Perovskite solar cell with modified hole transport layer and preparation method of perovskite solar cell

Abstract

The invention discloses a hole transport layer modified perovskite solar cell and a preparation method thereof, the hole transport layer modified perovskite solar cell comprises an ITO substrate layer, a hole transport layer, a 3MTPAI layer, a perovskite layer, an electron transport layer and an electrode layer which are arranged in sequence, and the hole transport layer is an SAM layer of MeO-2PACz; the preparation method comprises the following steps: sequentially carrying out ultrasonic cleaning on a glass / ITO substrate by using deionized water, acetone and isopropanol, blow-drying by using nitrogen, and carrying out ultraviolet ozone treatment; coating the MeO-2PACz solution on a glass / ITO (Indium Tin Oxide) substrate, and carrying out annealing treatment at the temperature of 100 DEG C; coating the glass / ITO / MeO-2PACz substrate with the 3MTPAI solution, and carrying out annealing treatment at the temperature of 100 DEG C; and coating the perovskite solution on a glass / ITO / MeO-2PACz / 3MTPAI substrate, carrying out annealing treatment at 100 DEG C, and then sequentially carrying out thermal evaporation on the C60 layer, the BCP thin film and the silver thin film. According to the invention, 3MTPAI is introduced between MeO-2PACz and perovskite, the introduction of 3MTPAI improves the work function of SAM, optimizes the energy level matching between a hole transport layer and a perovskite layer, and passivates the defects of a perovskite buried interface, thereby promoting the hole extraction and reducing the non-radiative recombination of the interface.

Description

Technical Field

[0001] The invention relates to the technical field of perovskite solar cells, in particular to a perovskite solar cell with a modified hole transport layer and a preparation method thereof. Background Art

[0002] In recent years, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has increased significantly, from 3.8% in 2009 to more than 26% today, highlighting the position of PSCs as the focus of the future photovoltaic cell field. Interface carrier recombination loss is an important factor affecting efficiency improvement, so interface engineering strategies are regarded as an effective method to achieve higher PCE. So far, researchers have a deep understanding of upper interface optimization, but upper interface post-treatment has become an indispensable technology for the efficient preparation of PSCs. However, compared with the upper interface, the optimization of the buried interface, which directly affects perovskite crystallization and interfacial charge transport, is more critical to the performance of solar cells.

[0003] The buried interface of perovskite films, due to its special location and the difficulty in direct regulation, often becomes the source of defect enrichment and carrier transport barriers. Introducing a self-assembled monolayer (SAM) as a passivation layer to passivate defects and inhibit non-radiative recombination has become an effective method. The dipole moment of SAM can increase the work function of the hole transport layer (HTL), reduce the interface barrier, and thus optimize the hole transport performance. However, how to further enhance the dipole moment of SAM while passivating perovskite defects to more effectively improve the properties of the buried interface is still an important direction of current research. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a perovskite solar cell with a modified hole transport layer and a preparation method thereof. The strategy of modifying the hole transport layer with ionic compounds is adopted, and 3MTPAI is introduced between the SAM material MeO-2PACz and the perovskite, and an inverted perovskite device is prepared as the hole transport layer. The introduction of 3MTPAI can improve the work function of the SAM, optimize the energy level matching between the hole transport layer and the perovskite layer, and passivate the defects of the perovskite buried interface, thereby promoting the extraction of holes and reducing the non-radiative recombination of the interface. The 3MTPAI molecular buried modification strategy with dual effects provides an effective way to improve the efficiency and stability of photovoltaic cells.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A perovskite solar cell with a modified hole transport layer comprises an ITO substrate layer, a hole transport layer, a 3MTPAI layer, a perovskite layer, an electron transport layer and an electrode layer which are arranged in sequence, wherein the hole transport layer is a SAM layer of MeO-2PACz.

[0007] The electron transport layer is a C 60 The electrode layer is a silver film with a thickness of 90 to 110 nm.

[0008] An interface modification layer is arranged between the electron transport layer and the electrode layer, and the interface modification layer is a BCP film with a thickness of 4 to 10 nm.

[0009] The C 60 The thickness of the layer is 24 nm, the thickness of the BCP film is 6 nm, and the thickness of the silver film is 100 nm.

[0010] A method for preparing a perovskite solar cell with a modified hole transport layer comprises the following steps:

[0011] (1) The glass / ITO substrate is ultrasonically cleaned with deionized water, acetone, and isopropanol in sequence, dried with nitrogen, and then treated with ultraviolet ozone. The glass / ITO substrate after ultraviolet ozone treatment is transferred to a glove box filled with nitrogen for subsequent preparation;

[0012] (2) coating a MeO-2PACz solution dissolved in ethanol on a glass / ITO substrate and annealing at 100° C. to obtain a glass / ITO / MeO-2PACz substrate;

[0013] (3) coating a 3MTPAI solution dissolved in isopropanol on a glass / ITO / MeO-2PACz substrate and annealing at 100° C. to obtain a glass / ITO / MeO-2PACz / 3MTPAI substrate;

[0014] (4) The perovskite solution was coated on a glass / ITO / MeO-2PACz / 3MTPAI substrate to prepare a perovskite film. After the perovskite film was annealed at 100°C, C 60 layer, BCP film, silver film.

[0015] Furthermore, the mass concentration of the MeO-2PACz solution in step (2) is 3-4 mg / ml; the mass concentration of the 3MTPAI solution in step (3) is 0.5-2 mg / ml; the mass concentration of the C 60 The thickness of the layer is 20-30 nm, the thickness of the BCP film is 4-10 nm, and the thickness of the silver film is 90-110 nm.

[0016] Furthermore, the mass concentration of the MeO-2PACz solution in step (2) is 3.3 mg / ml; the mass concentration of the 3MTPAI solution in step (3) is 1 mg / ml; the mass concentration of the C 60 The thickness of the layer is 24 nm, the thickness of the BCP film is 6 nm, and the thickness of the silver film is 100 nm.

[0017] Furthermore, the preparation method of the perovskite solution in step (4) is: CsI, FAI, MABr, PbI 2 、PbBr 2 Dissolved in a DMF-DMSO mixed solvent to prepare a perovskite precursor solution, the chemical formula of the perovskite precursor solution is: (FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 ) 3 , where PbI 2 The amount of addition is excessive; MACl is added to the perovskite precursor solution to prepare a perovskite solution.

[0018] Furthermore, the volume ratio of DMF:DMSO in the DMF-DMSO mixed solvent is 4:1; the PbI 2 Excess 10 mol%.

[0019] Furthermore, in step (1), the glass / ITO substrate is ultrasonically cleaned with deionized water, acetone, and isopropanol in sequence for 10 to 20 minutes, and the glass / ITO substrate is treated with ultraviolet ozone for 10 to 20 minutes; the annealing temperature in step (2), step (3), and step (4) is 90 to 100° C., and the annealing time is 5 to 40 minutes.

[0020] Furthermore, in step (1), the glass / ITO substrate is ultrasonically cleaned with deionized water, acetone, and isopropanol in sequence for 15 minutes, and the glass / ITO substrate is treated with ultraviolet ozone for 15 minutes; the annealing temperature in step (2) is 100° C., and the annealing time is 10 minutes; the annealing temperature in step (3) is 100° C., and the annealing time is 5 minutes; the annealing temperature in step (4) is 100° C., and the annealing time is 30 minutes.

[0021] Furthermore, the method for coating the MeO-2PACz solution on the glass / ITO substrate in step (2) is spin coating, the spin coating speed is 2500-3500 rpm, and the time is 20-40 s; the method for coating the 3MTPAI solution on the glass / ITO / MeO-2PACz substrate in step (3) is spin coating, the spin coating speed is 4000-6000 rpm, and the time is 20-40 s; the method for coating the perovskite solution on the glass / ITO / MeO-2PACz / 3MTPAI substrate in step (4) is spin coating, and the spin coating steps are: first spin coating at a speed of 1000-2000 rpm for 8-15 s, then spin coating at a speed of 4000-6000 rpm for 30-50 s, and 10-20 s before the end of spin coating, drip the CB solution into the center of the film.

[0022] Furthermore, the spin coating speed of the MeO-2PACz solution coated on the glass / ITO substrate in step (2) is 3000 rpm, and the time is 30 s; the spin coating speed of the 3MTPAI solution coated on the glass / ITO / MeO-2PACz substrate in step (3) is 5000 rpm, and the time is 30 s; the spin coating step of the perovskite solution coated on the glass / ITO / MeO-2PACz / 3MTPAI substrate in step (4) is: first spin coating at a speed of 1000 rpm for 10 s, then spin coating at a speed of 5000 rpm for 40 s, and 10 s before the end of spin coating, CB is dripped into the center of the film.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The preparation method of the perovskite solar cell with modified hole transport layer provided by the present invention requires mature raw material preparation technology, which can be purchased commercially, does not require laboratory design and synthesis of molecules, and does not require mixing of SAM layer and passivation layer. A single component can be selected for modification.

[0025] 2. In the present invention, MeO-2PACz is used as the SAM layer, and 3MTPAI is used to modify the SAM layer. The iodide ions in the 3MTPAI molecules increase the dipole moment of the SAM layer by interacting with MeO-2PACz, thereby increasing the atomic basin volume of the SAM molecules. This characteristic enables the MeO-2PACz molecules modified by 3MTPAI to show a higher advantage in filling the iodine vacancies of perovskite. Since the ion-dipole interaction is dominant in the intermolecular interaction, this leads to the decoration of the iodine ions in 3MTPAI on the MeO-2PACz molecules. The decoration of the iodine ions on the MeO-2PACz leads to an increase in the dipole moment of the modified MeO-2PACz, thereby increasing the atomic basin volume. This characteristic enables the MeO-2PACz molecules modified by 3MTPAI to show a higher advantage in filling the iodine vacancies. The molecules can modify Pb, I, and N in the buried interface of perovskite to form action sites to fill defects; the synergistic effect of 3MTPAI between the SAM layer and perovskite leads to an improvement in the quality of perovskite crystals, thereby increasing the device efficiency of perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Attached Figure 1 It is a schematic structural diagram of the perovskite solar cell of the present invention.

[0027] Attached Figure 2 This is the dipole moment contribution diagram of MeO-2PACz after 3MTPAI modification.

[0028] Attached Figure 3 This is a schematic diagram of the unmodified MeO-2PACz molecular structure.

[0029] Attached Figure 4 This is a schematic diagram of the molecular structure of 3MTPAI-modified MeO-2PACz.

[0030] Attached Figure 5 It is the spectrum diagram of the tested UPS.

[0031] Attached Figure 6 is the energy level diagram of the test.

[0032] Attached Figure 7 is the JV curve of the test. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the technical solution of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in conjunction with the drawings of specific embodiments of the present invention. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described 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.

[0034] like Figure 1 As shown, the present invention provides a perovskite solar cell with a modified hole transport layer, comprising an ITO substrate layer, a hole transport layer, a 3MTPAI layer, a perovskite layer, an electron transport layer, and an electrode layer arranged in sequence, wherein the hole transport layer is a SAM layer of MeO-2PACz.

[0035] In one embodiment, the electron transport layer (ETL) is a C 60 The electrode layer is a silver film with a thickness of 90 to 110 nm.

[0036] In one embodiment, an interface modification layer is provided between the electron transport layer and the electrode layer, and the interface modification layer is a BCP film with a thickness of 4 to 10 nm.

[0037] In one embodiment, the C 60 The thickness of the layer is 24 nm, the thickness of the BCP film is 6 nm, and the thickness of the silver film is 100 nm.

[0038] MeO-2PACz is a SAM material. In the present invention, MeO-2PACz is used as a hole transport layer, and 3MTPAI is introduced between MeO-2PACz and perovskite to prepare an inverted perovskite device as a hole transport layer. The introduction of 3MTPAI can improve the work function of the SAM, optimize the energy level matching between the hole transport layer and the perovskite layer, passivate the defects of the perovskite buried interface, thereby promoting the extraction of holes and reducing the non-radiative recombination of the interface.

[0039] A method for preparing a perovskite solar cell with a modified hole transport layer comprises the following steps:

[0040] Step (1): The glass / ITO substrate is ultrasonically cleaned with deionized water, acetone, and isopropanol in sequence, blown dry with nitrogen, and then treated with ultraviolet ozone. The glass / ITO substrate after ultraviolet ozone treatment is transferred to a glove box filled with nitrogen for subsequent preparation.

[0041] In step (1), the glass / ITO substrate is ultrasonically cleaned with deionized water, acetone, and isopropanol in sequence for 10 to 20 minutes. Exemplarily, the glass / ITO substrate is ultrasonically cleaned with deionized water, acetone, and isopropanol for 15 minutes each. Ultrasonic cleaning is used to remove contaminants (such as dust and organic matter) on the surface of the glass / ITO substrate.

[0042] The time for ultraviolet ozone treatment of glass / ITO substrate is 10 to 20 minutes, and illustratively, 15 minutes. Ultraviolet ozone treatment can improve the hydrophilicity of the surface of glass / ITO substrate, remove organic residues, increase surface oxygen vacancies, and improve hole extraction performance.

[0043] Step (2): coating a [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid MeO-2PACz solution dissolved in ethanol on a glass / ITO substrate and annealing at 100° C. to obtain a glass / ITO / MeO-2PACz substrate. The SAM material MeO-2PACz is used as a hole transport layer (HTL) to improve the interface contact between the ITO and the perovskite layer. The HOMO energy level of MeO-2PACz matches the valence band of the perovskite, promoting hole extraction and blocking electrons.

[0044] The mass concentration of the MeO-2PACz solution is 3-4 mg / ml. Exemplarily, the mass concentration of the MeO-2PACz solution is 3.3 mg / ml.

[0045] The method for coating the MeO-2PACz solution on the glass / ITO substrate is spin coating, with a spin coating speed of 2500-3500 rpm and a time of 20-40 s; illustratively, the spin coating speed of the MeO-2PACz solution on the glass / ITO substrate is 3000 rpm and the time is 30 s.

[0046] The annealing temperature in step (2) is 90-100° C., and the annealing time is 5-40 minutes. For example, the annealing temperature in step (2) is 100° C., and the annealing time is 10 minutes. Annealing can remove the solvent and enhance the orderly arrangement of molecules on the surface.

[0047] Step (3): Coat a [3-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphonic acid 3MTPAI solution dissolved in isopropanol on a glass / ITO / MeO-2PACz substrate and anneal at 100° C. to obtain a glass / ITO / MeO-2PACz / 3MTPAI substrate.

[0048] The mass concentration of the 3MTPAI solution is 0.5-2 mg / ml. Exemplarily, the mass concentration of the 3MTPAI solution is 1 mg / ml.

[0049] The method for coating the 3MTPAI solution on the glass / ITO / MeO-2PACz substrate is spin coating, with a spin coating speed of 4000-6000 rpm and a time of 20-40 s; illustratively, the spin coating speed of the 3MTPAI solution on the glass / ITO / MeO-2PACz substrate is 5000 rpm and the time is 30 s.

[0050] The annealing temperature in step (3) is 90-100° C., and the annealing time is 5-40 minutes; illustratively, the annealing temperature in step (2) is 100° C., and the annealing time is 5 minutes.

[0051] Step (4): The perovskite solution is coated on a glass / ITO / MeO-2PACz / 3MTPAI substrate to obtain a perovskite film. The perovskite film is annealed at 100°C and then placed in a high vacuum (<2×10 -4 Torr), and then thermally evaporate C 60 layer, BCP film, silver film.

[0052] The C 60 The thickness of the layer is 20 to 30 nm, the thickness of the BCP film is 4 to 10 nm, and the thickness of the silver film is 90 to 110 nm; illustratively, the C 60 The thickness of the layer is 24nm, the thickness of the BCP film is 6nm, and the thickness of the silver film is 100nm. The BCP film can improve the C 60 The interfacial contact with the silver electrode prevents holes from being directly transferred from the perovskite layer to the silver electrode.

[0053] The preparation method of the perovskite solution is: CsI, FAI, MABr, PbI 2 、PbBr 2 Dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to prepare a perovskite precursor solution, the chemical formula of which is: (FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 ) 3 , where PbI 2 The amount of PbI in the perovskite precursor solution is excessive; methyl ammonium chloride MACl is added to the perovskite precursor solution to prepare a perovskite solution. The volume ratio of DMF:DMSO in the DMF-DMSO mixed solvent is 4:1; 2 Excess 10 mol%.

[0054] The method for coating the perovskite solution on the glass / ITO / MeO-2PACz / 3MTPAI substrate is spin coating, and the steps of spin coating are: first spin coating at a speed of 1000-2000 rpm for 8-15 seconds, then spin coating at a speed of 4000-6000 rpm for 30-50 seconds, and 10-20 seconds before the end of the spin coating, drip the CB solution into the center of the film. Exemplarily, the spin coating steps for coating the perovskite solution on the glass / ITO / MeO-2PACz / 3MTPAI substrate are: first spin coating at a speed of 1000 rpm for 10 seconds, then spin coating at a speed of 5000 rpm for 40 seconds, and 10 seconds before the end of the spin coating, drip chlorobenzene CB into the center of the film.

[0055] The annealing temperature in step (4) is 90-100° C., and the annealing time is 5-15 minutes; illustratively, the annealing temperature in step (4) is 100° C., and the annealing time is 30 minutes.

[0056] The raw material preparation process required by the method of the present invention is mature and can be purchased commercially, without the need for laboratory design and synthesis of molecules; the preparation steps are simple, no SAM layer needs to be mixed, no passivation layer needs to be mixed, and a single component can be selected for modification. The iodide ions in the 3MTPAI molecule increase the dipole moment of the SAM layer by interacting with the SAM, thereby increasing the atomic basin volume of the SAM molecule. This characteristic enables the 3MTPAI-modified MeO-2PACz molecule to show a higher advantage in filling the iodine vacancies of the perovskite. The ion-dipole interaction is dominant in the intermolecular interaction, which leads to the decoration of the iodine ions in the 3MTPAI on the MeO-2PACz molecule. The decoration of the I ions on the MeO-2PACz leads to an increase in the dipole moment of the modified MeO-2PACz, and then an increase in the atomic basin. This characteristic enables the 3MTPAI-modified MeO-2PACz molecule to show a higher advantage in filling the iodine vacancies. The molecule can modify the Pb, I, and N in the buried interface of the perovskite to form an action site to fill the defects. The synergistic effect of 3MTPAI between the SAM layer and perovskite leads to an improvement in the quality of perovskite crystals, thereby increasing the device efficiency of perovskite solar cells.

[0057] Example 1

[0058] A method for preparing a perovskite solar cell with a modified hole transport layer comprises the following steps:

[0059] (1) The glass / ITO substrate was ultrasonically cleaned with deionized water, acetone, and isopropanol for 15 minutes in sequence, then dried with nitrogen, treated with ultraviolet ozone for 15 minutes, and then transferred to a glove box filled with nitrogen;

[0060] (2) Dissolving MeO-2PACz in ethanol solvent at a concentration of 3.3 mg / ml; coating the prepared 40 μL MeO-2PACz solution on glass / ITO at a speed of 3000 rpm for 30 s, and then annealing at 100 °C for 10 min to obtain a glass / ITO / MeO-2PACz substrate;

[0061] (3) 3MTPAI was dissolved in IPA at a concentration of 1 mg / ml; 40 μL of the prepared 3MTPAI solution was spin-coated on a glass / ITO / MeO-2PACz substrate at a speed of 5000 rpm for 30 s, and then annealed at 100°C for 5 min to obtain glass / ITO / MeO-2PACz / 3MTPAI;

[0062] (4) CsI, FAI, MABr, PbI 2 and PbBr 2 Mix in 1 ml DMF:DMSO (4:1 / v:v) mixed solvent to prepare 1.73 M perovskite precursor solution. The chemical formula of the perovskite precursor solution is (FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 ) 3 , 10 mol% PbI 2 The excess amount was used to improve the device performance; 15 mol% MACl was then added to the perovskite precursor solution and stirred for 3 h to obtain a perovskite solution; the perovskite solution was spin-coated on glass / ITO / MeO-2PACz / 3MTPAI at 1000 rpm for 10 s, and then spin-coated at 5000 rpm for 40 s. 10 s before the end of the spin coating, 180 μL of CB was slowly dripped into the center of the film; the prepared perovskite film was annealed on a hot plate at 100 °C for 30 min, and then placed in a high vacuum (<2×10 - 4 Torr) and then thermally evaporate 24nm C 60 , 6nm BCP and 100nm silver.

[0063] The device area prepared in Example 1 is 0.0625 cm 2 , test it.

[0064] The iodide ions in the 3MTPAI molecules increase the dipole moment of the SAM layer by interacting with SAM, thereby increasing the atomic basin volume of the SAM molecules. This property makes the 3MTPAI-modified MeO-2PACz molecules show a higher advantage in filling the iodine vacancies of perovskite.

[0065] like Figure 2 As shown in the figure, the dipole moment contribution of MeO-2PACz after 3MTPAI modification is shown. The yellow arrow represents the contribution of MeO-2PACz itself, the red arrow indicates the contribution of iodide ions, and the green arrow comprehensively reflects the direction and size of the overall dipole moment. The dipole contribution of iodide ions is consistent with the overall direction of MeO-2PACz, thus significantly enhancing the total dipole moment of the molecule. This enhanced dipole moment effect makes the 3MTPAI-modified MeO-2PACz molecule (such as Figure 4 As shown, ) compared to the unmodified MeO-2PACz molecule (e.g. Figure 3 As shown, ) has a larger atomic basin volume. This feature makes the 3MTPAI-modified MeO-2PACz molecule show a higher advantage in filling iodine vacancies, thereby effectively strengthening the PbI 2 Octahedral configuration.

[0066] The introduction of 3MTPAI changes the work function of MeO-2PACz and optimizes the energy levels of MeO-2PACz and perovskite, making the energy levels of the two more matched.

[0067] like Figure 5 As shown in the figure, it is the UPS spectrum of the test sample. Figure 6 The figure shows the energy level diagram of the test samples, where Control is a glass / ITO / MeO-2PACz sample and Target is a glass / ITO / MeO-2PACz / 3MTPAI sample. The energy levels of the surfaces of the glass / ITO / MeO-2PACz and glass / ITO / MeO-2PACz / 3MTPAI samples and the energy levels of the corresponding perovskites, as well as the work function of the hole transport layer (W F ) increased from 4.34eV to 4.69eV, and the valence band energy difference between the hole transport layer and the perovskite layer (ΔE VBM ) is reduced from 0.86eV to 0.36eV, reducing ΔE VBM and improved W F It is beneficial to the hole transport layer transport.

[0068] like Figure 7 As shown, 0.0625cm 2 The JV curve of the device shows that the efficiency of MeO-2PACz modified by 3MTPAI is increased from 23.9% to 25.3%; 2 The strategy was verified in perovskite solar devices, demonstrating the improvement of device efficiency.

[0069] Those skilled in the art should understand that the above-mentioned specific embodiments are merely examples and not limitations, and various modifications, combinations, partial combinations and replacements may be made to the embodiments of the present invention according to design requirements and other factors. As long as they are within the scope of the attached claims or their equivalents, they are within the scope of rights to be protected by the present invention.

Claims

1. A perovskite solar cell with a modified hole transport layer, characterized in that: The invention comprises an ITO substrate layer, a hole transport layer, a 3MTPAI layer, a perovskite layer, an electron transport layer and an electrode layer which are arranged in sequence, wherein the hole transport layer is a SAM layer of MeO-2PACz.

2. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 1, characterized in that: The following steps are involved: (1) The glass / ITO substrate was ultrasonically cleaned with deionized water, acetone, and isopropanol in sequence, dried with nitrogen, and then treated with ultraviolet ozone; (2) coating a MeO-2PACz solution dissolved in ethanol on a glass / ITO substrate and annealing at 100° C. to obtain a glass / ITO / MeO-2PACz substrate; (3) coating a 3MTPAI solution dissolved in isopropanol on a glass / ITO / MeO-2PACz substrate and annealing at 100° C. to obtain a glass / ITO / MeO-2PACz / 3MTPAI substrate; (4) The perovskite solution was coated on a glass / ITO / MeO-2PACz / 3MTPAI substrate to prepare a perovskite film. After the perovskite film was annealed at 100°C, C 60 layer, BCP film, silver film.

3. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 1, characterized in that: The mass concentration of the MeO-2PACz solution in step (2) is 3-4 mg / ml; The mass concentration of the 3MTPAI solution in step (3) is 0.5-2 mg / ml; Step (4) 60 The thickness of the layer is 20-30 nm, the thickness of the BCP film is 4-10 nm, and the thickness of the silver film is 90-110 nm.

4. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 3, characterized in that: The mass concentration of the MeO-2PACz solution in step (2) is 3.3 mg / ml; The mass concentration of the 3MTPAI solution in step (3) is 1 mg / ml; Step (4) 60 The thickness of the layer is 24 nm, the thickness of the BCP film is 6 nm, and the thickness of the silver film is 100 nm.

5. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 2, characterized in that: The preparation method of the perovskite solution in step (4) is: CsI, FAI, MABr, PbI2, and PbBr2 are dissolved in a DMF-DMSO mixed solvent to prepare a perovskite precursor solution, the chemical formula of the perovskite precursor solution is: (FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3, wherein the amount of PbI2 added is excessive; Adding MACl to the perovskite precursor solution to prepare a perovskite solution.

6. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 5, characterized in that: The volume ratio of DMF:DMSO in the DMF-DMSO mixed solvent is 4:1; the PbI2 in the perovskite precursor solution is in excess of 10 mol%.

7. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 2, characterized in that: In step (1), the glass / ITO substrate is ultrasonically cleaned with deionized water, acetone, and isopropanol in sequence for 10 to 20 minutes, and the glass / ITO substrate is treated with ultraviolet ozone for 10 to 20 minutes; The annealing temperature in step (2), step (3) and step (4) is 90 to 100° C., and the annealing time is 5 to 40 minutes.

8. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 7, characterized in that: In step (1), the glass / ITO substrate is ultrasonically cleaned with deionized water, acetone, and isopropanol for 15 minutes, and the glass / ITO substrate is treated with ultraviolet ozone for 15 minutes; The annealing temperature in step (2) is 100° C. and the annealing time is 10 minutes; The annealing temperature in step (3) is 100° C. and the annealing time is 5 minutes; The annealing temperature in step (4) is 100° C. and the annealing time is 30 minutes.

9. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 2, characterized in that: The method of coating the MeO-2PACz solution on the glass / ITO substrate in step (2) is spin coating, the spin coating speed is 2500-3500 rpm, and the time is 20-40 s; The method of coating the 3MTPAI solution on the glass / ITO / MeO-2PACz substrate in step (3) is spin coating, the spin coating speed is 4000-6000 rpm, and the time is 20-40 s; The method for coating the perovskite solution on the glass / ITO / MeO-2PACz / 3MTPAI substrate in step (4) is spin coating, and the spin coating steps are: first spin coating at a speed of 1000-2000 rpm for 8-15 seconds, then spin coating at a speed of 4000-6000 rpm for 30-50 seconds, and 10-20 seconds before the end of spin coating, drip the CB solution into the center of the film.

10. The method for preparing a perovskite solar cell with a modified hole transport layer according to claim 9, characterized in that: The spin coating speed of the MeO-2PACz solution coated on the glass / ITO substrate in step (2) is 3000 rpm for 30 seconds; The 3MTPAI solution in step (3) is coated on the glass / ITO / MeO-2PACz substrate at a spin coating speed of 5000 rpm for 30 seconds; The spin coating step of the perovskite solution coated on the glass / ITO / MeO-2PACz / 3MTPAI substrate in step (4) is as follows: first, the film is spin coated at a speed of 1000 rpm for 10 seconds, and then the film is spin coated at a speed of 5000 rpm for 40 seconds. 10 seconds before the end of the spin coating, CB is dropped into the center of the film.

Images