention

[0003] The purpose of this invention is to provide an ion-modified quantum dot polymer film for use in perovskite solar concentrators. The preparation method provided by this invention yields perovskite solar concentrators with high thermal stability and high optical conversion efficiency.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing ion-modified perovskite quantum dot thin films, the steps of which are as follows:

[0006] (1) Formamidin acetate, lead bromide, and ammonium bromide were used as perovskite precursors, and N,N-dimethyl-N-(3-sulfopropyl)-1-octadecaneammonium inner salt was used as a ligand. They were dissolved together with the polymer polyvinylidene fluoride in N,N-dimethylformamide to obtain a precursor solution.

[0007] (2) Calcium bromide was added to the solution in step (1) to obtain a calcium ion modified precursor solution;

[0008] (3) The solution in step (2) is coated and dried to obtain a calcium ion modified perovskite polymer film.

[0009] Furthermore, the drying conditions in step (3) are room temperature vacuum drying.

[0010] Furthermore, the drying time in step (3) is 2 hours.

[0011] The present invention also utilizes the ion-modified perovskite polymer film obtained by the above preparation method to prepare a perovskite solar energy collector.

[0012] Furthermore, the device structure is a glass substrate / calcium ion modified perovskite quantum dot thin film light-emitting layer / polyethylene terephthalate protective layer.

[0013] Advantages and positive effects of the present invention

[0014] This invention employs an ion modification strategy to successfully prepare a perovskite quantum dot thin film with good thermal stability, resulting in a high-efficiency, long-term stable perovskite solar concentrator. This invention demonstrates the role of ion modification in improving the thermal stability of perovskite quantum dots, broadening the application of perovskite materials in solar concentrators. This invention has the advantages of simple process and high operability, providing a new and feasible solution for the further development and performance optimization of solar concentrator technology. Attached Figure Description

[0015] Figure 1 These are the XRD patterns of Example 1 and Comparative Example 1 in this invention;

[0016] Figure 2 The ultraviolet absorption spectrum and fluorescence spectrum of Example 1 and Comparative Example 1 in this invention;

[0017] Figure 3 Fluorescence lifetime decay curves of Example 1 and Comparative Example 1 in this invention;

[0018] Figure 4 This is a graph showing the normalized fluorescence intensity values ​​as a function of temperature for Example 1 and Comparative Example 1 in this invention.

[0019] Figure 5 This is a graph showing the change in normalized fluorescence intensity values ​​after 1700 hours of storage in an outdoor environment with a maximum temperature of 38°C and a maximum humidity of 78% in Example 1 of this invention.

[0020] Figure 6 This is a four-sided emission pattern of the solar energy collecting device prepared in Example 2 of this invention;

[0021] Figure 7This is a current-voltage curve of the solar collector device prepared in Example 2 of this invention before and after coupling with a silicon cell;

[0022] Figure 8 The graph shows the normalized optical conversion efficiency values ​​as a function of temperature for the solar concentrator prepared in Example 2 and the luminous solar concentrator prepared in Comparative Example 2 of this invention. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0024] Example 1

[0025] (1) Weigh 0.02 mmol of formamidin acetate (0.0021 g), lead bromide (0.0073 g), ammonium bromide (0.0019 g), 0.002 mmol of N,N-dimethyl-N-(3-sulfopropyl)-1-octadecaneammonium inner salt (0.0008 g), 0.0005 mmol of calcium bromide (0.0001 g) and 0.168 g of polyvinylidene fluoride (PVDF) and dissolve them in 1 mL of N,N-dimethylformamide to obtain a precursor solution;

[0026] (2) The precursor solution was coated onto a clean glass substrate of 25 mm × 25 mm × 1 mm and dried under vacuum at room temperature for 2 h to obtain a calcium ion modified perovskite quantum dot film.

[0027] Example 2

[0028] The precursor solution from Example 1 was scraped onto a clean polyethylene terephthalate film. After vacuum drying at room temperature for 2 hours, one side of the perovskite quantum dot film was adhered to a clean glass substrate of 50 mm × 50 mm × 2 mm using a photocurable adhesive to obtain a calcium ion modified perovskite quantum dot solar collector.

[0029] Comparative Example 1

[0030] The difference between Comparative Example 1 and Example 1 is that step (1) is different:

[0031] (1) Weigh 0.02 mmol of formamidin acetate (0.0021 g), lead bromide (0.0073 g), ammonium bromide (0.0019 g), 0.002 mmol of N,N-dimethyl-N-(3-sulfopropyl)-1-octadecaneammonium inner salt (0.0008 g) and 0.168 g of polyvinylidene fluoride (PVDF) and dissolve them in 1 mL of N,N-dimethylformamide to obtain a precursor solution.

[0032] Comparative Example 2

[0033] The difference between Comparative Example 2 and Example 2 is that the precursor solution from Comparative Example 1 was used to prepare an unmodified perovskite solar collector.

[0034] Performance testing

[0035] XRD test

[0036] (The instruments used were XRD; PANalytical BV, X'Pert-PRO MPD diffractometer, Holland)

[0037] The XRD patterns of Example 1 and Comparative Example 1 are shown below. Figure 1 .

[0038] Ultraviolet absorption spectroscopy test

[0039] (The instrument used was a UV-vis Agilent Cary 5000 spectrophotometer, USA.)

[0040] Fluorescence spectroscopy test

[0041] (The instrument used was a QEPro spectrometer, Ocean Optics, America)

[0042] Fluorescence lifetime test

[0043] (The instrument used was a TR-PL; Edinburgh, FLS1000, UK, equipped with a 375 nm pulsed laser.)

[0044] The UV absorption and fluorescence spectra of Example 1 and Comparative Example 1 are shown in the figure. Figure 2 .

[0045] The fluorescence lifetime decay curves of Example 1 and Comparative Example 1 are shown in Figure 1. Figure 3 .

[0046] The normalized fluorescence intensity values ​​of PQDs-PVDF in Example 1 and Comparative Example 1 as a function of temperature are shown in the figure. Figure 4 .

[0047] The changes in normalized fluorescence intensity values ​​after 1700 hours of storage in an outdoor environment with a maximum temperature of 38°C and a maximum humidity of 78% in Example 1 are shown below. Figure 5 .

[0048] Performance testing of light-emitting solar collector devices

[0049] A digital source meter (Keithley 2450, Tektronix) was used under AM 1.5G illumination (100 mW cm⁻¹). -2The current-voltage characteristics of the luminescent solar collector device were measured using an LED solar simulator (SLS-LED-L100, Sollar). The solar simulator's light intensity was calibrated using a standard silicon solar cell certified by the National Renewable Energy Laboratory (NREL).

[0050] The circumferential emission pattern of the solar collector device prepared in Example 2 is shown below. Figure 6 ;

[0051] The current-voltage curves of the solar collector device prepared in Example 2 before and after coupling with the silicon cell are shown below. Figure 7 ;

[0052] The normalized optical conversion efficiency values ​​of the solar concentrator prepared in Example 2 and the luminous solar concentrator prepared in Comparative Example 2 as a function of temperature are shown below. Figure 8 .

[0053] from Figure 1 The XRD pattern shows diffraction peaks at 14.7°, 20.6°, 29.7°, and 33.4°, corresponding to the (001), (110), (002), and (012) crystal planes of cubic FAPbBr3, respectively. This indicates that the perovskite crystals synthesized in Example 1 and Comparative Example 1 are FAPbBr3 quantum dots.

[0054] from Figure 2 In the ultraviolet absorption and fluorescence spectra, the absorption band edge of Example 1 and Comparative Example 1 can be observed at 543 nm, and the fluorescence peak is located at 530 nm, which is green light emission.

[0055] from Figure 3 The fluorescence lifetime decay curves show that the fluorescence lifetimes of Example 1 and Comparative Example 1 are 53.69 ns and 59.14 ns, respectively.

[0056] Figure 4 In Example 1, the fluorescence intensity values ​​at 303 K, 313 K, 323 K, 333 K, 343 K, and 353 K were 100%, 98%, 95%, 92%, 88%, and 83%, respectively; in Comparative Example 1, the fluorescence intensity values ​​at 303 K, 313 K, 323 K, 333 K, 343 K, and 353 K were 100%, 94%, 86%, 78%, 67%, and 53%, respectively. Figure 4 The graph showing the change in fluorescence intensity with temperature indicates that Example 1 has stronger thermal stability compared to Comparative Example 1.

[0057] Figure 5Example 1 showed that after being stored in an outdoor environment with a maximum temperature of 38°C and a maximum humidity of 78% for 1700 hours, the fluorescence value was 80% of the initial value, indicating strong environmental stability.

[0058] from Figure 6 In the emission diagram, it can be observed that Example 2 emits fluorescence from the edge of the glass substrate under ultraviolet light excitation.

[0059] Figure 7 The maximum optical conversion efficiency of Example 2 can reach 7%.

[0060] Figure 8 The optical conversion efficiency values ​​of Example 2 at 303 K, 313 K, 323 K, 333 K, 343 K, and 353 K were 100%, 96%, 92%, 91%, 87%, and 83%, respectively; the optical conversion efficiency values ​​of Comparative Example 2 at 303 K, 313 K, 323 K, 333 K, 343 K, and 353 K were 100%, 93%, 88%, 82%, 76%, and 72%, respectively. Figure 8 The graph showing the change in optical conversion efficiency intensity value with temperature indicates that Example 2 has stronger thermal stability compared to Comparative Example 2.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing ion-modified perovskite quantum dot thin films, characterized in that, Includes the following steps: (1) Using formamidine acetate, lead bromide, and ammonium bromide as perovskite raw materials, and N,N-dimethyl-N-(3-sulfopropyl)-1-octadecaneammonium inner salt as ligand, the precursor solution was obtained by dissolving polyvinylidene fluoride together with N,N-dimethylformamide. (2) Calcium bromide is added to the solution in step (1) to obtain a calcium ion modified precursor solution; (3) The precursor solution in step (2) is coated and dried to obtain a calcium ion modified perovskite polymer film.

2. The preparation method according to claim 1, characterized in that, In step (2), the molar ratio of calcium bromide to perovskite raw material is 0.025:

1.

3. The preparation method according to claim 1, characterized in that, The drying conditions in step (3) are room temperature vacuum drying.

4. The preparation method according to claim 1, characterized in that, The drying time in step (3) is 2 hours.

5. A light-emitting solar energy concentrator device, characterized in that, Calcium-ion modified perovskite quantum dot films were used as the light-emitting layer.

6. The light-emitting solar collector according to claim 5, characterized in that, A solar energy collecting device with a structure of glass substrate / calcium ion modified perovskite quantum dot thin film light-emitting layer / polyethylene terephthalate protective layer was designed.

7. The light-emitting solar collector according to claim 5, characterized in that, The perovskite quantum dot film achieved a fluorescence quantum yield of 95%; maintained 83% luminescence intensity at 353 K; retained 80% luminescence intensity after 1700 h of outdoor storage; and realized a solar energy collector with an optical conversion efficiency of 6.9% on a 50 mm × 50 mm × 2 mm glass substrate.

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