Trans-perovskite solar cell and preparation method thereof

Abstract

The invention discloses a trans-perovskite solar cell and a preparation method thereof. The trans-perovskite solar cell sequentially comprises a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole barrier layer and a metal electrode, the hole transport layer comprises a nickel oxide thin film and an atomic layer deposited aluminum oxide thin film; and the material of the perovskite layer comprises a P-type self-assembly monomolecular material. The hole transport layer composed of the aluminum oxide thin film and the nickel oxide thin film deposited by the atomic layer is introduced, and the hole transport layer is matched with the P-type self-assembly monomolecular material in the material of the perovskite layer, so that the device efficiency and the device stability can be improved at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite solar cells, and in particular to an inverted perovskite solar cell and a preparation method thereof. Background Art

[0002] Existing inverse perovskite solar cells usually use nickel oxide, PTAA and VNPB to extract holes, block electrons and prevent carrier recombination. However, these materials generally have problems such as low efficiency or poor long-term stability.

[0003] Therefore, it is necessary to develop a perovskite solar cell structure that can effectively extract and transport hole carriers, effectively passivate interface defects, and have good long-term stability. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the first aspect of the present invention provides an inverted perovskite solar cell that can simultaneously improve device efficiency and have good long-term stability.

[0005] The second aspect of the present invention also provides a method for preparing an inverse perovskite solar cell.

[0006] An inverted perovskite solar cell provided according to the first aspect of the present invention comprises, in sequence, a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode;

[0007] The hole transport layer includes a nickel oxide film and an atomic layer deposited aluminum oxide film;

[0008] The material of the perovskite layer includes a P-type self-assembled monomolecular material.

[0009] The inverted perovskite solar cell according to the embodiment of the present invention has at least the following beneficial effects:

[0010] The present invention introduces a hole transport layer composed of an aluminum oxide film and a nickel oxide film deposited by an atomic layer, and cooperates with the P-type self-assembled monomolecular material in the perovskite layer material to simultaneously improve device efficiency and device stability. This is because the synergistic effect between the aluminum oxide film and the P-type self-assembled monomolecular material in the perovskite can not only improve the stability of the nickel oxide / perovskite interface, but also improve the hole extraction effect, thereby improving device performance.

[0011] Furthermore, the surface of the atomic layer deposited aluminum oxide film has a large number of hydroxyl groups, which can effectively form an anchor with the P-type self-assembled monomolecular material, thereby forming an interface layer between the perovskite and nickel oxide that can efficiently extract and transport holes, thereby improving the hole extraction capacity and reducing the efficiency loss caused by interface recombination.

[0012] According to some embodiments of the present invention, the thickness of the aluminum oxide film deposited by atomic layer deposition is 0.3 nm to 1 nm. Therefore, when the thickness of the aluminum oxide film is within the above range, it will not affect the conductivity. If the thickness is higher than 1 nm, the conductivity will be reduced.

[0013] According to some embodiments of the present invention, the nickel oxide film has a thickness of 5 to 20 nm.

[0014] According to some embodiments of the present invention, the P-type self-assembled monomolecular material is selected from at least one of MeO-2PACz (CAS: 2377770-18-6), Me-2PACz (CAS: 2996161-30-7), MeO-4PACz (CAS: 2922526-56-3), Me-4PACz (CAS: 2747959-96-0), 4PACz (CAS: 20999-36-4) or 2PACz (CAS: 20999-38-6).

[0015] According to some embodiments of the present invention, the material of the electron transport layer includes PCBM and fullerene C60.

[0016] According to some embodiments of the present invention, the material of the hole blocking layer includes BCP and tin oxide.

[0017] According to some embodiments of the present invention, the material of the metal electrode includes at least one of gold, silver, copper, aluminum or chromium.

[0018] According to some embodiments of the present invention, the substrate includes ITO conductive glass, FTO conductive glass or a transparent conductive flexible substrate.

[0019] According to a second aspect of the present invention, an embodiment provides a method for preparing an inverted perovskite solar cell, comprising the following steps:

[0020] S1, preparing a nickel oxide film on the surface of a substrate and annealing;

[0021] S2, preparing an aluminum oxide film on the surface of the obtained nickel oxide film by an atomic deposition method;

[0022] S3, coating a perovskite precursor solution containing a P-type self-assembled monomolecular material on the surface of the aluminum oxide film; annealing to obtain a perovskite layer;

[0023] S4. An electron transport layer, a hole blocking layer and a metal electrode are sequentially prepared on the surface of the perovskite layer.

[0024] According to some embodiments of the present invention, in step S3, the concentration of the perovskite precursor solution is 0.6-1.4 mM / mL.

[0025] According to some embodiments of the present invention, in step S1, the annealing temperature is 200°C to 300°C.

[0026] According to some embodiments of the present invention, in step S1, the annealing time is 10 to 30 minutes.

[0027] According to some embodiments of the present invention, in step S3, the annealing temperature is 100°C to 150°C.

[0028] According to some embodiments of the present invention, in step S3, the annealing time is 10 to 40 minutes.

[0029] According to some embodiments of the present invention, components of the perovskite precursor solution include cesium iodide, lead iodide, methylamine chloride and formamidine iodide.

[0030] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0032] Figure 1 JV curves of the inverse perovskite solar cell devices prepared in the embodiments of the present invention and the comparative examples

[0033] Figure 2 3 is a stability diagram of the inverse perovskite solar cell devices prepared in the embodiments of the present invention and the comparative examples. DETAILED DESCRIPTION

[0034] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0035] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0036] Example 1

[0037] This example provides an inverted perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode in sequence; and its preparation method is as follows:

[0038] Substrate pretreatment: Fluorine-doped tin oxide glass (FTO, 5×5 cm 2) The substrate was ultrasonically cleaned for 30 minutes, dried with nitrogen, and then treated with ozone for 20 minutes for standby use.

[0039] Prepare the precursor solution: ① Dissolve 10 mg of nickel oxide solid powder in 2 mL of ultrapure water, ultrasonically vibrate for 30 minutes and filter with a water filter to obtain a nickel oxide precursor solution; ② Dissolve 41.57 mg of cesium iodide, 368.8 mg of lead iodide, 16.20 mg of methylamine chloride, and 110.02 mg of formamidine iodide in 1 mL of a mixed solvent of dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) (DMF:DMSO=8:1), and add 0.2 mg of MeO-2PACz to the solution to obtain a perovskite precursor solution; ③ Dissolve 20 mg of PCBM in 1 mL of chlorobenzene to obtain an electron transport layer PCBM precursor solution.

[0040] S1, coating the nickel oxide precursor solution on the pre-prepared FTO substrate by scraping, and then annealing at 150° C. for 10 minutes to obtain a nickel oxide hole transport layer;

[0041] S2, preparing a layer of aluminum oxide film on the surface of the nickel oxide film by atomic layer deposition (ALD) technology, with a thickness set to 0.4 nm;

[0042] S3, coating the perovskite solution on the aluminum oxide film by slit coating, and immediately placing the coated film into a vacuum device for evacuation for about one minute to transform the light yellow transparent film into a translucent dark brown film, and then annealing at 100° C. for 30 minutes to obtain a perovskite layer;

[0043] S4. Spin-coat a PCBM electron transport layer on the perovskite layer (spin coating process is 2000 rpm, 30 s), and then prepare a 6 nm thick BCP hole blocking layer by vacuum evaporation, and then evaporate a 100 nm metal Ag electrode to obtain.

[0044] Example 2

[0045] This example provides an inverted perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode in sequence; its materials and preparation methods are basically the same as those in Example 1, the difference being that the P-type self-assembled monomolecular material is Me-2PACz.

[0046] Example 3

[0047] This example provides an inverted perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode in sequence; its materials and preparation methods are basically the same as those in Example 1, the difference being that the P-type self-assembled monomolecular material is 4PACz.

[0048] Comparative Example 1

[0049] This example provides an inverted perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode in sequence; its materials and preparation methods are basically the same as those in Example 1, the difference being that there is no aluminum oxide film between the nickel oxide and the perovskite layer.

[0050] Comparative Example 2

[0051] This example provides an inverted perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode in sequence; its materials and preparation methods are basically the same as those in Example 1, the difference being that the aluminum oxide film between the nickel oxide and the perovskite layer is replaced with a PTAA film.

[0052] The preparation method of PTAA is as follows: 1 mg PTAA is dissolved in 1 mL chlorobenzene to obtain a PTAA precursor solution, and the PTAA solution is spin-coated on the surface of the nickel oxide film and annealed at 100° C. for 10 minutes to obtain a PTAA film (spin coating process is 6000 rpm, 30 seconds).

[0053] Comparative Example 3

[0054] This example provides an inverted perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode in sequence; its materials and preparation methods are basically the same as those in Example 1, the difference being that the aluminum oxide film is prepared by spin coating.

[0055] The spin coating process for preparing aluminum oxide film is as follows: spin-coat the aluminum oxide nano-dispersion on the surface of the nickel oxide film and anneal at 100° C. for 10 minutes to obtain the aluminum oxide film (the concentration of the aluminum oxide nano-dispersion is 0.5 mg / mL, and the spin coating process is 3000 rpm for 30 seconds).

[0056] Comparative Example 4

[0057] This example provides an inverted perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode in sequence; its materials and preparation methods are basically the same as those in Example 1, except that no P-type self-assembled monomolecular material is added to the perovskite precursor solution in step S3.

[0058] Performance Testing

[0059] The inverse perovskite solar cells prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 4 were subjected to JV curve tests under a solar simulator. The data are shown in Tables 1 and Figure 1 .

[0060] The inverse perovskite solar cells prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 4 were tested for stability. The results are shown in Table 2 and Figure 2 .

[0061] The stability test method is as follows: the prepared device is tested for the first time to obtain the initial efficiency data, and then placed in an air environment with a certain humidity for 10 days and tested again to obtain the aging efficiency data. The stability calculation formula is as follows: stability = aging efficiency / initial efficiency.

[0062] Table 1

[0063] Voc(V) <![CDATA[Jsc(mA / cm 2 )]]> FF(%) PCE(%) Example 1 1.164 24.72 78.33 22.50 Example 2 1.135 24.45 78.17 21.59 Example 3 1.147 24.67 76.56 21.57 Comparative Example 1 1.087 24.42 77.16 20.48 Comparative Example 2 1.104 24.59 77.43 20.93 Comparative Example 3 1.123 24.49 74.23 20.33 Comparative Example 4 1.128 24.04 74.73 20.22

[0064] From Table 1, Example 1 has the highest open circuit voltage Voc and the highest short circuit current density Jsc, and thus has the highest conversion efficiency. According to the results of Examples 1, 2, 3 and Comparative Example 4, the additional addition of P-type self-assembly molecules to the perovskite can improve the performance of the device, and the effect of MeO-2PACz is better than Me-2PACz and 4PACz; from Example 1 and Comparative Examples 1, 2, and 3, a layer of aluminum oxide film is prepared on the surface of the nickel oxide hole transport layer. Compared with the pure nickel oxide hole transport layer device, the open circuit voltage is greatly improved, so that the final performance of the device is also significantly improved, and the performance of the nickel oxide / aluminum oxide film is better than that of nickel oxide / PTAA. At the same time, the aluminum oxide film prepared by ALD is slightly better than the aluminum oxide film prepared by spin coating.

[0065] Table 2

[0066] stability(%) Example 1 100.2 Example 2 96.3 Example 3 97.7 Comparative Example 1 83.3 Comparative Example 2 91.7 Comparative Example 3 95.5 Comparative Example 4 88.6

[0067] It can be seen from the data in Table 2 that P-type self-assembling molecules are beneficial to improving the stability of the device, and the effect of MeO-2PACz is better than that of Me-2PACz and 4PACz; in addition, preparing a layer of aluminum oxide on nickel oxide can greatly improve the stability of the device, and the performance does not decay after storage for 10 days.

[0068] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. An inverted perovskite solar cell, characterized in that: It includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal electrode in sequence; The hole transport layer includes a nickel oxide film and an atomic layer deposited aluminum oxide film; The material of the perovskite layer includes a P-type self-assembled monomolecular material.

2. The inverted perovskite solar cell according to claim 1, characterized in that: The thickness of the aluminum oxide film deposited by atomic layer deposition is 0.3nm-1nm.

3. The inverted perovskite solar cell according to claim 1, characterized in that: The P-type self-assembled monomolecular material is selected from at least one of MeO-2PACz, Me-2PACz, MeO-4PACz, Me-4PACz, 4PACz or 2PACz.

4. The inverted perovskite solar cell according to claim 1, characterized in that: The electron transport layer material includes PCBM and fullerene C60.

5. The inverted perovskite solar cell according to claim 1, characterized in that: The hole blocking material includes BCP and tin oxide.

6. The inverted perovskite solar cell according to claim 1, characterized in that: The material of the metal electrode includes at least one of gold, silver, copper, aluminum or chromium.

7. The method for preparing an inverse perovskite solar cell according to any one of claims 1 to 6, characterized in that: The steps include: S1, preparing a nickel oxide film on the surface of a substrate and annealing; S2, preparing an aluminum oxide film on the surface of the obtained nickel oxide film by an atomic deposition method; S3, coating a perovskite precursor solution containing a P-type self-assembled monomolecular material on the surface of the aluminum oxide film; annealing to obtain a perovskite layer; S4. An electron transport layer, a hole blocking layer and a metal electrode are sequentially prepared on the surface of the perovskite layer.

8. The method for preparing an inverse perovskite solar cell according to claim 7, characterized in that: In step S3, the concentration of the perovskite precursor solution is 0.6-1.4 mM / mL.

9. The method for preparing an inverse perovskite solar cell according to claim 7, characterized in that: In step S1, the annealing temperature is 200°C to 300°C.

10. The method for preparing an inverse perovskite solar cell according to claim 7, characterized in that: In step S3, the annealing temperature is 100°C to 150°C.

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