High-efficiency organic-inorganic ternary perovskite solar cell and preparation method thereof

Abstract

The invention discloses a high-efficiency organic-inorganic ternary perovskite solar cell and a preparation method thereof, and the solar cell sequentially comprises an ITO conductive glass substrate layer, a hole transport layer (MeO-2PACz), a ternary perovskite layer formed by mixing an ionic liquid TFPBF4 and a perovskite layer Cs0.05 (FA0.95 MA0.05) 0.95 Pb (I0.95 Br0.05) 3, a [6, 6]-phenyl-C61-butyric acid isomethyl ester electron transport layer (PCBM), a 2, 4, 6, 7, 8-tetramethyl-3, 7, 8-tetramethyl-3, 7, 8-tetramethyl-3, 7, 8-tetramethyl-3, 7, 8-tetramethyl-3, 7, 8-tetramethyl-3, 7, 8-tetramethyl-3, 7, 8-tetramethyl-3, 7, 8-tetramethyl-3, 8-tetramethyl-3 The thin film solar cell is characterized by comprising a metal electrode layer, a metal electrode layer, a hole blocking layer, a 9, 9-dimethyl-4, 7-biphenyl-1, 10-phenanthroline hole blocking layer (BCP) and a metal Ag electrode layer. According to the scheme, the fluorine-rich ionic liquid is introduced into the perovskite active layer, so that multi-point passivation of defects is realized, the photoluminescence intensity is improved, the form of the film is improved, the crystallinity is expanded, charge transfer is balanced, the photoelectric conversion efficiency is enhanced, the stability is improved, and the hysteresis effect of a device is effectively inhibited.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a high-efficiency organic-inorganic ternary perovskite solar cell and a preparation method thereof. Background Art

[0002] With the continuous development of human society, energy issues have become one of the most concerned issues in the world. In order to solve various problems caused by energy consumption and achieve green and sustainable development of the economic environment, a series of new energy technologies such as solar energy and nuclear energy have received widespread attention.

[0003] As the third generation of solar cells, perovskite solar cells have exceeded 25% photoelectric conversion efficiency in just twelve years. Compared with other solar cells, perovskite solar cells have the advantages of low cost and simple preparation process, and have broad future prospects; however, organic-inorganic ternary perovskites are sensitive to moisture and oxygen, resulting in a significant decrease in their performance in the ambient atmosphere. In addition, the incorporation of ionic liquids is described in many literatures to provide conductivity to the perovskite layer; however, fluorine-rich ionic liquids are usually deposited on top of or below the perovskite layer to form a double-layer or multi-layer thin film structure. Although the obtained multi-layer thin film structure perovskite solar cell has superior device performance, unbalanced charge transfer and the presence of various defects in the perovskite are still the main limiting factors. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high-efficiency organic-inorganic ternary perovskite solar cell and a preparation method thereof, and an organic-inorganic ternary perovskite solar cell in which a fluorine-rich conjugated ionic liquid is combined with a perovskite layer, which has the advantages of improved hydrophobicity, improved film morphology, improved crystallinity, improved charge transport and high stability.

[0005] In order to achieve the above technical effects, the present invention is implemented by the following technical solutions: a high-efficiency ternary perovskite solar cell, characterized in that it includes, from bottom to top, an ITO conductive glass layer, a (2-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid hole transport layer (MeO-2PACz), an ionic liquid TFPBF4 and a perovskite layer Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 mixed to form a ternary perovskite layer, [6,6]-phenyl-C61-butyric acid isomethyl ester electron transport layer (PCBM), 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline hole blocking layer (BCP) and a metal Ag electrode layer.

[0006] Furthermore, the preparation process of the ternary perovskite layer is as follows:

[0007] (1) CsI, MABr, FAI, PbI2 and PbBr2 were weighed and dissolved in a mixed solution of DMF and DMSO at a molar ratio of CsI:MABr:FAI:PbI2:PbBr2=0.05-0.1:0.05-0.1:1-2:1-2:0.05-0.1, and stirred at 60°C for 1 h to form a perovskite precursor solution with a concentration of 1.4 M;

[0008] (2) Mixing different masses of TFPBF4 with pure DMF to obtain a TFPBF4 solution;

[0009] (3) mixing TFPBF4 solutions of different concentrations with an organic-inorganic ternary perovskite precursor solution to form a TFPBF4-doped perovskite precursor solution;

[0010] (4) Coating the TFPBF4-doped perovskite precursor solution on the hole transport layer to form a ternary perovskite layer.

[0011] Furthermore, the concentrations of the TFPBF4 solutions of different concentrations are 0.25 mg / ml, 0.50 mg / ml, 0.75 mg / ml, and 1.00 mg / ml, respectively.

[0012] Another object of the present invention is to provide a method for preparing an organic-inorganic ternary perovskite solar cell, comprising the following steps:

[0013] (1) Clean the ITO glass substrate with detergent, isopropyl alcohol solution, deionized water and anhydrous ethanol in sequence, dry it and then clean it with a UV ozone cleaner for 20 minutes;

[0014] (2) spin coating the hole transport layer MeO-2PACz on the cleaned ITO glass substrate, followed by annealing at 100 °C for 10 min;

[0015] (3) Dynamically spin-coating the TFPBF4-doped organic-inorganic ternary perovskite precursor solution on the hole transport layer MeO-2PACz at 4000 rpm, followed by annealing at 100 °C for 50 min;

[0016] (4) spin coating the electron transport layer PCBM on the perovskite layer;

[0017] (5) depositing a hole blocking layer BCP on the electron transport layer in a vacuum coating machine with a thickness of 5 nm;

[0018] (6) A metal electrode Ag is evaporated onto the hole blocking layer in a vacuum coating machine with a thickness of 120 nm.

[0019] Beneficial effects:

[0020] 1. The present invention reduces the defect state density of perovskite, improves the hydrophobicity of the battery, and enhances the stability and life of the perovskite. It also enhances the electron mobility of the solar cell, thereby improving the photocurrent of the perovskite solar cell.

[0021] 2. In the present invention, the doping of fluorine-rich ionic liquid TFPBF4 in the perovskite light-absorbing layer can not only improve the conductivity of the perovskite, passivate the uncoordinated lead iodide defects, and increase the photocurrent of the battery device, but also TFPBF4 doping can effectively balance the charge transfer and inhibit the ion migration in the ternary composite material;

[0022] 3. In the present invention, the presence of the ternary heterojunction promotes the growth of perovskite crystals, passivates the defects of the perovskite layer, improves the film morphology, and limits ion migration, thereby suppressing the hysteresis effect of the current in the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 The photoelectric conversion efficiency statistics of ternary perovskite solar cells with and without TFPBF4 doping;

[0025] Figure 2 Absorption spectra of ternary perovskite solar cells with and without TFPBF4 doping;

[0026] Figure 3 PL diagram of ternary perovskite solar cells with and without TFPBF4 doping;

[0027] Figure 4 XRD patterns of ternary perovskite films with and without TFPBF4 doping;

[0028] Figure 5 Forward scan and reverse scan JV curves of ternary perovskite solar cells with and without TFPBF4 doping. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] When the high-efficiency ternary perovskite solar cell structure of the present invention is as follows from bottom to top:

[0032] ITO / MeO-2PACz / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 / PCBM / BCP / Ag;

[0033] The preparation method thereof comprises the following steps:

[0034] (1) Clean the ITO glass substrate with detergent, isopropyl alcohol solution, deionized water and anhydrous ethanol in sequence, dry it and then clean it with a UV ozone cleaner for 20 minutes;

[0035] (2) spin coating the hole transport layer MeO-2PACz on the cleaned ITO glass substrate, followed by annealing at 100 °C for 10 min;

[0036] (3) 1.4 M ternary perovskite precursor solution was dynamically spin-coated on the hole transport layer MeO-2PACz at 4000 rpm, followed by annealing at 100 °C for 50 min;

[0037] (4) spin coating the electron transport layer PCBM on the perovskite layer;

[0038] (5) depositing a hole blocking layer BCP on the electron transport layer in a vacuum coating machine with a thickness of 5 nm;

[0039] (6) A metal electrode Ag is evaporated onto the hole blocking layer in a vacuum coating machine with a thickness of 120 nm.

[0040] Example 2

[0041] When the high-efficiency ternary perovskite solar cell structure of the present invention is as follows from bottom to top:

[0042] ITO / MeO-4PACz / Cs 0.05 (FA 0.95 MA 0.05 )0.95 Pb(I 0.95 Br 0.05 )3+TFPBF4 / PCBM / BCP / Ag;

[0043] The preparation method thereof comprises the following steps:

[0044] (1) Clean the ITO glass substrate with detergent, isopropyl alcohol solution, deionized water and anhydrous ethanol in sequence, dry it and then clean it with a UV ozone cleaner for 20 minutes;

[0045] (2) spin coating the hole transport layer MeO-2PACz on the cleaned ITO glass substrate, followed by annealing at 100 °C for 10 min;

[0046] (3) 0.25 mg / ml-1.0 mg / ml TFPBF4-doped ternary perovskite precursor solution was dynamically spin-coated on the hole transport layer MeO-2PACz at 4000 rpm, followed by annealing at 100 °C for 50 min;

[0047] (4) spin coating the electron transport layer PCBM on the perovskite layer;

[0048] (5) depositing a hole blocking layer BCP on the electron transport layer in a vacuum coating machine with a thickness of 5 nm;

[0049] (6) A metal electrode Ag is evaporated onto the hole blocking layer in a vacuum coating machine with a thickness of 120 nm.

[0050] Example 3

[0051] This embodiment is a comparative example, which is as follows:

[0052] When the high-efficiency organic-inorganic ternary perovskite solar cell structure of the present invention is as follows from bottom to top:

[0053] ITO / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3;

[0054] The preparation method thereof comprises the following steps:

[0055] (1) Clean the ITO glass substrate with detergent, isopropyl alcohol solution, deionized water and anhydrous ethanol in sequence, dry it and then clean it with a UV ozone cleaner for 20 minutes;

[0056] (2) 0.5M-1.5M TFPBF4-doped ternary perovskite precursor solution was dynamically spin-coated on an ITO glass substrate at 4000 rpm, followed by annealing at 100 °C for 50 min.

[0057] Example 4

[0058] This embodiment is a comparative example, which is as follows:

[0059] When the high-efficiency organic-inorganic ternary perovskite solar cell structure of the present invention is as follows from bottom to top:

[0060] ITO / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3+TFPBF4

[0061] The preparation method thereof comprises the following steps:

[0062] (1) Clean the ITO glass substrate with detergent, isopropyl alcohol solution, deionized water and anhydrous ethanol in sequence, dry it and then clean it with a UV ozone cleaner for 20 minutes;

[0063] (2) 0.5 mg / ml TFPBF4-doped ternary perovskite precursor solution was dynamically spin-coated on an ITO glass substrate at 4000 rpm, followed by annealing at 100 °C for 50 min.

[0064] Example 5

[0065] The high-efficiency ternary perovskite solar cells with different structures prepared in combination with Examples 1-4 were tested for their respective performances, as follows:

[0066] By attaching Figure 1 It can be seen that the photoelectric conversion efficiency of the perovskite device formed by introducing TFPBF4 will be significantly improved. When the introduction amount of TFPBF4 is 0.5 mg / ml, its photoelectric conversion efficiency can be increased by more than 10%.

[0067] By attaching Figure 2 It can be seen that in the absorption spectrum, compared with the spectrum in the pure perovskite film, the spectrum in the TFPBF4-doped mixed perovskite is slightly blue-shifted due to the quantum confinement effect.

[0068] By attaching Figure 3 It can be seen that in the PL spectrum, the excitation intensity in the TFPBF4-doped hybrid perovskite is significantly higher than that in the pure perovskite film.

[0069] By attaching Figure 4It can be seen that the crystallization intensity of TFPBF4-doped organic-inorganic perovskite film is higher than that of undoped perovskite film, which indicates that TFPBF4-doped ternary solar cells have higher film quality, which is conducive to higher photocurrent.

[0070] By attaching Figure 5 It can be seen that the photocurrent hysteresis in TFPBF4-doped ternary solar cells is significantly lower than that in undoped perovskite devices. The significant reduction in photocurrent hysteresis can be attributed to the reduction in the number of defects and the emergence of chemical interactions between perovskite and TFPBF4.

Claims

1. A high-efficiency ternary perovskite solar cell, characterized in that: From bottom to top, it includes an ITO conductive glass layer, a (2-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid hole transport layer (MeO-2PACz), an ionic liquid TFPBF4 and a perovskite layer Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 mixed to form a ternary perovskite layer, [6,6]-phenyl-C61-butyric acid isomethyl ester electron transport layer (PCBM), 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline hole blocking layer (BCP) and a metal Ag electrode layer.

2. A high-efficiency ternary perovskite solar cell according to claim 1, characterized in that: The preparation process of the ternary perovskite layer is as follows: (1) CsI, MABr, FAI, PbI2 and PbBr2 were weighed and dissolved in a mixed solution of DMF and DMSO at a molar ratio of CsI:MABr:FAI:PbI2:PbBr2=0.05-0.1:0.05-0.1:1-2:1-2:0.05-0.1, and stirred at 60°C for 1 h to form a perovskite precursor solution with a concentration of 1.4 M; (2) Mixing different masses of TFPBF4 with pure DMF to obtain a TFPBF4 solution; (3) mixing TFPBF4 solutions of different concentrations with an organic-inorganic ternary perovskite precursor solution to form a TFPBF4-doped perovskite precursor solution; (4) Coating the TFPBF4-doped perovskite precursor solution on the hole transport layer to form a ternary perovskite layer.

3. A high-efficiency ternary perovskite solar cell according to claim 1, characterized in that: The concentrations of the TFPBF4 solutions of different concentrations are 0.25 mg / ml, 0.50 mg / ml, 0.75 mg / ml, and 1.00 mg / ml, respectively.

4. A method for preparing a high-efficiency ternary perovskite solar cell, characterized in that: The steps include: (1) Clean the ITO glass substrate with detergent, isopropyl alcohol solution, deionized water and anhydrous ethanol in sequence, dry it and then clean it with a UV ozone cleaner for 20 minutes; (2) spin coating the hole transport layer MeO-2PACz on the cleaned ITO glass substrate, followed by annealing at 100 °C for 10 min; (3) Dynamically spin-coating the TFPBF4-doped organic-inorganic ternary perovskite precursor solution on the hole transport layer MeO-2PACz at 4000 rpm, followed by annealing at 100 °C for 50 min; (4) spin coating the electron transport layer PCBM on the perovskite layer; (5) depositing a hole blocking layer BCP on the electron transport layer in a vacuum coating machine with a thickness of 5 nm; (6) A metal electrode Ag is evaporated onto the hole blocking layer in a vacuum coating machine with a thickness of 120 nm.

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