Eu for uv protection of polymer solar cells 3+ / Tb 3+ Doped diatomaceous shell coating and method

Abstract

The application discloses a kind of for polymer solar cell anti-ultraviolet Eu 3+ / Tb 3+ Doped diatom shell coating and method, Eu 3+ / Tb 3+ As the main component of absorption and conversion of ultraviolet is doped into diatom shell, and then the Eu 3+ / Tb 3+ A flexible light-emitting film is obtained by mixing cellulose acetate CA in a certain proportion, and a small amount of organic auxiliary agent is further added in the flexible light-emitting film to balance the ultraviolet absorption range, so that the ultraviolet absorption capacity in the range of 200-400 nm can be balancedly improved. The battery efficiency of the ETDS@CA coating is obviously improved compared with the efficiency of the battery without the coating, which is due to the fact that the ETDS@CA does not destroy the internal structure of the battery, but also enhances the incident light, improves the short-circuit current density, and further improves the battery efficiency.

Description

Technical Field

[0001] This invention relates to the field of cross-application of hybrid luminescent materials and polymer solar cells, and particularly to an Eu luminescent material for UV protection in polymer solar cells. 3+ / Tb 3+ Doped diatom shell coating and its preparation method. Background Technology

[0002] Currently, ultraviolet (UV) radiation accounts for 1-5% of sunlight, making it the most dangerous component of radiation. Furthermore, UV radiation can cause sunburn, premature skin aging, skin cancer, and other human diseases. UV radiation is also a major cause of degradation in the active layer of photovoltaic devices. It can also induce photolysis, photo-oxidation, and thermal oxidation of polymers, leading to material degradation and even affecting the performance of photovoltaic equipment. my country has abundant and inexpensive rare earth resources, and lanthanide ions possess unique electrical, magnetic, and optical properties (such as absorbing UV light and emitting visible light, UV protection capabilities, high fluorescence intensity, long lifetime, and tunable spectral wavelength). Summary of the Invention

[0003] This invention addresses the shortcomings of existing technologies by providing an Eu-based UV protection solution for polymer solar cells. 3+ / Tb 3 + Diatomaceous earth coating and method thereof.

[0004] The technical solution of this invention is as follows:

[0005] Eu for UV protection in polymer solar cells 3+ / Tb 3+ Preparation method of doped diatom shell coating, Eb 3+ / Tb 3+ A flexible light-emitting film is prepared by incorporating diatomaceous earth into the porous structure of diatomaceous earth and then incorporating it into cellulose acetate in a certain proportion. Organic additives are added to obtain a flexible light-emitting film with a uniform ultraviolet absorption range and high ultraviolet absorption intensity. This film is then spin-coated onto the back of a polymer solar cell. By absorbing and converting ultraviolet light into light useful to the battery, the film enhances the ultraviolet protection effect, thereby improving the battery efficiency and lifespan.

[0006] The preparation method specifically includes the following steps:

[0007] Step 1, Selection of diatom shells: Weke's seaweed was selected and cultured in F / 2 medium;

[0008] Step 2, preparation of hybrid luminescent material: the cultured frustules are centrifuged and taken out in ethanol solution, then EuCl3 is added and placed in a constant temperature oscillator for 2 hours per day for 7 days, after centrifugal drying, TbCl3 ethanol solution is added, and the constant temperature oscillator is used for 2 hours per day for 7 days, and the hybrid luminescent material is obtained after centrifugal drying, which is abbreviated as "ETDS";

[0009] Step 3, preparation of luminescent flexible film: the obtained hybrid luminescent material ETDS is mixed with cellulose acetate dissolved in DMF at a certain proportion, and an organic auxiliary agent is added, and the mixture is reacted at 70-90 DEG C for 1 hour, and then the luminescent flexible film is obtained by spin coating on a glass mold, which is abbreviated as "ETDS@CA";

[0010] Step 4, preparation of luminescent flexible film for polymer solar cell device: the prepared luminescent flexible film is coated on the back of the prepared polymer solar cell by spin coating, and annealing heat treatment is carried out at 60-80 DEG C for 5-10 minutes, and then the polymer solar cell coated with ETDS@CA is obtained.

[0011] In step 1 of the preparation method, the frustules of Willea marina are selected and placed in F / 2 culture medium for 14 days of culture.

[0012] In step 2 of the preparation method, the concentration ratio of EuCl3 to TbCl3 is 1:3, and the frustule DS solution is prepared according to the proportion of 100 mg in 60 ml ethanol solution.

[0013] In step 3 of the preparation method, 2g of cellulose acetate is dissolved in 30ml of DMF solution to prepare a cellulose acetate solution, and the mass fraction of ETDS in cellulose acetate is 0.1-0.6wt%.

[0014] In step 3 of the preparation method, the organic auxiliary agent is selected from salicyl ester phenyl ester, 2,4-dihydroxybenzophenone, phosphite, hexamethylphosphoramide, 2-hydroxy-4-methoxybenzophenone, and the amount is 0.2-1% of the mass of ETDS.

[0015] The Eu 3+ / Tb 3+ doped frustule coating.

[0016] The Eu 3+ / Tb 3+Doped into diatomite DS, by digital oscillator "soaking" way, method is simple and efficient, and then it is doped into the polar polymer easy processing cellulose acetate, the polar hydroxyl group on the surface of DS can be better dissolved and dispersed in cellulose acetate, Eu 3+ / Tb 3+ The ultraviolet absorption range is 200-350nm, and a small amount of organic auxiliary salicylate phenyl ester is added to make up and improve the ultraviolet absorption spectrum and ultraviolet absorption intensity of 350-370nm. The flexible light-emitting film finally obtained has balanced ultraviolet absorption of more than 80% in the range of 200-400nm, and more than 85% in the respective specific range. Spinning the film on the back of the polymer solar cell can absorb ultraviolet rays to prolong the service life of the cell, and convert ultraviolet rays into visible light useful to the cell to further improve the service life of the cell. The effect of relieving the degradation and aging of the device is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Eu 3+ / Tb 3+ -DS excitation intensity

[0018] Figure 2 Eu 3+ / Tb 3+ SEM image of doped DS

[0019] Figure 3 UV absorption image of ETDS

[0020] Figure 4 UV absorption image of ETDS@CA

[0021] Figure 5 PM6 and IT4F normalized curves

[0022] Figure 6 Internal conversion layer introduction device internal structure schematic diagram

[0023] Figure 7 External conversion layer ETDS@CA introduction device external structure schematic diagram

[0024] Figure 8 ETDS@CA doped solar cell back and reference solar cell J-V curve diagram DETAILED DESCRIPTION

[0025] The present application will be described in detail below in combination with specific embodiments.

[0026] Example 1: Selection of diatomite

[0027] (1) The experiment selected the diatom frustule of Stephanopyxis willei as the matrix, and the diatom frustule of Stephanopyxis willei was placed in F / 2 medium, and then was placed in a cold light source incubator at 25°C for 14 days. 100 ml of the suspension after 14 days of culture was centrifuged at 4000 rpm for 5 min. After centrifugation, the supernatant was poured out. Then the diatom frustule was washed with phosphate buffer solution at 3000 rpm for 4 times to remove impurities on the diatom frustule, and then was washed with distilled water for 5 times. Then the dried diatom frustule (DS) was collected in a drying box at 70°C.

[0028] Example Two: Preparation of Hybrid Luminescent Material

[0029] (1) 100 mg of the dried diatom frustule was taken out and placed in 60 ml of ethanol solution, and 1 ml of EuCl3 with a concentration of 0.01 mol / L was added. It was placed in a digital constant temperature oscillator, and the digital constant temperature oscillator was adjusted to 30 min timing, and was shaken evenly for 2 hours every day for 7 consecutive days. The supernatant of the sample shaken for 7 days was taken out by centrifugation, and the remaining Eu 3+ -DS was dried at 90°C to obtain Eb 3+ -DS.

[0030] (2) 30 mg of dried Eu 3+ -DS was taken out and added to 3 groups of 60 ml of ethanol solution containing 1 ml of Tbcl3 with concentrations of 0.01 mol / L, 0.02 mol / L and 0.03 mol / L respectively. The three groups were placed in a digital constant temperature oscillator, and the digital constant temperature oscillator was adjusted to 30 min timing, and was shaken evenly for 2 hours every day for 7 consecutive days. The supernatant of the three groups of samples shaken for 7 days was taken out by centrifugation, and the remaining three groups of Eu 3+ / Tb 3+ -DS was centrifuged and dried at 90°C. Finally, the hybrid luminescent material Eu 3+ / Tb 3+ -DS, abbreviated as "ETDS" was obtained by centrifugal drying. The concentration ratios of the three groups of samples Eu 3+ : Tb 3+ were 1:1, 1:2 and 1:3 respectively. After performance characterization, it was found that the performance of Eu 3+ : Tb 3+ with a concentration ratio of 1:3 was the best. As Figure 1 Eu 3+ / Tb 3+ -DS with different ratios of excitation intensity, the excitation intensity of Eu 3+ : Tb 3+ with a concentration ratio of 1:3 was the highest.

[0031] Example Three: Preparation of Eu 3+ / Tb 3+ -Silica Shell

[0032] The aforementioned 60 ml Eu 3+ : Tb 3+ (1:3 concentration ratio), sequentially through the digital constant temperature oscillator (vibrate for 30 min per day, shake for 2 hours), dry 100 mg of diatom shell at 90°C, and obtain Eu 3 + / Tb 3+ - diatom shell, referred to as "DS-EIPA-TDB". Figure 2 Eu 3+ / Tb 3+ The SEM image of the doped DS shows that Eu 3+ / Tb 3+ , Eu 3+ / Tb 3+ is anchored in the diatom shell DS, and the unique pore structure of the diatom shell DS provides a stable environment for Eu 3+ / Tb 3+ , which helps to produce higher ultraviolet absorption and excitation.

[0033] Example Four: Eu 3+ / Tb 3+ - Preparation of diatom shell incorporated cellulose acetate luminescent flexible film

[0034] (1) The obtained Eu 3+ : Tb 3+ Hybrid luminescent material ETDS with a concentration ratio of 1:3 is divided into three groups of 2 mg, 6 mg

[0035] and 12 mg, with mass fractions of 0.1wt%, 0.3wt% and 0.6wt% respectively, and mixed with 2g of cellulose acetate CA dissolved in 30ml of DMF in a certain proportion, and a small amount of 0.02mg of organic additive salicyl phenyl ester is added to each group, and mixed and stirred at 85°C for 1 hour, and then spin-coated into a glass mold, and dried at 60°C for 1 hour, to obtain a luminescent flexible film. Referred to as "ETDS@CA". The final small amount of organic additive ETDS@CA has significantly improved ultraviolet absorption compared with DS-EIPA-TDB. As shown in Figure 3 the ultraviolet absorption image of ETDS, Figure 4 the ultraviolet absorption image of ETDS@CA, the ultraviolet absorption intensity of ETDS@CA is significantly improved compared with ETDS in the ultraviolet range of 200-400nm, which is due to the addition of CA film and organic additive, which improves the ultraviolet absorption intensity.

[0036] (2) By characterizing the UV absorption, fluorescence lifetime and other properties of ETDS@CA films with ETDS mass fractions of 0.1wt%, 0.3wt% and 0.6wt% respectively, it is found that the ETDS@CA film with an ETDS mass fraction of 0.6wt% has the best performance.

[0037] Example Five: Preparation of a light-emitting flexible film for a polymer solar cell device

[0038] (1) The ITO transparent substrate was cleaned with different cleaning agents for multiple times of ultrasonic cleaning. After cleaning, the substrate was dried with nitrogen and immediately transferred into a plasma surface treatment instrument. The conductive substrate was treated by plasma under a pure oxygen environment at a pressure of 1 Pa for 5-10 minutes and then cooled to room temperature to form a clean conductive substrate;

[0039] (2) A hole transport layer PEDOT:PSS was spin-coated on the surface of the conductive substrate obtained in step (1) at a speed of 4000 rpm for 45 s, and then annealed at 150°C for 15 minutes;

[0040] (3) A non-fullerene system PM6:IT-4F active layer was spin-coated on the surface of the obtained hole transport layer at a speed of 2000 rpm for 40 s, and then annealed;

[0041] (4) An electron transport layer PFN-Br (concentration of 0.5 mg / ml) or PDINO (concentration of 1 mg / ml) was spin-coated on the surface of the obtained active layer at a speed of 3000 rpm for 35 s;

[0042] (5) A 100 nm metal aluminum cathode electrode was deposited on the surface of the electron transport layer obtained in step (4) using low-pressure evaporation in a vacuum evaporation instrument with a vacuum degree less than 2x10-4 Pa, to obtain a polymer solar cell.

[0043] (6) The evaporated solar cell was operated in a glove box, and an ETDS@CA solution (ETDS mass fraction of 0.6wt%) was spin-coated twice on the back of the cell at a speed of 1000 rpm for 10 s, and then annealed at 80°C for 5 min. As shown in Figure 5 、 6 、7, the ETDS@CA was spin-coated on the outside of the device in this study, which has the advantage of not damaging the mature device structure of the device compared to adding it inside the device. At the same time, ETDS@CA can absorb UV in the range of 200-400 nm, making up for the light absorption of PM6:IT4F in the range of 200-400 nm, and converting into more useful fluorescence of PM6:IT4F around 615 nm.

[0044] As shown in Figure 8ETDS@CA doped solar cell back and reference solar cell J-V curve diagram shown, the flexible light-emitting film ETDS@CA prepared in this embodiment is spin-coated on the polymer solar cell device, compared with the reference device, the open circuit voltage is basically unchanged, but the short circuit current density is increased from the original 21.65mA·cm -2 to 22.59mA·cm -2 The efficiency of the device is improved by about 4%, reaching 13.18%. Compared with the reference device, the device with the spin-coated ETDS@CA layer increases the incident light, improves the short circuit current density, and improves the J SC . In 60 days, the original cell efficiency decays about 60% of its initial value, while the ETDS@CA spin-coated cell efficiency decays about 80% of its initial value, which proves that the thin film has strong ultraviolet absorption ability and great application prospect for the service life of the cell.

[0045] It should be understood that those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. An Eu-based UV protection for polymer solar cells 3+ / Tb 3+ A method for preparing a doped diatom shell coating, characterized in that, Eb 3+ / Tb 3+ The porous structure of diatomaceous earth is incorporated into the polymer solar cell, then mixed with cellulose acetate in a certain proportion, and organic additives are added. This mixture is then spin-coated onto the back of the polymer solar cell to obtain Eu. 3+ / Tb 3+ The coating is made of diatomaceous earth, which is a flexible light-emitting film.

2. The preparation method according to claim 1, characterized in that, Includes the following steps: Step 1, Selection of diatom shells: Using *Lepiota villosa* as the substrate, place *Lepiota villosa* in F / 2 medium and then incubate it in a cold light source incubator at 25℃ for 14 days. Take 100 ml of the suspension after 14 days of incubation and centrifuge at 4000 rpm for 5 min. After centrifugation, pour off the supernatant. Then, centrifuge it 4 times at 3000 rpm with phosphate buffer solution to wash away impurities on the diatom shells. Wash it 5 times with distilled water and then collect the dried diatom shells in a drying oven at 70℃. Step 2, preparation of hybrid luminescent material: Take out the dried diatom shell and place it in an ethanol solution, then add EuCl3 and place it in a constant temperature shaker for 2 hours a day for 7 days. After centrifugation and drying, add TbCl3 to an ethanol solution and shake it in a constant temperature shaker for 2 hours a day for 7 days. After centrifugation and drying, the hybrid luminescent material, abbreviated as "ETDS", is obtained. Step 3, Preparation of the flexible light-emitting film: The obtained hybrid light-emitting material ETDS is mixed with cellulose acetate dissolved in DMF in a certain proportion, and then organic additives are added. The mixture is reacted at 70℃-90℃ for 1 hour. The mixture is then spin-coated onto the back of the polymer solar cell and annealed at 60℃-80℃ for 5-10 minutes. After the annealing process, the flexible light-emitting film is obtained.

3. The preparation method according to claim 2, characterized in that, In step 2, the concentration ratio of EuCl3 to TbCl3 is 1:3, and the diatom shell DS solution is prepared according to the ratio of 100 mg to 60 ml of ethanol solution.

4. The preparation method according to claim 2, characterized in that, In step 3, a cellulose acetate solution is prepared by dissolving 2g of cellulose acetate in 30ml of DMF solution, with ETDS accounting for 0.1-0.6wt% of the cellulose acetate mass.

5. The preparation method according to claim 2, characterized in that, In step 3, the organic additives are selected from: phenyl salicylate, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-methoxybenzophenone, and the amount used is 0.2-1% of the mass of ETDS.

6. Eu, used for UV protection in polymer solar cells, prepared by any one of the preparation methods described in claims 1-5. 3+ / Tb 3+ Doped with diatom shell coating.

7. The Eu according to claim 6 3+ / Tb 3+ Application of doped diatom shell coating in UV protection of solar cells.

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