Perovskite solar cell and preparation method thereof and laminated cell

Abstract

The present disclosure relates to a perovskite solar cell, a preparation method thereof and a laminated battery, the perovskite solar cell comprising, in sequence, a bottom electrode, a hole transport layer, a perovskite absorption layer, an optional first passivation layer, a second passivation layer, an electron transport layer and a counter electrode; wherein the first passivation layer contains an organic amine passivation agent, and the second passivation layer contains a benzothiazole derivative and / or a benzoisothiazole derivative. The perovskite solar cell of the present disclosure has a higher short-circuit current and fill factor, and a higher photoelectric conversion efficiency.

Description

Technical Field

[0001] This application relates to the field of new energy, specifically to a perovskite solar cell, its preparation method, and a tandem cell. Background Technology

[0002] Over the past decade, global research competition in tandem solar cells has been exceptionally fierce, with world records for tandem cell efficiency being continuously broken. As the top cell in a tandem solar cell, wide-bandgap (bandgap > 1.65 eV) perovskite (PVK) solar cells typically have an inverted pin device structure. However, nonradiative recombination in the wide-bandgap perovskite absorber layer and at the perovskite / charge extraction layer interface leads to efficiency losses in perovskite devices. This is because grain boundaries and surfaces in perovskite films tend to have much higher defect densities than the grain interior. Ion migration and photoinduced phase separation are significant challenges to the efficiency and stability of perovskite materials. In recent years, surface passivation of perovskite using interface engineering has become a very effective method, particularly by introducing organic ligands such as phenylethylammonium (PEA), butylammonium, and guanidine to form a two-dimensional perovskite on the top film surface. This reduces the defect state density on the perovskite surface and effectively suppresses nonradiative recombination.

[0003] CN117156884A discloses a mixed passivating agent using phenylethyl ammonium iodide (PEAI) and piperazine monoiodide (PI). The main function of the mixed passivating agent is to neutralize charged defects, utilizing organic amine cations to passivate negatively charged defects, such as incompletely coordinated X. - V Pb ;I - Anion passivation of positively charged defects, such as poorly coordinated Pb. 2+ I i+ etc. Amide group -NH and I in perovskite layer - Hydrogen bonds can form between them, but their effect on stabilizing organic cations is weak, and the presence of I in the perovskite precursor solution is not taken into account. - It is easily oxidized to I2, and the generated I2 is an important cause of nonradiative recombination. In addition, phenylethyl ammonium iodide (PEAI) combines with piperazine monoiodide (PI) to form 2D perovskite. Since the 2D perovskite layer between the electron transport layer (ETL) and the 3D perovskite absorber layer film is generally conducive to hole extraction, it leads to electron blockage at the 2D / 3D interface.

[0004] CN114420847A discloses a perovskite solar cell, belonging to the field of solar cell technology. This perovskite solar cell includes a perovskite layer, and an interface modification layer on the surface of the perovskite layer. The interface modification layer is made of a passivating agent and a modifying agent. The passivating agent is selected from one or more of 2-phenylethylamine hydroiodide (PEAI), 2-phenylethylamine hydrochloride, benzylamine hydrochloride, benzylamine hydroiodide, butylamine hydrobromide, ethylenediamine hydrochloride, ammonium halide, guanidine halide, tetramethylguanidine fluoroborate, or alkali metal halide salts. The modifying agent is selected from one or more of methylammonium thiocyanate (MASCN), formamidinium thiocyanate, methylamine halide, formamidinium halide, methylamine acetate, formamidinium acetate, formamidinium formate, methylamine formate, methylamine cyanate, or formamidinium cyanate. This invention effectively improves the crystallinity of perovskite, passivates surface defects, enhances the performance of perovskite solar cells, and improves device stability by using a mixed passivating agent composed of passivating agents and modifiers.

[0005] However, existing technologies add passivating molecules containing lone pair electrons (S or N) that can act as Lewis bases. Regardless of whether they are used to neutralize charges or enhance perovskite crystallization, the influence of I2 is not taken into account, resulting in problems such as weak synergistic effects of multiple passivations. Summary of the Invention

[0006] The purpose of this disclosure is to provide a perovskite solar cell, its fabrication method, and a tandem cell. The perovskite solar cell has a uniform and smooth surface morphology, and the device has high short-circuit current and fill factor, as well as high photoelectric conversion efficiency.

[0007] To achieve the above objectives, the first aspect of this disclosure provides a perovskite solar cell, the perovskite solar cell comprising a bottom electrode, a hole transport layer, a perovskite absorption layer, an optional first passivation layer, a second passivation layer, an electron transport layer, and a counter electrode stacked sequentially. The first passivation layer contains an organic amine passivating agent, and the second passivation layer contains a benzothiazole derivative and / or a benzoisothiazole derivative.

[0008] Optionally, the organic amine passivating agent is selected from one or more of phenylethyl iodide, phenylethyl ammonium chloride, benzylamine hydrochloride, benzylamine hydroiodide, ethylenediamine hydrochloride, and ammonium halides.

[0009] Optionally, the benzothiazole derivative includes substituted or unsubstituted 2-hydrazinobenzothiazole, and / or substituted or unsubstituted 3-methylbenzothiazole onium iodide; The benzisothiazol derivatives include substituted or unsubstituted 3-hydrazino-benzisothiazole, and / or substituted or unsubstituted 3-hydrazino-1,2-benzisothiazole 1,1-dioxide; In the substituted 2-hydrazinobenzothiazole, substituted 3-hydrazinobenzothiazole, substituted 3-hydrazino-1,2-benzoisothiazole 1,1-dioxide, and substituted 3-methylbenzothiazole onium iodide, the substituents are each independently one or more, and each is independently selected from one or more of halogen, methyl, ethyl, propyl, methoxy, ethoxy, trifluoromethyl, and trifluoromethoxy.

[0010] Optionally, the total thickness of the first passivation layer and the second passivation layer is 1-10 nm, preferably 1-5 nm. Optionally, the material of the bottom electrode includes indium tin oxide and / or fluorine-doped tin dioxide, and the thickness of the bottom electrode is 20-200 nm; The hole transport layer includes NiO. x And a self-assembled monolayer, wherein the self-assembled monolayer contains one or more of 4PACz, Me-4PACz, MeO-4PACz, 2PACz, Me-2PACz and MeO-2PACz; The perovskite absorber layer contains a compound represented by the chemical formula APbX3, where A is selected from CH3NH3. + CH(NH2)2 + Cs + and Rb + One or more of them, X is selected from Cl - ,Br - and I - One or more of the following; the thickness of the perovskite absorber layer is 300-800 nm; The material of the counter electrode includes Ag and / or Cu, and the thickness of the counter electrode is 50-150 nm.

[0011] A second aspect of this disclosure provides a method for preparing the perovskite solar cell provided in the first aspect of this disclosure, the method comprising: S1. A hole transport layer and a perovskite absorption layer are sequentially prepared on the bottom electrode to obtain the first substrate; S2. Optionally, after coating the perovskite absorber layer of the first substrate with the first solution and performing a first annealing treatment, a second solution is coated and a second annealing treatment is performed to obtain the second substrate; wherein, the first solution contains an organic amine passivating agent; and the second solution contains a benzothiazole derivative and / or a benzoisothiazole derivative. S3. An electron transport layer and a counter electrode are sequentially prepared on the side of the second substrate coated with the second solution.

[0012] Optionally, the content of organic amine passivating agent in the first solution is 0.05-15 mg / L, preferably 0.5-1.5 mg / L.

[0013] Optionally, the total content of benzothiazole derivatives and / or benzoisothiazole derivatives in the second solution is 0.01-10 mg / L, preferably 0.1-1 mg / L.

[0014] Optionally, the conditions for the first annealing treatment and the second annealing treatment each independently include: a temperature of 100-150°C and a time of 5-20 min.

[0015] A third aspect of this disclosure provides a stacked solar cell, the stacked solar cell including the perovskite solar cell provided in the first aspect of this disclosure.

[0016] Through the above technical solution, the perovskite solar cell disclosed herein contains a second passivation layer, which can reduce surface defects of the perovskite, thereby enabling the perovskite thin film to have a higher short-circuit current and fill factor, thus increasing the photoelectric conversion efficiency.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of the perovskite solar cell prepared in Embodiment 1 of this disclosure.

[0019] Figure 2 These are scanning electron microscope (SEM) images and atomic force microscope (AFM) images of the perovskite solar cell thin films prepared in Examples 1, 3, 1, and 2 of this disclosure.

[0020] Figure 3 This is an XPS spectrum of the perovskite solar cell thin film prepared in Example 1 and Comparative Example 1 of this disclosure.

[0021] Figure 4 This is another XPS spectrum of the perovskite solar cell thin film prepared in Example 1 and Comparative Example 1 of this disclosure.

[0022] Explanation of reference numerals in the attached figures 1. Bottom electrode; 2. Hole transport layer; 3. Perovskite absorber layer 4. First passivation layer; 5. Second passivation layer; 6. Electron transport layer 7. Counter electrode Detailed Implementation The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0023] The first aspect of this disclosure provides a perovskite solar cell, the perovskite solar cell comprising a bottom electrode 1, a hole transport layer 2, a perovskite absorber layer 3, an optional first passivation layer 4, a second passivation layer 5, an electron transport layer 6, and a counter electrode 7 stacked sequentially; wherein the first passivation layer 4 contains an organic amine passivating agent, and the second passivation layer 5 contains a benzothiazole derivative and / or a benzoisothiazole derivative.

[0024] The second passivation layer of the perovskite solar cell disclosed herein contains benzothiazole derivatives and / or benzoisothiazole derivatives. By providing the second passivation layer, the reducing hydrazine therein can react with I₂, which is easily oxidized to I₂ in the perovskite precursor solution. - The reaction avoids the formation of I2 and thus prevents nonradiative recombination. The lone pair electrons can form hydrogen bonds with the A-site cation, which can passivate the halogen vacancy defect V. x and Pb with insufficient passivation coordination 2+ Defects. Therefore, perovskite solar cells have a strong defect passivation capability, solving the technical problem in existing technologies where a large number of defects are generated during the crystallization of perovskite thin films, which seriously affects photoelectric performance. It achieves passivation modification of multiple defects in metal halide perovskite thin films, resulting in a significant reduction of surface defects in perovskite and a significant enhancement of the photoelectric conversion efficiency of perovskite solar cells.

[0025] In a preferred embodiment of this disclosure, the perovskite solar cell includes a bottom electrode, a hole transport layer, a perovskite absorber layer, a first passivation layer, a second passivation layer, an electron transport layer, and a counter electrode, which are stacked sequentially. In this embodiment, the synergistic effect of the first and second passivation layers makes the perovskite cell surface smoother, facilitating closer contact between the perovskite and the electron transport layer. This promotes carrier extraction and reduces interfacial recombination, further improving the short-circuit current and fill factor, resulting in superior photoelectric conversion efficiency.

[0026] In one specific embodiment of this disclosure, the organic amine passivating agent is selected from one or more of phenylethyl iodide, phenylethyl ammonium chloride, benzylamine hydrochloride, benzylamine hydroiodide, ethylenediamine hydrochloride and ammonium halide, preferably phenylethyl iodide.

[0027] In one specific embodiment of this disclosure, the benzothiazole derivative includes substituted or unsubstituted 2-hydrazinobenzothiazole, and / or substituted or unsubstituted 3-methylbenzothiazole onium iodide; wherein the substituent in the unsubstituted 2-hydrazinobenzothiazole and the substituted 3-methylbenzothiazole onium iodide is selected from one or more of halogen, methyl, ethyl, propyl, methoxy, ethoxy, trifluoromethyl and trifluoromethoxy.

[0028] In one embodiment, the substituted or unsubstituted 2-hydrazinobenzothiazole has the structure shown in Formula 1: In Formula 1, R1 is selected from hydrogen, halogen, methyl, ethyl, propyl, methoxy, ethoxy, trifluoromethyl, or trifluoromethoxy.

[0029] In one embodiment, the substituted or unsubstituted 3-methylbenzothiazolium iodide has the structure shown in Formula 2: In Formula 2, R2 is selected from hydrogen, halogen, methyl, ethyl, propyl, methoxy, ethoxy, trifluoromethyl or trifluoromethoxy, preferably hydrogen.

[0030] In one specific embodiment of this disclosure, the benzisothiazol derivative includes substituted or unsubstituted 3-hydrazino-benzisothiazole, and / or substituted or unsubstituted 3-hydrazino-1,2-benzisothiazole 1,1-dioxide; wherein the substituents in the substituted 3-hydrazino-benzisothiazole and the substituted 3-hydrazino-1,2-benzisothiazole 1,1-dioxide are each independently selected from one or more of halogen, methyl, ethyl, propyl, methoxy, ethoxy, trifluoromethyl, and trifluoromethoxy.

[0031] In one embodiment, the substituted or unsubstituted 3-hydrazino-benzisothiazole has the structure shown in Formula 3: In Formula 3, R3 is selected from hydrogen, halogen, methyl, ethyl, propyl, methoxy, ethoxy, trifluoromethyl or trifluoromethoxy, preferably hydrogen.

[0032] In one embodiment, the substituted or unsubstituted 3-hydrazino-1,2-benzisothiazole 1,1-dioxide has the structure shown in Formula 4: In Formula 4, R4 is selected from hydrogen, halogen, methyl, ethyl, propyl, methoxy, ethoxy, trifluoromethyl or trifluoromethoxy, preferably hydrogen.

[0033] According to this disclosure, the thicknesses of the first passivation layer and the second passivation layer can also be within a wide range. In one specific embodiment, the total thickness of the first passivation layer and the second passivation layer is 1-10 nm, preferably 1-5 nm. In this embodiment, the thickness of the passivation layer in the perovskite solar cell is suitable, allowing charge carriers to pass through the layer without introducing a large amount of series resistance, which can further improve the short-circuit current and fill factor of the device, thereby increasing the photoelectric conversion efficiency. The total thickness of the first and second passivation layers in this disclosure can be determined by analyzing a cross-section of the perovskite solar cell in the thickness direction using a scanning electron microscope (SEM). Ten arbitrary locations in the image are selected, and the total thickness of the first and second passivation layers at those locations is measured. The average of these ten sets of data is then calculated as the total thickness of the first and second passivation layers in the perovskite solar cell.

[0034] According to this disclosure, the material of the bottom electrode is well known to those skilled in the art. In one specific embodiment of this disclosure, the material of the bottom electrode includes indium tin oxide (ITO) and / or fluorine-doped tin dioxide (FTO), and the thickness of the bottom electrode is 20-200 nm.

[0035] According to this disclosure, the materials of the hole transport layer and the perovskite absorber layer are well known to those skilled in the art, and the hole transport layer may include NiO. x And a self-assembled monolayer, in one embodiment, the hole transport layer comprises NiO. x And in NiO x Self-assembled monolayer SAM and NiO deposited on top x The thickness can vary within a wide range, for example, from 10 to 50 nm. The SAM contains one or more of the following: 4PACz ([4-(9H-carbazole-9-yl)butyl]phosphonic acid), Me-4PACz ([4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid), MeO-4PACz ([4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid), 2PACz ([2-(9H-carbazole-9-yl)ethyl]phosphonic acid), Me-2PACz ([2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid), and MeO-2PACz ([2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid). The perovskite absorber layer contains a compound with the chemical formula APbX3, where A is selected from CH3NH3. + (MA + CH(NH2)2 + (FA + ), Cs + and Rb + One or more of them; X = Cl - ,Br - and I - One or more of the following, wherein the thickness of the perovskite absorber layer is 300-800 nm.

[0036] According to this disclosure, the material of the counter electrode is well known to those skilled in the art. In one embodiment, the material of the counter electrode includes Ag and / or Cu. In another embodiment, the counter electrode is an Ag electrode, a Cu electrode, or a Cu / Ag composite electrode. The thickness of the counter electrode can vary over a wide range, for example, 50-150 nm.

[0037] The second aspect of this disclosure provides a method for preparing the perovskite solar cell provided in the first aspect of this disclosure. The method includes: S1, sequentially preparing a hole transport layer and a perovskite absorber layer on a bottom electrode to obtain a first substrate; S2, optionally coating the perovskite absorber layer of the first substrate with a first solution and performing a first annealing treatment, then coating it with a second solution and performing a second annealing treatment to obtain a second substrate; wherein the first solution contains an organic amine passivating agent; the second solution contains a benzothiazole derivative and / or a benzoisothiazole derivative; S3, sequentially preparing an electron transport layer and a counter electrode on the side of the second substrate coated with the second solution.

[0038] The method disclosed herein can fabricate perovskite solar cells with high short-circuit current and fill factor, and increases photoelectric conversion efficiency. In this disclosure, the sequential coating of a hole transport layer and a perovskite absorber layer refers to the sequential coating of the hole transport layer and the perovskite absorber layer along the direction away from the bottom electrode.

[0039] In one specific embodiment of this disclosure, the method further includes: ultrasonically cleaning the transparent conductive glass sequentially with deionized water and isopropanol, followed by ultraviolet ozone treatment to obtain a clean bottom electrode.

[0040] According to this disclosure, methods for preparing a hole transport layer and a perovskite absorber layer on a bottom electrode are well known to those skilled in the art. In one specific embodiment of this disclosure, a bottom electrode coated with a hole transport layer and a perovskite absorber layer is prepared by a method comprising the following steps: (1) coating the bottom electrode with 10-20 mg / mL NiO. x After the aqueous solution is subjected to a third annealing treatment, a 0.3-1 mg / mL Me-4PACz isopropanol solution is spin-coated, and a fourth annealing treatment is performed to obtain a bottom electrode coated with a hole transport layer; (2) After coating the hole transport layer of the bottom electrode with a perovskite precursor solution, an antisolvent is coated and a fifth annealing treatment is performed to obtain a bottom electrode coated with a hole transport layer and a perovskite absorption layer. In this disclosure, the conditions for the third annealing treatment include: a temperature of 110-130℃ and a time of 10-20 min; the conditions for the fourth annealing treatment include: a temperature of 90-110℃ and a time of 5-15 min; the conditions for the fifth annealing treatment include: a temperature of 90-110℃ and a time of 15-25 min. The perovskite precursor solution in this disclosure has Cs 0.05 MA 0.15 FA 0.8 PbI 2.25 Br 0.75 The composition can be prepared by mixing CsI, FAI, PbI2, MABr, PbBr2 and a solvent. The solvent can be one that is well known to those skilled in the art, such as N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1.

[0041] According to this disclosure, the methods for preparing the electron transport layer and the counter electrode are well known to those skilled in the art. In one specific embodiment of this disclosure, after coating the side of the second substrate with the second solution with a solution containing a fullerene pyrrole derivative and performing a sixth annealing treatment to prepare the electron transport layer, the counter electrode is then prepared by vacuum evaporation on the electron transport layer.

[0042] In one specific embodiment of this disclosure, the content of organic amine passivating agent in the first solution is 0.05-15 mg / L, preferably 0.5-1.5 mg / L; the total content of benzothiazole derivative and / or benzoisothiazole derivative in the second solution is 0.01-10 mg / L, preferably 0.1-1 mg / L.

[0043] In one specific embodiment of this disclosure, the conditions for the first annealing treatment and the second annealing treatment each independently include: a temperature of 100-150°C and a time of 5-20 min; preferably, a temperature of 100-120°C and a time of 5-10 min. The annealing treatment can be performed in an apparatus well known to those skilled in the art, and will not be described in detail here.

[0044] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0045] Example 1 (1) Cleaning transparent conductive glass: ultrasonically cleaned with deionized water and isopropanol in sequence, and then treated with ultraviolet ozone.

[0046] (2) Preparation of hole transport layer: spin-coating 15 mg / mL NiO x The bottom electrode with a hole transport layer was obtained by spin-coating a 0.5 mg / mL Me-4PACz isopropanol solution at 120 °C for 15 min and annealing at 100 °C for 10 min.

[0047] (3) Preparation of perovskite absorber layer: Weigh CsI, FAI, PbI2, MABr and PbBr2 powders in sequence, add DMF and DMSO solvents with a volume ratio of 4:1, prepare 1.6M Cs0.05MA0.15FA0.8PbI2.25Br0.75 perovskite precursor solution, add antisolvent dropwise, anneal at 100℃ for 20min, and obtain bottom electrode coated with hole transport layer and perovskite absorber layer.

[0048] (4) Preparation of a double passivation layer: A first passivation layer is prepared by spin-coating a phenylethyl ammonium iodide (PEAI) solution in isopropanol (IPA) onto the perovskite absorber layer and annealing at 100°C for 5 min; a second passivation layer is prepared by spin-coating a 2-hydrazinobenzothiazole solution in isopropanol (IPA) and annealing at 100°C for 5 min. The concentration of the PEAI solution is 1 mg / mL, and the concentration of the 2-hydrazinobenzothiazole solution is 0.1 mg / mL, resulting in a bottom electrode sequentially coated with a hole transport layer, a perovskite absorber layer, a first passivation layer, and a second passivation layer.

[0049] (5) Preparation of electron transport layer: C60 (20 mg / mL CB solution) is spin-coated onto the second passivation layer, and BCP (1 mg / mL CB solution) is spin-coated onto the second passivation layer to obtain a bottom electrode sequentially coated with a hole transport layer, a perovskite absorption layer, a first passivation layer, a second passivation layer and an electron transport layer. (6) A 100 nm Ag electrode was vacuum-deposited on the electron transport layer to prepare a perovskite solar cell. The thickness of the transparent conductive glass was 150 nm, and the hole transport layer was NiO. x The thickness is 20 nm, the self-assembled layer is a monolayer, the thickness of the perovskite absorber layer is 350 nm, the total thickness of the first passivation layer and the second passivation layer is 2 nm, and the thickness of the electron transport layer is 15 nm.

[0050] Example 2 Perovskite solar cells were prepared using the same method as in Example 1, except that in step (4), 2-hydrazinobenzothiazole was replaced with an equal amount of 3-hydrazino-1,2-benzisothiazole 1,1-dioxide in the preparation of the double passivation layer.

[0051] Example 3 Perovskite solar cells were prepared using the same method as in Example 1, except that in step (4), only a solution of 2-hydrazinobenzothiazole in isopropanol (IPA) was coated on the perovskite absorber layer and annealed at 100°C for 5 min to obtain a bottom electrode sequentially coated with a hole transport layer, a perovskite absorber layer and a second passivation layer.

[0052] Comparative Example 1 Perovskite solar cells were prepared using the same method as in Example 1, except that no passivation treatment was performed.

[0053] Comparative Example 2 The perovskite solar cell was prepared using the same method as in Example 1, except that in step (4), the isopropanol (IPA) solution of phenylethyl iodide (PEAI) was coated only on the perovskite absorber layer in the preparation of the double passivation layer and annealed at 100°C for 5 min.

[0054] Test case This experiment used scanning electron microscopy (SEM, FEI Nova Nano 450) to characterize the surface morphology of the perovskite thin film. Atomic force microscopy (AFM, Bruker Dimension ICON) was used to measure the surface morphology and roughness of the film. The test results are as follows: Figure 2 As shown.

[0055] The perovskite thin film was tested and calculated using an Escalab 250Xi X-ray photoelectron spectroscopy (XPS) instrument. The test conditions included a monochromatic Al Kα excitation source (1486.6 eV) and a power of 300 W. The test results are as follows: Figure 3 As shown.

[0056] The electrical performance of the fabricated perovskite solar cell was analyzed using a solar simulator.

[0057] Table 1

[0058] Depend on Figure 2 It can be seen that the perovskite solar cell films prepared in Comparative Examples 1 and 2 and Examples 1 and 3 all have uniform and smooth surface morphology. The surface roughness of the perovskite solar cell film with a double passivation layer prepared in Example 3 is reduced to 12.6 nm. The perovskite surface with a double passivation layer in this disclosure facilitates close contact between the perovskite and the electron transport layer, thereby promoting carrier extraction and reducing interfacial recombination, resulting in higher short-circuit current and fill factor of the perovskite solar cell, and higher photoelectric conversion efficiency.

[0059] Depend on Figure 3 and Figure 4 It can be seen that the peaks of Pb 4f and I3d in the perovskite film after double-layer passivation in Example 1 show a significant shift, indicating that there is an interaction between the passivating agent molecules and the perovskite film. Compared with the perovskite film in Comparative Example 1, where the peaks at 137.15 eV and 618.33 eV correspond to the Pb 4f and I3d orbitals, respectively, the Pb 4f and I3d peaks of the perovskite film treated with double passivation shift to higher binding energies at 137.64 eV and 618.69 eV, respectively, by 0.49 eV and 0.36 eV. The gradual increase in binding energy indicates that the defect passivation ability of the perovskite solar cell is enhanced. The peak shifts of Pb 4f and I3d in the perovskite film after different post-treatments indicate that there is a direct interaction between different materials and the perovskite surface, thereby passivating surface defects.

[0060] As shown in Table 1, the perovskite solar cell disclosed in this invention has a high short-circuit current and fill factor, and a superior photoelectric conversion efficiency.

[0061] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0062] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0063] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A perovskite solar cell, characterized in that, The perovskite solar cell includes a bottom electrode (1), a hole transport layer (2), a perovskite absorption layer (3), an optional first passivation layer (4), a second passivation layer (5), an electron transport layer (6), and a counter electrode (7) stacked sequentially. The first passivation layer (4) contains an organic amine passivating agent, and the second passivation layer (5) contains a benzothiazole derivative and / or a benzoisothiazole derivative.

2. The perovskite solar cell according to claim 1, wherein, The organic amine passivating agent is selected from one or more of phenylethyl iodide, phenylethyl ammonium chloride, benzylamine hydrochloride, benzylamine hydroiodide, ethylenediamine hydrochloride, and ammonium halides.

3. The perovskite solar cell according to claim 1, wherein, The benzothiazole derivatives include substituted or unsubstituted 2-hydrazinobenzothiazole, and / or substituted or unsubstituted 3-methylbenzothiazole onium iodide; The benzisothiazol derivatives include substituted or unsubstituted 3-hydrazino-benzisothiazole, and / or substituted or unsubstituted 3-hydrazino-1,2-benzisothiazole 1,1-dioxide; In the substituted 2-hydrazinobenzothiazole, substituted 3-hydrazinobenzothiazole, substituted 3-hydrazino-1,2-benzoisothiazole 1,1-dioxide, and substituted 3-methylbenzothiazole onium iodide, the substituents are each independently one or more, and each is independently selected from one or more of halogen, methyl, ethyl, propyl, methoxy, ethoxy, trifluoromethyl, and trifluoromethoxy.

4. The perovskite solar cell according to claim 1, wherein, The total thickness of the first passivation layer and the second passivation layer is 1-10 nm, preferably 1-5 nm.

5. The perovskite solar cell according to claim 1, wherein, The bottom electrode is made of indium tin oxide and / or fluorine-doped tin dioxide, and the thickness of the bottom electrode is 20-200 nm. The hole transport layer includes NiO. x And a self-assembled monolayer, wherein the self-assembled monolayer contains one or more of 4PACz, Me-4PACz, MeO-4PACz, 2PACz, Me-2PACz and MeO-2PACz; The perovskite absorber layer contains a compound with the chemical formula APbX3, where A is selected from CH3NH3. + CH(NH2)2 + Cs + and Rb + One or more of them, X is selected from Cl - ,Br - and I - One or more of the following; the thickness of the perovskite absorber layer is 300-800 nm; The material of the counter electrode includes Ag and / or Cu, and the thickness of the counter electrode is 50-150 nm.

6. A method for preparing a perovskite solar cell according to any one of claims 1-5, characterized in that, The method includes: S1. A hole transport layer and a perovskite absorption layer are sequentially prepared on the bottom electrode to obtain the first substrate; S2. Optionally, after coating the perovskite absorber layer of the first substrate with the first solution and performing a first annealing treatment, a second solution is coated and a second annealing treatment is performed to obtain the second substrate; wherein, the first solution contains an organic amine passivating agent; and the second solution contains a benzothiazole derivative and / or a benzoisothiazole derivative. S3. An electron transport layer and a counter electrode are sequentially prepared on the side of the second substrate coated with the second solution.

7. The method according to claim 6, wherein, The content of organic amine passivating agent in the first solution is 0.05-15 mg / L, preferably 0.5-1.5 mg / L.

8. The method according to claim 6, wherein, The total content of benzothiazole derivatives and / or benzoisothiazole derivatives in the second solution is 0.01-10 mg / L, preferably 0.1-1 mg / L.

9. The method according to claim 6, wherein, The conditions for the first annealing treatment and the second annealing treatment each independently include: a temperature of 100-150℃ and a time of 5-20min.

10. A stacked battery, characterized in that, The stacked cell includes the perovskite solar cell according to any one of claims 1-5.

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