Perovskite solar cell, preparation method thereof and photovoltaic module
By introducing the interface modification layer of A3B2I9 compound and antimony salt solution treatment in perovskite solar cells, the photoelectric conversion efficiency and stability of perovskite solar cells are solved, achieving more efficient electron collection and longer device life.
Patent Information
- Application Number
- CN202411228135.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-03
- Publication Date
- 2024-12-20
AI Technical Summary
The photoelectric conversion efficiency of existing perovskite solar cells needs to be improved, and there are problems of photothermal stability and device life.
By introducing an interface modification layer into a perovskite solar cell, the A3B2I9 compound and the perovskite absorption layer are used to form a 2D homojunction, reducing the energy barrier during electron transport, improving the carrier extraction efficiency, and passing through antimony salt Solution application and annealing process form an interface modification layer to enhance electron collection rate and device stability.
It improves the photoelectric conversion efficiency and stability of perovskite solar cells, extends the device life, reduces the energy barrier between interfaces, enhances the electron collection rate and moisture-proof function, and inhibits metal electrode corrosion during oxidation.
Smart Images
Figure CN119173051A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of solar cells, and in particular to a perovskite solar cell and a preparation method thereof, and a photovoltaic module. Background Art
[0002] The rapid development of perovskite solar cells marks a revolution in the field of third-generation photovoltaic research. High-efficiency organic-inorganic hybrid perovskite solar cells have become one of the most promising solar cells due to their excellent optoelectronic properties, such as long carrier diffusion length and high absorption coefficient. With continuous technological innovation and device optimization, the certified photoelectric conversion efficiency (PCE) of perovskite solar cells has increased from 3.8% to 25.7%. + , NH2CH=NH2 + )-based nip-type devices have the highest certified PCE, which is mainly attributed to the FA + The strong thermal stability of FABX3, the wide visible light absorption range, the long carrier lifetime and the band gap closer to the Shockley-Queisser limit. However, even though FABX3 has great potential in achieving high efficiency and robust photothermal stability, there is still a problem that the photoelectric conversion efficiency needs to be improved. Summary of the invention
[0003] Based on this, some embodiments of the present application provide a perovskite solar cell, which helps to reduce the energy barrier in the electron transmission process and accelerate the extraction of carriers through the modification of the interface modification layer, thereby improving the photoelectric conversion efficiency.
[0004] In addition, some other embodiments of the present invention also provide a method for preparing a perovskite solar cell and a photovoltaic module.
[0005] A perovskite solar cell comprises a transparent conductive electrode, a hole transport layer, a perovskite absorption layer, an interface modification layer, an electron transport layer, a hole blocking layer and a counter electrode arranged in a stacked manner;
[0006] Among them, the material of the perovskite absorption layer includes ABX3, the material of the interface modification layer includes one or more compounds with the general formula A3B2I9, the interface modification layer and the perovskite absorption layer form a 2D homojunction, the A-site ions of the interface modification layer and the perovskite absorption layer both include formamidine ions, the B-site ions of the interface modification layer include one or more of antimony ions and bismuth ions, the B-site ions of the perovskite absorption layer include lead ions, and the X-site ions of the perovskite absorption layer include one or more of iodide ions, chloride ions, bromide ions and thiocyanate ions.
[0007] In some of the embodiments, the A-site ions of the perovskite absorption layer and the interface modification layer further include cesium ions.
[0008] In some of the embodiments, in the A-site ions of the perovskite absorption layer and the interface modification layer, the molar percentage of the formamidine ions is 90% to 92%, and the molar percentage of the cesium ions is 8% to 10%.
[0009] In some embodiments, the thickness of the interface modification layer is 6 nm to 10 nm.
[0010] A method for preparing a perovskite solar cell comprises the following steps:
[0011] Forming a stacked transparent conductive electrode, a hole transport layer, a perovskite absorption layer, an interface modification layer, an electron transport layer, a hole blocking layer and a counter electrode;
[0012] Among them, the material of the perovskite absorption layer includes ABX3, the material of the interface modification layer includes one or more compounds with the general formula A3B2I9, the interface modification layer and the perovskite absorption layer form a 2D homojunction, the A-site ions of the interface modification layer and the perovskite absorption layer both include formamidine ions, the B-site ions of the interface modification layer include one or more of antimony ions and bismuth ions, the B-site ions of the perovskite absorption layer include lead ions, and the X-site ions of the perovskite absorption layer include one or more of iodide ions, chloride ions, bromide ions and thiocyanate ions.
[0013] In some embodiments, the step of preparing the interface modification layer comprises:
[0014] Applying an antimony salt solution on the surface of the perovskite absorption layer and performing annealing treatment to obtain the interface modification layer;
[0015] The antimony salt includes antimony iodide, and optionally includes one or more of antimony acetate, antimony tartrate, antimony chloride and antimony fluoride.
[0016] In some embodiments, in the antimony salt solution, the total mass percentage concentration of the antimony salt is 0.5% to 2%; and / or,
[0017] In the antimony salt solution, the mass ratio of the antimony iodide to other antimony salts is (3-4.5):1, and other antimony salts include one or more of antimony acetate, antimony tartrate, antimony chloride and antimony fluoride.
[0018] In some embodiments, the annealing step includes: heating at 90° C. to 100° C. for 5 min to 7 min, and heating at 130° C. to 150° C. for 10 min to 15 min.
[0019] In some of the embodiments, after the step of applying the antimony salt solution to the surface of the perovskite absorption layer and before the step of annealing, the step further includes: standing for 30s to 60s.
[0020] A photovoltaic module comprises the above-mentioned perovskite solar cell or a perovskite solar cell prepared by the above-mentioned preparation method.
[0021] The above-mentioned perovskite solar cell uses ABX3 as the perovskite absorption layer, A includes formamidinium ions, and forms an interface modification layer of A3B2I9 between the perovskite absorption layer and the electron transport layer to form a 2D homojunction with the perovskite absorption layer. Compared with not setting an interface modification layer, it is not only beneficial to reduce the energy barrier between the interfaces, but also beneficial to increase the electron collection rate, thereby improving the photoelectric conversion efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0023] Figure 1 A schematic diagram of a structure of a perovskite solar cell in some embodiments of the present application;
[0024] Figure 2 In some embodiments of the present application, the energy band diagram after the surface of the perovskite absorption layer is modified with an interface modification layer;
[0025] Figure 3 A process flow chart of a method for preparing a perovskite solar cell in some embodiments of the present application;
[0026] Figure 4 is an XRD diagram of the homojunction formed by the perovskite absorption layer and the interface modification layer in Example 3;
[0027] Figure 5 Stability curves of the perovskite solar cell prepared in Example 3 and the perovskite solar cell prepared in Comparative Example 1.
[0028] Explanation of reference numerals: perovskite solar cell 100 , transparent conductive electrode 110 , hole transport layer 120 , perovskite absorption layer 130 , interface modification layer 140 , electron transport layer 150 , hole blocking layer 160 and counter electrode 170 . DETAILED DESCRIPTION
[0029] In order to facilitate the understanding of the present application, the present application will be described more comprehensively below in conjunction with the specific embodiments. The preferred embodiments of the present application are provided in the specific embodiments. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.
[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0031] Unless otherwise specified or there is a contradiction, the terms and phrases used in this application have the following meanings:
[0032] In this application, "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features.
[0033] In the description of the present application, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.
[0034] In this application, "one or several" refers to any one, any two or more of the listed items. Among them, "several" refers to any two or more of the listed items.
[0035] In this application, the percentage concentration involved, unless otherwise specified, refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.
[0036] The words "optionally" and the like in this application refer to embodiments of the present application that may provide certain beneficial effects in certain cases. However, other embodiments may also be optional under the same or other circumstances. In addition, the statement of one or more optional embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this application.
[0037] When a numerical range is disclosed in this application, the above range is considered to be continuous and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed in this application should be understood to include any and all subranges included therein.
[0038] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.
[0039] The terms "including" and "having" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or components that are inherent to these processes, methods, products, or devices.
[0040] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.
[0041] The first aspect of the present application provides a perovskite solar cell, comprising a transparent conductive electrode, a hole transport layer, a perovskite absorption layer, an interface modification layer, an electron transport layer, a hole blocking layer and a counter electrode arranged in a stacked manner;
[0042] The material of the perovskite absorption layer includes ABX3, the material of the interface modification layer includes one or more compounds of the general formula A3B2I9, the interface modification layer and the perovskite absorption layer form a 2D homojunction, and the A-site ions of the interface modification layer and the perovskite absorption layer both include formamidinium ions (FA + The B-site ions of the interface modification layer include antimony ions (Sb 3+ ) and bismuth ions (Bi 3+ ) one or more of the following, the B-site ions of the perovskite absorption layer include lead ions (Pb 2+ ), the X-site ions in the perovskite absorber layer include iodide ions (I - ), chloride ion (Cl - ), bromide ion (Br -) and thiocyanate ion (SCN - ) one or more of them.
[0043] The above-mentioned perovskite solar cell uses ABX3 as the perovskite absorption layer, and A includes formamidinium ions. By forming an interface modification layer of A3B2I9 between the perovskite absorption layer and the electron transport layer, it is not only beneficial to reduce the energy barrier between the interfaces, but also beneficial to increase the electron collection rate, thereby improving the photoelectric conversion efficiency of the solar cell. And the study found that using A3B2I9 as the interface modification layer is more beneficial to improving the photoelectric conversion efficiency and stability than A3B2Cl9.
[0044] In addition, due to the defects and softened bonds on the surface of the perovskite absorption layer, a poor chemical environment will be created, which will accelerate the intrusion of water / oxygen, and thus promote the decomposition of the perovskite film. The interface modification of the above-mentioned interface modification layer can effectively promote the transfer of charges and the moisture-proof function of the device. At the same time, due to the hydrophobicity of the interface modification layer itself, it also has a certain inhibitory effect on the corrosion of the metal electrode during the oxidation process, delaying the corrosion of the electrode, thereby achieving the purpose of extending the life of the device.
[0045] In some embodiments, the A-site ions of the perovskite absorption layer and the interface modification layer further include Cs + (cesium ion). Add Cs + It is beneficial to improve the stability of the perovskite lattice structure.
[0046] Specifically, in the A-site ions of the perovskite absorption layer and the interface modification layer, FA + The molar percentage of Cs is 90%~92%, + The molar percentage is 8%~10%.
[0047] In some embodiments, the thickness of the interface modification layer is 6 nm to 10 nm. Controlling the thickness of the interface modification layer is helpful to adjust the hydrophobicity of the perovskite absorption layer.
[0048] In some embodiments, the thickness of the perovskite absorption layer may be commonly used in the art, such as 400 nm to 500 nm. For example, the thickness of the perovskite absorption layer may be, but is not limited to, 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 490 nm, 500 nm, or a range consisting of any two of these values.
[0049] In some embodiments, the material of the perovskite absorption layer includes but is not limited to APbI3.
[0050] In some embodiments, the material of the hole transport layer includes but is not limited to PTAA and NiO. x One of the above.
[0051] In some embodiments, the thickness of the hole transport layer is 40 nm to 50 nm. For example, the thickness of the hole transport layer can be, but is not limited to, 40 nm, 42 nm, 44 nm, 46 nm, 48 nm, 50 nm, or a range consisting of any two of these values.
[0052] In some embodiments, the perovskite solar cell further comprises a hole blocking layer, which is disposed between the electron transport layer and the counter electrode. In an inverse perovskite solar cell, the hole blocking layer is mainly used to modify the electron transport layer and improve charge mobility, otherwise the charge will be recombinated, exacerbating performance loss.
[0053] Specifically, see Figure 1 The perovskite solar cell 100 includes a transparent conductive electrode 110, a hole transport layer 120, a perovskite absorption layer 130, an interface modification layer 140, an electron transport layer 150, a hole blocking layer 160 and a counter electrode 170 which are stacked in sequence.
[0054] In some embodiments, the transparent conductive electrode 110 includes but is not limited to transparent conductive glass. For example, the transparent conductive electrode 110 is FTO (fluorine-doped tin oxide) or ITO (indium tin oxide). The material of the electron transport layer 120 may be but is not limited to metal oxide. For example, the material of the electron transport layer 120 is C60, PCBM, etc. The material of the hole blocking layer 160 may be but is not limited to BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline). The counter electrode 170 may be but is not limited to a metal electrode. Specifically, the counter electrode 170 may be but is not limited to a silver electrode, a gold electrode, or a copper electrode.
[0055] It can be understood that only a few common materials for each layer are given above, but the present invention is not limited thereto.
[0056] In some embodiments, the thickness of the electron transport layer 120 is 25 nm to 35 nm.
[0057] In some embodiments, the thickness of the hole blocking layer 160 is 4 nm to 7 nm. For example, the thickness of the hole blocking layer 160 may be, but is not limited to, 4 nm, 5 nm, 6 nm, 7 nm, or a range consisting of any two of these values.
[0058] In some embodiments, the thickness of the counter electrode 170 is 60 nm to 100 nm. For example, the thickness of the counter electrode 170 may be, but is not limited to, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, or a range consisting of any two of these values.
[0059] See also Figure 2 , energy band diagram of the perovskite absorber layer after surface modification with interface modification layer. Figure 2 In the figure, the left side represents the energy band of the interface modification layer, and the right side represents the energy band of the electron transport layer (denoted as n-n+). Figure 2 In, E vac 、E c 、E F 、E v Represent vacuum level, conduction band, Fermi level, and valence band respectively. Figure 2 It can be seen that the Fermi level of the A3B2I9 post-treatment film after the homojunction is reconstructed above the PVK layer has shifted upward by about 0.06eV. This surface is more inclined to n-type doping than the control surface. It is equivalent to the reconstructed n / n+ homojunction in the perovskite film, which optimizes the energy level of the perovskite film. In the steady state, the Fermi levels of the control and post-treatment perovskites are equal, resulting in band bending. When the perovskite surface is n-doped, this causes a downward band bending on the perovskite surface, forming a beneficial "energy ladder" that is beneficial to charge separation and promotes charge extraction.
[0060] A second aspect of the present application provides a method for preparing a perovskite solar cell, comprising the following steps:
[0061] Forming a stacked transparent conductive electrode, a hole transport layer, a perovskite absorption layer, an interface modification layer, an electron transport layer, a hole blocking layer and a counter electrode;
[0062] The material of the perovskite absorption layer includes ABX3, the material of the interface modification layer includes one or more compounds of the general formula A3B2I9, the interface modification layer and the perovskite absorption layer form a 2D homojunction, and the A-site ions of the interface modification layer and the perovskite absorption layer both include formamidinium ions (FA + The B-site ions of the interface modification layer include antimony ions (Sb 3+ ) and bismuth ions (Bi 3+ ) one or more of the following, the B-site ions of the perovskite absorption layer include lead ions (Pb 2+ ), the X-site ions of the perovskite absorption layer include one or more of iodide ions, chloride ions, bromide ions and thiocyanate ions.
[0063] In some embodiments, the step of preparing the interface modification layer adopts a solution method, specifically comprising: applying an antimony salt solution to the surface of the perovskite absorption layer, and annealing to obtain the interface modification layer, wherein the anions in the antimony salt solution include iodide ions.
[0064] Furthermore, the anions in the antimony salt solution also include one or more of acetate ions, tartrate ions, chloride ions and fluoride ions.
[0065] Specifically, the antimony salt includes antimony iodide, and may optionally include one or more of antimony acetate, antimony tartrate, antimony chloride and antimony fluoride.
[0066] Antimony salts and free FA in the perovskite absorber layer + The reaction generates a perovskite homojunction, thereby reducing the energy barrier between interfaces and increasing the electron collection rate, thereby improving the photoelectric conversion efficiency of solar cells. The functional ions contained in the antimony salt can assist the growth of thin films and improve the quality of the homojunction during the formation of the perovskite homojunction, without the need for isopropyl alcohol rinsing. Some anions, such as acetate ions in antimony acetate and chloride ions in antimony chloride, can also connect with the incompletely reacted lead iodide in the perovskite absorption layer, adding more "channels" for carrier transport at the interface. The anions and cations in the antimony salt work synergistically to further improve the photoelectric conversion efficiency of solar cells.
[0067] In some embodiments, the solvent used for the antimony salt solution includes but is not limited to isopropanol.
[0068] In some embodiments, in the antimony salt solution, the total mass percentage concentration of the antimony salt is 0.5% to 2%. It is understood that the total mass percentage concentration of the antimony salt refers to the total mass percentage concentration of all antimony salts including antimony iodide and optionally one or more of antimony acid, antimony tartrate, antimony chloride and antimony fluoride.
[0069] Furthermore, the antimony salt includes antimony iodide and other antimony salts, and the other antimony salts include one or more of antimony acetate, antimony tartrate, antimony chloride and antimony fluoride. In the antimony salt solution, the mass ratio of antimony iodide to other antimony salts is (3~4.5):1.
[0070] In some embodiments, the step of applying the antimony salt solution to the surface of the perovskite absorption layer adopts a spin coating method. Specifically, the spin coating speed is 5000rpm~6500rpm, and the time is 30s~40s. For example, the spin coating speed can be but not limited to 5000rpm, 5200rpm, 5400rpm, 5500rpm, 5600rpm, 5800rpm, 6000rpm, 6200rpm, 6500rpm or a range consisting of any two of these values. The spin coating time can be but not limited to 30s, 32s, 34s, 35s, 36s, 38s, 40s or a range consisting of any two of these values.
[0071] In some embodiments, in the step of preparing the interface modification layer, a two-step annealing treatment is used, and the steps include: heating at 100°C~110°C for 5min~7min, heating at 130°C~150°C for 5min~10min. One-step high-temperature annealing may lead to poor crystallinity of 2D FA3Sb2I9, incomplete phase transformation, and the existence of 3D and 2D mixed phases, thereby affecting carrier transport and extraction. The advantage of two-step annealing is that 100°C~110°C is to quickly remove the surface IPA solution and provide a suitable synthesis temperature for the crystallization of FA3Sb2I9, and 130°C~150°C ensures the complete generation of 2D FA3Sb2I9.
[0072] In one embodiment, the step of preparing the interface modification layer includes: applying the antimony salt solution on the surface of the perovskite absorption layer by spin coating, the spin coating speed is 5000rpm~6500rpm, the time is 30s~40s, after the spin coating is completed, heating at 100℃~110℃ for 5min~7min, heating to 130℃~150℃ and heating for 5min~10min to prepare the interface modification layer.
[0073] Furthermore, after the step of applying the antimony salt solution to the surface of the perovskite absorption layer and before the step of annealing, the method further comprises: a step of standing. The standing time is 30s to 60s. For example, the standing time may be, but is not limited to, 30s, 35s, 40s, 45s, 50s, 55s, 60s, or a range consisting of any two of these values. The standing treatment allows the antimony salt to fully react with the perovskite absorption layer.
[0074] It is understood that in some other embodiments, the interface modification layer can also be formed by thermal evaporation or vapor deposition. Specifically, the steps of the thermal evaporation method include: using SbI3 as a target material and evaporating it on the surface of the perovskite absorption layer, and the steps of the vapor deposition method include: depositing SbI3 on the surface of the perovskite absorption layer.
[0075] In traditional technology, alkyl chains or amine salts are used to generate 2D homojunctions, but this type of homojunction requires a relatively precise and complex process during the generation process. For example, since the traditional process uses a one-step annealing process, it is usually necessary to use isopropanol for a second rinse after generation to rinse off a large amount of unreacted SbI3. Therefore, this will increase the time cost to a certain extent. In addition, the thickness of the 2D homojunction is uncontrollable during the rinsing process, and the uneven 2D homojunction will have a negative impact on the performance of the perovskite solar cell. The above-mentioned perovskite homojunction of the present application uses antimony salts and free FA in the perovskite film. +The reaction generates a weak n-type perovskite homojunction, thereby reducing the energy barrier between interfaces and increasing the electron collection rate, thereby improving the photoelectric conversion efficiency of solar cells. The anions in some antimony salts assist the growth of thin films and improve the quality of homojunctions during the formation of perovskite homojunctions. In addition, the unreacted SbI3 can be completely converted or the residual amount is small through two-step annealing treatment, which will not affect carrier transport, so there is no need for isopropyl alcohol washing, which is conducive to controlling the thickness of the interface modification layer and improving its uniformity.
[0076] In some embodiments, the perovskite solar cell further comprises an electron transport layer and a hole blocking layer. Figure 3 , the preparation method of the perovskite solar cell comprises the following steps:
[0077] Step S210: forming a hole transport layer on the surface of the transparent conductive electrode.
[0078] In some embodiments, the transparent conductive electrode includes but is not limited to transparent conductive glass, for example, the transparent conductive electrode is FTO (fluorine-doped tin oxide) or ITO (indium tin oxide).
[0079] In some embodiments, the material of the hole transport layer may be, but is not limited to, a metal oxide. For example, the material of the hole transport layer is NiO x .
[0080] In some embodiments, a solution method is used to form a hole transport layer. For example, the material of the hole transport layer is mixed with a solvent, the mixed solution is applied to the surface of the transparent conductive electrode, and annealed to prepare the hole transport layer. In a specific example, in the annealing step, annealing is performed at 100° C. to 110° C. for 15 min to 30 min.
[0081] Step S220: forming a perovskite absorption layer on the surface of the hole transport layer.
[0082] In some embodiments, the perovskite absorption layer is formed by a solution method. The solution method includes a one-step solution method and a two-step solution method. The specific coating method can be a spin coating method or a slit coating method.
[0083] In one embodiment, a solution containing a perovskite precursor material is applied to the surface of the hole transport layer, extracted using an anti-solvent, and annealed at 130° C. to 150° C. for 15 min to 30 min to prepare a perovskite absorption layer. The anti-solvent may be, but is not limited to, chlorobenzene, etc. The above only provides a more specific preparation step of the perovskite absorption layer, but is not limited to this.
[0084] In one embodiment, in the solution containing the perovskite precursor material, the solvent includes one or more of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). In a specific example, in the solution containing the perovskite precursor material, the solvent is a mixed solvent with a volume ratio of DMF:DMSO=4:1.
[0085] It is understood that in some other embodiments, the perovskite absorption layer may be formed by thermal evaporation. The specific process may be commonly used in the art and will not be described in detail.
[0086] Step S230: forming an interface modification layer on the surface of the perovskite absorption layer.
[0087] The specific steps of forming the interface modification layer are as described above and will not be repeated here.
[0088] Step S240: forming an electron transport layer on the surface of the interface modification layer.
[0089] In some embodiments, the material of the electron transport layer may be, but is not limited to, C 60 .
[0090] In some embodiments, the electron transport layer is formed by evaporation.
[0091] In some embodiments, the thickness of the electron transport layer is 25 nm to 35 nm. For example, the thickness of the electron transport layer can be, but is not limited to, 25 nm, 26 nm, 28 nm, 30 nm, 32 nm, 34 nm, 35 nm, or a range consisting of any two of these values.
[0092] Step S250: forming a hole blocking layer on the surface of the electron transport layer.
[0093] In some embodiments, the material of the hole blocking layer may be, but is not limited to, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline).
[0094] In some embodiments, the hole blocking layer is formed by evaporation.
[0095] In some embodiments, the thickness of the hole blocking layer is 4 nm to 7 nm. For example, the thickness of the hole blocking layer can be, but is not limited to, 4 nm, 5 nm, 6 nm, 7 nm, or a range consisting of any two of these values.
[0096] Step S260: forming a counter electrode on the surface of the hole blocking layer to prepare a perovskite solar cell.
[0097] In some embodiments, the counter electrode may be, but is not limited to, a metal electrode. Specifically, the counter electrode may be, but is not limited to, a silver electrode.
[0098] In some embodiments, the counter electrode is formed by evaporation.
[0099] In some embodiments, the thickness of the counter electrode is 60 nm to 100 nm. For example, the thickness of the counter electrode can be, but is not limited to, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, or a range consisting of any two of these values.
[0100] Understandably, Figure 3 This is a schematic diagram of a process for preparing a perovskite solar cell according to an embodiment of the present invention. Figure 3 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and they can be performed in other orders. Figure 3 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The order of execution is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of other sub-steps or stages.
[0101] A third aspect of the present application provides a photovoltaic module, comprising the above-mentioned perovskite solar cell.
[0102] It is understood that the photovoltaic module also includes photovoltaic glass, photovoltaic backplane, photovoltaic film, etc. In some embodiments, the photovoltaic module includes photovoltaic glass, a first photovoltaic film, a perovskite solar cell, a second photovoltaic film and a photovoltaic backplane stacked in sequence.
[0103] In order to make the purpose and advantages of the present application clearer, the perovskite solar cell of the present application and its effects are further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and shall not be used to limit the present application. The following embodiments do not include other components except for unavoidable impurities unless otherwise specified. The drugs and instruments used in the embodiments are conventionally selected in the art unless otherwise specified. The experimental methods for which specific conditions are not specified in the embodiments are implemented according to conventional conditions, such as the conditions described in the literature and books or the methods recommended by the manufacturer.
[0104] Example 1
[0105] This embodiment provides a perovskite solar cell, and the preparation steps are as follows:
[0106] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.
[0107] (2) NiO x Powder NiO x The mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.
[0108] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then the hole transport layer solution was spin-coated at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 20 minutes to prepare NiO x Hole transport layer.
[0109] (4) 1.5 mol FA 0.9 Cs 0.1 The PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO = 4:1 to obtain a perovskite precursor solution.
[0110] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3 perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and annealed at 150°C for 20 minutes to obtain FA. 0.9 Cs 0.1 PbI3 perovskite absorber layer.
[0111] (6) FA obtained in step (5) 0.9 Cs 0.1 A layer of antimony salt solution is spin-coated on the surface of the PbI3 perovskite absorption layer. The antimony salt solution is an isopropanol solution of SbI3 with a mass percentage concentration of 0.8%. The spin coating speed is 6000 rpm and the time is 35 s. After spin coating, it is allowed to stand for 45 s, and then heated at 100°C for 6 min and then heated at 130°C for 8 min to obtain an interface modification layer. The interface modification layer and the perovskite absorption layer form a 2D homojunction, which is recorded as Sb-I.
[0112] (7) Thermally evaporate 30 nm thick C on the surface of the interface modification layer obtained in step (6) 60 As electron transport layer.
[0113] (8) The surface of the electron transport layer in step (7) is again subjected to BCP thermal evaporation. The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination. The thickness is 5 nm.
[0114] (9) The effective area of the BCP barrier layer prepared in step (8) is 0.071 cm 2 , silver with a thickness of 80nm is used as the metal electrode to obtain the perovskite solar cell of this embodiment.
[0115] Example 2
[0116] This embodiment provides a perovskite solar cell, which is similar to the perovskite solar cell of embodiment 1, except that step (6) is different. Step (6) of this embodiment is as follows:
[0117] (6) FA obtained in step (5) 0.9 Cs 0.1 A layer of antimony salt solution is spin-coated on the surface of the PbI3 perovskite absorption layer. The antimony salt solution is an isopropanol solution of SbI3 and SbCl3 with mass percentage concentrations of 0.6% and 0.2% respectively. The spin coating speed is 6000 rpm and the time is 35 s. After spin coating, it is allowed to stand for 45 s, and then heated at 100 ° C for 6 min and then heated at 130 ° C for 8 min to obtain an interface modification layer, denoted as Sb-I-Cl.
[0118] Example 3
[0119] This embodiment provides a perovskite solar cell, which is similar to the perovskite solar cell of embodiment 1, except that step (6) is different. Step (6) of this embodiment is as follows:
[0120] (6) FA obtained in step (5) 0.9 Cs 0.1 A layer of antimony salt solution is spin-coated on the surface of the PbI3 perovskite absorption layer. The antimony salt solution is an isopropanol solution of SbI3 and Sb(CH3COO)3 with mass percentage concentrations of 0.65% and 0.15% respectively. The spin coating speed is 6000 rpm and the time is 35 s. After spin coating, it is allowed to stand for 45 s, heated at 100°C for 6 min, and then heated at 130°C for 8 min to obtain an interface modification layer, denoted as Sb-I-AC.
[0121] Example 4
[0122] This embodiment provides a perovskite solar cell, which is similar to the perovskite solar cell of embodiment 1, except that step (6) is different. Step (6) of this embodiment is as follows:
[0123] (6) FA obtained in step (5) 0.9 Cs 0.1A layer of antimony salt solution is spin-coated on the surface of the PbI3 perovskite absorption layer. The antimony salt solution is an isopropanol solution of SbI3. The mass percentage concentration of the antimony salt is 0.8%. The spin coating speed is 6000 rpm and the time is 35 s. After spin coating, it is allowed to stand for 45 s and annealed at 150°C for 8 min to obtain an interface modification layer, denoted as Sb-I.
[0124] Example 5
[0125] This embodiment provides a perovskite solar cell, which is similar to the perovskite solar cell of embodiment 1, except that step (6) is different. Step (6) of this embodiment is as follows:
[0126] (6) FA obtained in step (5) 0.9 Cs 0.1 A layer of bismuth salt solution is spin-coated on the surface of the PbI3 perovskite absorption layer. The bismuth salt solution is an isopropanol solution of BiI3. The mass percentage concentration of the bismuth salt is 0.8%. The spin coating speed is 6000 rpm and the time is 35 s. After spin coating, it is allowed to stand for 45 s and annealed at 150°C for 8 min to obtain an interface modification layer, denoted as Bi-I.
[0127] Comparative Example 1
[0128] Comparative Example 1 provides a perovskite solar cell, and the preparation steps are as follows:
[0129] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.
[0130] (2) NiO x Powder NiO x The mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.
[0131] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 20 minutes to prepare NiO x Hole transport layer.
[0132] (4) 1.5 mol FA 0.9 Cs 0.1 The PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO = 4:1, stirred at room temperature until completely dissolved, and filtered to obtain FA 0.9 Cs 0.1PbI3 perovskite precursor solution.
[0133] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3 perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and annealed at 150°C for 20 minutes to obtain FA. 0.9 Cs 0.1 PbI3 perovskite absorber layer.
[0134] (6) FA obtained in step (5) 0.9 Cs 0.1 30nm of C60 was thermally evaporated on the surface of the PbI3 perovskite absorption layer as an electron transport layer.
[0135] (7) The surface of the electron transport layer in step (6) is again subjected to BCP thermal evaporation. The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination. The thickness is 5 nm.
[0136] (8) The effective area of the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 80 nm was used as the metal electrode to obtain the perovskite solar cell of comparative example 1.
[0137] Comparative Example 2
[0138] Comparative Example 2 provides a perovskite solar cell, and the preparation steps are as follows:
[0139] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.
[0140] (2) NiO x Powder NiO x The mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.
[0141] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 20 minutes to prepare NiO x Hole transport layer.
[0142] (4) 1.5 mol FA 0.9 Cs 0.1The PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO = 4:1, stirred at room temperature until completely dissolved, and filtered to obtain FA 0.9 Cs 0.1 PbI3 perovskite precursor solution.
[0143] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3 perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and annealed at 150°C for 20 minutes to obtain FA. 0.9 Cs 0.1 PbI3 perovskite absorber layer.
[0144] (6) FA obtained in step (5) 0.9 Cs 0.1 A layer of antimony salt solution is spin-coated on the surface of the PbI3 perovskite absorption layer. The antimony salt solution is an isopropanol solution of SbCl3. The mass percentage concentration of SbCl3 is 1.5%. The spin coating speed is 6000rpm and the time is 35s. After spin coating, it is allowed to stand for 45s, and then heated at 100°C for 6min and then heated at 130°C for 8min to obtain an interface modification layer. The interface modification layer and the perovskite absorption layer form a 2D homojunction, denoted as Sb-Cl.
[0145] (7) Thermally evaporate 30 nm thick C on the surface of the interface modification layer obtained in step (6) 60 As electron transport layer.
[0146] (8) The surface of the electron transport layer in step (7) is again subjected to BCP thermal evaporation. The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination. The thickness is 5 nm.
[0147] (9) The effective area of the BCP barrier layer prepared in step (8) is 0.071 cm 2 , silver with a thickness of 80 nm was used as the metal electrode to obtain the perovskite solar cell of Comparative Example 2.
[0148] Comparative Example 3
[0149] Comparative Example 3 provides a perovskite solar cell, which is similar to the perovskite solar cell of Example 1, except that step (6) is different. Step (6) of Comparative Example 3 is as follows:
[0150] (6) FA obtained in step (5) 0.9 Cs 0.1A layer of antimony salt solution is spin-coated on the surface of the PbI3 perovskite absorption layer. The antimony salt solution is an isopropanol solution of Sb(CH3COO)3. The mass percentage concentration of antimony salt is 0.8%. The spin coating speed is 6000rpm and the time is 35s. After spin coating, it is allowed to stand for 45s, then heated at 100°C for 6min, and then heated at 130°C for 8min to obtain an interface modification layer.
[0151] The open circuit voltage (V oc )、Short circuit current(J SC ), fill factor (FF) and photoelectric conversion efficiency (PCE) were tested and calculated, and the results are shown in Table 1. Among them, the fill factor (FF) refers to the actual maximum available power (P m or V mp * J mp ) and theoretical (not actually achievable) power (J sc * V oc ). Therefore, FF can be determined by the following formula:
[0152] FF = (V mp * J mp ) / (J sc * V oc ).
[0153] Among them J mp and V mp Respectively represent the maximum power point (P m ) is obtained by changing the resistance in the circuit until J*V reaches its maximum value; J sc and V oc They represent short circuit current and open circuit voltage respectively. The open circuit voltage (Voc) is the potential difference between the anode and cathode of the device when there is no external load connected.
[0154] The PCE of a solar cell refers to the percentage of power converted from absorbed light to electrical energy. The PCE of a solar cell can be measured by the incident light irradiance (E: W / m 2 ) and the surface area of the solar cell (Ac:m 2 ) except the maximum power point (P m STC is usually calculated at a temperature of 25°C and a radiation intensity of 1000 W / m 2 , the spectrum of air quality 1.5 (AM1.5).
[0155] Table 1 Performance parameters of perovskite solar cells prepared in Examples and Comparative Examples
[0156]
[0157] It can be seen from Table 1 above that the photoelectric conversion efficiency of the perovskite solar cell prepared in the embodiment is better than that in the comparative example.
[0158] Figure 4 The XRD diagram of the homojunction formed by the perovskite absorption layer and the interface modification layer in Example 3. Figure 4 In the figure, the upper curve is the XRD diagram of Example 3, in which there is a two-dimensional XRD peak at an angle less than 10, namely A3Sb2I9. Figure 4 , the lower curve is the XRD diagram of the perovskite absorption layer in Comparative Example 1.
[0159] Figure 5 The stability diagram of the unpackaged perovskite device prepared in Example 3 and Comparative Example 1 after being placed for one month under 25°C and 40%RH storage conditions. Figure 5 It can be seen that the perovskite device without the A3Sb2I9 interface modification layer in Comparative Example 1 underwent severe decomposition, while the perovskite device with the A3Sb2I9 interface modification layer remained intact.
[0160] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0161] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the contents of the attached claims, and the description and drawings can be used to explain the contents of the claims.
Claims
1. A perovskite solar cell, characterized in that: It includes a transparent conductive electrode, a hole transport layer, a perovskite absorption layer, an interface modification layer, an electron transport layer, a hole blocking layer and a counter electrode which are stacked; Among them, the material of the perovskite absorption layer includes ABX3, the material of the interface modification layer includes one or more compounds with the general formula A3B2I9, the interface modification layer and the perovskite absorption layer form a 2D homojunction, the A-site ions of the interface modification layer and the perovskite absorption layer both include formamidine ions, the B-site ions of the interface modification layer include one or more of antimony ions and bismuth ions, the B-site ions of the perovskite absorption layer include lead ions, and the X-site ions of the perovskite absorption layer include one or more of iodide ions, chloride ions, bromide ions and thiocyanate ions.
2. The perovskite solar cell according to claim 1, characterized in that The A-site ions of the perovskite absorption layer and the interface modification layer further include cesium ions.
3. The perovskite solar cell according to claim 2, characterized in that: In the A-site ions of the perovskite absorption layer and the interface modification layer, the molar percentage of the formamidinium ions is 90% to 92%, and the molar percentage of the cesium ions is 8% to 10%.
4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that The thickness of the interface modification layer is 6nm-10nm.
5. A method for preparing a perovskite solar cell, characterized in that: The steps include: Forming a stacked transparent conductive electrode, a hole transport layer, a perovskite absorption layer, an interface modification layer, an electron transport layer, a hole blocking layer and a counter electrode; Among them, the material of the perovskite absorption layer includes ABX3, the material of the interface modification layer includes one or more compounds with the general formula A3B2I9, the interface modification layer and the perovskite absorption layer form a 2D homojunction, the A-site ions of the interface modification layer and the perovskite absorption layer both include formamidine ions, the B-site ions of the interface modification layer include one or more of antimony ions and bismuth ions, the B-site ions of the perovskite absorption layer include lead ions, and the X-site ions of the perovskite absorption layer include one or more of iodide ions, chloride ions, bromide ions and thiocyanate ions.
6. The method for preparing a perovskite solar cell according to claim 5, characterized in that: The steps of preparing the interface modification layer include: Applying an antimony salt solution on the surface of the perovskite absorption layer and performing annealing treatment to obtain the interface modification layer; The antimony salt includes antimony iodide, and optionally includes one or more of antimony acetate, antimony tartrate, antimony chloride and antimony fluoride.
7. The method for preparing a perovskite solar cell according to claim 6, characterized in that: In the antimony salt solution, the total mass percentage concentration of the antimony salt is 0.5% to 2%; and / or, In the antimony salt solution, the mass ratio of the antimony iodide to other antimony salts is (3-4.5):1, and other antimony salts include one or more of antimony acetate, antimony tartrate, antimony chloride and antimony fluoride.
8. The method for preparing a perovskite solar cell according to claim 6, characterized in that: The annealing treatment steps include: heating at 90°C-100°C for 5min-7min, heating at 130°C-150°C for 10min-15min.
9. The method for preparing a perovskite solar cell according to any one of claims 6 to 8, characterized in that: After the step of applying the antimony salt solution to the surface of the perovskite absorption layer and before the step of annealing, the method further includes: standing for 30s to 60s.
10. A photovoltaic module, characterized in that: A perovskite solar cell comprising the perovskite solar cell according to any one of claims 1 to 4 or a perovskite solar cell prepared by the preparation method according to any one of claims 5 to 9.