A buried substrate compound and its application in perovskite solar cells

Abstract

This invention provides a buried substrate compound and its application in perovskite solar cells, relating to the field of perovskite solar cell technology. The buried substrate compound has the following structure: at least one of R1 and R2 is an organic group containing one or more elements selected from O, S, N, and P; or at least one of R1 and R2 contains a halogen. The buried substrate compound of this invention, used in the buried substrate of perovskite solar cells, can improve the stability of the photoelectric conversion efficiency of perovskite solar cells.

Description

Technical Field

[0001] This invention belongs to the field of perovskite battery technology, and relates to a buried material compound and its application in perovskite batteries. Background Technology

[0002] Perovskite materials have attracted widespread attention due to their excellent photoelectric properties. In just over a decade, the efficiency of perovskite solar cells has increased from 3.8% to 26.1%. Among existing technologies, nickel oxide is widely used as the hole transport layer in inverted perovskite solar cells due to its advantages such as low cost, simple preparation process, and good stability.

[0003] Due to poor energy level matching between nickel oxide and the perovskite layer, as well as high interface defect density, the efficiency and stability of the entire perovskite solar cell are not high. The main component responsible for the hole transport layer in nickel oxide is Ni. 3+ passivated Ni 2+ To enhance Ni 3+ The ratio is an effective way to improve hole transport efficiency. However, perovskites themselves also have some defects, including iodine defects, lead defects, and cation vacancy defects, which can significantly reduce charge transport efficiency and battery stability. Research has found that a buried layer can be placed between the nickel oxide hole transport layer and the perovskite layer to simultaneously passivate the Ni in the nickel oxide layer. 2+ Pb in the perovskite layer 2+ The defect strategy promotes charge transport, increases the crystallinity of perovskite, reduces the defect density at the interface, reduces non-radiative recombination, increases the open-circuit voltage and hole transport efficiency of the cell, and also avoids the Ni in the nickel oxide layer. 3+ With I in the perovskite layer - Direct contact leads to the degradation of perovskite solar cells, thereby improving their efficiency and stability.

[0004] Currently, the industry has proposed a variety of embedding materials, but the applicant believes that the embedding materials still need further improvement. Summary of the Invention

[0005] The applicant has discovered that using highly polar pyridine compounds as a substrate material can effectively passivate Ni in the nickel oxide layer. 2+ And improve Ni 3+ The proportion of Pb in the passivated perovskite layer 2+ This invention addresses defects and increases the crystallinity of the perovskite layer, thereby improving the overall open-circuit voltage and hole transport efficiency of the perovskite solar cell. Based on this, the present invention provides a buried substrate material compound and its application in perovskite solar cells.

[0006] The technical solution of the present invention is as follows:

[0007] A substrate material compound having the structure shown in formula (Ⅰ),

[0008]

[0009] Wherein, at least one of R1 and R2 is an organic group containing one or more elements of O, S, N and P, or at least one of R1 and R2 contains a halogen.

[0010] Preferably, the organic group is selected from one of carbonyl, nitro, thiocarbonyl, phosphonoyl, sulfonic acid, ester, thioamide, amino, hydroxyl, amide, sulfonamide, carboxyl, C1-C4 acyl, C1-C4 alkoxy, sulfonamide, amidine, porphyrinamide and mercapto.

[0011] More preferably, R1 and R2 are not both C1-C4 alkoxy groups.

[0012] Preferably, the substrate material compound has the structure shown in formula (II).

[0013]

[0014] R1 is selected from one of carbonyl, nitro, thiocarbonyl, phosphono, sulfonic acid, ester, thioamide, amino, hydroxy, amide, sulfonamide, carboxyl, C1-C4 acyl, C1-C4 alkoxy, sulfonamide, amidine, porphyrinamide, C1-C4 alkyl, and mercapto; R2 is selected from one of C1-C4 alkyl, C1-C4 alkoxy, C1-C4 carboxyl, Cl, Br, nitro, amino, mercapto, and C2-C6 ester.

[0015] More preferably, the substrate material compound is selected from one or a combination of two or more of the following: sulfamethoxypyridine, methylamide pyridine, 5-methyl-2-pyridinesulfonamide, 6-aminopyridine-3-thioamide, 5-methoxypyridine linamide, 2-amidinylpyridinecarboxylic acid, pyridine-2,5-dicarboxylic acid, 5-chloro-2-hydroxypyridine, 5-bromo-2-nitropyridine, methyl 5-methyl-2-carboxylate pyridine, 2-acetyl-6-bromopyridine, methyl 2,5-pyridinedicarboxylate, and 2-mercapto-5-nitropyridine.

[0016] A perovskite solar cell comprises a hole transport layer, a buried layer, and a perovskite layer stacked sequentially.

[0017] The buried layer is composed of the buried material compound described in any of the above embodiments.

[0018] Preferably, the thickness of the buried layer is 1-20 nm.

[0019] Preferably, the method for preparing the buried substrate includes:

[0020] The substrate material compound was dissolved in an organic solvent to prepare a solution of 0.1-10 mg / ml;

[0021] The solution is spin-coated onto the surface of the hole transport layer and then annealed to obtain the buried substrate.

[0022] More preferably, the purity of the substrate material compound is not less than 99%.

[0023] Preferably, the thickness of the hole transport layer is 5-30 nm.

[0024] The beneficial effects of this invention are:

[0025] (1) The present invention uses a highly polar compound containing pyridine as a buried material, which can be formed between the hole transport layer and the perovskite layer by spin coating. This can effectively increase the hole transport efficiency and reduce the interface defect density, improve the open circuit voltage and hole transport efficiency of the perovskite solar cell, and enhance the stability of the perovskite solar cell.

[0026] (2) The raw materials of the buried material compound of the present invention are readily available, have many selectivity and good effect, and have good application prospects. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the inverted perovskite solar cell in Example 1.

[0028] 1-ITO conductive glass, 2-Nickel oxide hole transport layer, 3-Buried substrate, 4-Three-dimensional perovskite layer, 5-C 60 Layer 6, BCP layer, 7-silver anode layer.

[0029] Figure 2 This is a comparison of the relationship between current density (JSC) and voltage (V) of the inverted perovskite solar cells of Example 1 and Comparative Example 1.

[0030] Figure 3 This is a comparison of the stability of the inverted perovskite solar cells of Example 1 and Comparative Example 1 under high temperature and high humidity tests.

[0031] Figure 4 This is a comparison of the stability of the inverted perovskite solar cells of Example 2 and Comparative Example 2 under high temperature and high humidity tests.

[0032] Figure 5 This is a comparison of the stability of the inverted perovskite solar cells of Example 3 and Comparative Example 3 under high temperature and high humidity tests. Detailed Implementation

[0033] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0034] On one hand, the present invention provides a buried material compound having the structure shown in formula (Ⅰ).

[0035]

[0036] Wherein, at least one of R1 and R2 is an organic group containing one or more elements of O, S, N and P, or at least one of R1 and R2 contains a halogen.

[0037] Pyridine is a nitrogen-containing six-membered heterocyclic compound with high polarity. Adding heteroatom-containing substituents to the pyridine molecule further enhances the polarity of the embedded material compound. In this invention, a compound with the structure shown in formula (I)—a heteroatom-substituent pyridine—is used as the embedded material. This embedded material has high polarity, and the heteroatom contains lone pairs of electrons, which can generate strong van der Waals forces and resist metal ions (such as Ni). 2+ Pb 2+ It exhibits good adsorption and affinity effects, and can effectively adsorb and passivate Ni in the hole transport layer. 2+ and / or Pb of the perovskite layer 2+ Enhance Ni in the hole transport layer 3+ The ratio and / or reduction of the defect density of the perovskite layer can improve the open-circuit voltage and hole transport efficiency of perovskite solar cells, and isolate the perovskite layer and hole transport layer to enhance the stability of perovskite solar cells.

[0038] In a preferred embodiment of the present invention, the organic group is selected from one of carbonyl, nitro, thiocarbonyl, phosphonoyl, sulfonic acid, ester, thioamide, amino, hydroxyl, amide, sulfonamide, carboxyl, C1-C4 acyl, C1-C4 alkoxy, sulfonamide, amidine, porphyrinamide and mercapto.

[0039] In a more preferred embodiment of the present invention, R1 and R2 are not both C1-C4 alkoxy groups. Because alkoxy groups have relatively low polarity, when R1 and R2 are both C1-C4 alkoxy groups, the polarity of the buried material compound is not high enough, resulting in poor adsorption and affinity for metal ions.

[0040] In this invention, R1 and R2 can be the same or different. When R1 and R2 are the same, both R1 and R2 are organic groups containing one or more of the elements O, S, N, and P, such as amino, hydroxyl, amide, sulfonamide, carboxyl, carbonyl, nitro, thiocarbonyl, phosphonyl, sulfonic acid, ester, thioamide, etc. When R1 and R2 are different, one of R1 and R2 is an organic group containing one or more of the elements O, S, N, and P, and the other can be an organic group containing one or more of the elements O, S, N, and P, or a C1-C4 alkoxy or C1-C4 alkyl.

[0041] In a preferred embodiment of the present invention, the substrate material compound is a pyridine compound substituted at the 2,5 positions, having the structure shown in formula (II).

[0042]

[0043] R1 is selected from one of carbonyl, nitro, thiocarbonyl, phosphono, sulfonic acid, ester, thioamide, amino, hydroxy, amide, sulfonamide, carboxyl, C1-C4 acyl, C1-C4 alkoxy, sulfonamide, amidine, porphyrinamide, C1-C4 alkyl, and mercapto; R2 is selected from one of C1-C4 alkyl, C1-C4 alkoxy, C1-C4 carboxyl, Cl, Br, nitro, amino, mercapto, and C2-C6 ester.

[0044] In a more preferred embodiment of the present invention, the substrate material compound is selected from one or a combination of two or more of the following: sulfamethoxypyridine, methylamide pyridine, 5-methyl-2-pyridinesulfonamide, 6-aminopyridine-3-thioamide, 5-methoxypyridine linamide, 2-amidinylpyridinecarboxylic acid, pyridine-2,5-dicarboxylic acid, 5-chloro-2-hydroxypyridine, 5-bromo-2-nitropyridine, methyl 5-methyl-2-carboxylate pyridine, 2-acetyl-6-bromopyridine, methyl 2,5-pyridinedicarboxylate, and 2-mercapto-5-nitropyridine.

[0045] On the other hand, the present invention provides a perovskite solar cell comprising a hole transport layer, a buried layer and a perovskite layer stacked sequentially.

[0046] The buried layer is composed of the buried material compound described in any of the above embodiments.

[0047] In this invention, a buried layer composed of the aforementioned buried material compound is disposed between the hole transport layer and the perovskite layer, isolating the hole transport layer and the perovskite layer. The buried layer has a lower Pb content than the perovskite layer. 2+ It exhibits good adsorption and affinity properties, and can effectively adsorb and passivate Pb in the perovskite layer. 2+This reduces the defect density of the perovskite layer, thereby improving the open-circuit voltage of perovskite solar cells. When the hole transport layer is a nickel oxide layer, the buried layer has a significant impact on Ni... 2+ It exhibits good adsorption and affinity properties, and can effectively adsorb and passivate Ni in the hole transport layer. 2+ Enhance Ni in the hole transport layer 3+ This increases the proportion of hole transmission efficiency.

[0048] For example, the perovskite solar cell of the present invention can be an inverted structure, which may include, from bottom to top, a substrate, a positive electrode layer, a hole transport layer, a buried layer, a perovskite layer, an electron transport layer, and a negative electrode layer stacked sequentially. For example, the substrate can be glass, a flexible substrate, a heterojunction cell, a crystalline silicon cell, or other thin-film solar cells. For example, the thickness of the perovskite layer can be 300-900 nm, and the general structural formula of perovskite can be expressed as Cs. a Rb b FA c MA d PbI x Br y Where FA represents formamidinium, MA represents methylamine, a≥0, b≥0, c≥0, d≥0, a+b+c+d=1, a+b≤0.2, x+y=3, y≤0.6. For example, the positive electrode layer includes ITO, FTO, or IZO, etc. For example, the electron transport layer includes C... 60 +BCP, PCBM+BCP or C 60 +SnO2, etc. For example, the negative electrode layer includes ITO electrode, silver electrode, copper electrode, gold electrode, or aluminum electrode, etc.

[0049] In a preferred embodiment of the present invention, the thickness of the buried substrate is 1-20 nm. For example, the thickness of the buried substrate can be any value from 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc., without any particular limitation.

[0050] In a preferred embodiment of the present invention, the method for preparing the buried substrate includes:

[0051] The substrate material compound is dissolved in an organic solvent to prepare a solution of 0.1-10 mg / ml;

[0052] The solution is spin-coated onto the surface of the hole transport layer and then annealed to obtain a buried layer.

[0053] The embedded substrate prepared by spin coating can achieve nanometer-scale thickness and relatively uniform film. The organic solvent can be any one or a mixture of several solvents selected from methanol, ethanol, isopropanol, acetonitrile, toluene, dimethyl sulfoxide, DMF, DMAc, and acetone. The spin coating speed can be 3000-5000 r / min, the annealing temperature can be 20℃-100℃, and the annealing time can be 1 min-10 min. There are no particular restrictions on the concentration of the prepared solution; it can be 0.1 mg / ml, 0.5 mg / ml, 1 mg / ml, 2 mg / ml, 3 mg / ml, 4 mg / ml, 5 mg / ml, 6 mg / ml, 7 mg / ml, 8 mg / ml, 9 mg / ml, 10 mg / ml, etc.

[0054] In a more preferred embodiment of the present invention, the purity of the substrate material compound is not less than 99%. Insufficient purity of the substrate material compound, with the presence of numerous impurities, will affect the function and effectiveness of the substrate material compound.

[0055] In a preferred embodiment of the present invention, the thickness of the hole transport layer is 5-30 nm. For example, the hole transport layer may be a nickel oxide hole transport layer, and the thickness may be any value among 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, etc., without any particular limitation.

[0056] The perovskite solar cell of the present invention has a buried layer composed of the above-mentioned buried material composition between the hole transport layer and the perovskite layer, which has high photoelectric conversion efficiency and open circuit voltage, while also having high stability of photoelectric conversion efficiency.

[0057] The technical solutions of the present invention will be further described and explained below with reference to various embodiments.

[0058] Example 1

[0059] This embodiment provides a buried material compound and a method for preparing an inverted perovskite solar cell, including the following steps (1)-(5):

[0060] (1) Prepare a solution of the substrate compound, wherein the substrate compound is 2-sulfanilamide-5-methylpyridine, the solvent is isopropanol, and the concentration of the substrate compound is 0.75 mg / ml.

[0061] (2) Provide ITO conductive glass, and spin-coat nickel oxide nano solution on the surface of ITO conductive glass to form a hole transport layer with a thickness of 10nm.

[0062] (3) Spin-coating the buried material compound solution onto the surface of the nickel oxide layer to form a buried liquid film at a speed of 4000 r / min; annealing the buried liquid film at a temperature of 80℃ for 5 min to obtain a buried layer with a thickness of 8 nm.

[0063] (4) A three-dimensional perovskite layer is formed on the surface of the hole transport layer by spin coating. The material of the three-dimensional perovskite layer is Cs. 0.05 FA 0.95 PbI3, with a thickness of 600 nm.

[0064] (5) A 20 nm thick C layer was sequentially deposited on the surface of the three-dimensional perovskite layer using a vacuum evaporation process. 60 A layer, an 8nm thick BCP layer, and a 120nm silver anode layer were used to obtain an effective area of ​​0.09cm². 2 The schematic diagram of the inverted perovskite solar cell is shown in the attached figure. Figure 1 As shown.

[0065] The photoelectric conversion efficiency of the perovskite solar cell prepared in this embodiment was tested. The initial efficiency was 23.6%, the open-circuit voltage was 1.18V, and the short-circuit current density was 23.8mA / cm². 2 The fill factor was 84.2%. The prepared perovskite solar cell achieved 94% of its initial efficiency after 1200 hours of operation under high temperature and high humidity (85℃, RH 85%) conditions, demonstrating high initial efficiency and good efficiency stability.

[0066] Comparative Example 1

[0067] The difference between this comparative example and Example 1 is that no buried layer is placed between the three-dimensional perovskite layer and the nickel oxide hole transport layer in Example 1. The remaining steps remain unchanged.

[0068] The photoelectric conversion efficiency of the perovskite solar cell prepared in this comparative example was tested. The initial efficiency was 21.6%, the open-circuit voltage was 1.07 V, and the short-circuit current density was 24.0 mA / cm². 2 The fill factor was 83.8%. The prepared perovskite solar cell retained 55% of its initial efficiency after operating for 1200 hours under high temperature and high humidity conditions (85℃, RH 85%).

[0069] The comparison of the current density (JSC) versus voltage (V) of the inverted perovskite solar cells in this comparative example and Example 1, as well as the comparison of their stability under high temperature and high humidity tests, are shown in the appendices. Figure 2 and attached Figure 3 As shown.

[0070] Example 2

[0071] This embodiment provides a buried material compound and a method for preparing an inverted perovskite solar cell, including the following steps (1)-(6):

[0072] (1) Prepare a solution of the substrate compound, the substrate compound is 5-methyl-2-pyridinesulfonamide, the solvent is a mixed solution of isopropanol and DMF (volume ratio of 19:1), and the concentration of the substrate compound is 0.5 mg / ml.

[0073] (2) Provide a heterojunction cell, and form an ITO cathode layer with a thickness of 30 nm on the surface of the heterojunction cell by physical vapor deposition (PVD);

[0074] (3) A 10 nm nickel oxide hole transport layer is formed on the surface of the ITO layer of conductive glass by magnetron sputtering.

[0075] (4) Spin-coating the solution of the buried material compound onto the surface of the nickel oxide layer to form a buried liquid film at a speed of 4000 r / min; annealing the passivation liquid film at a temperature of 60°C for 8 min to obtain a buried layer with a thickness of 5 nm.

[0076] (5) A three-dimensional perovskite layer was formed on the surface of the hole transport layer by spin coating. The material of the three-dimensional perovskite layer was Cs. 0.05 FA 0.8 MA 0.15 PbI 2.4 Br 0.6 The thickness is 650nm.

[0077] (6) A 20 nm thick C layer was deposited on the passivation layer surface using a vacuum evaporation process. 60 A 20nm thick SnO2 layer was deposited using atomic layer deposition, followed by a 30nm ITO layer by magnetron sputtering. Finally, a 120nm silver anode layer was vacuum-deposited, resulting in an effective area of ​​1cm². 2 Perovskite / heterojunction tandem solar cells.

[0078] The photoelectric conversion efficiency of the prepared perovskite / heterojunction tandem solar cell was tested, and the initial efficiency was 28.0%. After operating under high temperature and high humidity conditions (85℃, RH 85%) for 1200 h, the efficiency of the prepared perovskite / heterojunction tandem solar cell reached 92% of the initial efficiency.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Example 2 is that in Example 2, no buried layer is placed between the three-dimensional perovskite layer and the nickel oxide hole transport layer. The remaining steps remain unchanged.

[0081] The photoelectric conversion efficiency of the perovskite solar cell prepared in this comparative example was tested, and the initial efficiency was 26.7%. After operating under high temperature and high humidity conditions (85℃, RH 85%) for 1200 h, the prepared perovskite solar cell maintained 52% of its initial efficiency.

[0082] The stability of the inverted perovskite solar cells in this comparative example and Example 2 under high temperature and high humidity tests is compared in the appendix. Figure 4 As shown.

[0083] Example 3

[0084] This embodiment provides a buried material compound and a method for preparing a buried layer for an inverted perovskite solar cell, including the following steps (1)-(6):

[0085] (1) Prepare a solution of the substrate compound, the substrate compound is 6-aminopyridine-3-thioamide, the solvent is methanol, and the concentration of the substrate compound is 1 mg / ml.

[0086] (2) Provide a copper indium gallium selenide thin film solar cell, wherein a 20 nm ITO positive electrode layer is formed on the electrode surface of the copper indium gallium selenide thin film solar cell by physical vapor deposition (PVD).

[0087] (3) A nickel oxide hole transport layer is formed on the surface of ITO conductive glass by spin coating, and the thickness of the hole transport layer is 12nm.

[0088] (4) Spin-coating the buried material compound solution onto the surface of the nickel oxide hole transport layer to form a buried liquid film at a speed of 4000 r / min; annealing the buried liquid film at a temperature of 70°C for 6 min to obtain a buried layer with a thickness of 10 nm.

[0089] (5) A three-dimensional perovskite layer was formed on the surface of the hole transport layer by spin coating. The material of the three-dimensional perovskite layer was Cs. 0.05 FA 0.77 MA 0.22 PbI 2.35 Br 0.65 The thickness is 700nm.

[0090] (6) A 15nm thick C layer was deposited on the surface of the passivation layer using a vacuum evaporation process. 60 A 20nm thick SnO2 layer was deposited using atomic layer deposition, followed by a 30nm ITO layer by magnetron sputtering. Finally, a 100nm silver anode layer was vacuum-deposited, resulting in an effective area of ​​1cm². 2 Perovskite / copper indium gallium selenide tandem solar cells.

[0091] The photoelectric conversion efficiency of the perovskite / copper indium gallium selenide tandem solar cell prepared in this embodiment was tested, and the initial efficiency was 21.7%. After running for 1200 hours under high temperature and high humidity (85°C, RH 85%) conditions, the prepared perovskite / copper indium gallium selenide tandem solar cell maintained 90% of the initial efficiency.

[0092] Comparative Example 3

[0093] The difference between this comparative example and Example 3 is that in Example 3, no buried layer is placed between the three-dimensional perovskite layer and the nickel oxide hole transport layer. The remaining steps remain unchanged.

[0094] The photoelectric conversion efficiency of the perovskite solar cell prepared in this comparative example was tested, and the initial efficiency was 20.2%. After operating under high temperature and high humidity conditions (85℃, RH 85%) for 1200 h, the prepared perovskite solar cell maintained 50% of its initial efficiency.

[0095] The stability of the inverted perovskite solar cells in this comparative example and Example 3 under high temperature and high humidity tests is compared in the attached figure. Figure 5 As shown.

[0096] Example 4

[0097] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the substrate material compound was changed from 2-sulfanilamide-5-methylpyridine to 5-methyl-2-pyridinecarboxamide, while the other steps remained unchanged.

[0098] The photoelectric conversion efficiency of the perovskite solar cell prepared in this embodiment was tested, and the initial efficiency was 23.1%. After operating for 1200 hours under high temperature and high humidity conditions (85℃, RH 85%), the efficiency of the prepared perovskite solar cell was 91% of the initial efficiency, indicating high initial efficiency and good efficiency stability.

[0099] Example 5

[0100] The difference between this embodiment and Example 1 is that in Example 1, the substrate compound was changed from 2-sulfanilamide-5-methylpyridine to 5-methoxypyridine linamide, the concentration of the substrate compound solution was 2 mg / ml, and the thickness of the substrate layer was 15 nm. The remaining steps remained unchanged.

[0101] The photoelectric conversion efficiency of the perovskite solar cell prepared in this embodiment was tested, and the initial efficiency was 23.3%. After operating for 1200 hours under high temperature and high humidity conditions (85℃, RH 85%), the efficiency of the prepared perovskite solar cell was 92% of the initial efficiency, indicating high initial efficiency and good efficiency stability.

[0102] Example 6

[0103] The difference between this embodiment and Embodiment 2 is that in Embodiment 2, the substrate compound was changed from 5-methyl-2-pyridinesulfonamide to 5-bromo-2-nitropyridine, the concentration of the substrate compound solution was 1 mg / ml, and the thickness of the substrate layer was 12 nm. The remaining steps remained unchanged.

[0104] The photoelectric conversion efficiency of the perovskite / heterojunction tandem solar cell prepared in this embodiment was tested, and the initial efficiency was 27.5%. After operating for 1200 hours under high temperature and high humidity conditions (85℃, RH 85%), the efficiency of the prepared perovskite / heterojunction tandem solar cell was 91% of the initial efficiency, indicating high initial efficiency and good efficiency stability.

[0105] As described above, the basic principles, main features, and advantages of the present invention have been shown and described. Those skilled in the art should understand that the present invention is not limited to the above embodiments, which are merely preferred embodiments and should not be construed as limiting the scope of the invention. All equivalent changes and modifications made in accordance with the scope of the patent and the description should still fall within the scope of the present invention. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A perovskite solar cell, characterized in that, It consists of a hole transport layer, a buried layer, and a perovskite layer stacked in sequence; The buried layer is composed of a buried layer material compound; The substrate material compound is selected from one of 5-methyl-2-pyridinesulfonamide, 6-aminopyridine-3-thioamide, 5-methyl-2-pyridinecarboxamide, and 5-bromo-2-nitropyridine.

2. The perovskite solar cell according to claim 1, characterized in that, The thickness of the buried layer is 1-20 nm.

3. The perovskite solar cell according to claim 1, characterized in that, The method for preparing the buried layer includes: The substrate material compound was dissolved in an organic solvent to prepare a solution of 0.1-10 mg / ml; The solution is spin-coated onto the surface of the hole transport layer and then annealed to obtain the buried substrate.

4. The perovskite solar cell according to claim 3, characterized in that, The purity of the buried material compound is not less than 99%.

5. The perovskite solar cell according to claim 1, characterized in that, The thickness of the hole transport layer is 5-30 nm.

Images