Multifunctional guanidine salt doped perovskite solar cell and preparation method thereof

Abstract

The invention discloses a multifunctional guanidine salt doped perovskite solar cell and a preparation method thereof. The cell comprises an ITO (indium tin oxide) conductive glass substrate layer, a hole transport layer (MeO-4PACz), a perovskite layer Cs0.05 (FA0.95 MA0.05) 0.95 Pb (I0.95 Br0.05) 3 doped with biguanide hydrochloride (BH), a [6, 6]-phenyl-C61-butyric acid isomethyl ester electron transport layer (PCBM), a 2, 9-dimethyl-4, 7-biphenyl-1, 10-phenanthrene hole blocking layer (BCP) and a metal Ag electrode layer from bottom to top. During preparation, by means of the strong chemical action of nitrogen atoms in BH and Pb < 2 + > ions, the crystallization direction of perovskite is changed, the defect state density is reduced, non-radiative recombination is inhibited, and the carrier separation and transmission efficiency is improved. According to the invention, BH is introduced into the perovskite active layer, so that the application of guanidine derivatives in perovskite photovoltaic materials is expanded, and a new way is provided for preparing stable and efficient perovskite solar cells.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a multifunctional guanidine salt-doped perovskite solar cell and a preparation method thereof. Background Art

[0002] Organic-inorganic perovskites (represented by ABX3) have become a focus of research and industry due to their outstanding advantages, including abundant raw materials, simple synthesis, high light absorption coefficient, long carrier transport distance, strong low-temperature desorption ability, and flexible band gap adjustment. Currently, the highest power conversion efficiency (PCE) of single-junction perovskite solar cells has climbed to 26.41%. Inverted perovskite solar cells (IPSCs), with their simple structure, low-temperature manufacturing process, diverse choice of charge transport materials, excellent stability, and good compatibility, are expected to become the main force of the next generation of thin-film photovoltaic cells.

[0003] However, in order to create high-performance perovskite solar cells, the key problem of incomplete perovskite crystallization needs to be overcome urgently, which is closely related to non-radiative recombination and chemical transmission losses. The defects of perovskite itself are the main bottleneck restricting its progress towards higher PCE. These defects cause crystal deformation, generate non-radiative carriers, and then cause voltage loss, abnormal delay of current density-voltage (JV) curve and phase separation, which seriously reduce the photoelectric performance and stability of perovskite solar cells. Moreover, the prepared film will undergo external aging under the influence of the environment, resulting in various defects, which greatly reduce the battery efficiency and long-term stability. For example, the lack of halogen ions will cause unpaired Pb 2+ Cations remain on the perovskite film and grain boundary surfaces, exhibiting a Lewis acid effect, adsorbing electrons and forming trap states that are unfavorable for redox reactions. Therefore, eliminating these defects is imperative to extend the life of perovskite solar cells and approach the maximum photovoltaic conversion efficiency. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a multifunctional guanidine salt-doped perovskite solar cell and a preparation method thereof, and introduces the multifunctional guanidine salt small molecule biguanide hydrochloride (BH) into the perovskite layer of the organic-inorganic ternary perovskite solar cell to achieve multi-stage regulation, so that it has the advantages of improving the stability of the precursor solution, improving the film morphology, increasing the crystallinity, improving the 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 multifunctional guanidine salt doped 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 multifunctional guanidine salt small molecule biguanide hydrochloride (BH) and a perovskite layer Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 blended 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-diazophenanthroline hole blocking layer (BCP) and a metal Ag electrode layer.

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

[0007] S1. 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, and dissolve CsI, MABr, FAI, PbI2, and PbBr2 in a mixed solution of DMF and DMSO, and then stir at 60°C for 2h to form a perovskite precursor solution with a concentration of 1.45M;

[0008] S2, mixing different masses of BH with pure DMF to obtain BH solutions of different concentrations;

[0009] S3, mixing BH solutions of different concentrations with the ternary perovskite precursor solution to form a BH-doped perovskite precursor solution;

[0010] S4. Applying a BH-doped perovskite precursor solution on the hole transport layer to form a ternary perovskite layer.

[0011] Furthermore, the concentrations of the BH solutions of different concentrations are 0.10 mmol / ml, 0.20 mmol / ml, 0.30 mmol / ml, 0.40 mmol / ml, 0.50 mmol / ml, 0.60 mmol / ml, 0.70 mmol / ml and 0.80 mmol / ml respectively.

[0012] Another object of the present invention is to provide a method for preparing a multifunctional guanidine-doped perovskite solar cell, comprising the following steps:

[0013] (1) Cleaning the glass sheet: During the cleaning process, the ITO glass substrate is ultrasonically cleaned for 15 to 20 minutes using glass cleaning solution, isopropyl alcohol solution, deionized water, and anhydrous ethanol in sequence, and then placed in a drying oven for drying. After drying, it is cleaned with a UV ozone cleaner for 10 minutes;

[0014] (2) The hole transport layer MeO-4PACz was spin-coated on the cleaned ITO glass substrate and then annealed at 100 °C for 10 min;

[0015] (3) Dynamically spin-coating the BH-doped ternary perovskite precursor solution on the hole transport layer MeO-4PACz at a speed of 6000-7000 rpm, and dynamically spin-coating 0.15 ml of chlorobenzene as an antisolvent, followed by annealing at 100 °C for 1 h;

[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) In a vacuum coating machine, a metal electrode Ag is evaporated onto the hole blocking layer with a thickness of 120 nm.

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

[0020] 1. The present invention introduces a multifunctional guanidine salt small molecule BH into the perovskite layer, thereby reducing the defect state density of the perovskite, improving the hydrophobicity of the battery, and enhancing the stability and life of the perovskite. At the same time, 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 the multifunctional guanidine salt small molecule BH 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 BH 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 BH 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 paying any creative work.

[0024] Figure 1 Statistical graph of the photoelectric conversion efficiency of the perovskite solar cell with and without multifunctional guanidine salt doping of the present invention;

[0025] Figure 2 The XPS graphs of the perovskite solar cell with and without multifunctional guanidine doping of the present invention are shown;

[0026] Figure 3 PL graphs of the perovskite solar cell with and without multifunctional guanidine salt doping according to the present invention;

[0027] Figure 4 The XRD diagram of the ternary perovskite film with or without multifunctional guanidine salt doping of the present invention;

[0028] Figure 5 The forward scan and reverse scan JV curves of the perovskite solar cell with or without multifunctional guanidine salt doping of the present invention are shown;

[0029] Figure 6 The power conversion efficiency (PCE) and short-circuit current density (J) of the perovskite solar cell without multifunctional guanidine doping are shown in FIG. SC ) and open circuit voltage (V OC ) Schematic diagram;

[0030] Figure 7 This is a comparison chart of the power conversion efficiency (PCE) of the perovskite solar cell without multifunctional guanidine salt doping of the present invention and the control cell after use. DETAILED DESCRIPTION

[0031] 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.

[0032] Example 1

[0033] When the structure of the multifunctional guanidine-doped perovskite solar cell of the present invention is as follows from bottom to top:

[0034] 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;

[0035] The preparation method comprises the following steps:

[0036] (1) Ultrasonic cleaning of the ITO glass substrate was performed using glass cleaning solution, isopropyl alcohol solution, deionized water, and anhydrous ethanol for 15 min, followed by drying and then cleaning with an ultraviolet ozone cleaner for 10 min;

[0037] (2) The hole transport layer MeO-4PACz was spin-coated on the cleaned ITO glass substrate and then annealed at 100 °C for 10 min;

[0038] (3) 1.45 M ternary perovskite precursor solution was dynamically spin-coated on the hole transport layer MeO-4PACz at 6000 rpm, and 0.15 ml of chlorobenzene was dynamically spin-coated as an antisolvent, followed by annealing at 100 °C for 1 h;

[0039] (4) Spin coating the electron transport layer PCBM on the perovskite layer;

[0040] (5) depositing a hole blocking layer (BCP) on the electron transport layer in a vacuum coating machine with a thickness of 5 nm;

[0041] (6) In a vacuum coating machine, a metal electrode Ag is evaporated onto the hole blocking layer with a thickness of 120 nm.

[0042] Example 2

[0043] When the structure of a multifunctional guanidine-doped perovskite solar cell 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+BH / PCBM / BCP / Ag;

[0045] The preparation method comprises the following steps:

[0046] (1) Ultrasonic cleaning of the ITO glass substrate was performed using glass cleaning solution, isopropyl alcohol solution, deionized water, and anhydrous ethanol for 15 min, followed by drying and then cleaning with an ultraviolet ozone cleaner for 10 min;

[0047] (2) The hole transport layer MeO-4PACz was spin-coated on the cleaned ITO glass substrate and then annealed at 100 °C for 10 min;

[0048] (3) 0.1 mmol / ml-0.8 mmol / ml BH-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 antisolvent, followed by annealing at 100 °C for 1 h;

[0049] (4) Spin coating the electron transport layer PCBM on the perovskite layer;

[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.

[0052] Example 3

[0053] This embodiment is a comparative example, and is as follows:

[0054] When the structure of the multifunctional guanidine salt-doped perovskite solar cell of the present invention 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 method comprises the following steps:

[0057] (1) Ultrasonic cleaning of the ITO glass substrate was performed using glass cleaning solution, isopropyl alcohol solution, deionized water, and anhydrous ethanol for 15 min, followed by drying and then cleaning with an ultraviolet ozone cleaner for 10 min;

[0058] (2) 0.1 mmol / ml-0.8 mmol / ml BH-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 antisolvent, followed by annealing at 100 °C for 1 h.

[0059] Example 4

[0060] This embodiment is a comparative example, and is as follows:

[0061] When the structure of the multifunctional guanidine salt-doped perovskite solar cell of the present invention is as follows from bottom to top:

[0062] ITO / Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I0.95 Br 0.05 )3+BH

[0063] The preparation method comprises the following steps:

[0064] (1) Ultrasonic cleaning of the ITO glass substrate was performed using glass cleaning solution, isopropyl alcohol solution, deionized water, and anhydrous ethanol for 15 min, followed by drying and then cleaning with an ultraviolet ozone cleaner for 10 min;

[0065] (2) 0.5 mmol / ml BH-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 antisolvent, followed by annealing at 100 °C for 1 h.

[0066] Example 5

[0067] The performance of the multifunctional guanidine-doped perovskite solar cells with different structures prepared in combination with Examples 1-4 was tested as follows:

[0068] By attaching Figure 1 It can be seen that the photoelectric conversion efficiency of the perovskite device formed by introducing multifunctional guanidine salt (BH) will be significantly improved. When the BH introduction amount is 0.5 mmol / ml, its photoelectric conversion efficiency can be increased by more than 15%.

[0069] By attaching Figure 2 It can be seen that in XPS, the spectra of BH-doped mixed perovskite are slightly red-shifted compared with those of pure perovskite film. 2+ Produce strong chemical interactions.

[0070] By attaching Figure 3 It can be seen that in the PL spectrum, the excitation intensity in the BH-doped mixed 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 the BH-doped perovskite film is higher than that of the undoped perovskite film, which indicates that the multifunctional guanidine-doped perovskite solar cell has higher film quality and is conducive to higher photocurrent.

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

[0073] By attaching Figure 6It can be seen that the BH-doped perovskite solar cell achieved a power conversion efficiency (PCE) of 23.51% and a short-circuit current density (J SC ) up to 24.85 mA cm -2 , open circuit voltage (V OC ) is 1.13V.

[0074] By attaching Figure 7 It can be seen that after aging for 1500 hours in an environment with a relative humidity of 35%, the initial PCE of the BH-doped perovskite solar cell still remains at 95.1%, far exceeding the control device.

Claims

1. A multifunctional guanidine-doped perovskite solar cell, characterized in that: From bottom to top, it includes an ITO conductive glass layer, a (2-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid hole transport layer (MeO-4PACz), a multifunctional guanidine salt small molecule biguanide hydrochloride (BH) and a perovskite layer Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 blended 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-diazophenanthroline hole blocking layer (BCP) and a metal Ag electrode layer.

2. A multifunctional guanidine-doped perovskite solar cell according to claim 1, characterized in that: The preparation process of the ternary perovskite layer is as follows: S1. 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, and dissolve CsI, MABr, FAI, PbI2, and PbBr2 in a mixed solution of DMF and DMSO, and then stir at 60°C for 2h to form a perovskite precursor solution with a concentration of 1.45M; S2, mixing different masses of BH with pure DMF to obtain BH solutions of different concentrations; S3, mixing BH solutions of different concentrations with the ternary perovskite precursor solution to form a BH-doped perovskite precursor solution; S4. Applying a BH-doped perovskite precursor solution on the hole transport layer to form a ternary perovskite layer.

3. The multifunctional guanidine-doped perovskite solar cell according to claim 1, characterized in that: The concentrations of the BH solutions of different concentrations are 0.10 mmol / ml, 0.20 mmol / ml, 0.30 mmol / ml, 0.40 mmol / ml, 0.50 mmol / ml, 0.60 mmol / ml, 0.70 mmol / ml and 0.80 mmol / ml respectively.

4. A method for preparing a multifunctional guanidine-doped perovskite solar cell, characterized in that: The steps include: (1) Cleaning the glass sheet: During the cleaning process, the ITO glass substrate is ultrasonically cleaned for 15 to 20 minutes using glass cleaning solution, isopropyl alcohol solution, deionized water, and anhydrous ethanol in sequence, and then placed in a drying oven for drying. After drying, it is cleaned with a UV ozone cleaner for 10 minutes; (2) The hole transport layer MeO-4PACz was spin-coated on the cleaned ITO glass substrate and then annealed at 100 °C for 10 min; (3) Dynamically spin-coating the BH-doped ternary perovskite precursor solution on the hole transport layer MeO-4PACz at a speed of 6000-7000 rpm, and dynamically spin-coating 0.15 ml of chlorobenzene as an antisolvent, followed by annealing at 100 °C for 1 h; (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) In a vacuum coating machine, a metal electrode Ag is evaporated onto the hole blocking layer with a thickness of 120 nm.

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