A luminescent solar concentrator with photovoltaic and dimming functions and a preparation method thereof

Abstract

The application discloses a bifunctional luminescent solar concentrator with photovoltaic and dimming functions and a preparation method thereof. The bifunctional luminescent solar concentrator is a layered structure and is prepared by blade coating a thermochromic layer on a glass substrate. Under the action of N,N-dimethylformamide gas, the thermochromic layer of the bifunctional luminescent solar concentrator can reversibly change between the bleached state and the colored state at room temperature, thereby realizing the transmittance adjustment of incident sunlight. Meanwhile, the thermochromic layer of the bifunctional luminescent solar concentrator has strong luminescence when in the colored state, and the PLQY can reach 49%, and the bifunctional luminescent solar concentrator has good photovoltaic performance, and can be coupled with a solar cell at the edge to realize photoelectric conversion. The application realizes the bifunctional luminescent solar concentrator which can be integrated into the photovoltaic and dimming functions of a building glass, can regulate the fluorescence and the transmittance of sunlight, and realizes the functions of photovoltaic and dimming.

Description

TECHNICAL FIELD

[0001] The present application relates to a bifunctional luminescent solar concentrator with photovoltaic and dimming functions and a preparation method thereof, and belongs to the field of optoelectronic devices. BACKGROUND

[0002] Modern building energy consumption accounts for more than 40% of the total global energy consumption, among which windows are considered to be the largest energy consumption component in buildings. Traditional glass windows lack dynamic regulation ability for solar radiation spectrum, and cannot balance the contradiction between indoor lighting demand and thermal management. Therefore, in order to reduce energy consumption without sacrificing thermal comfort, it is crucial to develop intelligent windows. Intelligent windows are made of optical materials and glass substrates, which can spontaneously change transparency or color according to external stimuli such as electricity, heat, light and changes in chemical environment, thereby achieving extensive control of solar radiation into the room. Among them, thermochromic materials can automatically adjust the solar transmittance in response to changes in environmental temperature, which has considerable application potential. Current thermochromic material systems mainly include vanadium dioxide, hydrogel and ionic liquid, etc. However, these materials generally have low visible light transmittance and high preparation cost.

[0003] In recent years, thermochromic perovskite materials have a wide application prospect in the field of thermochromic intelligent windows due to their excellent light transmittance and dimming ability, as well as simpler production process compared to other materials. At the same time, a luminescent solar concentrator is a large-area, optically transparent photoelectric conversion device that can absorb front incident sunlight and concentrate and transmit the generated fluorescence to the side through a transparent waveguide medium, and finally convert the sunlight into electrical energy through a side-coupled photovoltaic device.

[0004] Compared with opaque silicon solar cells, luminescent solar concentrators not only can realize photoelectric conversion while ensuring indoor lighting, but also do not have the thermal spot effect that seriously affects the performance of silicon solar cells, so they can be integrated with thermochromic intelligent windows, while meeting the needs of indoor lighting and photoelectric energy regeneration.

[0005] At present, there is no relevant design or production case for such bifunctional photovoltaic devices with integrated photovoltaic and dimming functions. SUMMARY

[0006] The purpose of the present application is to provide a bifunctional luminescent solar concentrator with photovoltaic and dimming functions and a preparation method thereof, so as to regulate its fluorescence and solar transmittance under the action of N,N-dimethylformamide gas.

[0007] To achieve the above purpose, the technical scheme adopted by the present application is as follows: a preparation method of a bifunctional luminescent solar concentrator with photovoltaic and dimming functions, comprising the following steps:

[0008] Step (1) dissolving raw materials containing methyl amine iodide MAI, lead iodide PbI2 and octyl amine iodide OAI in N, N-dimethylformamide in a container, obtaining a transparent perovskite precursor solution after the raw materials are completely dissolved;

[0009] Step (2) adding polyvinylidene fluoride PVDF powder into the transparent perovskite precursor solution obtained in step (1), forming a perovskite precursor-polymer slurry after heating and stirring;

[0010] Step (3) scraping the perovskite precursor-polymer slurry obtained in step (2) on a glass substrate to form a uniform perovskite precursor-polymer liquid film;

[0011] Step (4) performing vacuum low-temperature drying treatment on the perovskite precursor-polymer liquid film obtained in step (3) to remove the solvent;

[0012] Step (5) heating the film obtained in step (4) at a high temperature to generate perovskite in situ in the polymer matrix, obtaining a luminescent solar concentrator with photovoltaic and dimming functions.

[0013] As a preferred mode of the present application, in step (1), the molar ratio of methyl amine iodide MAI, lead iodide PbI2 and octyl amine iodide OAI is 0.8 ~ 1:0.8:0.6, and the concentration of N, N-dimethylformamide is 0.08 ~ 0.1 mol / L.

[0014] As a preferred mode of the present application, in step (1), the raw materials are dissolved in an ultrasonic cleaner for 3 ~ 5 minutes continuously.

[0015] As a preferred mode of the present application, in step (2), the solvent of the perovskite precursor-polymer slurry is N, N-dimethylformamide, the polymer concentration is 0.09 ~ 0.1 g / mL, the heating temperature during stirring is 55 ~ 60℃, and the continuous stirring time is 6 ~ 12 h.

[0016] As a preferred mode of the present application, in step (3), the perovskite precursor-polymer liquid film is prepared by scraping, and the scraping height is 80 ~ 100 μm.

[0017] As a preferred mode of the present application, in step (4), the perovskite precursor-polymer liquid film is dried by vacuum heating, the heating temperature is 55 ~ 60℃, and the heating time is 5 ~ 10 min.

[0018] As a preferred mode of the present application, in step (5), the heating temperature of the perovskite-polymer composite thin film is 130-140 DEG C, and the heating time is 2-3 min.

[0019] The application also provides a luminescent solar concentrator with photovoltaic and dimming functions, which is a layered structure and is prepared by the preparation method; under the action of N,N-dimethylformamide gas, the thermochromic layer of the bifunctional luminescent solar concentrator can reversibly change between the bleached state and the colored state at room temperature, so that the transmittance of incident sunlight is adjusted; the thermochromic layer of the bifunctional luminescent solar concentrator emits light strongly when in the colored state, and the PLQY can reach 49 %, so that the luminescent solar concentrator has good photovoltaic performance, and a solar cell can be coupled at the edge of the luminescent solar concentrator to perform photoelectric conversion.

[0020] The bleached state is the thermochromic layer of the bifunctional luminescent solar concentrator in a non-fluorescent emission state.

[0021] The colored state is the thermochromic layer of the bifunctional luminescent solar concentrator in a strong fluorescent emission state, and the PLQY is 49 %.

[0022] Compared with the prior art, the luminescent solar concentrator has the following beneficial effects:

[0023] (1) simple operation, high material utilization rate, small dependence on equipment, and short preparation period;

[0024] (2) high optical transmittance, which can ensure indoor lighting;

[0025] (3) the luminescent solar concentrator solves the problem of weak light emission in the colored state of the existing thermochromic layer, and the PLQY of the thermochromic layer in the luminescent state can reach 49 %;

[0026] (4) the thermochromic layer in the application can reversibly change between the bleached state and the colored state at room temperature under the action of N,N-dimethylformamide gas;

[0027] (5) the reversible change between the bleached state and the colored state of the thermochromic layer in the application has good cycle performance;

[0028] (6) the luminescent solar concentrator has excellent environmental stability and can be applied to high-humidity environments and rainy days;

[0029] (7) the luminescent solar concentrator has both photovoltaic and dimming functions, and the two functions are compatible. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 PLE and PL spectra of the perovskite-polymer composite thin film in Example 1.

[0031] Figure 2 Figure 1 is a PLQY graph of the perovskite-polymer composite thin film in Example 1.

[0032] Figure 3 Figure 2 is a transmittance spectrum comparison graph of the perovskite-polymer composite thin film in Example 2 in the colored state and the bleached state, respectively.

[0033] Figure 4 Figure 3 is a PL spectrum comparison graph of the perovskite-polymer composite thin film in Example 2 in the colored state and the bleached state, respectively.

[0034] Figure 5 Figure 4 is a PL spectrum of the perovskite-polymer composite thin film in Example 2 in the colored state under multiple colored state and bleached state reversible transition cycles.

[0035] Figure 6 Figure 5 is a current-voltage curve graph of the perovskite-polymer composite thin film in Example 2 in the colored state and the bleached state, respectively. DETAILED DESCRIPTION

[0036] The present application will be further explained in conjunction with the embodiments and the accompanying drawings, and the following examples are only used to illustrate the present application, but not to limit the scope of the present application.

[0037] Example 1

[0038] (1) Preparation of perovskite precursor solution: methylammonium iodide MAI, lead iodide PbI2 and octylammonium iodide OAI were added to 10 mL N,N-dimethylformamide according to the molar ratio of MAI: PbI2: OAI = 1.0: 0.8: 0.6, and were ultrasonically dispersed and dissolved.

[0039] (2) Preparation of perovskite-polymer composite thin film: 1 g of polyvinylidene fluoride PVDF powder was added to the perovskite precursor solution in step (1), and the mixture was fully stirred and dissolved in a 60 °C oil bath to form a viscous perovskite precursor-polymer slurry.

[0040] (3) The perovskite precursor-polymer slurry was blade-coated on a glass substrate with a blade-coating height parameter of 100 μm, and the glass substrate size was 10*10*0.2 cm 3 ; a uniform perovskite precursor-polymer liquid thin film was formed.

[0041] (4) The glass substrate coated with the liquid thin film was dried at 60 °C under vacuum for 5 min to remove the solvent.

[0042] (5) The perovskite-polymer composite film (MAPbI3@PVDF film) is obtained by heating at 140 °C for 3 min.

[0043] The film is cooled and placed for standby, and then PLE, PL, and PLQY tests are performed.

[0044] Figure 1 The PLE and PL spectra of the perovskite-polymer composite film prepared by doctor blading are shown. The optimal excitation peak of the perovskite-polymer composite film is located near 470 nm, and the emission peak is located near 618 nm.

[0045] Figure 2 The PLQY graph of the perovskite-polymer composite film prepared by doctor blading is shown. The emission center of the perovskite-polymer composite film is located near 690 nm, and it exhibits a fluorescence quantum yield of 48.76%, indicating that the film has good photovoltaic performance and can be applied to building-integrated photovoltaics.

[0046] Example 2

[0047] (1) Perovskite precursor solution preparation: Methylammonium iodide MAI, lead iodide PbI2, and octylammonium iodide OAI are added to 10 mL of N,N-dimethylformamide in a molar ratio of MAI:PbI2:OAI = 1.0:0.8:0.6, ultrasonically dispersed and dissolved.

[0048] (2) Perovskite-polymer composite film preparation: 1 g of polyvinylidene fluoride PVDF powder is added to the perovskite precursor solution in step (1), and the mixture is fully stirred and dissolved in a 60 °C oil bath, forming a viscous perovskite precursor-polymer slurry. The perovskite precursor-polymer slurry is doctor bladed onto a glass substrate with a doctor blading height parameter of 100 μm, and the glass substrate size is 10*10*0.2 cm 3 . The glass substrate coated with the liquid film is dried and heated at 60 °C for 5 min, and then a perovskite-polymer composite film (MAPbI3@PVDF film) is obtained by heating at 140 °C for 3 min.

[0049] (3) Transition from colored to bleached state of perovskite-polymer composite film: The perovskite-polymer composite film from step (2) was placed in a sealed space filled with N,N-dimethylformamide. The perovskite-polymer composite film will transition from the colored state to the bleached state, and the fluorescence of the perovskite-polymer composite film will completely disappear. The perovskite-polymer composite film in the bleached state was placed on a constant temperature heating stage and heated to 30 °C. The perovskite-polymer composite film will then transition back from the bleached state to the colored state, and the fluorescence will be restored. Transmission spectroscopy, photoluminescence (PL) testing, and cycle life testing were performed on the perovskite-polymer composite films in the colored and bleached states, respectively. Current-voltage testing was also performed on the silicon solar cell coupled to the glass substrate side of the perovskite-polymer composite film.

[0050] Figure 3 The transmission spectra of the perovskite-polymer composite films in their colored and bleached states are shown. The average visible light transmittance of the colored perovskite-polymer composite film is 63.83%, while that of the bleached state is 73.73%. The increased visible light transmittance compared to the colored state indicates that the film described in this invention can achieve dimming functionality. Furthermore, both the colored and bleached states of the perovskite-polymer composite film exhibit good average visible light transmittance, demonstrating that the film possesses excellent light transmittance and can achieve photoelectric conversion while ensuring adequate indoor lighting.

[0051] Figure 4 The photoluminescence (PL) spectra of the perovskite-polymer composite films in their colored and bleached states are shown. The colored state of the perovskite-polymer composite film exhibits a fluorescence emission peak near 618 nm, while the bleached state shows no fluorescence emission.

[0052] Figure 5 The photoluminescence (PL) spectra of the perovskite-polymer composite film in the colored state are shown after multiple reversible transformation cycles between the colored and bleached states. Notably, after 20 cycles, the position and intensity of the PL peak in the colored state of the perovskite-polymer composite film did not change significantly, indicating that the film described in this invention exhibits good cyclicity in its reversible transformation between the bleached and colored states.

[0053] Figure 6 The current-voltage curves of the perovskite-polymer composite film in its colored and bleached states are shown. The energy conversion efficiency of the perovskite-polymer composite film in the bleached state is 0.4860%, while that in the colored state is 0.7692%, significantly higher than that in the bleached state, indicating that the film described in this invention possesses certain photovoltaic functionality.

[0054] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for preparing a light-emitting solar concentrator that combines photovoltaic and dimming functions, characterized in that: Includes the following steps: Step (1) Dissolve the raw material containing methyl iodide (MAI), lead iodide (PbI2) and octyl iodide (OAI) in N,N-dimethylformamide in a container. After the raw material is completely dissolved, a transparent perovskite precursor solution is obtained. Step (2) Add polyvinylidene fluoride (PVDF) powder to the transparent perovskite precursor solution obtained in step (1), and heat and stir to form a perovskite precursor-polymer slurry; Step (3) The perovskite precursor-polymer slurry obtained in step (2) is coated onto a glass substrate to form a uniform perovskite precursor-polymer liquid film. Step (4) The perovskite precursor-polymer liquid film obtained in step (3) is subjected to vacuum low-temperature drying to remove the solvent; Step (5) The thin film obtained in step (4) is heated at high temperature to generate perovskite in situ in the polymer matrix, thereby obtaining a light-emitting solar concentrator that combines photovoltaic and dimming functions. In step (1), the molar ratio of methylamine iodide (MAI), lead iodide (PbI2), and octylamine iodide (OAI) is (0.8 ~ 1): 0.8: 0.6, and the concentration of N,N-dimethylformamide is 0.08 ~ 0.1 mol / L; In step (1), when the raw material is dissolved, it is continuously ultrasonicated in an ultrasonic cleaner for 3 to 5 minutes. In step (2), the solvent for the perovskite precursor-polymer slurry is N,N-dimethylformamide, the polymer concentration is 0.09 ~ 0.1 g / mL, the heating temperature during the stirring process is 55 ~ 60 ℃, and the continuous stirring time is 6 ~ 12 h; In step (5), the heating temperature of the perovskite-polymer composite film is 130 ~ 140 ℃, and the heating time is 2 ~ 3 min.

2. The method for preparing a photovoltaic and dimming solar concentrator according to claim 1, characterized in that: In step (3), a perovskite precursor-polymer liquid film is prepared by a blade coating method, with a coating height of 80 ~ 100 μm.

3. The method for preparing a photovoltaic and dimming solar concentrator according to claim 1, characterized in that: In step (4), the perovskite precursor-polymer liquid film is dried by vacuum heating at a temperature of 55-60°C for 5-10 minutes.

4. A light-emitting solar concentrator that combines photovoltaic and dimming functions, characterized in that: It was prepared using the preparation method described in any one of claims 1-3.

5. A photovoltaic and dimming solar concentrator according to claim 4, characterized in that: The concentrator has a layered structure, including a glass substrate and a thermochromic layer covering the glass substrate.

6. A photovoltaic and dimming solar concentrator according to claim 5, characterized in that: The thermochromic layer can undergo reversible transitions between a bleached state and a colored state at room temperature; the bleached state is the thermochromic layer of a dual-function light-emitting solar concentrator in a state of no fluorescence emission; the colored state is the thermochromic layer of a dual-function light-emitting solar concentrator in a state of strong fluorescence emission, at which point PLQY is 49%.

Images