Solar cell and preparation method thereof, photovoltaic module, system and power utilization device

Abstract

The invention relates to a solar cell and a preparation method thereof, a photovoltaic module, a system and an electric device. The solar cell comprises a first electrode layer, a first hole transport layer, a perovskite light absorption layer and a second electrode layer which are stacked, the component of the first hole transport layer comprises P-type tin oxide. The solar cell has high photoelectric conversion efficiency.

Description

Technical Field

[0001] The present application relates to the field of material technology, and in particular to a solar cell and a preparation method thereof, a photovoltaic module, a system and an electrical device. Background Art

[0002] Perovskite materials are organic-inorganic metal halides ABX3, which have an octahedral structure, abundant raw material reserves, and can be widely synthesized artificially. Perovskite materials have many advantages such as high photoelectric absorption coefficient, long carrier diffusion length, and shallow defect energy level, which make perovskite materials have small photoelectric losses. Solar cells with perovskite materials as light absorption layers have the advantages of cost reduction and efficiency improvement, high weak light effect, and broad application scenarios. They are an excellent choice for the new generation of mass-produced photovoltaic cells.

[0003] However, the photoelectric conversion efficiency of perovskite solar cells still needs to be improved. Summary of the invention

[0004] Based on this, the present application aims to provide a solar cell and its preparation method, photovoltaic module, system and electrical device that can improve the photoelectric conversion efficiency.

[0005] A first aspect of the present application provides a solar cell, comprising a first electrode layer, a first hole transport layer, a perovskite light absorption layer and a second electrode layer which are stacked; a component of the first hole transport layer comprises P-type tin oxide.

[0006] Without wishing to be limited to any theory, the above solar cell, by providing a first hole transport layer containing P-type tin oxide between the perovskite light absorption layer and the first electrode layer, is beneficial to improving the stability of the perovskite light absorption layer and having better hole transport properties, thereby improving the photoelectric conversion efficiency of the solar cell device.

[0007] In any embodiment of the present application, the chemical formula of the P-type tin oxide is SnOx, 1≤x<2;

[0008] Optionally, 1≤x≤1.8;

[0009] More optionally, 1.2≤x≤1.8;

[0010] Further optionally, 1.5≤x≤1.8.

[0011] In any embodiment of the present application, the components of the first hole transport layer further include a non-tin metal inorganic compound;

[0012] Optionally, the non-tin metal inorganic compound includes at least one of Al2O3, MoO3, Cu2O, CuI, CuSCN and CuO.

[0013] In any embodiment of the present application, the first hole transport layer includes a mixed layer formed by the non-tin metal inorganic compound and the P-type tin oxide.

[0014] In any embodiment of the present application, in the mixed layer, the mass fraction of the P-type tin oxide is >0 and ≤50%; optionally 5% to 50%, more optionally 20% to 50%.

[0015] In any embodiment of the present application, the first hole transport layer includes a P-type tin oxide layer and an intermediate layer, the intermediate layer includes the non-tin metal inorganic compound, and the P-type tin oxide layer is located between the intermediate layer and the perovskite light absorption layer.

[0016] In any embodiment of the present application, in the total thickness of the first hole transport layer, the thickness of the P-type tin oxide layer accounts for >0 and ≤50%; optionally 5% to 50%, more optionally 20% to 50%.

[0017] In any embodiment of the present application, the solar cell further includes a second hole transport layer, the second hole transport layer is disposed between the first electrode layer and the first hole transport layer, and the second hole transport layer and the first hole transport layer are made of different materials.

[0018] In any embodiment of the present application, the solar cell satisfies at least one of the following conditions:

[0019] (1) The second hole transport layer includes at least one of PTAA, nickel oxide, Spiro-OMeTAD, WO3, PEDOT:PSS, poly-3-hexylthiophene, triphenylamine compounds and carbazole compounds; optionally, the second hole transport layer includes at least one of PTAA and nickel oxide;

[0020] (2) The thickness ratio of the second hole transport layer to the first hole transport layer is (0.8-10):1, optionally (2-10):1, and more optionally (2-6):1; optionally, the thickness of the first hole transport layer does not exceed 20 nm, and more optionally 5-10 nm; optionally, the thickness of the second hole transport layer is 15-30 nm;

[0021] (3) The first electrode layer is a transparent electrode layer.

[0022] The second aspect of the present application provides a method for preparing the solar cell according to the first aspect of the present application, comprising the following steps:

[0023] Forming the first electrode layer, the first hole transport layer, the perovskite light absorption layer and the second electrode layer in a stacked manner;

[0024] Optionally, the method further includes forming a second hole transport layer between the first electrode layer and the first hole transport layer.

[0025] The third aspect of the present application provides a photovoltaic assembly, comprising the solar cell provided in the first aspect of the present application.

[0026] A fourth aspect of the present application provides a photovoltaic system, comprising the photovoltaic assembly provided by the third aspect of the present application.

[0027] The fifth aspect of the present application provides an electrical device, comprising at least one selected from the solar cell provided in the first aspect of the present application and the photovoltaic module provided in the third aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of a solar cell according to an embodiment of the present application;

[0029] Figure 2 is a schematic diagram of a solar cell according to another embodiment of the present application;

[0030] Figure 3 It is a schematic diagram of an electrical device using a solar cell as a power source according to one embodiment of the present application.

[0031] Description of reference numerals:

[0032] 1. Solar cell; 11. Transparent electrode; 12. Second hole transport layer; 13. First hole transport layer; 14. Perovskite light absorption layer; 15. Electron transport layer; 16. Counter electrode layer; 2. Electrical device. DETAILED DESCRIPTION

[0033] Hereinafter, the embodiments of the present application are specifically disclosed in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0034] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0035] If there is no special description, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. If there is no special description, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0036] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0037] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or included, or only the listed components may be included or included.

[0038] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0039] An embodiment of the present application provides a solar cell, comprising a first electrode layer, a first hole transport layer, a perovskite light absorption layer and a second electrode layer stacked in layers. The first hole transport layer comprises P-type tin oxide.

[0040] Without wishing to be limited to any theory, the above-mentioned solar cell, by providing a first hole transport layer containing P-type tin oxide between the perovskite light absorption layer and the first electrode layer, is beneficial to improving the stability of the perovskite light absorption layer, while having better hole transport properties, thereby improving the photoelectric conversion efficiency of the solar cell device.

[0041] In addition, the conventional technology uses acidic PEDOT:PSS as the first hole transport layer, which accelerates the degradation of perovskite materials when in contact with perovskite materials, which is not conducive to improving the stability of solar cell devices and thus improving their photoelectric conversion efficiency; at the same time, PEDOT:PSS is an organic hole transport material, which is often prepared by spin coating, which is not conducive to the industrial production of large-area perovskite components. Compared with PEDOT:PSS, the first hole transport layer of the above solar cell contains P-type tin oxide, which is not only conducive to improving the stability of solar cell devices and thus improving their photoelectric conversion efficiency, but also can be used in physical vapor deposition, chemical vapor deposition and other processes, which is conducive to industrial production.

[0042] In some embodiments, the thickness of the perovskite light absorbing layer is 200nm to 1000nm. As an example, the thickness of the perovskite light absorbing layer is 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm; optionally, 400nm to 500nm.

[0043] The perovskite light absorbing layer can be prepared by a common preparation method in the art, including but not limited to sol-gel method, coating, multi-source co-evaporation and other methods. It is understood that coating includes but is not limited to spin coating, slit coating, brush coating, rubbing coating, scraping coating, screen coating and spraying. Further, the perovskite light absorbing layer is a three-dimensional perovskite film.

[0044] In some embodiments, the perovskite light absorbing layer contains a perovskite material. The general formula of the perovskite material is ABX3 or A2CDX6; the A ion is a monovalent cation, the B ion is a divalent metal cation, the C ion is a monovalent metal cation, the D ion is a trivalent metal cation, and the X ion is a monovalent anion.

[0045] Optionally, the A ion includes at least one of an organic cation and a metal cation. More preferably, the organic cation includes at least one of an organic amine ion, a formamidine group (FA) and an imidazole group; More preferably, the metal cation includes Li + 、Na + , K + , Rb + and Cs + Further, the organic amine ion includes at least one of methylamine (MA), ethylamine, propylamine, butylamine, pentylamine and hexylamine.

[0046] Optionally, the B ions include Pb 2+ Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ 、Zn 2+ ,Ge 2+ , Fe 2+ 、Co 2+ , Cu 2+ and Ni 2+ More preferably, the B ions include Pb 2+ and Sn 2+ One or both of the following.

[0047] Optionally, the C ions include Cs + 、Ag + , K + And Ru + At least one of .

[0048] Optionally, the D ions include Bi 3+ 、Ni 3+ , Fe 3+ and Cu 3+ At least one of;

[0049] Optionally, the X ions include F - , Cl - Br - and I - At least one of; Optionally, the X ions include Cl - Br - and I -At least one of .

[0050] It can be understood that the perovskite material in the above-mentioned perovskite light absorbing layer can be selected from at least one of CsFAPbX3, CsMAPbX3, CsFAMAPbX3, CsPbX3, MAPbX3, FAPbX3, CsFAPbSnX3, CsMAPbSnX3, CsFAMAPbSnX3, CsPbSnX3, MAPbSnX3 and FAPbSnX3. Further, as an example, the perovskite material in the above-mentioned perovskite light absorbing layer can be selected from at least one of CsFAPbI3, CsPbI3, and FAPbI3.

[0051] As an example, the general formula of perovskite materials is as follows: Cs a FA b MA c Pb d Sn e I f Br g , among them, a=0~0.05, b=0.8~0.95, c=0~0.1, d=0.5~1, e=0~0.5, f=2.0~3, g=0~1, a+b+c=1, d+e=1, f+g=3.

[0052] In some embodiments, the chemical formula of the P-type tin oxide is SnOx, where 1≤x<2. The tin oxide of this chemical formula has oxygen vacancies, and thus has good hole transport properties.

[0053] As an example, x may be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9. Alternatively, 1≤x≤1.8; more preferably, 1.2≤x≤1.8. More preferably, 1.5≤x≤1.8.

[0054] It can be understood that in some embodiments, the component of the first hole transport layer is P-type tin oxide, and no other hole transport material is added.

[0055] In some other embodiments, the components of the first hole transport layer also include non-tin metal inorganic compounds. It is understood that "non-tin metal inorganic compounds" refer to inorganic compounds formed by metals other than tin. Further, the non-tin metal inorganic compounds include at least one of Al2O3, MoO3, Cu2O, CuI, CuSCN and CuO. In other words, the hole transport material of the first hole transport layer includes not only P-type tin oxide, but also non-tin metal inorganic compounds, such as at least one of Al2O3, MoO3, Cu2O, CuI, CuSCN and CuO.

[0056] Furthermore, in one example, the first hole transport layer includes a mixed layer formed by a non-tin metal inorganic compound and P-type tin oxide; for example, a mixed layer formed by at least one of Al2O3, MoO3, Cu2O, CuI, CuSCN and CuO and P-type tin oxide. By regulating the composition and proportion of the mixed layer, the energy levels between the first hole transport layer and other functional layers are more matched, so that the performance of the solar cell device is better.

[0057] Further, in the mixed layer, the mass fraction of P-type tin oxide is >0 and ≤50%, optionally 5% to 50%, or 20% to 50%. As an example, in the mixed layer, the mass fraction of P-type tin oxide may be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%.

[0058] It is understandable that the mixed layer can be prepared by adding multiple raw materials. For example, when using the atomic deposition method, two deposition raw materials can be used.

[0059] Further, in another example, the first hole transport layer includes a P-type tin oxide layer and an intermediate layer. The intermediate layer includes a non-tin metal inorganic compound, such as at least one of Al2O3, MoO3, Cu2O, CuI, CuSCN and CuO, and the P-type tin oxide layer is located between the intermediate layer and the perovskite light absorption layer. The P-type tin oxide layer includes P-type tin oxide, or the material of the P-type tin oxide is P-type tin oxide.

[0060] As an example, the first hole transport layer includes a stacked P-type tin oxide layer and an intermediate layer, and the intermediate layer may be an aluminum oxide layer, a molybdenum oxide layer or a cuprous oxide layer, or a layer formed of at least two of aluminum oxide, molybdenum oxide and cuprous oxide.

[0061] Further, in the total thickness of the first hole transport layer, the thickness of the P-type tin oxide layer accounts for >0 and ≤50%; optionally 5% to 50%, or 20% to 50%. As an example, in the total thickness of the first hole transport layer, the thickness of the P-type tin oxide layer may account for 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%.

[0062] It is understood that the stack of the P-type tin oxide layer and the intermediate layer can be prepared in two steps, and the preparation method of each layer can be specifically selected. It is understood that in some combination schemes, the first hole transport layer can simultaneously contain the above-mentioned mixed layer and the stack of the P-type tin oxide layer and the intermediate layer, and the relative positions of the three stacks are not limited; optionally, the P-type tin oxide layer is in direct contact with the perovskite light absorption layer.

[0063] Furthermore, the preparation method of the first hole transport layer can be PVD (physical vapor deposition), CVD (chemical vapor deposition), ALD (atomic deposition technology), spin coating and other processes, preferably ALD (atomic deposition technology).

[0064] In some embodiments, the solar cell further comprises a second hole transport layer. The second hole transport layer is disposed between the first electrode layer and the first hole transport layer. The second hole transport layer and the first hole transport layer are made of different materials. By disposing a first hole transport layer of different materials between the second hole transport layer and the perovskite light absorption layer, and the component of the first hole transport layer comprises P-type tin oxide, the double-layer hole transport layer structure thus formed can improve the hole transport performance of the solar cell compared to the traditional single-layer hole transport layer, thereby improving the photoelectric conversion efficiency of the solar cell device.

[0065] In some embodiments, the material of the second hole transport layer includes but is not limited to at least one of the following materials and their derivatives: poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA), NiOx (nickel oxide), 2,2',7,7'-tetrakis [N,N-di (4-methoxyphenyl) amino] -9,9'-spirobifluorene (Spiro-OMeTAD), WO3, poly 3,4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT: PSS), poly-3 hexylthiophene (P3HT), triphenylamine compounds and carbazole compounds and other materials that can transport holes and block electrons. One or more.

[0066] Among them, triphenylamine compounds include but are not limited to triphenylamine (H101) with triptycene as the core, 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA). Carbazole compounds include but are not limited to N-(4-phenylamino)carbazole-spirobifluorene (CzPAF-SBF) and phosphate carbazole compounds. Furthermore, the second hole transport layer includes at least one of PTAA and nickel oxide (NiOx) compounds.

[0067] The hole transport materials that are currently widely used in inverse perovskite solar cells include NiOx and PTAA.

[0068] When NiOx is in direct contact with the perovskite light absorption layer, Ni in NiOx 3+ It will undergo redox reaction with the organic cations of the perovskite material in the perovskite light absorption layer, causing degradation of the perovskite material and seriously limiting its service life. Therefore, when the material of the second hole transport layer is NiOx, a first hole transport layer containing P-type tin oxide is provided between the second hole transport layer and the perovskite light absorption layer, thereby suppressing Ni 3+The redox reaction between the organic cations and the perovskite material inhibits the degradation of the perovskite material, which is beneficial to improve the stability of the perovskite light absorption layer and solar cell devices and extend the service life of the solar cell devices.

[0069] The strong hydrophobicity of PTAA causes the perovskite precursor solution to have extremely poor wettability on its surface, thereby affecting the crystallization of the perovskite material and being detrimental to the preparation of high-performance solar cell devices. Therefore, when the material of the second hole transport layer is PTAA, by providing a first hole transport layer containing P-type tin oxide between the second hole transport layer and the perovskite light absorption layer, the wettability of PTAA and the perovskite precursor solution during the preparation process can be improved, which is beneficial to improving the crystallization quality of the obtained perovskite material and promoting the industrial production of solar cell devices.

[0070] In some embodiments, the thickness ratio of the second hole transport layer to the first hole transport layer is (0.8-10):1; as an example, the thickness ratio may be 0.8:1, 1:1, 2:1, 2.5:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1. The thickness ratio of the second hole transport layer to the first hole transport layer may be (2-10):1, and more preferably (2-6):1.

[0071] In some of the embodiments, the thickness of the first hole transport layer does not exceed 10 nm, and may be 5 to 10 nm. As an example, the thickness of the first hole transport layer may be 2 nm, 3 nm, 5 nm, 7 nm, 8 nm, 9 nm, or 10 nm.

[0072] In some of the embodiments, the thickness of the second hole transport layer is 15-30 nm. As an example, the thickness of the second hole transport layer may be 15 nm, 20 nm, 25 nm, or 30 nm.

[0073] Optionally, the solar cell may further include an electron blocking layer between the first electrode layer and the second hole transport layer. The material of the electron blocking layer may be a known material.

[0074] In some of the embodiments, the solar cell may further include an electron transport layer, wherein the electron transport layer is located between the perovskite light absorbing layer and the second electrode layer.

[0075] As an example, the material of the electron transport layer can be but is not limited to at least one of the following materials and their derivatives: imide compounds, quinone compounds, fullerenes and their derivatives, methoxytriphenylamine-fluoroformamidine (OMeTPA-FA), [6,6]-phenyl C61 butyric acid methyl ester (PCBM), [6,6]-phenyl C71 butyric acid methyl ester (PC71BM), calcium titanate (CaTiO3), lithium fluoride (LiF), calcium fluoride (CaF2), poly (3,4-ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT:PSS), poly 3-hexylthiophene (P3HT), triphenylamine with triptycene as the core (H101), 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N-(4-phenylamino)carbazole-spirobifluorene (CzPAF-SBF), polythiophene, metal oxides (metal elements are selected from Mg, Ni, Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, or Cr), silicon oxide (SiO2), strontium titanate (SrTiO3), and cuprous thiocyanate (CuSCN).

[0076] Optionally, the solar cell may further include a hole blocking layer between the second electrode layer and the electron transport layer.

[0077] The material of the hole blocking layer may include, but is not limited to, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline).

[0078] In a specific example, the electron transport layer adopts a PCBM layer, and the hole blocking layer adopts a BCP layer. The BCP layer serves as a passivation layer of the electron transport layer. The BCP molecular structure contains N atoms with lone pairs of electrons, which can effectively passivate the surface defects of the PCBM layer, promote the transfer and separation of charges at the interface, and help eliminate the current hysteresis of the battery device.

[0079] It can be understood that in order to enable light to be effectively transmitted to the perovskite light absorption layer, at least one electrode in the solar cell is set as a transparent electrode and the other is a counter electrode layer.

[0080] It can be understood that the solar cell includes a regular structure and a transverse structure in terms of structure. Optionally, one of the first electrode layer and the second electrode layer is a transparent electrode; and the other may be a counter electrode layer.

[0081] The transparent electrode may be a transparent conductive metal oxide electrode. As an example, the material of the transparent electrode may be, for example, transparent conductive glass such as FTO, ITO, AZO, BZO, and IZO. It is understandable that in addition to using glass as a substrate, the transparent electrode may also use a transparent flexible substrate. Specifically, the material of the transparent flexible substrate may be, for example, an organic polymer material, which may be mixed in different proportions by one or more of the following materials: polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), and polydimethylsiloxane (PDMS).

[0082] The material of the counter electrode layer includes but is not limited to organic materials, or inorganic materials, or conductive materials mixed in different proportions of organic materials and inorganic materials. Further, the counter electrode layer is a metal electrode. The metal conductive material of the counter electrode layer includes but is not limited to gold Au, silver Ag, copper Cu, aluminum Al, nickel Ni, chromium Cr, bismuth Bi, platinum Pt, magnesium Mg or a mixture thereof.

[0083] For the trans structure, as an example, Figure 1 As shown, the solar cell includes a transparent electrode 11 and a second hole transport layer 12, a first hole transport layer 13, a perovskite light absorption layer 14, an electron transport layer 15 and a counter electrode layer 16 stacked sequentially on the transparent electrode 11. The first electrode layer is the transparent electrode 11, and the second electrode layer is the counter electrode layer 16.

[0084] For a formal structure, as an example, Figure 2 As shown, the solar cell includes a transparent electrode 11 and an electron transport layer 15, a perovskite light absorption layer 14, a first hole transport layer 13, a second hole transport layer 12 and a counter electrode layer 16 stacked sequentially on the transparent electrode 11. Among them, the first electrode layer is the counter electrode layer, and the second electrode layer is a transparent electrode.

[0085] The present application also provides a method for preparing the above-mentioned solar cell, comprising the steps of forming a stacked first electrode layer, a second hole transport layer, a first hole transport layer, a perovskite light absorption layer and a second electrode layer.

[0086] In some embodiments, the preparation method includes the following steps S11 to S14.

[0087] S11, forming a second hole transport layer on the first electrode layer;

[0088] S12, forming a first hole transport layer on a surface of the second hole transport layer away from the first electrode layer;

[0089] S13, forming a perovskite light absorption layer on a surface of the first hole transport layer away from the second hole transport layer.

[0090] S14, forming a first electrode layer on a surface of the perovskite light absorption layer away from the first hole transport layer.

[0091] Specifically, as an example, the solar cell is a trans type, and the preparation method thereof includes the following steps:

[0092] Step 1: Etching and cleaning the transparent electrode and drying;

[0093] Step 2: sequentially preparing a second hole transport layer and a first hole transport layer on the transparent electrode;

[0094] Step 3: preparing a perovskite light absorption layer on the first hole transport layer;

[0095] Step 4: preparing an electron transport layer on the perovskite light absorption layer;

[0096] Step 5: Prepare a counter electrode layer on the electron transport layer.

[0097] It is understandable that when the solar cell is formal, its preparation sequence is slightly different and can be slightly adjusted according to its structure.

[0098] In some examples, the method for preparing the above-mentioned perovskite light absorption layer includes the following steps: mixing material A, BX2 and a solvent to obtain a perovskite precursor solution; then coating the perovskite precursor solution on a corresponding substrate, annealing, and obtaining a perovskite light absorption layer.

[0099] The above-mentioned first electrode, second hole transport layer, first hole transport layer, electron transport layer and second electrode can be prepared by the commonly used preparation methods in the art, including but not limited to solution method and solid deposition method. The solution method includes any one of spin coating, spray coating, scraper coating and slit coating, and the solid deposition method includes any one of vacuum evaporation, sputtering deposition, plasma deposition and ion deposition.

[0100] An embodiment of the present application further provides a photovoltaic module, which includes the above-mentioned solar cell.

[0101] The solar cell has high light conversion efficiency and good stability, and can improve the efficiency of photovoltaic modules.

[0102] The photovoltaic module includes one or more of the above-mentioned solar cells, which can be selected according to the specific application scenario; further, the photovoltaic module includes a plurality of the above-mentioned solar cells, and the plurality of the above-mentioned solar cells are connected in series or in parallel to form a battery cell. Further, the photovoltaic module may also include a laminated battery, and the laminated battery includes one or more of the above-mentioned solar cells. Among them, the laminated battery includes but is not limited to crystalline silicon / perovskite laminated battery, full perovskite laminated battery, copper indium gallium selenide and other thin film batteries / perovskite laminated batteries.

[0103] In some of the embodiments, the photovoltaic module further includes a photovoltaic glass layer, a bonding layer and a back sheet.

[0104] Adhesive layers are respectively arranged on the two surfaces of the solar cell, a back plate is arranged on the surface of one of the adhesive layers away from the solar cell, and a photovoltaic glass layer is arranged on the surface of the other adhesive layer away from the solar cell.

[0105] The photovoltaic glass layer and the back panel are used to protect the solar cells, and they have the functions of sealing, insulation and waterproofing; the bonding layer plays the role of bonding the photovoltaic glass layer to the battery cell, and bonding the back panel to the battery cell.

[0106] Optionally, the photovoltaic glass layer is made of tempered glass, the back panel is made of TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the adhesive layer is made of EVA (polyethylene-polyvinyl acetate copolymer).

[0107] Furthermore, the above photovoltaic assembly also includes a junction box and an outer frame.

[0108] The junction box is used to protect the power generation system of the entire photovoltaic module. It is equivalent to a current transfer station. When a battery cell short-circuits, the junction box will automatically disconnect the short-circuited battery string.

[0109] The outer frame can support and protect the entire photovoltaic module. The frame can be made of aluminum alloy, which has excellent strength and corrosion resistance.

[0110] Furthermore, the connection between the frame and other parts of the photovoltaic module is bonded and sealed by silicone. The photovoltaic module can convert solar energy into electrical energy, or send it to a battery for storage, or drive a load to work.

[0111] In some embodiments, the photovoltaic component is a solar panel.

[0112] An embodiment of the present application further provides a photovoltaic system, comprising the above-mentioned photovoltaic module.

[0113] The photovoltaic system utilizes the photovoltaic effect of the solar cells in the photovoltaic modules to directly convert solar radiation energy into electrical energy with high efficiency; further, the photovoltaic system is a photovoltaic power generation system.

[0114] Photovoltaic modules are the core part of photovoltaic power generation systems. The above photovoltaic system includes one or more photovoltaic modules, which can be selected according to specific application scenarios; further, when the above photovoltaic system includes multiple photovoltaic modules, the multiple photovoltaic modules form a photovoltaic array.

[0115] The above photovoltaic system can be an independent photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0116] An independent photovoltaic power generation system includes a photovoltaic array, a battery pack, a charging controller, a power electronic converter (inverter), a load, etc. Its working principle is that the solar radiation energy is first converted into electrical energy through the photovoltaic array, and then converted by the power electronic converter to supply power to the load. At the same time, the excess electrical energy is stored in the energy storage device in the form of chemical energy after passing through the charging controller. In this way, when the sunshine is insufficient, the energy stored in the battery can be converted into AC 220V, 50Hz electrical energy after being stepped up by the power electronic inverter, filtering and power frequency transformer for use by the AC load.

[0117] The grid-connected photovoltaic power generation system includes a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter) and system monitoring. Its working principle is that the solar radiation energy is converted by the photovoltaic array, and then converted into high-voltage DC power by high-frequency DC conversion, and then inverted by the power electronic inverter to output a sinusoidal AC current with the same frequency as the grid voltage to the grid.

[0118] The above two photovoltaic power generation systems have their own characteristics and can be selected according to specific application scenarios.

[0119] One embodiment of the present application provides an electrical device, including the above-mentioned solar cell or the above-mentioned photovoltaic module.

[0120] In some of the embodiments, the solar cell or photovoltaic module can be used as a power source for an electrical device, or can be used as an energy storage unit for an electrical device.

[0121] Furthermore, the above-mentioned electrical devices may include mobile devices, such as mobile phones, laptop computers, etc., electric vehicles, electric trains, ships and satellites, etc., but are not limited thereto.

[0122] Figure 3 The power consumption device 2 is used as an example. The power consumption device 2 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.

[0123] In order to make the technical problems, technical solutions and beneficial effects solved by the present application clearer, the present application will be further described in detail below in conjunction with the embodiments and drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its applications. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0124] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0125] 1. Device Preparation

[0126] Example 1

[0127] A method for preparing a solar cell device with an inverted structure is as follows:

[0128] 1) Preparation of FTO conductive glass electrode: Specification is 2.0*2.0cm 2 The FTO conductive glass was removed by laser etching at both ends to remove 0.35 cm of FTO to expose the glass substrate; the etched FTO conductive glass was ultrasonically cleaned several times with water, acetone, and isopropanol, and then dried with nitrogen for later use;

[0129] 2) Preparation of the second hole transport layer: FTO was treated with UV ozone, and then nickel oxide with a thickness of about 20 nm was magnetron sputtered, and annealed at 300° C. for 60 min to obtain the second hole transport layer;

[0130] 3) Preparation of the first hole transport layer: SnOx (x=1.76, obtained by XPS test of the film; the value of x is controlled by controlling the oxygen flow rate during the atomic deposition method, the same below) with a thickness of about 5 nm is prepared on the surface of the second hole transport layer to obtain the first hole transport layer;

[0131] 4) Preparation of perovskite light absorbing layer: The perovskite light absorbing layer was prepared by a one-step method. Specifically, the perovskite precursor solution was spin-coated on the prepared first hole transport layer at a speed of 4000 rpm for 20-40 seconds, 300-600 uL of anti-solvent was added at about 10 seconds after the start of spin coating, and then the film was placed on a hot plate and annealed at 120°C for 60 minutes to obtain a perovskite light absorbing layer with a thickness of 500 nm. The composition of the perovskite material in the perovskite light absorbing layer was Cs 0.05 FA 0.95 PbI3;

[0132] 5) Preparation of electron transport layer: Place the device with perovskite light absorption layer prepared in step 4) into the evaporation apparatus and wait until the evaporation vacuum reaches 5*10 -4 Pa or less, an electron transport layer (C60 layer) with a thickness of 30 nm and a passivation layer (or hole blocking layer, made of BCP) with a thickness of 5 nm disposed on the electron transport layer were sequentially deposited at a rate of 0.05 A / s;

[0133] 6) Preparation of metal counter electrode: Place the thin film with electron transport layer prepared in step 5) into the evaporation apparatus and wait until the evaporation vacuum reaches 5*10 -4 Pa, a metal Cu back electrode with a thickness of 80 nm was evaporated at a rate of 0.1 A / s.

[0134] Example 2

[0135] Except for step 2), the other steps are the same as those in Example 1. Step 2) is specifically as follows.

[0136] 2) Preparation of the second hole transport layer: FTO was treated with UV ozone, and then a 2 mg / mL PTAA organic hole transport layer was spin-coated at a rate of 5000 rpm / s, followed by annealing on a 100°C hot stage for 10 minutes; a second hole transport layer with a thickness of about 30 nm was obtained.

[0137] Embodiments 3 to 5

[0138] It is basically the same as Example 1, except that by controlling the oxygen flux during the atomic deposition method in step 3) of the first hole transport layer, the x of SnOx in the first hole transport layer (SnOx layer) is regulated to be different, as shown in Table 1.

[0139] Embodiments 6 to 8

[0140] It is basically the same as Example 1, except that the thickness of the first hole transport layer (SnOx layer) is regulated by controlling the time during the atomic deposition method in step 3) of the first hole transport layer, as shown in Table 1.

[0141] Example 9

[0142] It is basically the same as Example 1, except that the second hole transport layer is omitted and only the first hole transport layer is included, as shown in Table 1.

[0143] Embodiments 10 to 15

[0144] It is basically the same as Example 1, except that, on the basis of keeping the thickness of the first hole transport layer unchanged, the raw materials of the atomic deposition method process in step 3) of the first hole transport layer are controlled to be different, so that the deposited first hole transport layer is controlled to be a mixed layer; the mass content of SnOx in the mixed layer is controlled by controlling the ratio of the raw materials, as shown in Table 2.

[0145] Embodiments 16 to 21

[0146] It is basically the same as Example 1, except that after the P-type SnOx layer is deposited in step 3), an intermediate layer is formed on the basis of the P-type SnOx layer by atomic deposition; and a subsequent perovskite light absorbing layer is formed on the intermediate layer, as shown in Table 3.

[0147] Comparative Example 1

[0148] It is basically the same as Example 1, except that the type of the first hole transport layer deposited in step 3) is different, as follows:

[0149] 3) Preparation of the first hole transport layer: Aluminum oxide with a thickness of about 5 nm was prepared on the surface of the second hole transport layer by an atomic deposition method to obtain the first hole transport layer.

[0150] Comparative Example 2

[0151] It is basically the same as Example 1, except that the type of the first hole transport layer deposited in step 3) is different, as follows:

[0152] 3) Preparation of the first hole transport layer: cuprous oxide with a thickness of about 5 nm is prepared on the surface of the second hole transport layer by an atomic deposition method to obtain the first hole transport layer.

[0153] Comparative Example 3

[0154] It is basically the same as Example 2, except that the type of the first hole transport layer deposited in step 3) is different, as follows:

[0155] 3) Preparation of the first hole transport layer: Aluminum oxide with a thickness of about 5 nm was prepared on the surface of the second hole transport layer by an atomic deposition method to obtain the first hole transport layer.

[0156] Comparative Example 4

[0157] It is basically the same as Example 2, except that the type of the first hole transport layer deposited in step 3) is different, as follows:

[0158] 3) Preparation of the first hole transport layer: Molybdenum oxide with a thickness of about 5 nm was prepared on the surface of the second hole transport layer by an atomic deposition method to obtain the first hole transport layer.

[0159] 2. Performance Test

[0160] Photovoltaic conversion efficiency of perovskite solar cells

[0161] Using Keithley2400SMU, AM 1.5G solar irradiation at 100mW / cm 2 The battery performance is tested under the light source, and the photoelectric conversion efficiency is calculated as follows:

[0162] PCE=Pout / Popt

[0163] =Voc×Jsc×(Vmpp×Jmpp) / (Voc×Jsc)

[0164] =Voc×Jsc×FF

[0165] Among them, Pout, Popt, Vmpp, Jmpp, Voc and Jsc are the battery operating output power, incident light power, battery maximum power point voltage, battery maximum power point current, open circuit voltage and short circuit current respectively.

[0166] According to the above process, 4 perovskite solar cells obtained in each of the above embodiments and comparative examples were tested respectively, and the obtained results were averaged. For specific results, see Tables 1 to 3.

[0167] Table 1

[0168]

[0169] Table 2

[0170]

[0171]

[0172] Table 3

[0173]

[0174] It can be seen from Tables 1 to 3 that the photoelectric conversion performance of the solar cells prepared in Examples 1 to 20 is higher than that of the comparative examples.

[0175] In Table 1, the only difference between Examples 1 and 2 is that the material type of the second hole transport layer is different, and the solar cells prepared therefrom all have good photoelectric conversion performance; the only difference between Examples 1 and 3 to 5 is that the x of SnOx in the first hole transport layer (SnOx layer) is different, and x is further 1.2 to 1.8, and the solar cells prepared therefrom have good photoelectric conversion performance. The only difference between Examples 1 and 6 to 8 is that the thickness of the first hole transport layer is different, and the thickness is further 5nm to 10nm, and the solar cells prepared therefrom have good photoelectric conversion performance. Example 9 contains only the first hole transport layer, and does not contain the second hole transport layer, and the solar cell prepared therefrom also has good photoelectric conversion performance.

[0176] As can be seen from Table 2, the difference between Examples 10 to 15 and Example 1 is that, on the basis of the unchanged thickness of the first hole transport layer, a mixed material is used to form the first hole transport layer. Compared with Example 1, the solar cells prepared in Examples 10 to 15 have better photoelectric conversion performance; further, the mass content of SnOx in the first hole transport layer is controlled to be 20% to 50%, and the prepared solar cells have better photoelectric conversion performance.

[0177] It can be seen from Table 3 that the difference between Examples 16 to 21 and Example 1 is that, on the basis of keeping the thickness of the SnOx layer unchanged, another material is used to form an intermediate layer in the SnOx layer, and the SnOx layer and the intermediate layer together serve as the first hole transport layer; compared with Example 1, the solar cells prepared in Examples 16 to 21 have better photoelectric conversion performance; further, the thickness of the SnOx layer in the first hole transport layer is controlled to account for 20% to 50%, and the obtained solar cells have better photoelectric conversion performance.

[0178] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A solar cell, characterized in that: It includes a first electrode layer, a first hole transport layer, a perovskite light absorption layer and a second electrode layer which are stacked; the component of the first hole transport layer includes P-type tin oxide.

2. The solar cell according to claim 1, characterized in that: The chemical formula of the P-type tin oxide is SnOx, 1≤x<2; Optionally, 1≤x≤1.8; More optionally, 1.2≤x≤1.8; Further optionally, 1.5≤x≤1.

8.

3. The solar cell according to claim 1, characterized in that The components of the first hole transport layer also include a non-tin metal inorganic compound; Optionally, the non-tin metal inorganic compound includes at least one of Al2O3, MoO3, Cu2O, CuI, CuSCN and CuO.

4. The solar cell according to claim 3, characterized in that: The first hole transport layer includes a mixed layer formed by the non-tin metal inorganic compound and the P-type tin oxide.

5. The solar cell according to claim 4, characterized in that: In the mixed layer, the mass fraction of the P-type tin oxide is greater than 0 and less than or equal to 50%; optionally, 5% to 50%, and more optionally, 20% to 50%.

6. The solar cell according to claim 3, characterized in that: The first hole transport layer includes a P-type tin oxide layer and an intermediate layer, the intermediate layer includes the non-tin metal inorganic compound, and the P-type tin oxide layer is located between the intermediate layer and the perovskite light absorption layer.

7. The solar cell according to claim 6, characterized in that: In the total thickness of the first hole transport layer, the thickness of the P-type tin oxide layer accounts for >0 and ≤50%; optionally 5% to 50%, more optionally 20% to 50%.

8. The solar cell according to any one of claims 1 to 7, characterized in that: The solar cell further includes a second hole transport layer, which is disposed between the first electrode layer and the first hole transport layer, and the second hole transport layer and the first hole transport layer are made of different materials.

9. The solar cell according to claim 8, characterized in that The solar cell satisfies at least one of the following conditions: (1) The second hole transport layer includes at least one of PTAA, nickel oxide, Spiro-OMeTAD, WO3, PEDOT:PSS, poly-3-hexylthiophene, triphenylamine compounds and carbazole compounds; optionally, the second hole transport layer includes at least one of PTAA and nickel oxide; (2) The thickness ratio of the second hole transport layer to the first hole transport layer is (0.8-10):1, optionally (2-10):1, and more optionally (2-6):1; optionally, the thickness of the first hole transport layer does not exceed 20 nm, and more optionally 5-10 nm; optionally, the thickness of the second hole transport layer is 15-30 nm; (3) The first electrode layer is a transparent electrode layer.

10. A method for preparing a solar cell according to any one of claims 1 to 9, characterized in that: The steps include: Forming the first electrode layer, the first hole transport layer, the perovskite light absorption layer and the second electrode layer in a stacked manner; Optionally, the method further includes forming a second hole transport layer between the first electrode layer and the first hole transport layer.

11. A photovoltaic module, characterized in that: The invention comprises the solar cell according to any one of claims 1 to 9.

12. A photovoltaic system, characterized in that: Comprising the photovoltaic module as claimed in claim 11.

13. An electrical device, characterized in that: The invention comprises at least one selected from the group consisting of the solar cell according to any one of claims 1 to 9 and the photovoltaic module according to claim 11.

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