Multifunctional carbon paste for perovskite solar cell and preparation method and application thereof

Abstract

The invention discloses multifunctional carbon paste for a perovskite solar cell. The carbon paste comprises carbon paste and polyaniline paste. The perovskite active layer of the perovskite solar cell prepared from the carbon paste containing the polyaniline paste is more tightly combined with the interface of the carbon electrode, the photoelectric conversion efficiency is higher, and the prepared carbon electrode is higher in work function and higher and better in hydrophobicity.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of perovskite solar cells, and particularly relates to a multifunctional carbon paste for perovskite solar cells and a preparation method and application thereof. BACKGROUND

[0002] As a main utilization way of solar energy, solar cells can convert light energy into electrical energy. Among them, perovskite solar cells have strong photoelectric conversion capacity, adjustable band gap, simple manufacturing process, and the efficiency of perovskite solar cells has developed from 3.8% to 26%.

[0003] Compared with traditional structure perovskite solar cells, carbon-based hole transport layer-free perovskite solar cells have simple process, low cost and good stability, and do not need expensive hole transport layer materials and noble metal electrodes. However, compared with traditional full structure perovskite solar cells, the power conversion efficiency (PCE) of C-PSCs (hole transport layer-free devices based on carbon electrodes) is significantly lower. This performance decline is mainly due to the poor interface contact between perovskite (PVK) and carbon electrode caused by the absence of HTL, which inevitably forms pinholes. Therefore, these common interface defects cause significant non-radiative recombination, reducing the overall efficiency of the device. In addition, the inherent energy level misalignment between the carbon electrode and the PVK layer seriously hinders the extraction of holes, making the open-circuit voltage (Voc) of HTL-free C-PSCs significantly lower than that of traditional structures, thus leading to a significant decline in the performance of C-PSCs. Therefore, it is necessary to develop a multifunctional carbon paste with small energy level difference with the perovskite layer, which can repair and passivate the interface problem, thereby improving the photoelectric conversion efficiency, accelerating industrialization and reducing the cost. SUMMARY

[0004] The present application aims to solve the technical problem of poor contact between the perovskite layer and the carbon electrode in the existing carbon paste prepared perovskite solar cells, and provides a multifunctional carbon paste for perovskite solar cells and a preparation method and application thereof.

[0005] The multifunctional carbon paste for perovskite solar cells of the present application comprises carbon paste and polyaniline paste.

[0006] Preferably, the carbon paste in the carbon paste accounts for 50-90wt%, preferably 55-85wt%, more preferably 70wt%, and the polyaniline paste in the carbon paste accounts for 10-50wt%, preferably 20-45wt%, more preferably 30wt%.

[0007] Preferably, the polyaniline slurry comprises polyaniline powder, organic acid and polar solvent, preferably, the polyaniline powder accounts for 1-10wt% of the sum of the amount of polyaniline powder and polar solvent, the polar solvent accounts for 90-99wt% of the sum of the amount of polyaniline powder and polar solvent, and the molar ratio of the polyaniline powder to the organic acid is 2:1; preferably, the organic acid is selected from one or more of acetic acid, benzene sulfonic acid, camphor sulfonic acid, salicylic acid, sulfosalicylic acid and sodium dodecyl benzene sulfonate; and preferably, the polar solvent is selected from one or more of m-cresol, N,N-dimethylformamide (DMF), N-methylformamide (NMF) and N-methyl pyrrolidone (NMP) and the like high-polarity solvents.

[0008] Preferably, the carbon paste comprises graphite powder, carbon black, a binder and a mixed solvent containing alcohol solvent, ester solvent and ether solvent.

[0009] The alcohol solvent is selected from one or both of isopropyl alcohol and ethanol, the ester solvent is selected from one or both of ethyl acetate and butyl acetate, and the ether solvent is selected from one or both of propylene glycol methyl ether acetate and propylene glycol monomethyl ether.

[0010] The binder is selected from one or both of cellulose derivatives and acrylic resins, and preferably, the cellulose derivatives comprise hydroxypropyl cellulose.

[0011] The mass ratio of the graphite powder is 80-99% of the sum of the mass of the graphite powder and the carbon black, the mass ratio of the carbon black is 1-20% of the sum of the mass of the graphite powder and the carbon black, and the mass ratio of the binder is 1-20% of the sum of the mass of the graphite powder and the carbon black.

[0012] The volume ratio of the alcohol solvent, the ester solvent and the ether solvent is 4:9:11.

[0013] Another object of the present application is to provide a method for preparing a multifunctional carbon paste for perovskite solar cells, which comprises:

[0014] In step S1, carbon black, graphite powder and a binder are ball milled in a mixed solvent containing alcohol solvent, ester solvent and ether solvent to prepare a carbon paste; preferably, the ball milling time is 18-30h, more preferably 24h; preferably, the binder is selected from one or both of cellulose derivatives and acrylic resins, the alcohol solvent is selected from one or both of isopropyl alcohol and ethanol, the ester solvent is selected from one or both of ethyl acetate and butyl acetate, and the ether solvent is selected from one or both of propylene glycol methyl ether acetate and propylene glycol monomethyl ether; and preferably, the cellulose derivatives comprise hydroxypropyl cellulose.

[0015] Step S2, preparing polyaniline slurry by heating and stirring polyaniline powder and organic acid in a polar solvent, preferably, stirring at 55-70℃ for 18-30h, more preferably, stirring at 60℃ for 24h, preferably, the polar solvent is selected from one or more of m-cresol, N,N-dimethylformamide (DMF), N-methylformamide (NMF) and N-methylpyrrolidone (NMP) and the like high-polar solvents, preferably, the organic acid is selected from one or more of acetic acid, benzene sulfonic acid, camphor sulfonic acid, salicylic acid, sulfosalicylic acid and sodium dodecyl benzene sulfonate;

[0016] Step S3, preparing multifunctional carbon slurry by ball milling the carbon paste in step S1 and the polyaniline slurry in step S2, preferably, ball milling in a ball milling tank for 1.5-5h, preferably, 2h.

[0017] Preferably, the multifunctional carbon slurry for perovskite solar cells is applied in perovskite solar cells.

[0018] The application also provides a carbon electrode for perovskite solar cells, which is prepared by coating the multifunctional carbon slurry for perovskite solar cells on a perovskite layer by screen printing, spin coating, blade coating or slot extrusion and then annealing, preferably, the annealing temperature is 100-120℃ and the annealing time is 10-30min.

[0019] The application also provides a formal planar structure carbon-based hole-free perovskite solar cell, which comprises, from bottom to top, a glass substrate, an electron transport layer, a perovskite layer and the carbon electrode of claim 8.

[0020] Preferably, the perovskite in the perovskite solar cell has a molecular formula of ABX3, wherein A is selected from one or both of methylamine ion and formamidinium ion, B is lead ion and X is halogen.

[0021] The application also provides a method for preparing a formal planar structure carbon-based hole-free perovskite solar cell, characterized in that the method comprises:

[0022] Step S1, cleaning a glass substrate;

[0023] Step S2, coating an electron transport layer on the cleaned glass substrate;

[0024] Step S3, uniformly coating a perovskite precursor solution on the surface of the electron transport layer, and obtaining a perovskite layer by annealing the perovskite wet film;

[0025] Step S5, coating the carbon paste of any one of claims 1-5 on the perovskite layer, and curing to form a carbon electrode after annealing, preferably the polyaniline paste in the carbon paste accounts for 10-50wt%, more preferably 20-45wt%, more preferably 30wt%; preferably the fixing temperature is 100-120℃, and the fixing time is 10-30min, more preferably the fixing temperature is 120℃, and the fixing time is 20min.

[0026] The positive progress effect of the present application is that:

[0027] 1) Adding polyaniline paste in the carbon paste for preparing carbon electrode can promote the close combination of perovskite active layer and carbon electrode at the interface, passivate the interface defects of perovskite and carbon electrode, and realize the interface repair function;

[0028] 2) Adding polyaniline paste in the carbon paste for preparing carbon electrode can improve the work function of carbon electrode;

[0029] 3) Adding polyaniline paste in the carbon paste for preparing carbon electrode can enhance the hydrophobicity of carbon electrode, and improve the humidity stability of the device;

[0030] 4) Using carbon paste added with polyaniline paste can improve the photoelectric conversion efficiency of planar structure carbon-based perovskite solar cell without hole transport layer. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The work function of carbon electrode prepared by using carbon paste in Examples 1-3 of the present application and carbon electrode prepared by using comparative examples was tested;

[0032] Figure 2 The water drop contact angle of carbon electrode prepared by using carbon paste in Example 2 of the present application and carbon electrode prepared by using comparative examples was tested;

[0033] Figure 3 The cross-sectional scanning electron microscope image of planar structure carbon-based perovskite solar cell prepared by using comparative examples and Example 11 of the present application;

[0034] Figure 4 The photocurrent-voltage curve of planar structure carbon-based perovskite solar cell prepared by using comparative examples and Example 11 of the present application. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described below through specific and concrete examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure of the present specification. The present application can also be implemented or applied by means of other different specific embodiments, and various modifications or changes can be made to the details in the present specification based on different viewpoints and applications without departing from the spirit of the present application.

[0036] Examples 1-3 and Examples A-C

[0037] Preparation of multifunctional carbon paste

[0038] Step S11, carbon paste preparation: M11 g of conductive carbon black, M12 g of graphite and M13 g of binder were weighed and placed in V11 mL of alcohol solvent, V12 mL of ester solvent and V13 mL of ether solvent for ball milling t11 h to obtain the carbon paste.

[0039] Step S12, polyaniline paste preparation: M14 g of polyaniline powder and M15 g of organic acid were dissolved in V14 mL of polar solvent, and stirred at T11 ℃ for t12 h to obtain the polyaniline paste.

[0040] Step S13, multifunctional carbon paste preparation: M16 g of polyaniline paste obtained in step S11 and M17 g of carbon paste obtained in step S12 were ball milled in a ball milling tank for t13 h to obtain the multifunctional carbon paste, at which time the mass fraction of polyaniline paste in the carbon paste was ωwt%.

[0041] Step S1', the carbon paste was screen printed on the surface of the glass substrate, and annealed at 120℃ in air for 10 min to solidify and form a carbon electrode.

[0042] Examples 4-12

[0043] Preparation of formal planar structure carbon-based hole-free perovskite solar cell

[0044] Steps S11-S13, preparation of multifunctional carbon paste: same as steps S11-S13 of Examples 1-3;

[0045] Step S21, cleaning of glass substrate: the substrate was ultrasonically cleaned with absolute ethanol, household detergent, deionized water, isopropyl alcohol and absolute ethanol in sequence for 15 min, then dried in an oven at 60℃ for 10 min, and then treated with ultraviolet ozone (UV) for 10 min.

[0046] Step S22, spin coating of electron transport layer on the glass substrate cleaned in step S21: 250 μL of 15wt% tin dioxide (SnO2) aqueous dispersion was mixed with 1 mL of deionized water to obtain a tin oxide solution, and then 45 μL of the tin oxide solution was spin coated on the 1×1 cm 2 ITO glass substrate of step S21, the spin coater was started, the spin coating speed was 4000 r / min, the spin coating time was 30 s, and the tin dioxide electron transport layer was obtained by annealing at 150℃ for 30 min.

[0047] Step S23, preparation of perovskite precursor solution: 2.3 mmol of lead iodide and 2.3 mmol of methylammonium iodide (MAI) were dissolved in 100 μL of dimethyl sulfoxide (DMSO) and 900 μL of dimethylformamide (DMF) to form a perovskite precursor solution, and the mixture was stirred for 5 h.

[0048] Step S24, preparation of perovskite layer by spin coating the perovskite precursor solution of S23 on the electron transport layer of S22: the uniformly stirred perovskite precursor solution was filtered with a sterile disposable syringe filter with a polytetrafluoroethylene organic membrane, and 40 μL of the perovskite precursor solution was drawn with a pipette and coated on the 1 x 1 cm 2 glass substrate electron transport layer at a speed of 3000 r / min for 30 s, 300 μL of anti-solvent ethyl acetate was added dropwise on the electron transport layer within 10-15 s of high-speed rotation, and then annealing at 130°C for 15 min to obtain a perovskite layer.

[0049] Step S25, preparation of carbon electrode: the multifunctional carbon paste of step S13 was screen printed on the perovskite layer of S24, and annealed at T21°C for t21 min in air to form a carbon electrode, thereby forming a formal planar structure carbon-based hole-free perovskite solar cell arranged in order from bottom to top as glass substrate, electron transport layer, perovskite layer and carbon electrode.

[0050] Comparative examples a-e

[0051] Preparation of carbon-based perovskite solar cell

[0052] Steps S31-S34 are the same as steps S21-S24 in this example.

[0053] Step S35, a commercial conductive carbon paste was printed on the surface of the perovskite layer of step S24 using a screen printing method, and a carbon electrode was obtained after annealing at T21°C for t21 min.

[0054] Table 1 Preparation parameters of multifunctional carbon paste of examples 1-3

[0055]

[0056]

[0057] Table 1 (continued) Preparation parameters of multifunctional carbon paste of examples A-C

[0058]

[0059]

[0060] By Figure 1As shown, after the carbon electrodes were prepared using the carbon pastes of Examples 1-3, the work function obtained by ultraviolet photoelectron spectroscopy was 4.59 eV. This means that, at the same curing temperature and time, the work functions of the carbon electrodes prepared using the carbon pastes containing 10 wt%, 30 wt%, and 50 wt% polyaniline paste in Examples 1-3 were all greater than the work function of the carbon electrodes prepared using ordinary commercial conductive carbon paste in the comparative example. This indicates that the carbon electrodes prepared using carbon paste containing polyaniline paste have a stronger ability to bind electrons. Furthermore, in Example 3, the work function was the highest when the mass percentage of polyaniline paste in the carbon paste was 50 wt%, indicating that the higher the mass percentage of polyaniline paste, the higher the work function of the carbon electrode prepared using that carbon paste.

[0061] Depend on Figure 2 As shown, after the carbon electrode was prepared using the carbon paste of Examples 1-2, a water droplet contact angle of 120.91° was obtained. That is, the water droplet contact angle of the carbon electrode prepared using the carbon paste with a mass ratio of 30wt% polyaniline paste in Example 2 is greater than the water droplet contact angle of the carbon electrode prepared using ordinary commercial conductive carbon paste in the comparative example. This shows that using carbon paste with added polyaniline paste can enhance the hydrophobicity of the carbon electrode and improve the humidity stability of the device.

[0062] Table 2. Parameters in step S25 and in the comparative examples of perovskite solar cell fabrication in Examples 4-12 and Comparative Examples a-e.

[0063]

[0064]

[0065] Table 3 shows the performance of perovskite solar cells prepared in Examples 4-12 and Comparative Examples a-e.

[0066]

[0067] (1) As shown in Table 3, adding polyaniline paste to the multifunctional carbon paste can greatly improve the performance of perovskite solar cells. By comparing the data in Examples 4 to 6, when forming carbon electrodes by annealing and curing at 100°C for 10 min, the higher the mass ratio of polyaniline paste in the multifunctional carbon paste, the better the performance of the prepared perovskite solar cells.

[0068] (2) Through Figure 3 It is known that using carbon paste containing polyaniline paste in the preparation of perovskite solar cells can promote a tight bond between the perovskite active layer and the carbon electrode interface, passivate defects at the perovskite-carbon electrode interface, and achieve interface repair function.

[0069] (3) By comparing the data in Examples 7-12 with the comparative examples and Figure 4It can be seen that when the mass ratio of polyaniline slurry in the multifunctional carbon slurry is 30wt% in Example 11, the performance of the perovskite solar cell formed after the carbon electrode is annealed and solidified at 120℃ for 20min is optimal, and the photoelectric conversion efficiency can reach 18.23%.

[0070] The above embodiments of the present application are described in detail with reference to the accompanying drawings. Those skilled in the art can make various changes to the present application according to the above description. Therefore, some details in the embodiments should not be construed as limiting the present application, and the present application will be protected within the scope defined by the appended claims.

Claims

1. A multifunctional carbon paste for perovskite solar cells, characterized by, The carbon paste comprises carbon paste and polyaniline slurry.

2. The multifunctional carbon paste for perovskite solar cells according to claim 1, wherein The carbon paste in the carbon paste accounts for 50-90wt%, preferably 55-85wt%, more preferably 70wt%, and the polyaniline slurry in the carbon paste accounts for 10-50wt%, preferably 20-45wt%, more preferably 30wt%.

3. The multifunctional carbon paste for perovskite solar cells according to claim 1, wherein The polyaniline slurry comprises polyaniline powder, organic acid and polar solvent, preferably, the polyaniline powder accounts for 1-10wt% of the sum of the amount of polyaniline powder and polar solvent, the polar solvent accounts for 90-99wt% of the sum of the amount of polyaniline powder and polar solvent, and the molar ratio of the polyaniline powder to the organic acid is 2:1; preferably, the organic acid is selected from one or more of acetic acid, benzene sulfonic acid, camphor sulfonic acid, salicylic acid, sulfosalicylic acid and sodium dodecyl benzene sulfonate, and preferably, the polar solvent is selected from one or more of m-cresol, N,N-dimethylformamide, N-methylformamide and N-methyl pyrrolidone.

4. The multifunctional carbon paste for perovskite solar cells according to claim 1, wherein The carbon paste comprises graphite powder, carbon black, binder and mixed solvent containing alcohol solvent, ester solvent and ether solvent; The alcohol solvent is selected from one or both of isopropyl alcohol and ethanol, the ester solvent is selected from one or both of ethyl acetate and butyl acetate, and the ether solvent is selected from one or both of propylene glycol methyl ether acetate and propylene glycol monomethyl ether; The binder is selected from one or both of cellulose derivative and acrylic resin, and preferably, the cellulose derivative comprises hydroxypropyl cellulose.

5. The multifunctional carbon paste for perovskite solar cells according to claim 4, wherein The mass ratio of the graphite powder is 80-99% of the sum of the mass of graphite powder and carbon black, the mass ratio of the carbon black is 1-20% of the sum of the mass of graphite powder and carbon black, and the mass ratio of the binder is 1-20% of the sum of the mass of graphite powder and carbon black; The volume ratio of the alcohol solvent, the ester solvent and the ether solvent is 4:9:

11.

6. A method of preparing the multifunctional carbon paste for perovskite solar cells according to any one of claims 1 to 5, characterized in that, The method comprises: Step S1, ball milling carbon black, graphite powder and binder in a mixed solvent containing alcohol solvent, ester solvent and ether solvent to prepare carbon paste; preferably, the ball milling time is 18-30h, more preferably 24h; preferably, the binder is selected from one or both of cellulose derivative and acrylic resin, the alcohol solvent is selected from one or both of isopropyl alcohol and ethanol, the ester solvent is selected from one or both of ethyl acetate and butyl acetate, and the ether solvent is selected from one or both of propylene glycol methyl ether acetate and propylene glycol monomethyl ether; preferably, the cellulose derivative comprises hydroxypropyl cellulose; Step S2, heating and stirring polyaniline powder and organic acid in a polar solvent to prepare polyaniline slurry, preferably, stirring at 55-70℃ for 18-30h, more preferably stirring at 60℃ for 24h, preferably, the polar solvent is selected from one or more of m-cresol, N,N-dimethylformamide, N-methylformamide and N-methyl pyrrolidone, and preferably, the organic acid is selected from one or more of acetic acid, benzene sulfonic acid, camphor sulfonic acid, salicylic acid, sulfosalicylic acid and sodium dodecyl benzene sulfonate; Step S3, mixing the carbon paste in step S1 with the polyaniline slurry in step S2 by ball milling to prepare a multifunctional carbon slurry, preferably ball milling in a ball milling tank for 1.5-5h, preferably 2h.

7. Use of the multifunctional carbon slurry for perovskite solar cells according to any one of claims 1-5 in a perovskite solar cell.

8. A carbon electrode of a perovskite solar cell, characterized by, The multifunctional carbon slurry for perovskite solar cells according to any one of claims 1-5 is coated on the perovskite layer by screen printing, spin coating, doctor blade coating or slot-die coating and annealed to obtain, preferably, the annealing temperature is 100-120℃ and the annealing time is 10-30min.

9. A formal planar structure carbon-based hole-free perovskite solar cell, characterized in that, The perovskite solar cell comprises, from bottom to top, a glass substrate, an electron transport layer, a perovskite layer and the carbon electrode according to claim 8.

10. A method of making the formal planar structure carbon-based hole-free perovskite solar cell of claim 9, characterized in that, The method comprises: Step S1, cleaning the glass substrate; Step S2, coating the electron transport layer on the cleaned glass substrate; Step S3, uniformly coating the perovskite precursor solution on the surface of the electron transport layer, and annealing the perovskite wet film to obtain the perovskite layer; Step S5, coating the carbon slurry according to any one of claims 1-5 on the perovskite layer, and solidifying to form the carbon electrode after annealing, preferably the polyaniline slurry in the carbon slurry accounts for 10-50wt%, more preferably 20-45wt%, and more preferably 30wt%; preferably the fixing temperature is 100-120℃ and the fixing time is 10-30min, more preferably the fixing temperature is 120℃ and the fixing time is 20min.

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