Perovskite solar cell and preparation method thereof

Abstract

The invention discloses a perovskite solar cell and a preparation method thereof. In order to solve the problem that the photoelectric conversion efficiency and the long-term stability are reduced due to the fact that a large number of defects are easily formed in the rapid crystallization process of an existing three-dimensional perovskite active layer, benzamidine hydrochloride or 2-pyridine formamidine hydrochloride is used for preparing a one-dimensional perovskite ligand solution; and spin-coating the one-dimensional perovskite ligand solution on the surface of the three-dimensional perovskite layer, and annealing to form the one-dimensional perovskite layer. Due to the existence of the one-dimensional perovskite layer, non-radiative recombination caused by surface defects of the three-dimensional perovskite layer is effectively reduced, and transmission and extraction of carriers are promoted; in addition, the one-dimensional perovskite has better hydrophobicity, and the stability of the three-dimensional perovskite layer is improved. The perovskite solar cell prepared by using the method has significantly enhanced photoelectric properties and stability.

Description

Technical Field

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

[0002] Perovskite thin-film solar cells are a disruptive photovoltaic technology that has attracted widespread attention. They have become ideal photovoltaic devices due to their low cost and excellent optoelectronic performance. However, the main problem facing this technology is that the conventional three-dimensional perovskite active layer will inevitably form defects during the rapid crystallization process. In particular, the defects distributed on the surface of the perovskite layer will cause non-radiative recombination of charges, which will seriously hinder the extraction and transmission of carriers during battery operation. At the same time, the defects are more likely to become invasion sites for external factors to the perovskite layer, making the three-dimensional perovskite active layer susceptible to factors such as water and oxygen, leading to the decomposition of the perovskite material, and ultimately resulting in a decrease in the optoelectronic performance and stability of the perovskite solar cell.

[0003] The introduction of large-sized or long-chain molecules into perovskite will form a one-dimensional perovskite structure. Compared with three-dimensional perovskites, one-dimensional perovskites usually have stronger hydrophobicity and thus better stability, but the limited charge transfer also leads to weaker photoelectric properties.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a perovskite solar cell and a method for preparing the same, aiming to solve the problem of low photoelectric conversion efficiency and low stability caused by defects in the existing three-dimensional perovskite active layer.

[0006] A first aspect of the present invention provides a method for preparing a perovskite solar cell, comprising the steps of:

[0007] Preparation of three-dimensional perovskite layers;

[0008] preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer;

[0009] Wherein, the step of preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer specifically includes:

[0010] Providing a one-dimensional perovskite ligand solution, wherein the one-dimensional perovskite ligand comprises benzamidine hydrochloride or 2-pyridinecarboxamidine hydrochloride;

[0011] The one-dimensional perovskite ligand solution is spin-coated on the surface of the three-dimensional perovskite layer, and annealing is performed to obtain the one-dimensional perovskite layer.

[0012] Optionally, the one-dimensional perovskite ligand solution is prepared by dissolving a one-dimensional perovskite ligand in an organic solvent, and the organic solvent is isopropanol or ethanol.

[0013] Optionally, in the step of spin coating the one-dimensional perovskite ligand solution on the surface of the three-dimensional perovskite layer and performing annealing treatment to obtain the one-dimensional perovskite layer, the spin coating parameters include: a rotation speed of 3000-6000 rpm and a time of 30-45 s;

[0014] The parameters of the annealing treatment include: temperature of 90-120° C. and time of 3-6 min.

[0015] Optionally, the thickness of the three-dimensional perovskite layer is 600-700 nm, and the thickness of the one-dimensional perovskite layer is 50-100 nm.

[0016] Optionally, the step of preparing the three-dimensional perovskite layer specifically includes:

[0017] Mixing lead iodide and cesium iodide in an organic solvent to obtain a lead iodide solution;

[0018] After spin coating the lead iodide solution, annealing is performed to obtain a lead iodide layer;

[0019] Mixing formamidine iodide, methylammonium chloride and methylammonium bromide in an organic solvent to obtain an organic halogen solution;

[0020] After the organic halogen solution is spin-coated on the surface of the lead iodide layer, an annealing treatment is performed to obtain a three-dimensional perovskite layer.

[0021] Optionally, the method for preparing the perovskite solar cell specifically comprises the steps of:

[0022] providing a conductive substrate;

[0023] Preparing an electron transport layer on the surface of the conductive substrate;

[0024] Preparing a three-dimensional perovskite layer on the surface of the electron transport layer;

[0025] preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer;

[0026] preparing a hole transport layer on the surface of the one-dimensional perovskite layer;

[0027] An electrode is prepared on the surface of the hole transport layer.

[0028] A second aspect of the present invention provides a perovskite solar cell, wherein the perovskite solar cell is prepared by the method described in the present invention.

[0029] According to a third aspect of the present invention, a perovskite solar cell is provided, wherein the perovskite solar cell comprises a three-dimensional perovskite layer and a one-dimensional perovskite layer disposed on the surface of the three-dimensional perovskite layer.

[0030] Optionally, the one-dimensional perovskite layer includes benzamidine hydrochloride or 2-pyridinecarboxamidine hydrochloride; and the one-dimensional perovskite is rod-shaped.

[0031] Optionally, the perovskite solar cell specifically includes a transparent conductive substrate, an electron transport layer, a three-dimensional perovskite layer, a one-dimensional perovskite layer, a hole transport layer and a metal electrode which are stacked in sequence.

[0032] Beneficial effects: The present invention provides a perovskite solar cell and a preparation method thereof. The method uses benzamidine hydrochloride or 2-pyridinecarboxamidine hydrochloride as a one-dimensional perovskite ligand to form a one-dimensional perovskite layer on the surface of a three-dimensional perovskite layer. The presence of the one-dimensional perovskite layer effectively reduces the non-radiative recombination caused by surface defects of the three-dimensional perovskite layer, and promotes the transmission and extraction of carriers. In addition, the one-dimensional perovskite has better hydrophobicity, which improves the stability of the three-dimensional perovskite layer. The perovskite solar cell prepared using this method has significantly enhanced photoelectric performance and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the structure of the perovskite solar cell prepared in Examples 3 and 4 of the present invention; wherein: 1 is a transparent conductive substrate, 2 is an electron transport layer, 3 is a three-dimensional perovskite layer, 4 is a one-dimensional perovskite layer, 5 is a hole transport layer, and 6 is a metal electrode.

[0034] Figure 2 The scanning electron microscope images of the perovskite layer prepared in Comparative Example 1 and Examples 1 and 2 of the present invention are shown.

[0035] Figure 3 It is a comparison diagram of the steady-state fluorescence spectra of the perovskite layers prepared in Comparative Example 1 and Examples 1 and 2 of the present invention.

[0036] Figure 4 The photoelectric conversion current-voltage curves of the perovskite solar cells prepared in Comparative Example 2 and Examples 3 and 4 of the present invention are shown; wherein (a) is Comparative Example 2, (b) is Example 3, and (c) is Example 4.

[0037] Figure 5 This is a comparison chart of the long-term stability of the perovskite solar cells prepared in Comparative Example 2 and Examples 3 and 4 of the present invention. DETAILED DESCRIPTION

[0038] The present invention provides a perovskite solar cell and a method for preparing the same. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] The existing three-dimensional perovskite layer is prone to forming a large number of defects during the rapid crystallization process, resulting in low photoelectric conversion efficiency and instability of perovskite solar cells. The introduction of large-sized or long-chain molecules into perovskite will form a one-dimensional perovskite structure. Compared with the three-dimensional perovskite structure, the one-dimensional perovskite usually has stronger hydrophobicity and thus better stability, but the limited charge transfer also leads to its weak photoelectric performance. Therefore, the inventors explored and developed new ligand materials, combined the advantages of one-dimensional and three-dimensional perovskites, and prepared efficient and stable hybrid dimensional perovskite solar cells.

[0040] Specifically, an embodiment of the present invention provides a method for preparing a perovskite solar cell, which comprises the steps of:

[0041] Preparation of three-dimensional perovskite layers;

[0042] preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer;

[0043] Wherein, the step of preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer specifically includes:

[0044] Providing a one-dimensional perovskite ligand solution, wherein the one-dimensional perovskite ligand comprises benzamidine hydrochloride (BZCl) or 2-pyridinecarboxamidine hydrochloride (2-APCl);

[0045] The one-dimensional perovskite ligand solution is spin-coated on the surface of the three-dimensional perovskite layer, and annealing is performed to obtain the one-dimensional perovskite layer.

[0046] The method uses benzamidine hydrochloride or 2-pyridinecarboxamidine hydrochloride as a one-dimensional perovskite ligand to form a one-dimensional perovskite layer (the one-dimensional perovskite is in a rod shape) on the surface of the three-dimensional perovskite layer. The presence of the one-dimensional perovskite layer effectively reduces the non-radiative recombination caused by surface defects of the three-dimensional perovskite layer, promotes the transmission and extraction of carriers; in addition, the one-dimensional perovskite has better hydrophobicity, which improves the stability of the three-dimensional perovskite layer. The perovskite solar cell prepared using this method has significantly enhanced photoelectric performance and stability.

[0047] In one embodiment, the method for preparing the perovskite solar cell comprises the steps of:

[0048] Step 1, providing a conductive substrate;

[0049] Step 2, preparing an electron transport layer on the surface of the conductive substrate;

[0050] Step 3, preparing a three-dimensional perovskite layer on the surface of the electron transport layer, comprising the steps of:

[0051] Provide lead iodide solution and organohalogen solution;

[0052] Spin coating the lead iodide solution on the surface of the electron transport layer and performing annealing to obtain a lead iodide layer;

[0053] Spin coating the organic halogen solution on the surface of the lead iodide layer and performing annealing treatment to obtain a three-dimensional perovskite layer;

[0054] Step 4, preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer, comprising the steps of:

[0055] Providing a one-dimensional perovskite ligand solution;

[0056] Spin coating the one-dimensional perovskite ligand solution on the surface of the three-dimensional perovskite layer and performing annealing treatment to obtain a one-dimensional perovskite layer;

[0057] Step 5, preparing a hole transport layer on the surface of the one-dimensional perovskite layer;

[0058] Step 6, preparing an electrode on the surface of the hole transport layer to complete the preparation of the perovskite solar cell.

[0059] The present invention prepares a rod-shaped one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer. The presence of the one-dimensional perovskite layer effectively reduces the non-radiative recombination caused by surface defects of the three-dimensional perovskite layer, and promotes the transmission and extraction of carriers; in addition, the one-dimensional perovskite has better hydrophobicity, which improves the stability of the three-dimensional perovskite layer. The perovskite solar cell prepared by this method has significantly enhanced photoelectric performance and stability.

[0060] It should be noted that the present invention is not limited to preparing perovskite solar cells according to the above preparation sequence, but can also first prepare a hole transport layer on the surface of a conductive substrate, prepare a three-dimensional perovskite layer on the surface of the hole transport layer, prepare a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer, prepare an electron transport layer on the surface of the one-dimensional perovskite layer, and prepare an electrode on the surface of the electron transport layer to complete the preparation of the perovskite solar cell.

[0061] In step 1, in one embodiment, the conductive substrate is a transparent conductive substrate. Further, the transparent conductive substrate is etched indium tin oxide (ITO) glass.

[0062] In one embodiment, the conductive substrate is a conductive substrate that has been cleaned and treated with ultraviolet ozone. Specifically, it is ultrasonically cleaned with detergent, ultrapure water and isopropyl alcohol in sequence and blown dry with a nitrogen gun, and the etched surface is treated with ultraviolet ozone for 15-30 minutes.

[0063] In step 2, in one embodiment, the step of preparing an electron transport layer on the surface of the conductive substrate specifically includes:

[0064] preparing an electron transport material solution;

[0065] The electron transport material solution is spin-coated on the surface of a conductive substrate and annealed to obtain the electron transport layer.

[0066] In one embodiment, the electron transport material solution is a mixed solution of a 15 wt % tin dioxide (SnO 2 ) aqueous solution and ultrapure water in a volume ratio of 1:5.

[0067] In one embodiment, the spin coating parameters include: a rotation speed of 2000-4000 rpm and a time of 30 s.

[0068] In one embodiment, the annealing parameters include: temperature of 150° C. and time of 30 min.

[0069] In one embodiment, the electron transport layer is a SnO2 electron transport layer with a thickness of 20-60 nm.

[0070] In step 3, in one embodiment, the step of preparing a three-dimensional perovskite layer on the surface of the electron transport layer specifically includes:

[0071] Step 3.1, mixing lead iodide (PbI2) and cesium iodide (CsI) and fully dissolving them in an organic solvent, and filtering to obtain a clear lead iodide solution;

[0072] Step 3.2, spin coating a lead iodide solution on the surface of the electron transport layer, and performing an annealing treatment to obtain a lead iodide layer;

[0073] Step 3.3, mixing formamidine iodide (FAI), methylammonium chloride (MACl), and methylammonium bromide (MABr) and fully dissolving them in an organic solvent, and filtering to obtain a clear organic halogen solution;

[0074] Step 3.4, spin-coating an organic halogen solution on the surface of the lead iodide layer and performing annealing treatment to obtain a three-dimensional perovskite layer.

[0075] In one embodiment, in step 3.1, the molar ratio of PbI2 and CsI is 20:1, and the total concentration in the lead iodide solution is 1.2-1.7M;

[0076] The organic solvent is a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the volume ratio of DMF to DMSO is 19:1.

[0077] In one embodiment, in step 3.2, the spin coating parameters include: a rotation speed of 1000-2500 rpm, a time of 30s-50s, such as 30s, 40s, 50s, etc.;

[0078] The parameters of the annealing treatment include: temperature of 50-80° C. and time of 40-80 s.

[0079] In one embodiment, in step 3.3, the mass ratio of FAI, MACl and MABr is 10:1:1, the total concentration in the organic halogen solution is 0.4-0.7 M, and the organic solvent is isopropanol (IPA) or ethanol (EtOH), preferably IPA.

[0080] In one embodiment, in step 3.4, the spin coating parameters include: a rotation speed of 1000-2500 rpm and a time of 30-50 s;

[0081] The parameters of the annealing treatment include: temperature of 130-150° C. and time of 10-20 min.

[0082] In step 4, a one-dimensional perovskite layer is prepared on the surface of the three-dimensional perovskite layer. After forming a one-dimensional / three-dimensional perovskite heterojunction on the surface of the three-dimensional perovskite, the ability of carrier migration can be effectively increased, and the passivation defects can be enhanced, thereby effectively improving the stability of the three-dimensional perovskite and protecting the three-dimensional perovskite crystal. At the same time, it can also effectively inhibit the ion migration of the perovskite surface, thereby improving the life of the perovskite.

[0083] In one embodiment, preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer specifically includes:

[0084] Step 4.1, in order to obtain a stable and efficient one-dimensional perovskite, the structurally similar ionic liquid -BZCl or 2-APCl is fully dissolved in an organic solvent, and filtered to obtain a clear one-dimensional perovskite ligand solution. Since BZCl and 2-APCl contain a benzene ring and a pyridine ring, respectively, they can produce a strong interaction with the three-dimensional perovskite, and their electronegativity and dipole moment are conducive to the formation of one-dimensional perovskite, passivation of defects and improvement of device performance. The corresponding perovskite film and device have higher hydrophobicity, stronger carrier transport capacity and more matching energy levels.

[0085] Step 4.2, spin-coating the one-dimensional perovskite ligand solution onto the surface of the three-dimensional perovskite layer, and performing annealing treatment to obtain a one-dimensional perovskite layer.

[0086] In one embodiment, in step 4.1, the mass of the BZCl or 2-APCl is 1-10 mg, the volume of the organic solvent is 1-1.5 mL; and the organic solvent is IPA or EtOH, preferably IPA.

[0087] In one embodiment, in step 4.2, the spin coating parameters include: a rotation speed of 3000-6000 rpm and a time of 30-60 s;

[0088] The parameters of the annealing treatment include: temperature of 90-120° C. and time of 3-6 min.

[0089] In step 5, in one embodiment, the step of preparing a hole transport layer on the surface of the one-dimensional perovskite layer specifically includes:

[0090] providing a hole transport material solution;

[0091] The hole transport material solution is spin-coated on the surface of the one-dimensional perovskite layer, and stored in a dry state away from light to obtain a hole transport layer.

[0092] In one embodiment, the method for preparing the hole transport material solution specifically includes: fully dissolving 72.3 mg of Spiro-OMeTAD in 1 mL of chlorobenzene (CB), adding 35 μL of 260 mg / mL Li-TFSI (lithium bis(trifluoromethanesulfonyl)imide) solution and 30 μL of TBP (tributyl phosphate), and filtering to obtain a clear hole transport material solution.

[0093] In one embodiment, the spin coating parameters include: a rotation speed of 4000 rpm and a time of 30 s.

[0094] In one embodiment, the hole transport layer is Spiro-OMeTAD with a thickness of 100-300 nm.

[0095] In step 6, in one embodiment, the electrode is a metal electrode. Further, the metal electrode is a gold electrode with a thickness of 60-90 nm.

[0096] In one embodiment, a metal electrode is prepared on the surface of the hole transport layer by evaporation, and finally a perovskite solar cell is obtained.

[0097] An embodiment of the present invention provides a perovskite solar cell, wherein the perovskite solar cell is prepared by the method described above in the embodiment of the present invention.

[0098] An embodiment of the present invention provides a perovskite solar cell, wherein the perovskite solar cell includes a three-dimensional perovskite layer and a one-dimensional perovskite layer disposed on the surface of the three-dimensional perovskite layer.

[0099] In one embodiment, the one-dimensional perovskite layer includes benzamidine hydrochloride or 2-pyridinecarboxamidine hydrochloride; and the one-dimensional perovskite is rod-shaped.

[0100] In one embodiment, the thickness of the three-dimensional perovskite layer is 650-750 nm, such as 650 nm, 700 nm, 750 nm, etc., and the thickness of the one-dimensional perovskite layer is 40-80 nm, such as 40 nm, 60 nm, 80 nm, etc.

[0101] In one embodiment, the perovskite solar cell specifically includes a transparent conductive substrate, an electron transport layer, a three-dimensional perovskite layer, a one-dimensional perovskite layer, a hole transport layer and a metal electrode which are stacked in sequence.

[0102] The present invention will be further described below by means of specific examples.

[0103] Example 1

[0104] This embodiment provides a method for preparing a perovskite film, comprising the following steps:

[0105] Step 1: Select a transparent glass substrate and cut it into 1.5×1.5cm 2 The size was ultrasonically cleaned with detergent, ultrapure water and isopropanol in turn and dried with a nitrogen gun. The surface was treated with UV-ozone for 20 minutes before use.

[0106] Step 2, preparing a three-dimensional perovskite layer on the surface of the transparent glass substrate treated in step 1, the specific steps are as follows:

[0107] Step 2.1, 600.6 mg of PbI2 and 19.5 mg of CsI were mixed and fully dissolved in 1 mL of a mixed solution of DMF and DMSO (the volume ratio of DMF to DMSO was 9:1), and a clear lead iodide solution was obtained by filtration;

[0108] Step 2.2, spin coating the lead iodide solution on the surface of the transparent glass substrate, the spin coating process is 1500 rpm for 30 seconds, and annealing on a hot plate at 70° C. for 1 minute to obtain a lead iodide layer;

[0109] Step 2.3, 60 mg of FAI, 6 mg of MACl and 6 mg of MABr were mixed and fully dissolved in IPA, and filtered to obtain a clear organic halogen solution;

[0110] Step 2.4, spin coating the organic halogen solution on the surface of the lead iodide layer, the spin coating process is 1500 rpm for 30 seconds, and annealing on a hot plate at 150° C. for 20 minutes to obtain a three-dimensional perovskite layer;

[0111] Step 3, preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer, the specific steps are as follows:

[0112] Step 3.1, 2 mg of BZCl was fully dissolved in 2 mL of IPA and filtered to obtain a clear one-dimensional perovskite ligand solution;

[0113] Step 3.2, spin coating the one-dimensional perovskite ligand solution on the surface of the three-dimensional perovskite layer, the spin coating process is 4000 rpm for 30 seconds, and annealing is performed on a hot plate at 100° C. for 3 minutes to obtain the one-dimensional perovskite layer.

[0114] Example 2

[0115] This embodiment provides a method for preparing a perovskite active layer film, and the specific steps are the same as those in Embodiment 1, except that:

[0116] Step 3.1, 2 mg of 2-APCl was fully dissolved in 2 mL of IPA and filtered to obtain a clear one-dimensional perovskite ligand solution.

[0117] Example 3

[0118] This embodiment provides a method for preparing a high-efficiency perovskite solar cell, comprising the following steps:

[0119] Step 1: Select the ITO conductive glass substrate and cut it into 1.5×1.5cm 2 The size was ultrasonically cleaned with detergent, ultrapure water and isopropanol in turn and dried with a nitrogen gun. The etched surface was treated with UV ozone for 20 minutes before use.

[0120] Step 2, preparing an electron transport layer on the surface of the ITO conductive glass substrate treated in step 1: fully mixing a 15wt% SnO2 aqueous solution and ultrapure water in a volume ratio of 1:5, and spin coating the mixed solution on the etched surface of the ITO conductive glass substrate at 3000rpm for 30s, followed by annealing on a 150°C hot stage for 30min;

[0121] Step 3, preparing a three-dimensional perovskite layer on the surface of the electron transport layer, the specific steps are as follows:

[0122] Step 3.1, 600.6 mg of PbI2 and 19.5 mg of CsI were mixed and fully dissolved in 1 mL of a mixed solution of DMF and DMSO (the volume ratio of DMF to DMSO was 9:1), and filtered to obtain a clear lead iodide solution;

[0123] Step 3.2, spin coating the lead iodide solution on the surface of the electron transport layer, the spin coating process is 1500 rpm for 30 seconds, and annealing on a hot plate at 70° C. for 1 minute to obtain a lead iodide layer;

[0124] Step 3.3, 60 mg of FAI, 6 mg of MACl and 6 mg of MABr were mixed and fully dissolved in IPA, and filtered to obtain a clear organic halogen solution;

[0125] Step 3.4, spin coating the organic halogen solution on the surface of the lead iodide layer, the spin coating process is 1500 rpm for 30 seconds, and annealing on a hot plate at 150° C. for 20 minutes to obtain a three-dimensional perovskite layer;

[0126] Step 4, preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer, the specific steps are as follows:

[0127] Step 4.1, 2 mg of BZCl was fully dissolved in 1.5 mL of IPA and filtered to obtain a clear one-dimensional perovskite ligand solution;

[0128] Step 4.2, spin coating the one-dimensional perovskite ligand solution on the surface of the three-dimensional perovskite layer, the spin coating process is 4000 rpm for 30 seconds, and annealing on a hot plate at 100° C. for 3 minutes to obtain the one-dimensional perovskite layer;

[0129] Step 5, preparing a hole transport layer on the surface of the one-dimensional perovskite layer, the specific steps are as follows:

[0130] Step 5.1, 72.3 mg of Spiro-OMeTAD was fully dissolved in 1 mL of chlorobenzene (CB), 35 μL of 260 mg / mL Li-TFSI solution and 30 μL of TBP solution were added, and the solution was filtered to obtain a clear hole transport material solution;

[0131] Step 5.2, spin coating the hole transport material solution on the surface of the one-dimensional perovskite layer at 4000 rpm for 30 seconds, and store it in a dark and dry place for more than 12 hours to obtain a hole transport layer;

[0132] Step 6, preparing a gold electrode on the surface of the hole transport layer by using an evaporation method.

[0133] Example 4

[0134] This embodiment provides a method for preparing a perovskite solar cell. The specific steps are the same as those in Embodiment 3, except that:

[0135] Step 4.1, 2 mg of 2-APCl was fully dissolved in 1.5 mL of IPA and filtered to obtain a clear one-dimensional perovskite ligand solution.

[0136] Comparative Example 1

[0137] This comparative example provides a method for preparing a perovskite film, and the specific steps are the same as those in Example 1, except that:

[0138] Step 3, i.e., the step of preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer, is skipped.

[0139] Comparative Example 2

[0140] This comparative example provides a method for preparing a perovskite solar cell, and the specific steps are the same as those in Example 3, except that:

[0141] Step 4, i.e., the step of preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer, is skipped, and step 5 is changed to preparing a hole transport layer on the surface of the three-dimensional perovskite layer.

[0142] Performance evaluation of embodiments and comparative examples:

[0143] The structure of the perovskite solar cell prepared in Examples 3 and 4 of the present invention is as follows Figure 1 As shown; wherein, 1 is transparent conductive glass, 2 is an electron transport layer, 3 is a three-dimensional perovskite layer, 4 is a one-dimensional perovskite layer, 5 is a hole transport layer, and 6 is a metal electrode.

[0144] The surface morphology of the perovskite layer obtained in Comparative Example 1 and Examples 1 and 2 was photographed using a scanning electron microscope. Figure 2 .

[0145] The steady-state fluorescence emission spectrum of the perovskite layer prepared in Comparative Example 1 and Examples 1 and 2 was tested using a fluorescence analyzer. The measured fluorescence emission spectrum is shown in FIG. Figure 3 .

[0146] Using a calibrated solar simulator, the 2 ) was used to test the photoelectric conversion efficiency of the perovskite solar cells prepared in Comparative Example 2 and Examples 3 and 4. The measured current-voltage curves are shown in FIG. Figure 4 ; Wherein (a) is Comparative Example 2, (b) is Example 3, (c) is Example 4, and the relevant photovoltaic performance parameters are shown in Table 1; The efficiency stability results of the perovskite solar cells prepared in Comparative Example 2 and Examples 3 and 4 were stored and tracked at room temperature and about 40% relative humidity. Figure 5 .

[0147] Table 1. Performance parameters of perovskite solar cells prepared in comparative examples and examples

[0148]

[0149] It can be seen from the above test results that a rod-shaped one-dimensional perovskite layer is obtained by treating the surface of the three-dimensional perovskite layer with a one-dimensional perovskite ligand solution. The improvement of the fluorescence emission spectrum proves that the presence of the one-dimensional perovskite active layer effectively suppresses the defects on the surface of the three-dimensional perovskite and reduces the non-radiative recombination caused by the defects, thereby significantly improving the quality of the perovskite layer. The perovskite solar cell prepared using the perovskite layer has a significant improvement in photovoltaic performance compared to the traditional three-dimensional perovskite solar cell prepared in Comparative Example 2. In addition, one-dimensional perovskites generally have good hydrophobicity, so perovskite solar cells have better long-term stability in a relatively humid environment after the introduction of a one-dimensional perovskite layer. In summary, the perovskite solar cell provided by the present invention has excellent photovoltaic performance and long-term stability.

[0150] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a perovskite solar cell, It is characterized in that Includes steps: Preparation of three-dimensional perovskite layers; preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer; Wherein, the step of preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer specifically includes: Providing a one-dimensional perovskite ligand solution, wherein the one-dimensional perovskite ligand comprises benzamidine hydrochloride or 2-pyridinecarboxamidine hydrochloride; The one-dimensional perovskite ligand solution is spin-coated on the surface of the three-dimensional perovskite layer, and annealing is performed to obtain the one-dimensional perovskite layer.

2. The method for preparing a perovskite solar cell according to claim 1, It is characterized in that The one-dimensional perovskite ligand solution is prepared by dissolving the one-dimensional perovskite ligand in an organic solvent, and the organic solvent is isopropanol or ethanol.

3. The method for preparing a perovskite solar cell according to claim 1, It is characterized in that In the step of spin coating the one-dimensional perovskite ligand solution on the surface of the three-dimensional perovskite layer and performing annealing treatment to obtain the one-dimensional perovskite layer, the spin coating parameters include: a rotation speed of 3000-6000 rpm and a time of 30-45 s; The parameters of the annealing treatment include: temperature of 90-120° C. and time of 3-6 min.

4. The method for preparing a perovskite solar cell according to claim 1, It is characterized in that The thickness of the three-dimensional perovskite layer is 600-700 nm, and the thickness of the one-dimensional perovskite layer is 50-100 nm.

5. The method for preparing a perovskite solar cell according to claim 1, It is characterized in that The step of preparing the three-dimensional perovskite layer specifically includes: Mixing lead iodide and cesium iodide in an organic solvent to obtain a lead iodide solution; After spin coating the lead iodide solution, annealing is performed to obtain a lead iodide layer; Mixing formamidine iodide, methylammonium chloride and methylammonium bromide in an organic solvent to obtain an organic halogen solution; After the organic halogen solution is spin-coated on the surface of the lead iodide layer, an annealing treatment is performed to obtain a three-dimensional perovskite layer.

6. The method for preparing a perovskite solar cell according to claim 1, It is characterized in that The method for preparing the perovskite solar cell specifically comprises the steps of: providing a conductive substrate; Preparing an electron transport layer on the surface of the conductive substrate; Preparing a three-dimensional perovskite layer on the surface of the electron transport layer; preparing a one-dimensional perovskite layer on the surface of the three-dimensional perovskite layer; preparing a hole transport layer on the surface of the one-dimensional perovskite layer; An electrode is prepared on the surface of the hole transport layer.

7. A perovskite solar cell, It is characterized in that The perovskite solar cell is prepared by the method according to any one of claims 1 to 6.

8. A perovskite solar cell, It is characterized in that The perovskite solar cell includes a three-dimensional perovskite layer and a one-dimensional perovskite layer arranged on the surface of the three-dimensional perovskite layer.

9. The perovskite solar cell according to claim 8, It is characterized in that The one-dimensional perovskite layer includes benzamidine hydrochloride or 2-pyridinecarboxamidine hydrochloride; the one-dimensional perovskite is in a rod shape.

10. The perovskite solar cell according to claim 8, It is characterized in that The perovskite solar cell specifically includes a transparent conductive substrate, an electron transport layer, a three-dimensional perovskite layer, a one-dimensional perovskite layer, a hole transport layer and a metal electrode which are stacked in sequence.

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