Perovskite solar cell and preparation method therefor

Abstract

Disclosed are a perovskite solar cell and a preparation method therefor. The perovskite solar cell comprises a perovskite layer (3), a passivation layer (4), and an electron transport layer (5). The passivation layer (4) is located between the perovskite layer (3) and the electron transport layer (5), and the passivation layer (4) comprises a composite material formed from a polydopamine cross-linked modified layered bimetallic hydroxide compound. By means of selecting the composite material as the material of the passivation layer, the defect passivation effect at the interface of the perovskite layer (3) is good, and the electron extraction and transfer capabilities are improved.

Description

A perovskite solar cell and its preparation method

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 28, 2023, with application number 202311869407.3 and invention name “A perovskite solar cell and its preparation method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the field of solar cells, and in particular to a perovskite solar cell and a preparation method thereof. Background Art

[0003] The perovskite layer, composed of semiconductor materials with a perovskite structure, is a crucial component of perovskite solar cells. Perovskites absorb light and generate excitons. At the interface between the perovskite layer and the electron transport layer, these excitons dissociate, generating free carriers. Free electrons are collected by the electron transport layer and are then collected by the working electrode, while free holes are collected by the hole transport layer and are then collected by the counter electrode. This creates a potential difference between the two electrodes, generating current through an external circuit.

[0004] However, the perovskite layer has a large number of defects at its interface, and the electrons generated by exciton dissociation easily recombine with these defects, resulting in a decrease in the electron transfer efficiency of the perovskite solar cell and a reduction in the cell conversion efficiency. At the same time, a large number of defects can affect the crystallization quality of the perovskite, resulting in a poor stability of the perovskite solar cell. Summary of the Invention

[0005] In order to further improve the electron transfer efficiency and battery conversion efficiency of perovskite solar cells, the present invention discloses a perovskite solar cell and a preparation method thereof.

[0006] In a first aspect, the present application provides a perovskite solar cell.

[0007] The perovskite solar cell comprises a perovskite layer, a passivation layer and an electron transport layer, wherein the passivation layer is located between the perovskite layer and the electron transport layer, and the passivation layer comprises a composite material formed by cross-linking and modifying a layered double metal hydroxide with polydopamine.

[0008] As an optional embodiment, in an embodiment of the present invention, the method for preparing the composite material includes the following steps:

[0009] Preparation of bimetallic composite oxide: calcining the layered bimetallic hydroxide to obtain the bimetallic composite oxide;

[0010] The composite material is prepared by mixing the bimetallic composite oxide with water to cause a hydration reaction of the bimetallic composite oxide, and then adding dopamine hydrochloride to carry out a cross-linking reaction, and obtaining the composite material after the reaction.

[0011] As an optional implementation, in an embodiment of the present invention, the calcination temperature is 250° C. to 600° C., and the calcination time is 2 h to 3.5 h.

[0012] As an optional embodiment, in an embodiment of the present invention, in the step of preparing the composite material, the bimetallic composite oxide is mixed with water and then subjected to ultrasonic treatment; and / or, in the step of preparing the composite material, after the dopamine hydrochloride is added, the pH is adjusted to 8 to 9, and the reaction is carried out at 80°C to 100°C for 16h to 24h to obtain the composite material; and / or, the layered double metal hydroxide is prepared by a coprecipitation method.

[0013] As an optional embodiment, in an embodiment of the present invention, the layered double metal hydroxide comprises divalent positive metal ions, trivalent positive metal ions and interlayer anions.

[0014] As an optional embodiment, in an embodiment of the present invention, the divalent positive metal ions include Ti 2+ 、Zn 2+ Any one of the following, wherein the trivalent metal ion includes Al 3+ 、Fe 3+ and Ni 3+ Any one of the above, wherein the interlayer anion is CO3 2- 、Cl - and Br - Any one of .

[0015] As an optional embodiment, in an embodiment of the present invention, the ratio of the mole of the trivalent metal ion to the sum of the moles of the trivalent metal ion and the divalent metal ion is 1:(0.17~0.33), and the mole ratio of the divalent metal ion to the trivalent metal ion is (3~6):1.

[0016] As an optional embodiment, in an embodiment of the present invention, the mass percentage of the polydopamine in the composite material is 1% to 75%, and the mass percentage of the layered double metal hydroxide in the composite material is 25% to 99%.

[0017] As an optional embodiment, in an embodiment of the present invention, the thickness of the passivation layer is 15nm to 25nm; and / or the thickness of the perovskite layer is 800nm ​​to 1000nm; and / or the thickness of the electron transport layer is 25nm to 30nm.

[0018] As an optional implementation, in an embodiment of the present invention, the perovskite solar cell includes a single-junction perovskite solar cell or a perovskite tandem solar cell.

[0019] As an optional implementation manner, in an embodiment of the present invention, the perovskite solar cell is a single-junction perovskite solar cell, and the single-junction perovskite solar cell further includes:

[0020] Transparent conductive substrate;

[0021] A hole transport layer, the hole transport layer being stacked on the surface of the transparent conductive substrate;

[0022] The perovskite layer, the passivation layer and the electron transport layer are sequentially stacked on the surface of the hole transport layer;

[0023] A positive electrode and a negative electrode, wherein the positive electrode forms an ohmic contact with the transparent conductive substrate, and the negative electrode forms an ohmic contact with the electron transport layer;

[0024] Alternatively, the single-junction perovskite solar cell further comprises:

[0025] Transparent conductive substrate;

[0026] The electron transport layer, the passivation layer and the perovskite layer are stacked in sequence on the surface of the transparent conductive substrate;

[0027] A hole transport layer, the hole transport layer is stacked on the surface of the perovskite layer, and the perovskite layer is stacked on the surface of the hole transport layer;

[0028] A positive electrode and a negative electrode, wherein the positive electrode forms an ohmic contact with the transparent conductive substrate, and the negative electrode forms an ohmic contact with the hole transport layer.

[0029] As an optional implementation, in an embodiment of the present invention, the perovskite solar cell is a perovskite tandem solar cell, and the perovskite tandem solar cell further includes:

[0030] Silicon bottom cell;

[0031] A hole transport layer, the hole transport layer being stacked on the surface of the silicon bottom cell;

[0032] The perovskite layer, the passivation layer and the electron transport layer are sequentially stacked on the surface of the hole transport layer;

[0033] A positive electrode and a negative electrode, wherein the positive electrode forms an ohmic contact with the silicon bottom cell, and the negative electrode forms an ohmic contact with the electron transport layer;

[0034] Alternatively, the perovskite tandem solar cell further comprises:

[0035] Silicon bottom cell;

[0036] The electron transport layer, the passivation layer and the perovskite layer are stacked in sequence on the surface of the silicon bottom cell;

[0037] A hole transport layer, the hole transport layer is stacked on the surface of the perovskite layer, and the perovskite layer is stacked on the surface of the hole transport layer;

[0038] A positive electrode and a negative electrode, wherein the positive electrode forms an ohmic contact with the silicon bottom cell, and the negative electrode forms an ohmic contact with the hole transport layer.

[0039] As an optional embodiment, in an embodiment of the present invention, the hole transport layer is nickel oxide; and / or the electron transport layer is C 60 or its derivatives; and / or, the thickness of the hole transport layer is 18nm to 22nm; and / or, the thickness of the positive electrode is 250nm to 300nm; and / or, the thickness of the negative electrode is 250nm to 300nm; and / or, a buffer layer is further provided on the side of the electron transport layer away from the perovskite layer.

[0040] In a second aspect, the present application provides a method for preparing a perovskite solar cell.

[0041] The preparation method of perovskite solar cell comprises the following steps:

[0042] preparing a perovskite layer of the perovskite solar cell;

[0043] A passivation layer is prepared on the perovskite layer, and the preparation method of the passivation layer comprises the following steps:

[0044] preparing a composite material solution formed by cross-linking polydopamine and modifying a layered double metal hydroxide, coating the composite material solution on the perovskite layer by a solution method, and obtaining a passivation layer after annealing;

[0045] An electron transport layer is prepared on the passivation layer.

[0046] As an optional implementation, in an embodiment of the present invention, the concentration of the composite material solution is 0.5 mg / mL to 2 mg / mL.

[0047] As an optional embodiment, in an embodiment of the present invention, the solvent of the composite material solution is a short-chain alcohol; and / or, the composite material solution is coated onto the perovskite layer by spin coating, the spin coating atmosphere is 5% RH to 10% RH, the spin coating speed is 3500rpm to 5000rpm, the acceleration is 3500rpm / s to 5000rpm / s, and the spin coating time is 25s to 35s; and / or, in the preparation step of the passivation layer, the annealing is annealing at 100℃ to 125℃ for 10min to 15min.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. Layered double hydroxides are a type of hydrotalcite-like intercalation material assembled through intercalation. They are composed of positively charged host layers and interlayer anions assembled through non-covalent interactions. The layered double hydroxide has a high specific surface area and a large number of hydroxyl groups distributed on its surface. Polydopamine, on the other hand, has a large number of primary amine, tertiary amino, and catechol functional groups distributed on its surface. The phenolic hydroxyl groups on polydopamine readily cross-link with the hydroxyl groups on the surface of the layered double hydroxide, forming a composite material. The combined action of strong covalent, non-covalent, and π-π* bonds on the layered double hydroxide allows polydopamine to be uniformly and stably dispersed throughout the layered double hydroxide, overcoming the drawback of polydopamine's tendency to agglomerate and significantly improving its dispersibility within the passivation layer.

[0050] The composite material produced by the cross-linking reaction of polydopamine and layered double metal hydroxides is used as a passivation layer. On the one hand, the functional groups such as primary amines, tertiary amines, and catechol on the surface of polydopamine are able to fully contact the perovskite at the interface, better passivating the defects at the interface of the perovskite layer, reducing electron recombination at the interface, and improving the electron transfer efficiency. On the other hand, due to the excellent light-collecting ability and conductivity of polydopamine, it has good light capture and electron transfer capabilities. Polydopamine with excellent dispersion can better improve the optical and electrical properties of the perovskite layer. Furthermore, polydopamine and perovskite produce a synergistic effect, which can open up new electron transfer channels and improve electron transfer efficiency.

[0051] In addition to providing more reaction sites for polydopamine, the layered structure of the layered double metal hydroxide can also better support the electron transport layer, reduce the contact between the electron transport layer and the perovskite layer, and improve the parasitic absorption between the perovskite layer and the electron transport layer.

[0052] 2. The layered double hydroxide compound is first calcined at 250°C to 600°C, then hydrated to restore the layered structure, and then modified with polydopamine. The resulting composite material retains some of its ability to promote electron separation while also enhancing its electron extraction and transfer capabilities. Furthermore, the polydopamine modification further enhances the composite material's light-collecting capacity and electrical conductivity. By combining this composite material with the surface of the perovskite layer, it can fully passivate the perovskite layer's interfacial defects, enhance the perovskite layer's electron transfer capacity and stability, and ultimately improve the perovskite solar cell's overall electron transfer capacity and energy conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] FIG1 is a schematic structural diagram of a perovskite solar cell disclosed in an embodiment of the present invention;

[0055] FIG2 is a schematic diagram of the reaction between polydopamine and layered double metal hydroxides.

[0056] Icon: 1. Transparent conductive substrate; 2. Hole transport layer; 3. Perovskite layer; 4. Passivation layer; 5. Electron transport layer; 6. Buffer layer; 7. Negative electrode; 8. Positive electrode. DETAILED DESCRIPTION

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0058] The technical solution of the present invention will be further described below in conjunction with embodiments and drawings.

[0059] In a first aspect, an embodiment of the present application provides a perovskite solar cell.

[0060] As shown in Figure 1, Figure 1 is a schematic structural diagram of a perovskite solar cell in an embodiment of the present application. The perovskite solar cell includes a perovskite layer 3, a passivation layer 4 and an electron transport layer 5. The passivation layer 4 is located between the perovskite layer 3 and the electron transport layer 5. The passivation layer 4 includes a composite material composed of a polydopamine cross-linked modified layered double metal hydroxide.

[0061] Layered double metal hydroxides are a type of hydrotalcite-like intercalation material assembled through intercalation. They are compounds assembled from positively charged main platelets and interlayer anions through non-covalent interactions. The layered double metal hydroxide has a high specific surface area and a large number of hydroxyl groups distributed on its surface. Polydopamine, on the other hand, has a large number of primary amine, tertiary amino, and catechol functional groups distributed on its surface. The phenolic hydroxyl groups on polydopamine easily undergo cross-linking reactions with the hydroxyl groups on the surface of the layered double metal hydroxide to form a composite material. Under the combined action of strong covalent bonds, non-covalent bonds, and π-π* bonds, polydopamine is uniformly and stably dispersed on the layered double metal hydroxide. Polydopamine is not easily agglomerated, and its dispersibility in the passivation layer 4 is significantly improved.

[0062] The composite material produced by the cross-linking reaction of polydopamine and layered double metal hydroxides is used as the passivation layer 4. On the one hand, the functional groups such as primary amines, tertiary amines, and catechol on the surface of the polydopamine are able to fully contact the perovskite at the interface, better passivating the defects at the interface of the perovskite layer 3, reducing electron recombination at the interface, and improving electron transfer efficiency. On the other hand, due to its excellent light-collecting ability and conductivity, polydopamine has good light-harvesting and electron-transfer capabilities. The highly dispersed polydopamine can further improve the optical and electrical properties of the perovskite layer 3. Furthermore, the synergistic effect of polydopamine and perovskite can open up new electron transfer channels and improve electron transfer efficiency.

[0063] In addition to providing more reaction sites for polydopamine, the layered double metal hydroxide has a layered structure that can better support the electron transport layer 5, reduce the contact between the electron transport layer 5 and the perovskite layer 3, and improve the parasitic absorption between the perovskite layer 3 and the electron transport layer 5.

[0064] In addition, the raw materials for preparing layered double metal hydroxides, such as zinc nitrate (7,500 yuan / ton), aluminum nitrate (3,100 / ton), and sodium carbonate (2,200 / ton), are cheap, and the raw materials for preparing polydopamine, such as dopamine hydrochloride (22,000 / ton), are also relatively cheap, while lithium fluoride is expensive (80,000 / ton). It can be seen that compared with the raw materials of the lithium fluoride passivation layer 4, the material cost of the passivation layer 4 made of the above-mentioned composite material is lower, which is conducive to reducing production costs and promoting industrial production.

[0065] It should be noted that in perovskite solar cells, in addition to the perovskite layer, passivation layer and electron transport layer mentioned above, it also includes a hole transport layer and a substrate. The hole transport layer is located on the side of the perovskite layer away from the passivation layer, and the substrate is stacked on the surface of the electron transport layer or the hole transport layer away from the perovskite layer. The substrate can be a velvet pyramid structure or a fully polished planar structure.

[0066] In some embodiments, the composite material is prepared as follows:

[0067] Preparation of bimetallic composite oxide: calcining the layered bimetallic hydroxide to obtain the bimetallic composite oxide;

[0068] Preparation of composite materials: mixing bimetallic composite oxides with water to make the bimetallic composite oxides undergo hydration reaction, then adding dopamine hydrochloride to carry out cross-linking reaction, and obtaining composite materials after the reaction.

[0069] In the process of preparing the composite material, the layered double metal hydroxide is first calcined. During the calcination process, the interlayer moisture, hydroxyl groups, and charge-balancing anions of the layered bimetallic composite oxide are lost, and the layered structure collapses, forming a bimetallic composite oxide with semiconductor properties and photoelectric properties. For example, Zn-Al bimetallic composite oxide can generate ZnO and ZnAl2O4 after calcination. These metal oxides have certain electron extraction and transfer capabilities, and can cooperate with the electron transport layer 5 material of the perovskite solar cell to further improve the electron transfer efficiency and extraction efficiency.

[0070] Layered double metal complex hydroxides have a memory effect. After the calcined double metal complex oxide is mixed with water, hydration occurs. During the hydration process, it undergoes reconstruction, partially restoring the layered structure of the layered double metal complex hydroxide, while retaining the ability to promote electron separation. After the addition of dopamine hydrochloride, polydopamine is generated through self-polymerization. As shown in Figure 2, polydopamine contains a large number of hydroxyl groups on the surface of the reconstructed layered double metal complex hydroxide. Under the combined action of strong covalent, non-covalent bonds and π-π* bonds, polydopamine is attached to the surface of the reconstructed layered double metal complex hydroxide through the reaction to obtain a composite material.

[0071] In summary, the composite material retains some of its ability to promote electron separation while also enhancing its ability to extract and transfer electrons. Furthermore, the polydopamine modification further enhances the composite material's light-collecting capacity and electrical conductivity. By binding the composite material to the surface of the perovskite layer 3, the interfacial defects of the perovskite layer 3 are fully passivated, thereby enhancing the electron transfer capacity and stability of the perovskite layer 3, and ultimately improving the overall electron transfer capacity and energy conversion efficiency of the perovskite solar cell.

[0072] In some embodiments, the calcination temperature is 250° C. to 600° C., and the calcination time is 2 h to 3.5 h.

[0073] When the air temperature is below 200℃, the bimetallic composite oxide only loses part of the interlayer moisture, which has no effect on the structure. When the temperature rises to 250℃~450℃, the bimetallic composite oxide loses more moisture, and the interlayer anion CO3 2-The ordered layered structure of the layered bimetallic composite hydroxide is partially destroyed, carbon dioxide is generated, and bimetallic composite oxides begin to form. When the temperature rises to 450℃~600℃, the interlayer anion CO3 2- The metal oxides formed after decomposition begin to sinter, resulting in a decrease in surface area and pore volume.

[0074] Therefore, when the calcination temperature is between 250°C and 600°C, the electron extraction and transfer effects of the bimetallic composite oxide are significantly improved. For example, the calcination temperatures are 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, and 600°C, and the calcination times are 2h, 2.5h, 3h, and 3.5h.

[0075] In some embodiments, the bimetallic composite oxide is mixed with water and then subjected to ultrasonic treatment.

[0076] After ultrasonic treatment, the dispersion effect of water and the bimetallic composite oxide is better, and the water fully contacts and enters the bimetallic composite oxide, and fully undergoes a hydration reaction with the bimetallic composite oxide, so that the bimetallic composite oxide restores the layered structure. The hydroxyl content on the surface of the reconstructed layered bimetallic composite hydroxide increases and the specific surface area is larger, which is conducive to the full reaction of polydopamine with the reconstructed layered bimetallic composite hydroxide. Through the reaction, polydopamine can be better and more evenly dispersed on the surface of the reconstructed layered bimetallic composite hydroxide, thereby further improving the passivation effect of the perovskite layer 3.

[0077] In some embodiments, after dopamine hydrochloride is added, the pH is adjusted to 8-9, and the reaction is carried out at 80° C. to 100° C. for 16 h to 24 h to obtain a composite material.

[0078] Under these conditions, dopamine hydrochloride can quickly self-polymerize to form polydopamine. Polydopamine still has high reactivity and can continue to react with the reconstructed layered bimetallic complex hydroxide to form a composite material.

[0079] Illustratively, the pH of the cross-linking reaction is 8, 8.3, 8.5, 8.7 and 9, etc., the reaction temperature is 80°C, 85°C, 90°C, 95°C, 100°C, etc., and the reaction time is 16h, 18h, 20h, 22h and 24h, etc.

[0080] In some embodiments, the layered double metal hydroxide is prepared by a co-precipitation method.

[0081] The coprecipitation method for preparing layered double metal hydroxides involves adding two metal ions and an alkaline solution to water, allowing these components to precipitate together to form a layered hydroxide. Layered double metal hydroxides prepared via coprecipitation exhibit high crystallinity and an ordered layered structure.

[0082] The above raw materials are dissolved to form a mixture, and then the pH and reaction temperature are adjusted to perform a coprecipitation reaction to form a layered double metal hydroxide. Specifically, the method for preparing the layered double metal hydroxide by coprecipitation is as follows:

[0083] A soluble positive divalent metal ion salt, a soluble positive trivalent metal ion salt and a carbonate are dissolved in water, a pH regulator is added to adjust the pH to 10±0.5, co-precipitation is carried out at 75° C. to 85° C. for 8 to 10 hours, and centrifugation, washing and drying are sequentially performed to obtain a layered double metal hydroxide.

[0084] In some embodiments, the layered double metal hydroxide comprises a divalent positive metal ion, a trivalent positive metal ion, and an interlayer anion, wherein the divalent positive metal ion comprises Ti 2+ 、Zn 2+ Any of the trivalent metal ions including Al 3+ 、Fe 3+ and Ni 3+ Any one of the above, the interlayer anion is CO3 2- 、Cl - and Br - Any one of .

[0085] In some embodiments, the ratio of the moles of trivalent metal ions to the sum of the moles of trivalent metal ions and divalent metal ions is 1:(0.17-0.33), and the molar ratio of divalent metal ions to trivalent metal ions is 4:1.

[0086] The ratio of the moles of trivalent metal ions to the moles of the trivalent metal ions and the divalent metal ions is 1:(0.17-0.33), and the resulting layered double metal hydroxide has a complete interlayer structure. By further adjusting the ratio or type of divalent metal ions and trivalent metal ions, the layered double metal hydroxide has semiconductor properties and obtains photoelectric properties. The present application regulates the metal types of the layered double metal hydroxide and matches the divalent metal ions and trivalent metal ions in the above ratio, thereby improving the electron extraction and transfer capabilities of the composite material.

[0087] In some embodiments, the weight percentage of polydopamine in the composite material is 1% to 75%, and the weight percentage of the layered double metal hydroxide in the composite material is 25% to 99%.

[0088] The layered structure of the layered double hydroxide provides polydopamine with numerous reaction sites. By regulating the ratio of polydopamine to the layered double hydroxide, the reaction between polydopamine and the layered double hydroxide is optimized, and the polydopamine can evenly adhere to the surface of the layered double hydroxide through the reaction. The composite material is applied to the surface of the perovskite layer 3 as the material for the passivation layer 4, allowing the well-dispersed polydopamine to fully contact the perovskite layer 3. This facilitates the passivation of defects in the perovskite layer 3, thereby reducing the recombination of electrons and holes at defects in the perovskite layer 3 and improving the efficiency of electron transfer and energy conversion. Exemplarily, the mass percentage of polydopamine in the composite material is 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% and 75%, etc., and the mass percentage of layered double metal hydroxide in the composite material is 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% and 99%, etc.

[0089] In some embodiments, the thickness of the passivation layer 4 is 15 nm to 25 nm; and / or the thickness of the perovskite layer 3 is 800 nm to 1000 nm; and / or the thickness of the electron transport layer 5 is 25 nm to 30 nm.

[0090] The passivation layer 4 of the aforementioned thickness has a better ability to extract electrons and facilitates light penetration into the perovskite layer 3, thereby further enhancing the light absorption effect of the perovskite layer 3. When the thickness of the passivation layer 4 is too low, it is not conducive to electron extraction. When the thickness of the passivation layer 4 is too high, it is easy to block light from penetrating into the perovskite layer 3, adversely affecting the light absorption of the perovskite layer 3.

[0091] Exemplarily, the thickness of the passivation layer 4 is 15 nm, 17 nm, 19 nm, 21 nm, 23 nm and 25 nm, etc., the thickness of the perovskite layer 3 is 800 nm, 830 nm, 850 nm, 880 nm, 900 nm, 920 nm, 940 nm, 960 nm, 980 nm and 1000 nm, etc., and the thickness of the electron transport layer 5 is 25 nm, 26 nm, 27 nm, 28 nm, 29 nm and 30 nm, etc.

[0092] In some embodiments, the perovskite solar cell includes a single-junction perovskite solar cell or a perovskite tandem solar cell.

[0093] Perovskite solar cells are single-junction perovskite solar cells, which also include:

[0094] Transparent conductive substrate 1;

[0095] A hole transport layer 2, the hole transport layer 2 is stacked on the surface of the transparent conductive substrate 1;

[0096] The perovskite layer 3, the passivation layer 4 and the electron transport layer 5 are sequentially stacked on the surface of the hole transport layer 2;

[0097] A positive electrode 8 and a negative electrode 7, wherein the positive electrode 8 forms an ohmic contact with the transparent conductive substrate 1, and the negative electrode 7 forms an ohmic contact with the electron transport layer 5;

[0098] Single-junction perovskite solar cells also include:

[0099] Transparent conductive substrate 1;

[0100] The electron transport layer 5, the passivation layer 4 and the perovskite layer 3 are sequentially stacked on the surface of the transparent conductive substrate 1;

[0101] Hole transport layer 2, the hole transport layer 2 is stacked on the surface of the perovskite layer 3, the perovskite layer 3 is stacked on the surface of the hole transport layer 2;

[0102] The positive electrode 8 and the negative electrode 7 form an ohmic contact with the transparent conductive substrate 1 , and the negative electrode 7 forms an ohmic contact with the hole transport layer 2 .

[0103] Perovskite solar cells are perovskite tandem solar cells, which also include:

[0104] Silicon bottom cell;

[0105] Hole transport layer 2, which is stacked on the surface of the silicon bottom cell;

[0106] The perovskite layer 3, the passivation layer 4 and the electron transport layer 5 are sequentially stacked on the surface of the hole transport layer 2;

[0107] A positive electrode 8 and a negative electrode 7, wherein the positive electrode 8 forms an ohmic contact with the silicon bottom cell, and the negative electrode 7 forms an ohmic contact with the electron transport layer 5;

[0108] Perovskite tandem solar cells also include:

[0109] Silicon bottom cell;

[0110] The electron transport layer 5, the passivation layer 4 and the perovskite layer 3 are stacked in sequence on the surface of the silicon bottom cell;

[0111] Hole transport layer 2, the hole transport layer 2 is stacked on the surface of the perovskite layer 3, the perovskite layer 3 is stacked on the surface of the hole transport layer 2;

[0112] The positive electrode 8 and the negative electrode 7 form an ohmic contact with the silicon bottom cell, and the negative electrode 7 forms an ohmic contact with the hole transport layer 2.

[0113] In some embodiments, the hole transport layer 2 is nickel oxide; and / or the electron transport layer 5 is C60 or its derivatives; and / or the thickness of the transparent conductive substrate 1 is 1100 nm, and the thickness of the hole transport layer 2 is 18 nm to 22 nm; and / or the thickness of the positive electrode 8 is 250 nm to 300 nm; and / or the thickness of the negative electrode 7 is 250 nm to 300 nm; and / or a buffer layer 6 is further provided on the side of the electron transport layer 5 facing away from the perovskite layer 3.

[0114] The transparent conductive substrate 1 is a transparent conductive glass substrate, the material of which may be indium tin oxide ITO, and the buffer layer 6 may be 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, whose English name is Bathocuproine, or BCP for short.

[0115] In a second aspect, the present application provides a method for preparing a perovskite solar cell.

[0116] The preparation method of perovskite solar cell comprises the following steps:

[0117] Preparation of perovskite layer 3 of perovskite solar cell;

[0118] A passivation layer 4 is prepared on the perovskite layer 3. The preparation method of the passivation layer 4 includes the following steps:

[0119] A composite material solution of polydopamine cross-linked modified layered double metal hydroxide is prepared, the composite material solution is coated on the perovskite layer 3 by a solution method, and a passivation layer 4 is obtained after annealing;

[0120] An electron transport layer 5 is formed on the passivation layer 4 .

[0121] The composite material is coated onto the surface of the perovskite layer 3 by a solution method, so that the composite material is in full contact with the surface of the perovskite layer 3, effectively improving the interface defects of the perovskite layer 3, improving the stability of the perovskite solar cell, and improving the electron extraction and transfer capabilities.

[0122] In some embodiments, the concentration of the composite material solution is 0.5 mg / mL to 2 mg / mL.

[0123] The composite material solution of the above concentration has good wettability and coverage on the surface of the perovskite layer 3, and can be evenly dispersed and covered on the surface of the perovskite layer 3. If the concentration of the composite material solution is too high, its wettability on the surface of the perovskite layer 3 is poor, it is difficult to fully spread on the surface of the perovskite layer 3, and the passivation effect of the perovskite layer 3 is reduced. If the concentration of the composite material solution is too low, its coverage on the surface of the perovskite layer 3 is poor, it is difficult to prepare a passivation layer 4 with uniform thickness and electron transfer effect, which will also lead to a reduction in the passivation effect of the perovskite layer 3.

[0124] In some embodiments, the solvent of the composite material solution is a short-chain alcohol.

[0125] The short-chain alcohol has less than five carbon atoms, and the composite material has better solubility in the short-chain alcohol and better dispersion stability and is not easy to delaminate. For example, the short-chain alcohol can be isopropyl alcohol, ethanol, methanol, etc.

[0126] In some embodiments, the composite material solution is applied to the perovskite layer 3 by spin coating, the spin coating atmosphere is 5% RH to 10% RH, the spin coating speed is 3500 rpm to 5000 rpm, the acceleration is 3500 rpm / s to 5000 rpm / s, and the spin coating time is 25s to 35s.

[0127] In some embodiments, in the step of preparing the passivation layer 4 , the annealing step is performed at 100° C. to 125° C. for 10 min to 15 min.

[0128] In some embodiments, when the perovskite layer 3 is prepared, a certain amount of cesium iodide, methylamine bromide, lead bromide, iodomethane and lead iodide are respectively weighed and dissolved in a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide, and stirred evenly to obtain a perovskite solution. For example, 0.022g of cesium iodide, 0.042g of methylamine bromide, 0.147g of lead bromide, 0.214g of iodomethane and 0.599g of lead iodide are weighed and dissolved in 10mL of a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide with a volume ratio of 4:1, stirred for 1h to obtain a perovskite solution. The perovskite solution is applied to the surface of the hole transport layer 2, and the perovskite layer 3 is obtained after annealing. The coating method can be selected from slit coating, screen printing, spin coating, spray coating, blade coating, etc. Taking spin coating as an example, 150 μL of perovskite solution was transferred and spin-coated onto the electron transport layer 5 at rotation speeds of 500 rpm, 1500 rpm, and 5000 rpm for 5 s, 90 s, and 10 s respectively. 200 μL of chlorobenzene was added in the 8th second before the entire spin coating process, and then annealed at 100°C and a relative humidity of 5% RH for 15 minutes to form a perovskite layer 3.

[0129] In some embodiments, the perovskite solar cell is a single-junction perovskite solar cell, and the method for preparing the single-junction perovskite solar cell further comprises the following steps:

[0130] Providing a transparent conductive substrate 1;

[0131] A hole transport layer 2 is prepared on a transparent conductive substrate 1;

[0132] Prepare a perovskite layer 3 on the surface of the hole transport layer 2;

[0133] A positive electrode 8 is prepared on the transparent conductive substrate 1, and a negative electrode 7 is prepared on the electron transport layer 5;

[0134] Alternatively, the single-junction perovskite solar cell further comprises the following steps:

[0135] Providing a transparent conductive substrate 1;

[0136] An electron transport layer 5 is prepared on a transparent conductive substrate 1;

[0137] Prepare a hole transport layer 2 on the surface of the perovskite layer 3;

[0138] A positive electrode 8 is prepared on the transparent conductive substrate 1 , and a negative electrode 7 is prepared on the hole transport layer 2 .

[0139] In some embodiments, the perovskite solar cell is a perovskite tandem solar cell, and the method for preparing the perovskite tandem solar cell further comprises the following steps:

[0140] Provide silicon bottom cells;

[0141] Prepare a hole transport layer 2 on the silicon bottom cell;

[0142] Prepare a perovskite layer 3 on the surface of the hole transport layer 2;

[0143] A positive electrode 8 is prepared on the silicon bottom cell, and a negative electrode 7 is prepared on the electron transport layer 5;

[0144] Alternatively, the method for preparing the perovskite tandem solar cell further comprises the following steps:

[0145] Silicon bottom cell;

[0146] Prepare an electron transport layer 5 on the silicon bottom cell;

[0147] A hole transport layer 2 is prepared on the perovskite layer 3;

[0148] A positive electrode 8 is prepared on the silicon bottom cell, and a negative electrode 7 is prepared on the hole transport layer 2;

[0149] In some embodiments, the hole transport layer 2 is prepared by magnetron sputtering; and / or, the perovskite layer 3 is prepared by a solution method; and / or, the electron transport layer 5 is prepared by evaporation; and / or, the positive electrode 8 is prepared by evaporation; and / or, the negative electrode 7 is prepared by evaporation.

[0150] Taking the selection of transparent conductive substrate 1 as an example, during the preparation of perovskite solar cells, high-temperature tape is pasted in advance at the silver electrode evaporation position to protect the electrode position, and then ultraviolet ozone activation treatment is performed to reduce the adhesion of pollutants to the transparent conductive substrate 1.

[0151] A hole transport layer 2 is prepared on a transparent conductive substrate 1 that has been activated with UV ozone. Using nickel oxide as the material for the hole transport layer 2, a magnetron sputtering process uses a rotating target with a nickel oxide content of 99.99%. At a process pressure of 0.52 Pa and a process atmosphere of Ar:O2 = (500-700) sccm:5 sccm, the nickel oxide hole transport layer 2 is formed by at least two reciprocating depositions.

[0152] The electron transport layer 5 is C 60 For materials, use less than The film is obtained by evaporation coating at a rate of .

[0153] A buffer layer 6 is also prepared on the electron transport layer 5. The material of the buffer layer 6 can be BCP. The preparation method of the buffer layer 6 is as follows: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) is dissolved in an ethanol solvent to obtain a 1 mg / mL BCP solution. The BCP solution is spin-coated onto the electron transport layer 5 at 4000 rpm, 30 s, and 2000 rpm / s. The buffer layer 6 is annealed at 100°C and 5% RH for 10 min to obtain the buffer layer 6.

[0154] The technical solution of the present invention will be further described below in conjunction with more specific embodiments and drawings.

[0155] Example 1

[0156] A perovskite solar cell, comprising:

[0157] The transparent conductive substrate 1 is made of indium tin oxide and has a thickness of 1100 nm.

[0158] The hole transport layer 2 stacked on the transparent conductive substrate 1 is a nickel oxide layer with a thickness of 20 nm.

[0159] The perovskite layer 3 is stacked on the side of the hole transport layer 2 facing away from the transparent conductive substrate 1 , and the thickness of the perovskite layer 3 is 900 nm.

[0160] The passivation layer 4 stacked on the side of the perovskite layer 3 facing away from the transparent conductive substrate 1 is a composite material layer formed by cross-linking polydopamine and modifying layered double metal hydroxides, and has a thickness of 20 nm.

[0161] The electron transport layer 5 is stacked on the side of the passivation layer 4 away from the transparent conductive substrate 1, and the electron transport layer 5 is C 60 layer with a thickness of 25 nm.

[0162] The buffer layer 6 is stacked on the electron transport layer 5 , and the material of the buffer layer 6 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0163] Electrodes include a silver positive electrode 8 and a silver negative electrode 7 , the thickness of the silver positive electrode 8 and the silver negative electrode 7 is 275 nm, the silver positive electrode 8 forms an ohmic contact with the transparent conductive substrate 1 , and the silver negative electrode 7 forms an ohmic contact with the buffer layer 6 .

[0164] A method for preparing a perovskite solar cell comprises the following steps:

[0165] Providing a transparent conductive substrate 1, and performing ultraviolet ozone activation on the transparent conductive substrate 1 for 15 minutes to decompose impurities in the transparent conductive substrate 1;

[0166] The hole transport layer 2 is prepared on the transparent conductive substrate 1 by magnetron sputtering. The preparation method of the hole transport layer 2 is as follows: NiO with a content of 99.99% is used. x The target is rotated, the process pressure is 0.55Pa, the process atmosphere is Ar:O2=500:5~700:5, and the coating transmission times are 12 times.

[0167] A perovskite layer 3 was prepared on the hole transport layer 2 by a solution spin coating method. The preparation method of the perovskite layer 3 was as follows: 0.022 g of cesium iodide, 0.042 g of bromomethylamine, 0.147 g of lead bromide, 0.214 g of iodomethane, and 0.599 g of lead iodide were dissolved in 10 mL of a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide with a volume ratio of 4:1, and stirred for 1 hour to obtain a perovskite solution. 150 μL of the perovskite solution was transferred using a pipette and spin-coated onto the hole transport layer 2 at rotation speeds of 500 rpm, 1500 rpm, and 5000 rpm for 5 seconds, 90 seconds, and 10 seconds, respectively. 200 μL of chlorobenzene was added dropwise in the 8th second before the entire spin coating process, and then annealed at 100° C. and a relative humidity of 5% RH for 15 minutes to form a perovskite layer 3.

[0168] A passivation layer 4 is prepared on the perovskite layer 3. The preparation method of the passivation layer 4 is as follows: 2 mg of the composite material is dissolved in 2 mL of isopropanol and fully dispersed in a mixer to obtain a composite material solution with a concentration of 1 mg / mL. 100 μL of the composite material solution is spin-coated on the perovskite layer 3. The spin-coating atmosphere is 5% RH, the spin-coating speed is 4000 rpm, the acceleration is 4000 rpm / s, and the spin-coating time is 30 s. Then, the passivation layer 4 is obtained by annealing at 100° C. for 10 min. The preparation method of the composite material is as follows:

[0169] Preparation of layered double metal hydroxide: 1684 mg Zn(NO3)2·6H2O, 375 mg Al(NO3)3·9H2O and 50 mg Na2CO3 were dissolved in 100 mL water, and sodium hydroxide solution was added to adjust the pH to 10±0.5. The mixture was coprecipitated at 80°C for 8 h, centrifuged at 6000 r / min, washed with deionized water, and finally dried at 60°C for 12 h to obtain Zn 2+ and Al 3+ The molar ratio is 4:1, and the interlayer anion is CO3 2- Layered double metal hydroxides;

[0170] Preparation of bimetallic composite oxide: calcining the above-mentioned layered bimetallic hydroxide in air at 250° C. for 2 h to obtain a bimetallic composite oxide;

[0171] Preparation of composite materials: 200 mg of bimetallic composite oxide was mixed with 100 mL of water, ultrasonically dispersed for 1 hour, and then 10 mL of Tris-HCl and 100 mg of dopamine hydrochloride were added to obtain a mixture solution. The pH of the mixture solution was adjusted to 8.5 by adding NaOH solution, and the mixture was placed in an 80°C oil bath and magnetically stirred for 24 hours. Then, the precipitate was centrifuged at 7000 rpm and washed with deionized water several times to remove excess dopamine, and dried in an oven at 60°C for 12 hours to obtain a composite material.

[0172] The electron transport layer 5 is prepared by evaporation on the side of the passivation layer 4 away from the transparent conductive substrate 1. The preparation method of the electron transport layer 5 is as follows: weigh 200 mg of C 60 In the metal evaporation boat, The film is evaporated at a rate of , to obtain an electron transport layer 5.

[0173] A BCP buffer layer 6 was prepared on the electron transport layer 5 by a solution spin coating method. The preparation method of the BCP buffer layer 6 was as follows: 0.5 mg of BCP (2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline) was dissolved in 5 mL of ethanol solvent to obtain a BCP solution with a mass fraction of 0.5 mg / mL. The solution was spin-coated on the electron transport layer 5 at 4000 rpm for 30 seconds, and annealed at 100° C. for 10 minutes at a relative humidity of 5% to obtain the buffer layer 6.

[0174] After the BCP solution is spin-coated, the high-temperature tape that has been attached in advance is used to evaporate the silver negative electrode 7 on the buffer layer 6 , and to evaporate the silver positive electrode 8 on the transparent conductive substrate 1 .

[0175] Example 2

[0176] The embodiment of the present application provides a perovskite solar cell, which differs from the first embodiment in that in the step of preparing the bimetallic composite oxide, the calcination temperature is 400° C., and the rest is consistent with the first embodiment.

[0177] Example 3

[0178] The embodiment of the present application provides a perovskite solar cell, which differs from the first embodiment in that in the step of preparing the bimetallic composite oxide, the calcination temperature is 500° C., and the rest is consistent with the first embodiment.

[0179] Example 4

[0180] The embodiment of the present application provides a perovskite solar cell, which differs from the first embodiment in that in the step of preparing the bimetallic composite oxide, the calcination temperature is 600° C., and the rest is consistent with the first embodiment.

[0181] Example 5

[0182] The embodiment of the present application provides a perovskite solar cell, which differs from the second embodiment in that in the step of preparing the layered double metal hydroxide, NaCl is used in an equal molar amount to replace Na2CO3, and the rest is consistent with the first embodiment.

[0183] Example 6

[0184] The embodiment of the present application provides a perovskite solar cell, which differs from the second embodiment in that in the step of preparing the layered double metal hydroxide, NaBr is used in an equal molar amount to replace Na2CO3, and the rest is consistent with the first embodiment.

[0185] Example 7

[0186] The present embodiment provides a perovskite solar cell, which differs from the second embodiment in that: in the step of preparing the layered double metal hydroxide, 1263 mg of Zn(NO3)2·6H2O and 375 mg of Al(NO3)3·9H2O are added, and Zn 2+ and Al 3+ The molar ratio of is 3:1, and the rest is consistent with Example 1.

[0187] Example 8

[0188] The present embodiment provides a perovskite solar cell, which differs from the second embodiment in that: in the step of preparing the layered double metal hydroxide, 842 mg of Zn(NO3)2·6H2O and 375 mg of Al(NO3)3·9H2O are added, so that Zn 2+ and Al 3+ The molar ratio of the input was 2:1, and the rest was consistent with Example 1.

[0189] Embodiment 9

[0190] The present embodiment provides a perovskite solar cell, which differs from the second embodiment in that: in the step of preparing the layered double metal hydroxide, Ti is used. 2+ Replacement of Zn 2+ , Ti(NO3)2·6H2O was added in 1744mg, Al(NO3)3·9H2O was added in 375mg, and Ti 2+ and Al 3+ The molar ratio of the input was 4:1, and the rest was consistent with Example 1.

[0191] Example 10

[0192] The embodiment of the present application provides a perovskite solar cell, which differs from the third embodiment in that no calcination treatment is performed in the step of preparing the bimetallic composite oxide, and the rest is consistent with the first embodiment.

[0193] experiment

[0194] Comparative Example 1

[0195] The comparative example of the present application provides a perovskite solar cell, which differs from the third embodiment in that the passivation layer 4 is made of LiF and is prepared by vacuum evaporation process, with an evaporation rate of The thickness is 1nm.

[0196] The energy conversion efficiency and electron mobility of the above-mentioned perovskite solar cell were tested. The energy conversion efficiency was tested by an offline IV test system, and the electron mobility was tested by a Hall test. The test results are shown in Table 1.

[0197] Table 1

[0198] In Comparative Example 1, LiF is used as a commonly used passivation material. The preferred thickness is currently 1 nm. This thickness is the thickness selected for the LiF layer to achieve both excellent passivation effect and conductivity. When the thickness of LiF is further increased, the battery conversion efficiency is likely to decrease due to the poor conductivity of LiF. The data in Table 1 show that compared with Comparative Example 1 using LiF as the passivation layer material, Example 3 using the composite material as the passivation layer increases the battery conversion efficiency by 4.17% and the electron transfer rate by 7.631×10 -2 , proving that the composite material has a better defect passivation effect on the perovskite layer, which is more conducive to the extraction and migration of electrons, significantly improving the electron mobility and further improving the conversion efficiency of the battery.

[0199] From the comparison between Example 3 and Example 10, it can be seen that the battery conversion efficiency of Example 3 is improved by 3.13%, and the electron transfer rate is improved by 7.463×10-2 , proving that after calcination, the electron transport effect of the passivation layer in Example 3 is improved. Combining the comparison of Example 1, Example 2, Example 3 and Example 4, it can be seen that after the layered double hydroxide is calcined at 250°C to 600°C, the composite material formed by the cross-linking reaction of the layered double hydroxide and polydopamine has a significantly improved passivation effect on the perovskite layer and the ability to promote electron migration, proving that when the layered double hydroxide is calcined within a specific temperature range, the battery conversion efficiency and electron transfer rate are more significantly improved. It can be seen that after calcination within a specific temperature range, the passivation effect of the composite material on the perovskite layer and its own electron transport effect are further improved.

[0200] The above is a detailed introduction to the perovskite solar cell and its preparation method disclosed in the embodiment of the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the perovskite solar cell and its preparation method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention. The above is a detailed introduction to the perovskite silicon tandem solar cell and its preparation method disclosed in the embodiment of the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the perovskite silicon tandem solar cell and its preparation method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A perovskite solar cell, comprising a perovskite layer, a passivation layer, and an electron transport layer, wherein the passivation layer is located between the perovskite layer and the electron transport layer, and the passivation layer comprises a composite material formed by crosslinking and modifying layered double metal hydroxide with polydopamine.

2. The perovskite solar cell according to claim 1, wherein, The preparation method of the composite material comprises the following steps: Preparing a double metal composite oxide: taking layered double metal hydroxide and performing calcination treatment to obtain a double metal composite oxide; Preparing the composite material: mixing the double metal composite oxide with water to cause the double metal composite oxide to undergo a hydration reaction, and then adding dopamine hydrochloride for crosslinking reaction, and obtaining the composite material after the reaction.

3. The perovskite solar cell according to claim 2, wherein, The temperature of the calcination is 250°C to 600°C, and the time of the calcination is 2h to 3.5h.

4. The perovskite solar cell according to any one of claims 2 to 3, wherein, In the step of preparing the composite material, after the double metal composite oxide is mixed with water, ultrasonic treatment is performed.

5. The perovskite solar cell according to any one of claims 2 to 4, wherein, In the step of preparing the composite material, after the dopamine hydrochloride is added, the pH is adjusted to 8 to 9, and the reaction is carried out at 80°C to 100°C for 16h to 24h to obtain the composite material.

6. The perovskite solar cell according to any one of claims 2 to 5, wherein, The layered double metal hydroxide is prepared by a co-precipitation method.

7. The perovskite solar cell according to any one of claims 1 to 6, wherein, The layered double metal hydroxide comprises divalent metal ions, trivalent metal ions, and interlayer anions.

8. The perovskite solar cell according to claim 7, wherein, The divalent metal ions include Ti 2+ , Zn 2+ , and any one of the trivalent metal ions includes Al 3+ , Fe 3+ , and Ni 3+ , and any one of the interlayer anions is CO3 2- , Cl - , and Br - .

9. The perovskite solar cell according to claim 7, wherein, The ratio of the mole of the trivalent metal ions to the sum of the moles of the trivalent metal ions and the divalent metal ions is 1:(0.17 to 0.33), and the molar ratio of the divalent metal ions to the trivalent metal ions is (3 to 6):

1.

10. The perovskite solar cell according to any one of claims 1 to 9, wherein, The mass percentage of the polydopamine in the composite material is 1% to 75%, and the mass percentage of the layered double metal hydroxide in the composite material is 25% to 99%.

11. The perovskite solar cell according to any one of claims 1 to 10, wherein, The thickness of the passivation layer is 15nm to 25nm.

12. The perovskite solar cell according to any one of claims 1 to 11, wherein, The thickness of the perovskite layer is 800nm to 1000nm.

13. The perovskite solar cell according to any one of claims 1 to 12, wherein, The thickness of the electron transport layer is 25nm to 30nm.

14. The perovskite solar cell according to any one of claims 1 to 13, wherein, The perovskite solar cell comprises a single-junction perovskite solar cell or a perovskite tandem solar cell.

15. The perovskite solar cell according to claim 14, wherein, The perovskite solar cell is a single-junction perovskite solar cell, and the single-junction perovskite solar cell further comprises: A transparent conductive substrate; A hole transport layer, which is stacked on the surface of the transparent conductive substrate; The perovskite layer, the passivation layer, and the electron transport layer are sequentially stacked on the surface of the hole transport layer; A positive electrode and a negative electrode, wherein the positive electrode forms an ohmic contact with the transparent conductive substrate, and the negative electrode forms an ohmic contact with the electron transport layer.

16. The perovskite solar cell according to claim 14, wherein, The single-junction perovskite solar cell further comprises: A transparent conductive substrate; The electron transport layer, the passivation layer, and the perovskite layer are sequentially stacked on the surface of the transparent conductive substrate; A hole transport layer, which is stacked on the surface of the perovskite layer, and the perovskite layer is stacked on the surface of the hole transport layer; A positive electrode and a negative electrode, wherein the positive electrode forms an ohmic contact with the transparent conductive substrate, and the negative electrode forms an ohmic contact with the hole transport layer.

17. The perovskite solar cell according to claim 14, wherein, The perovskite solar cell is a perovskite tandem solar cell, and the perovskite tandem solar cell further comprises: A silicon bottom cell; A hole transport layer, which is stacked on the surface of the silicon bottom cell; The perovskite layer, the passivation layer and the electron transport layer are sequentially stacked on the surface of the hole transport layer; A positive electrode and a negative electrode, the positive electrode forms an ohmic contact with the silicon bottom cell, and the negative electrode forms an ohmic contact with the electron transport layer.

18. The perovskite solar cell according to claim 14, wherein, The perovskite stacked solar cell further includes: A silicon bottom cell; The electron transport layer is stacked on the surface of the silicon bottom cell; A hole transport layer, the hole transport layer is stacked on the surface of the perovskite layer, and the perovskite layer is stacked on the surface of the hole transport layer; A positive electrode and a negative electrode, the positive electrode forms an ohmic contact with the silicon bottom cell, and the negative electrode forms an ohmic contact with the hole transport layer.

19. The perovskite solar cell according to any one of claims 15 to 18, wherein, The hole transport layer is nickel oxide.

20. The perovskite solar cell according to any one of claims 15 to 19, wherein, The electron transport layer is C 60 or its derivatives.

21. The perovskite solar cell according to any one of claims 15 to 20, wherein, The thickness of the transparent conductive substrate is 1100 nm, and the thickness of the hole transport layer is 18 nm to 22 nm.

22. The perovskite solar cell according to any one of claims 15 to 21, wherein, The thickness of the positive electrode is 250 nm to 300 nm.

23. The perovskite solar cell according to any one of claims 15 to 22, wherein, The thickness of the negative electrode is 250 nm to 300 nm.

24. The perovskite solar cell according to any one of claims 15 to 18, wherein, A buffer layer is further provided on the side of the electron transport layer away from the perovskite layer.

25. A method for preparing a perovskite solar cell, comprising the following steps: Preparing the perovskite layer of the perovskite solar cell; Preparing a passivation layer on the perovskite layer, and the preparation method of the passivation layer comprises the following steps: Configuring a composite material solution formed by crosslinking and modifying layered double metal hydroxide with polydopamine, coating the composite material solution onto the perovskite layer by a solution method, and annealing to obtain the passivation layer; Preparing an electron transport layer on the passivation layer.

26. The preparation method of the perovskite solar cell according to claim 25, wherein, The concentration of the composite material solution is 0.5 mg / mL to 2 mg / mL.

27. The preparation method of the perovskite solar cell according to any one of claims 25 to 26, wherein, The solvent of the composite material solution is short-chain alcohol.

28. The preparation method of the perovskite solar cell according to any one of claims 25 to 27, wherein, The composite material solution is coated onto the perovskite layer by spin coating, the spin coating atmosphere is 5% RH to 10% RH, the spin coating speed is 3500 rpm to 5000 rpm, the acceleration is 3500 rpm / s to 5000 rpm / s, and the spin coating time is 25 s to 35 s.

29. The preparation method of the perovskite solar cell according to any one of claims 25 to 28, wherein, In the preparation step of the passivation layer, the annealing is carried out at 100 °C to 125 °C for 10 min to 15 min.

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