High-efficiency ternary perovskite solar cell and preparation method thereof

Abstract

The invention discloses a high-efficiency ternary perovskite solar cell and a preparation method thereof, and the cell sequentially comprises an ITO conductive glass layer, a (4-(3, 6-dimethyl-9H-carbazole-9-yl) butyl) phosphonic acid hole transport layer (MeO-4PACz), a ternary perovskite layer formed by mixing an ionic liquid BzMIMBr and a perovskite layer Cs0.05 (FA0.95 MA0.05) 0.95 Pb (I0.95 Br0.05) 3, a C60 electron transport layer, 2, 9-dimethyl-4, 4 '-diazole-4, 4'-diazole-4, 4 '-diazole-4, 4'-diazole-4, 4 '-diazole-4, 4'-diazole-4 '-diazole-4, 4'-diazole-4 '-diazole-4'-diazole-4 ' the hole barrier layer is a 1, 7-biphenyl-1, 10-phenanthroline hole barrier layer (BCP); and the metal Al electrode layer is formed on the hole barrier layer. According to the scheme, the conjugated ionic liquid is introduced into the perovskite active layer, so that multi-point passivation of defects is realized, the external quantum efficiency is improved, the film form 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 relates to the technical field of solar cells, and in particular to a high-efficiency 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 sustainable development of the green economy and environment, a series of new energy technologies such as solar energy and nuclear energy have received widespread attention.

[0003] Perovskite solar cells, as the third generation of 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, 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 to provide conductivity to the perovskite layer is described in many literatures. However, the ionic liquids are usually deposited on top of or below the perovskite layer to form a double-layer or multilayer thin film structure. Although the resulting multilayer thin film structure perovskite solar cell has superior device performance, unbalanced charge transport and the presence of various defects in the perovskite remain the main limiting factors. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high-efficiency ternary perovskite solar cell, which combines electron-rich, imidazole-based conjugated ionic liquids into a perovskite layer, and has the advantages of increased conductivity, improved film morphology, expanded crystallinity, balanced charge transfer and high stability.

[0005] In order to achieve the above technical objectives, 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 (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid hole transport layer (MeO-4PACz), an ionic liquid BzMIMBr 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, C 60 The electron transport layer, the 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline hole blocking layer (BCP) and the metal Al electrode layer.

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

[0007] (1) CsI, MABr, FAI, PbI2 and PbBr2 are weighed in a molar ratio of 0.05-0.1:0.05-0.1:1-2:1-2:0.05-0.1, and then the weighed CsI, MABr, FAI, PbI2 and PbBr2 are dissolved in a mixed solution of DMF and DMSO, and stirred at 58-62° C. for 1-1.2 h to form a ternary perovskite precursor solution with a concentration of 1.4 M;

[0008] (2) BzMIMBr with different molar masses was mixed with 1 ml of pure ACN to obtain BzMIMBr solutions with different concentrations;

[0009] (3) 100 μl of BzMIMBr solution of different concentrations is mixed with 900 μl of ternary perovskite precursor solution to form a BzMIMBr-doped perovskite precursor solution, thereby obtaining a ternary perovskite layer.

[0010] Furthermore, the different concentrations of the BzMIMBr solution are 0.5M, 1.0M, and 1.5M respectively.

[0011] Another object of the present invention is to provide a method for preparing a ternary perovskite solar cell, comprising the following steps:

[0012] S1. Clean the ITO glass substrate with detergent, isopropyl alcohol solution, deionized water and anhydrous ethanol in sequence, and then clean it with a UV ozone cleaner for 18 to 22 minutes after drying;

[0013] S2, spin coating the hole transport layer MeO-4PACz on the cleaned ITO glass substrate, and then annealing at 100-110°C for 9-11 min;

[0014] S3, dynamically spin-coating the BzMIMBr-doped ternary perovskite precursor solution on the hole transport layer MeO-4PACz at 4000 rpm, followed by annealing at 100-110°C for 48-52 min;

[0015] S4. Evaporating the electron transport layer C onto the perovskite layer in a vacuum coating machine 60 , thickness is 14-16nm;

[0016] S5, evaporating a hole blocking layer BCP on the electron transport layer in a vacuum coating machine, with a thickness of 4.5 to 5.5 nm;

[0017] S6. In a vacuum coating machine, a metal electrode Al is evaporated onto the hole blocking layer with a thickness of 115 to 125 nm.

[0018] The beneficial effects of the present invention are:

[0019] 1) In the present invention, the imidazole ionic liquid is introduced into the perovskite layer, which reduces the defect state density of the perovskite, improves the stability and life of the perovskite, and also enhances the electron mobility of the solar cell, thereby improving the photocurrent of the perovskite solar cell;

[0020] 2) In the present invention, the doping of imidazole ionic liquid BzMIMBr 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 BzMIMBr doping can effectively balance the charge transfer and inhibit the ion migration in the ternary composite material;

[0021] 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

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0023] Figure 1 The photoelectric conversion efficiency statistics of the ternary perovskite solar cell with or without BzMIMBr doping of the present invention are shown in FIG.

[0024] Figure 2 The absorption spectrum of the ternary perovskite solar cell with or without BzMIMBr doping of the present invention;

[0025] Figure 3 The photoelectric conversion efficiency statistics of the ternary perovskite solar cell with or without BzMIMBr doping of the present invention are shown in FIG.

[0026] Figure 4 The external quantum efficiency diagram of the ternary perovskite solar cell with or without BzMIMBr doping of the present invention;

[0027] Figure 5 It is a forward scan JV curve diagram of the ternary perovskite solar cell with or without BzMIMBr doping of the present invention;

[0028] Figure 6 It is a reverse scan JV curve diagram of the ternary perovskite solar cell with or without BzMIMBr doping according to the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] A high-efficiency ternary perovskite solar cell structure from bottom to top: ITO / MeO-4PACz / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 / C 60 / BCP / Al;

[0032] The preparation method thereof comprises the following steps:

[0033] (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;

[0034] (2) spin coating the hole transport layer MeO-4PACz on the cleaned ITO glass substrate, followed by annealing at 100 °C for 10 min;

[0035] (3) 1.4 M ternary perovskite precursor solution was dynamically spin-coated on the hole transport layer MeO-4PACz at 4000 rpm, followed by annealing at 100 °C for 50 min;

[0036] (4) Evaporating the electron transport layer C onto the perovskite layer in a vacuum coating machine 60 , thickness is 15nm;

[0037] (5) depositing a hole blocking layer BCP on the electron transport layer in a vacuum coating machine with a thickness of 5 nm;

[0038] (6) A metal electrode Al is evaporated onto the hole blocking layer in a vacuum coating machine with a thickness of 120 nm.

[0039] Example 2

[0040] A high-efficiency ternary perovskite solar cell structure from bottom to top: ITO / MeO-4PACz / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I0.95 Br 0.05 )3+BzMIMBr / C 60 / BCP / Al;

[0041] The preparation method thereof comprises the following steps:

[0042] (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;

[0043] (2) spin coating the hole transport layer MeO-4PACz on the cleaned ITO glass substrate, followed by annealing at 100 °C for 10 min;

[0044] (3) 0.5M-1.5M BzMIMBr-doped ternary perovskite precursor solution was dynamically spin-coated on the hole transport layer MeO-4PACz at 4000 rpm, followed by annealing at 100 °C for 50 min;

[0045] (4) Evaporating the electron transport layer C onto the perovskite layer in a vacuum coating machine 60 , thickness is 15nm;

[0046] (5) depositing a hole blocking layer BCP on the electron transport layer in a vacuum coating machine with a thickness of 5 nm;

[0047] (6) A metal electrode Al is evaporated onto the hole blocking layer in a vacuum coating machine with a thickness of 120 nm.

[0048] Example 3

[0049] The high-efficiency ternary perovskite solar cells with different structures prepared in combination with Examples 1-2 were tested for their respective performances, as follows:

[0050] As can be seen from the above, compared with Example 1, Example 2 introduces BzMIMBr into the ternary perovskite layer, and Figure 1 It can be seen that the photoelectric conversion efficiency of the perovskite device formed by introducing BzMIMBr can be significantly improved. When the introduction amount of BzMIMBr is 1.0 mol, the photoelectric conversion efficiency can be increased by more than 10%.

[0051] 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 BzMIMBr-doped mixed perovskite is slightly blue-shifted due to the quantum confinement effect.

[0052] By attaching Figure 3It can be seen that the photoelectric conversion efficiency of BzMIMBr-doped ternary perovskite solar cells is significantly better than that of undoped perovskite solar cells.

[0053] By attaching Figure 4 It can be seen that the external quantum efficiency of BzMIMBr-doped ternary solar cells in the range of 350-750nm is higher than that of undoped perovskite devices, which indicates that BzMIMBr-doped ternary solar cells have higher photoquantum conversion efficiency, which is conducive to higher photocurrent.

[0054] By attaching Figure 5 It can be seen that the photocurrent hysteresis in BzMIMBr-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 BzMIMBr.

Claims

1. A high-efficiency ternary perovskite solar cell, characterized in that: From bottom to top, it includes an ITO conductive glass layer, a (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid hole transport layer (MeO-4PACz), an ionic liquid BzMIMBr 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, C 60 The electron transport layer, the 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline hole blocking layer (BCP) and the metal Al 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 are weighed in a molar ratio of 0.05-0.1:0.05-0.1:1-2:1-2:0.05-0.1, and then the weighed CsI, MABr, FAI, PbI2 and PbBr2 are dissolved in a mixed solution of DMF and DMSO, and stirred at 58-62° C. for 1-1.2 h to form a ternary perovskite precursor solution with a concentration of 1.4 M; (2) BzMIMBr with different molar masses was mixed with 1 ml of pure ACN to obtain BzMIMBr solutions with different concentrations; (3) 100 μl of BzMIMBr solution of different concentrations is mixed with 900 μl of ternary perovskite precursor solution to form a BzMIMBr-doped perovskite precursor solution, thereby obtaining a ternary perovskite layer.

3. A high-efficiency ternary perovskite solar cell according to claim 3, characterized in that: The different concentrations of the BzMIMBr solution are 0.5M, 1.0M, and 1.5M respectively.

4. A method for preparing a high-efficiency ternary perovskite solar cell, characterized in that: The steps include: S1. Clean the ITO glass substrate with detergent, isopropyl alcohol solution, deionized water and anhydrous ethanol in sequence, and then clean it with a UV ozone cleaner for 18 to 22 minutes after drying; S2, spin coating the hole transport layer MeO-4PACz on the cleaned ITO glass substrate, and then annealing at 100-110°C for 9-11 min; S3, dynamically spin-coating the BzMIMBr-doped ternary perovskite precursor solution on the hole transport layer MeO-4PACz at 4000 rpm, followed by annealing at 100-110°C for 48-52 min; S4. Evaporating the electron transport layer C onto the perovskite layer in a vacuum coating machine 60 , thickness is 14-16nm; S5, evaporating a hole blocking layer BCP on the electron transport layer in a vacuum coating machine, with a thickness of 4.5 to 5.5 nm; S6. In a vacuum coating machine, a metal electrode Al is evaporated onto the hole blocking layer with a thickness of 115 to 125 nm.

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