High-efficiency stable ternary perovskite solar cell and preparation method thereof

Abstract

The invention discloses a high-efficiency stable ternary perovskite solar cell and a preparation method thereof, and the solar cell sequentially comprises, from bottom to top, an ITO conductive glass substrate layer, a hole transport layer MeO-4PACz, a ternary perovskite layer formed by mixing a multi-active-site micromolecule TFSP 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, 2 '-biphenyl-2, 6'-biphenyl-2, 6 '-biphenyl-2, 6'-biphenyl-2, 6 '-biphenyl-2, 6'-biphenyl-2, 6 '-biphenyl-2, 6'-biphenyl-2, 6 '-biphenyl-2, 6'-biphenyl-2, 6 '-biphenyl-2, 6 The thin film solar cell is characterized by comprising a metal electrode layer, a 9, 9-dimethyl-4, 7-biphenyl-1, 10-phenanthroline hole barrier layer BCP and a metal Ag electrode layer. By introducing multi-active-site small molecules into the perovskite active layer, multi-stage regulation and control are 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 and stable ternary perovskite solar cell and a preparation method thereof. Background Art

[0002] Photovoltaic power generation has experienced rapid development and has become an important source of electricity. In order to solve the problems of high energy consumption in the preparation of silicon-based solar cells and low photoelectric conversion efficiency, and to achieve leapfrog development in photovoltaic power generation technology, a series of new photovoltaic cells such as perovskite solar cells have received widespread attention.

[0003] As the third generation of solar cells, perovskite solar cells have exceeded 26% photoelectric conversion efficiency in just sixteen 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, many literatures describe the small molecule doping of perovskites or transport layers to improve the performance of the perovskite layer or transport layer; however, this method can only change the properties of a single layer and cannot solve the problems existing in other active layers, resulting in the inability to achieve optimal regulation of perovskite solar cells, while increasing the difficulty of further improving their performance. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high-efficiency and stable ternary perovskite solar cell and a preparation method thereof, which introduces multi-active site small molecules into the organic-inorganic ternary perovskite perovskite solar cell of the perovskite layer to achieve multi-stage regulation, so that it has the advantages of improving the stability of the precursor solution, improving the film morphology, improving the crystallinity, improving the charge transfer 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-4PACz, a multi-active site small molecule TFSP and a perovskite layer Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 ) 3 The ternary perovskite layer, the [6,6]-phenyl-C61-butyric acid isomethyl ester electron transport layer PCBM, the 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline hole blocking layer BCP and the metal Ag electrode layer are formed by mixing.

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

[0007] 1) The molar ratio is CsI:MABr:FAI:PbI 2 :PbBr 2 =0.05~0.1:0.05~0.1:1~2:1~2:0.05~0.1 Weigh CsI, MABr, FAI, PbI 2 and PbBr 2 , and then weigh CsI, MABr, FAI, PbI 2 and PbBr 2 Dissolve in a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and stir at 58-62° C. for 2-2.5 hours to form a perovskite precursor solution with a concentration of 1.45 M;

[0008] 2) Mixing different masses of TFSP with pure DMF to obtain TFSP solutions of different concentrations;

[0009] 3) Mixing TFSP solutions of different concentrations with the ternary perovskite precursor solution to form a TFSP-doped perovskite precursor solution;

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

[0011] Furthermore, the concentrations of the TFSP solutions of different concentrations are 0.05 mg / ml, 0.10 mg / ml, 0.50 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] S1, using glass cleaning liquid, isopropyl alcohol solution, deionized water and anhydrous ethanol to ultrasonically clean the ITO glass substrate for 15 to 20 minutes, and then drying it and cleaning it with an ultraviolet ozone cleaning machine for 10 to 15 minutes;

[0014] S2, spin coating the hole transport layer MeO-4PACz on the cleaned ITO glass substrate, and then annealing at 100-120°C for 10-15min;

[0015] S3, dynamically spin-coating the TFSP-doped ternary perovskite precursor solution on the hole transport layer MeO-4PACz at 6000 rpm, and dynamically spin-coating 0.15 ml of chlorobenzene as an anti-solvent, followed by annealing at 100-120°C for 1-1.5 h;

[0016] S4, spin coating an electron transport layer PCBM on the perovskite layer with a thickness of 10 to 20 nm;

[0017] S5, evaporating a hole blocking layer BCP on the electron transport layer in a vacuum coating machine, with a thickness of 5 to 7 nm;

[0018] S6. In a vacuum coating machine, a metal electrode Ag is evaporated onto the hole blocking layer with a thickness of 120 to 130 nm.

[0019] The beneficial effects of the present invention are:

[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 and fill factor of the perovskite solar cell.

[0021] 2. In the present invention, the doping of multi-active site small molecule TFSP 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 TFSP doping can effectively balance the charge transfer and inhibit the ion migration in the ternary composite material;

[0022] 3. In the present invention, the interaction between TFSP and the perovskite precursor solution regulates the crystallization process, 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 TFSP doping;

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

[0028] Figure 5 Forward scan and reverse scan JV curves of ternary perovskite solar cells with and without TFSP 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] This embodiment prepares a high-efficiency ternary perovskite solar cell, and the specific steps are as follows:

[0032] When the high-efficiency and stable ternary perovskite solar cell structure of the present invention is as follows from bottom to top:

[0033] 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;

[0034] The specific preparation of high-efficiency ternary perovskite solar cells includes the following steps:

[0035] (1) ultrasonically cleaning the ITO glass substrate with glass cleaning solution, isopropyl alcohol solution, deionized water and anhydrous ethanol for 15 minutes, and then cleaning it with a UV ozone cleaning machine for 10 minutes after drying;

[0036] (2) spin coating the hole transport layer MeO-4PACz on the cleaned ITO glass substrate, followed by annealing at 100 °C for 10 min;

[0037] (3) 1.45 M ternary perovskite precursor solution was dynamically spin-coated at 6000 rpm on the hole transport layer MeO-4PACz, and 0.15 ml chlorobenzene was dynamically spin-coated as an anti-solvent, followed by annealing at 100 °C for 1 h;

[0038] (4) Spin coating the electron transport layer PCBM on the perovskite layer ， Thickness: 15nm;

[0039] (5) depositing a hole blocking layer BCP on the electron transport layer in a vacuum coating machine with a thickness of 5 nm;

[0040] (6) In a vacuum coating machine, a metal electrode Ag is evaporated onto the hole blocking layer with a thickness of 120 nm; thus, a high-efficiency ternary perovskite solar cell is obtained.

[0041] Example 2

[0042] This embodiment prepares a high-efficiency ternary perovskite solar cell, and the specific steps are as follows:

[0043] When the high-efficiency ternary perovskite solar cell structure of the present invention is as follows from bottom to top:

[0044] ITO / MeO-4PACz / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 ) 3 +TFSP / PCBM / BCP / Ag;

[0045] The specific preparation of high-efficiency ternary perovskite solar cells includes the following steps:

[0046] (1) ultrasonically cleaning the ITO glass substrate with glass cleaning solution, isopropyl alcohol solution, deionized water and anhydrous ethanol for 15 minutes, and then cleaning it with a UV ozone cleaning machine for 10 minutes after drying;

[0047] (2) spin coating the hole transport layer MeO-4PACz on the cleaned ITO glass substrate, followed by annealing at 100 °C for 10 min;

[0048] (3) 0.05 mg / ml-1.0 mg / ml TFSP-doped ternary perovskite precursor solution was dynamically spin-coated on the hole transport layer MeO-4PACz at 6000 rpm, and 0.15 ml chlorobenzene was dynamically spin-coated as an anti-solvent, followed by annealing at 100 °C for 1 h;

[0049] (4) Spin coating the electron transport layer PCBM on the perovskite layer ， Thickness: 15nm;

[0050] (5) depositing a hole blocking layer BCP on the electron transport layer in a vacuum coating machine with a thickness of 5 nm;

[0051] (6) In a vacuum coating machine, a metal electrode Ag is evaporated onto the hole blocking layer with a thickness of 120 nm; thus, a high-efficiency ternary perovskite solar cell is obtained.

[0052] Example 3

[0053] This embodiment is Comparative Example 1, which is as follows:

[0054] When the structure of the prepared high-efficiency ternary perovskite solar cell is as follows from bottom to top:

[0055] ITO / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 ) 3 ;

[0056] The preparation of high-efficiency ternary perovskite solar cells specifically includes the following steps:

[0057] (1) ultrasonically cleaning the ITO glass substrate with glass cleaning solution, isopropyl alcohol solution, deionized water and anhydrous ethanol for 15 minutes, and then cleaning it with a UV ozone cleaning machine for 10 minutes after drying;

[0058] (2) 0.5M-1.5M TFSP-doped ternary perovskite precursor solution was dynamically spin-coated on an ITO glass substrate at 6000 rpm, and 0.15 ml of chlorobenzene was dynamically spin-coated as an anti-solvent, followed by annealing at 100 degrees Celsius for 1 hour; thus, the first comparative high-efficiency ternary perovskite solar cell was obtained.

[0059] Example 4

[0060] This embodiment is Comparative Example 2, which is as follows:

[0061] When the structure of the prepared high-efficiency ternary perovskite solar cell is as follows from bottom to top:

[0062] ITO / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 ) 3 +TFSP;

[0063] The preparation of high-efficiency ternary perovskite solar cells specifically includes the following steps:

[0064] (1) ultrasonically cleaning the ITO glass substrate with glass cleaning solution, isopropyl alcohol solution, deionized water and anhydrous ethanol for 15 minutes, and then cleaning it with a UV ozone cleaning machine for 10 minutes after drying;

[0065] (2) 0.1 mg / ml TFSP-doped ternary perovskite precursor solution was dynamically spin-coated on an ITO glass substrate at 6000 rpm, and 0.15 ml chlorobenzene was dynamically spin-coated as an anti-solvent, followed by annealing at 100 degrees Celsius for 1 hour; thus, a second comparative high-efficiency ternary perovskite solar cell was obtained.

[0066] Example 5

[0067] 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:

[0068] By attaching Figure 1 It can be seen that the photoelectric conversion efficiency of the perovskite device formed by introducing TFSP can be significantly improved. When the introduction amount of TFSP is 0.1 mg / ml, the photoelectric conversion efficiency can be increased by more than 10%.

[0069] 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 TFSP-doped hybrid perovskite is slightly blue-shifted due to the quantum confinement effect.

[0070] By attaching Figure 3 It can be seen that in the PL spectrum, the excitation intensity in the TFSP-doped hybrid perovskite is significantly higher than that in the pure perovskite film.

[0071] By attaching Figure 4 It can be seen that the crystallization intensity of TFSP-doped organic-inorganic perovskite film is higher than that of undoped perovskite film, which indicates that TFSP-doped ternary solar cells have higher film quality and are conducive to higher photocurrent.

[0072] By attaching Figure 5 It can be seen that the photocurrent hysteresis in TFSP-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 TFSP.

Claims

1. A high-efficiency and stable ternary perovskite solar cell, characterized in that: From bottom to top, it includes ITO conductive glass layer, (2-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid hole transport layer MeO-4PACz, multi-active site small molecule TFSP and 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 and stable ternary perovskite solar cell according to claim 1, characterized in that: The preparation process of the ternary perovskite layer is as follows: 1) Weigh CsI, MABr, FAI, PbI2 and PbBr2 in 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, then dissolve the weighed CsI, MABr, FAI, PbI2 and PbBr2 in a mixed solution of N,N-dimethylformamide DMF and dimethyl sulfoxide DMSO, and stir at 58-62°C for 2-2.5h to form a perovskite precursor solution with a concentration of 1.45M; 2) Mixing different masses of TFSP with pure DMF to obtain TFSP solutions of different concentrations; 3) Mixing TFSP solutions of different concentrations with the ternary perovskite precursor solution to form a TFSP-doped perovskite precursor solution; 4) Coating the TFSP-doped perovskite precursor solution on the hole transport layer MeO-4PACz to form a ternary perovskite layer.

3. A high-efficiency and stable ternary perovskite solar cell according to claim 1, characterized in that: The concentrations of the TFSP solutions of different concentrations are 0.05 mg / ml, 0.10 mg / ml, 0.50 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: S1, using glass cleaning liquid, isopropyl alcohol solution, deionized water and anhydrous ethanol to ultrasonically clean the ITO glass substrate for 15 to 20 minutes, and then drying it and cleaning it with an ultraviolet ozone cleaning machine for 10 to 15 minutes; S2, spin coating the hole transport layer MeO-4PACz on the cleaned ITO glass substrate, and then annealing at 100-120°C for 10-15min; S3, dynamically spin-coating the TFSP-doped ternary perovskite precursor solution on the hole transport layer MeO-4PACz at 6000 rpm, and dynamically spin-coating 0.15 ml of chlorobenzene as an anti-solvent, followed by annealing at 100-120°C for 1-1.5 h; S4, spin coating an electron transport layer PCBM on the perovskite layer with a thickness of 10 to 20 nm; S5, evaporating a hole blocking layer BCP on the electron transport layer in a vacuum coating machine, with a thickness of 5 to 7 nm; S6. In a vacuum coating machine, a metal electrode Ag is evaporated onto the hole blocking layer with a thickness of 120 to 130 nm.

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