Perovskite solar cells and manufacturing methods

Abstract

The present invention provides a perovskite solar cell including at least an electrode, an electron transport layer, a hole transport layer, a perovskite layer, and a passivation layer, wherein the passivation layer contains a passivation agent, the passivation agent including an aza-fused bicyclic compound and / or an organic salt formed from the aza-fused bicyclic compound and an acid, each fused ring of the aza-fused bicyclic compound is independently a five- or six-membered saturated, unsaturated, or aromatic ring, and the fused ring of the aza-fused bicyclic compound includes 1 to 5 nitrogen atoms, and the fused ring is either an unsubstituted ring or substituted with 1 or 2 substituents having 1 to 3 carbon atoms.

Description

Technical Field

[0001] The present invention relates to a perovskite solar cell with improved stability and a method for manufacturing a perovskite solar cell.

Background Art

[0002] As the mitigation of the progress of global warming and the construction of an eco-civilization are attracting more and more attention, the diversification of energy and the development of green energy are also gathering more interest. Here, photovoltaic power generation that converts solar energy into electrical energy has been widely applied because there is no carbon emission during energy conversion and the freedom of equipment installation is high. However, the current mainstream photovoltaic power generation device is a silicon-based solar cell panel using single-crystalline silicon or polycrystalline silicon, and this silicon-based solar cell panel has problems such as a large weight of the cell panel, a complicated production process, and large energy consumption and cost in the production process.

[0003] In order to solve the above problems, solar cells that can be manufactured by a solution process have been proposed. Among them, a solar cell including a perovskite-type crystal structure as a light conversion layer has attracted much attention because its conversion efficiency is close to that of a silicon-based solar cell.

[0004] However, the perovskite-type crystal structure is fragile and it is difficult to maintain the lattice form constant for a long time under the use environment, which becomes a factor that significantly affects the life of the perovskite solar cell.

[0005] In order to improve the stability of the perovskite-type crystal, CN106062983A proposes that when manufacturing a perovskite solar cell, a passivation layer containing a passivating agent such as thiophene or pyridine is further formed on the deposited perovskite layer. However, the present inventor has found room for improvement in the selection of the passivating agent in the prior art.

[0006] Furthermore, in conventional techniques, a method for forming a passivation layer generally involves coating a layer supporting a perovskite layer with a solution containing a perovskite precursor, then coating it with a poor solvent to extract the perovskite solvent and precipitate the perovskite structure, heating to remove excess solvent, converting the perovskite into an effective perovskite phase, coating the perovskite surface with a passivating agent, and finally annealing to remove the solvent, thereby forming a passivation layer on the perovskite layer. However, there is room for further simplification of this method for generating a passivation layer. [Overview of the project] [Problems that the invention aims to solve]

[0007] During the manufacturing process and operation of perovskite solar cells, deep and shallow level defects exist, and these defects seriously affect the efficiency and long-term stability of the cells. Experiments have shown that small organic ammonium salts can passivate defects on the perovskite surface, improving device efficiency and stability. However, many current passivators are monocyclic small organic amines, which are ineffective in improving battery device efficiency and stability. The result It's still not enough.

[0008] The problem that the present invention aims to solve is to provide a perovskite solar cell containing a passivation layer that is more effective in improving battery efficiency and stability, and a method for manufacturing the perovskite solar cell containing the passivation layer. [Means for solving the problem]

[0009] One aspect of the present invention is a perovskite solar cell comprising at least an electrode, an electron transport layer, a hole transport layer, a perovskite layer, and a passivation layer. The passivation layer contains a passivating agent, the passivating agent contains an aza-condensed bicyclic compound and / or an organic salt formed from an aza-condensed bicyclic compound and an acid, each condensed ring of the aza-condensed bicyclic compound is independently a five-membered or six-membered saturated ring, an unsaturated ring, or an aromatic ring, and the condensed ring of the aza-condensed bicyclic compound contains 1 to 5 nitrogen atoms, and the condensed ring is either an unsubstituted ring or a ring substituted with 1 or 2 substituents having 1 to 3 carbon atoms.

[0010] In the above perovskite solar cell, the aza-condensed bicyclic compound is preferably selected from pteridine, 1,5,7-triazidobicyclo(4.4.0)deca-5-ene, quinazoline, quinoline, 1,5-diazabicyclo[4.3.0]-5-nonene, imidazo[1,2-a]pyrimidine, 5,6,7,8-tetrahydroindolidine, 1-methyl-2,3-dihydro-1H-pyrrolidine, and 2,4-dimethylquinoline.

[0011] In the above-described perovskite solar cell, preferably, the acid ion in the organic salt is selected from one of the acid ions including O, S, P, N, F, I, Br, Cl, C, and H.

[0012] In the above-described perovskite solar cell, the acid ion is preferably selected from an acid ion derived from one of the following: acetic acid, phosphoric acid, nitric acid, chloric acid, sulfonic acid, sulfuric acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, and hydroiodic acid.

[0013] In the above-described perovskite solar cell, preferably, the passivation layer is a layer formed by coating a poor solvent containing a passivating agent onto the perovskite layer. The poor solvent is selected from at least one of toluene, chlorobenzene, dichlorobenzene, ethyl acetate, ethyl ether, benzene, anhydrous ethanol, isopropanol, butanol, chloroform, methyl butyrate, anisole, xylene, and mesitylene.

[0014] In the above-described perovskite solar cell, preferably, the ratio of the molar amounts of perovskite in the perovskite layer to the passivating agent in the passivation layer is 100 to 800, and may be 200 to 600 or 250 to 400.

[0015] As a result, by using the above-mentioned passivating agent, a perovskite solar cell with improved battery efficiency and stability can be obtained.

[0016] Another aspect of the present invention provides a power generation device using the perovskite solar cell described above. This makes it possible to provide a power generation device with improved efficiency and stability.

[0017] Another aspect of the present invention provides a power consumption device using the perovskite solar cell described above. This makes it possible to provide a power consumption device with improved efficiency and stability.

[0018] Another aspect of the present invention provides a method for forming a passivation layer in the above-mentioned perovskite solar cell, the method being: The method is characterized by comprising the steps of coating a perovskite precursor solution onto a layer supporting a perovskite layer, directly coating it with a poor solvent containing a passivating agent, and then performing annealing. Here, the passivating agent includes an aza-condensed bicyclic compound and / or an organic salt formed from an aza-condensed bicyclic compound and an acid, wherein each condensed ring of the aza-condensed bicyclic compound is independently a five-membered or six-membered saturated ring, an unsaturated ring, or an aromatic ring, and the condensed ring of the aza-condensed bicyclic compound contains 1 to 5 nitrogen atoms, and the condensed ring is either an unsubstituted ring or a ring substituted with 1 or 2 substituents having 1 to 3 carbon atoms.

[0019] In the above method, preferably, the azabicyclic compound is selected from one of pteridine, 1,5,7-triazabicyclo(4.4.0)dec-5-ene, quinazoline, quinoline, 1,5-diazabicyclo[4.3.0]-5-nonene, imidazo[1,2-a]pyrimidine, 5,6,7,8-tetrahydroindolizine, 1-methyl-2,3-dihydro-1H-pyrrolidine, and 2,4-dimethylquinoline.

[0020] In the above method, preferably, the acid ion in the organic salt is selected from one of acid ions containing O, S, P, N, F, I, Br, Cl, C, and H.

[0021] In the above method, preferably, the acid ion is selected from one of acid ions derived from acetic acid, phosphoric acid, nitric acid, chloric acid, sulfonic acid, sulfuric acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, and hydroiodic acid.

[0022] In the above method, preferably, the poor solvent is selected from at least one of toluene, chlorobenzene, dichlorobenzene, ethyl acetate, ethyl ether, benzene, absolute ethanol, isopropanol, butanol, chloroform, methyl butyrate, anisole, xylene, and mesitylene.

[0023] In the above method, preferably, in the poor solvent, the concentration of the passivating agent is 0.1 to 10 mmol / mL.

[0024] In the above method, preferably, the molar ratio of the perovskite precursor in the perovskite precursor solution to the passivating agent in the poor solvent is 200 to 8000, and may be 800 to 1600 or 1000 to 1200.

[0025] Thereby, a passivation layer can be formed by a simpler method, the surface and grain boundaries of the perovskite structure can be passivated from all directions, and a perovskite solar cell with higher battery efficiency and stability can be provided.

Advantages of the Invention

[0026] The perovskite solar cell according to the present invention can improve battery efficiency and stability, and the manufacturing method according to the present invention can provide a perovskite solar cell having the above advantages in a simpler manner.

Brief Description of the Drawings

[0027] [Figure 1] It is a schematic diagram of the structure of a perovskite solar cell. [Figure 2] It is a schematic diagram of the structure of a perovskite structure.

Embodiments for Carrying Out the Invention

[0028] In order to more clearly illustrate the technical problems, technical solutions and beneficial effects to be solved by the present invention, the present invention will be described in more detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only for interpreting the present invention and not for limiting the present invention.

[0029] 1 Perovskite solar cells First, the perovskite solar cell of the present invention will be briefly described. As shown in FIG. 1, the perovskite solar cell of the present invention includes a first electrode layer 2, an electron transport layer 3, a perovskite layer 4, a passivation layer 5, a hole transport layer 6, and a second electrode layer 7 in sequence. When light is irradiated onto the perovskite layer, the perovskite structure absorbs the energy of photons to generate free electrons and holes (hereinafter, electrons and holes may be collectively referred to as "carriers"), and the generated free electrons and holes are respectively conducted to the first electrode and the second electrode through the electron transport layer and the hole transport layer, generating a voltage between the first electrode and the second electrode, thereby realizing the energy conversion between light and electricity. It should be noted that FIG. 1 only schematically shows one embodiment in which a passivation layer 5 is formed on one side of the perovskite layer 4, but the present invention is not limited to this structure. For example, the passivation layer 5 may be formed on either one side or both sides of the perovskite layer 4.

[0030] 1.1 Perovskite layer 4 The perovskite layer contains crystalline perovskite structures and has the crystalline structure shown in Figure 2. The perovskite structure commonly used in solar cells may also be represented as an ABX3 structure, where A is a positively charged ion of a certain size, such as alkali metal ions such as cesium, or nitrogen-containing small organic molecule ions such as methylamine (CH3NH2) or formamidine (HNCHNH2); the B site is an ion of a transition metal element, such as Pb or Sn; and the X site is a halogen ion, such as Br or I.

[0031] It should be explained that in a typical ABX3 structure, a lattice structure is formed by filling BX octahedra, composed of B and X, with A. Therefore, the A site cations have a size requirement, which is generally called the "acceptance factor," and this acceptance factor must be between 0.8 and 1.2. If the acceptance factor is too large or too small, it will significantly affect the stability of the lattice structure or prevent the formation of the desired structure.

[0032] The instability of the perovskite structure is specifically related to deep and shallow energy level defects present during the manufacturing process and device operation of perovskite solar cells. These defects have a serious impact on the efficiency and long-term stability of the cells. Another cause of instability in the calcium structure is its susceptibility to hydrolysis when it comes into contact with water.

[0033] 1.2 Passivation layer 5 The passivation layer is a layer placed between the perovskite layer and the electron transport layer and / or hole transport layer to improve the stability of the perovskite structure and the lifespan of the solar cell equipment, and it contains a passivating agent.

[0034] The inventors have found that the passivating agent described below is more effective in improving battery efficiency and extending battery life compared to conventional passivating agents. The passivating agent in the present invention comprises an aza-condensed bicyclic compound and / or an organic salt formed from an aza-condensed bicyclic compound and an acid, wherein each condensed ring of the aza-condensed bicyclic compound is independently a five-membered or six-membered saturated ring, an unsaturated ring, or an aromatic ring, and the condensed ring of the aza-condensed bicyclic compound contains 1 to 5 nitrogen atoms, and the condensed ring is either an unsubstituted ring or a ring substituted with 1 or 2 substituents having 1 to 3 carbon atoms.

[0035] The substituents on the condensed ring may be hydrocarbon groups, alcohol groups, ether groups, ester groups, aldehyde groups, ketone groups, carboxyl groups, carbonyl groups, amide groups, imide groups, or combinations thereof. Specifically, examples include methyl groups, ethyl groups, n-propyl groups, isopropyl groups, carbinol groups, alcohol groups, n-propanol groups, isopropanol groups, methyl ether groups, ethyl ether groups, propyl ether groups, methyl ester groups, ethyl ester groups, propioester groups, formaldehyde groups, acetaldehyde groups, propionaldehyde groups, methyl ketone groups, ethyl ketone groups, acetone groups, formic acid groups, acetic acid groups, propionic acid groups, formamide groups, acetamide groups, and propionamide groups.

[0036] When formamidine is used at site A, for example, formamidine is an organic component, and both high temperatures due to direct sunlight and non-radiative recombination due to defects lead to an increase in device temperature, causing formamidine to volatilize and creating defects at site A. Many conventional interfacial passivators form a two-dimensional structure, which prevents the volatilization of cations at site A, but displacement can occur at site A, potentially creating multiple defects. As defects increase, carriers such as free electrons or holes are captured, leading to an increase in the internal resistance of the device, making carrier extraction difficult and reducing the short-circuit current. Furthermore, the decomposition of the perovskite causes a decrease in device stability. For this reason, passivation using conventional passivators is not highly effective in improving the long-term stability of the device.

[0037] In this invention, the passivating agent containing an aza-condensed bicyclic compound and / or an organic salt formed from the same and an acid is used to passivate perovskite grain boundaries and surface defects.

[0038] In the passivating agent of the present invention, the nitrogen atom on the ring of the aza-condensed bicyclic compound and / or the organic salt formed therefrom with an acid has strong proton-bonding ability and forms a strong chemical bond with the A-site, thereby preventing the decomposition or volatilization of the A-site cation due to various causes. This reduces the generation of harmful hydrogen vacancies during use, improving the stability of passivation and the efficiency of the device.

[0039] Specific examples of the aza-condensed bicyclic compounds include the substances used in the examples, but the present invention is not limited to these compounds.

[0040] Although the principle is not yet clearly understood, it can be inferred that, compared to conventional techniques, the compounds used in this invention have an increased number of rings, improving the hydrophobicity of the material, allowing them to be introduced as hydrophobic functional groups, and significantly improving the water stability of the perovskite. Furthermore, the nitrogen on the aza ring and the A-site of the perovskite have strong proton bonding energy, which can suppress the leaching of A-site ions, thereby enhancing the passivation effect.

[0041] The acid ion in the organic salt formed with the above compound is selected from one of the acid ions containing O, S, P, N, F, I, Br, Cl, C, and H.

[0042] Specifically, the acid ions are selected from one of the following: acetic acid, phosphoric acid, nitric acid, chloric acid, sulfonic acid, sulfuric acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, and hydroiodic acid.

[0043] The acid ion is preferably derived from one selected from hydrofluoric acid, hydrochloric acid, hydrobromic acid, and hydroiodic acid, because when a halogen is selected as the acid ion, it can fill the halogen vacancies on the perovskite surface. The acid ion is preferably derived from hydrofluoric acid because it can fill defects at the X site and stabilize the A site cation by forming hydrogen bonds with it.

[0044] Furthermore, the acid ions are preferably derived from one of the acids containing oxygen, sulfur, phosphorus, etc., such as carboxylic acids, sulfonic acids, sulfuric acid, and phosphoric acid. This is because the acid ions derived from these acids can form hydrogen bonds with the ions at site A and anchor the ions at site B, thereby stabilizing the ions at sites A and B, further stabilizing the perovskite structure, and achieving the effect of improving the long-term stability of the battery device.

[0045] In the above-described perovskite solar cell, preferably, the molar ratio of perovskite in the perovskite layer to the passivating agent in the passivation layer (moles of perovskite / molars of passivating agent) is 100 to 800, but may also be 200 to 600 or 300 to 400. If the amount of passivating agent is too small relative to the perovskite, the defects in the perovskite structure cannot be sufficiently passed through, and ideal hydrophobicity cannot be imparted. If the amount of passivating agent is too large, the passivation effect will reach saturation, reducing the cost-effectiveness ratio, and there is also a possibility of adverse effects such as interference with carrier transport, increased internal resistance, and ultimately battery failure.

[0046] 1.3 Electron transport layer 3 and hole transport layer 6 The electron transport layer and hole transport layer are layers formed on both sides of the perovskite layer and passivation layer, and are for transporting free electrons and holes generated on the perovskite layer, respectively. By separating electrons and holes and further transporting them to the first and second electrodes, a decrease in conversion efficiency due to recombination of holes and electrons is avoided. It should be noted that Figure 1 shows only one possible embodiment of the present invention, and the positions of the electron transport layer and hole transport layer in the present invention may be interchanged.

[0047] At least one of the electron transport layer and the hole transport layer has a light transmittance of 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more in the visible light wavelength range.

[0048] As an electron transport layer, the layer is composed of a general electron transport material, which can be appropriately selected by those skilled in the art within a range advantageous for conversion efficiency. For example, tin oxide, titanium oxide, PCBM, and C60 may be used, with tin oxide being preferred. As for the manufacturing method of the layer, it can be manufactured by appropriately combining general methods such as coating, vapor deposition, and annealing.

[0049] As a hole transport layer, the layer is composed of a general hole transport material, which can be appropriately selected by those skilled in the art within a range advantageous for conversion efficiency. For example, PTAA, spiro, or PEDOT:PSS may be used, and spiro is preferred. As for the manufacturing method of the layer, it can be manufactured by appropriately combining general methods such as coating, vapor deposition, and annealing.

[0050] 1.4 First electrode 2 and second electrode 7 The first electrode is stacked in the direction opposite to the direction of the perovskite layer of the electron transport layer, and is an electrode that guides electrons conducted from the electron transport layer to the outside for use. The second electrode is stacked in the direction opposite to the direction of the perovskite layer of the hole transport layer, and is an electrode that guides holes conducted from the hole transport layer to the outside for use. It should be noted that Figure 1 shows only one possible embodiment of the present invention, and the positions of the first electrode and the second electrode of the present invention may be interchanged.

[0051] When the first and second electrodes are opaque electrodes, they may be made of common electrode materials, and those skilled in the art can appropriately select them within a range advantageous for conversion efficiency. For example, gold, silver, copper, aluminum, etc. may be used, with gold being preferred. As for the manufacturing method of the layer, it can be manufactured by appropriately combining common methods such as coating, vapor deposition, and annealing.

[0052] At least one of the first electrode and the second electrode is a transparent electrode, and the light transmittance of the transparent electrode in the visible light wavelength range is 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more. When it is a transparent electrode, it may be made of a general material for transparent electrodes, and a person skilled in the art can appropriately select it within a range advantageous for conversion efficiency. For example, conductive oxides, metal grids, ultrathin metal layers, metal nanowires, carbon-based transparent materials, polymers, etc. may be used. Conductive oxides are preferably used because they have high light transmittance. Furthermore, the electrode can be manufactured by appropriately combining general methods such as coating, vapor deposition, and annealing.

[0053] 1.5 Base 1 If necessary, the first and / or second electrodes may have an additional base outside them. The base is used to support the entire perovskite solar cell and to facilitate handling and assembly, etc.

[0054] The base may be an organic or inorganic flexible material such as polyamide (PI), polybutylene terephthalate (PET), polyamide (PA), polycarbonate (PC), or ultrathin glass, or it may be a rigid material such as a glass plate or metal plate.

[0055] When both the first and second electrodes have bases on their outsides, at least one of the bases has a visible light wavelength range of 50%, 60%, 70%, 80%, 90%, or 95% or more. The light-transmitting base is then positioned on one side of the transparent electrode.

[0056] Furthermore, the base may be omitted when the first electrode and / or the second electrode have sufficient capacity to support the perovskite solar cell.

[0057] 2 Method for manufacturing perovskite solar cells The method for manufacturing a perovskite solar cell according to the present invention is as follows: The process includes applying a perovskite precursor solution onto a layer supporting a perovskite layer (Step 1), directly applying a poor solvent containing the passivating agent onto the perovskite precursor solution layer (Step 2), and performing annealing (Step 3). Here, the application in Steps 1 and 2 can be carried out using common methods such as rotary coating, blade coating, roll coating, or spray coating, but rotary coating is preferred from the viewpoint of being able to control the thickness well.

[0058] This manufacturing method simplifies the passivation layer production steps and avoids the impact of multiple annealing processes on the perovskite structure. Furthermore, passivation can be achieved during the process of forming the perovskite structure.

[0059] Specifically, the method of the present invention reduces the number of annealing processes compared to the conventional technology, avoids multiple annealing of perovskites, saves time and costs, and improves manufacturing efficiency.

[0060] Furthermore, in the method of the present invention, a passivator is added when the perovskite phase is unstable, and the passivator can bond better with the perovskite at the grain boundaries and surface, further stabilizing the perovskite phase.

[0061] The passivating agent can not only be present on the surface of the perovskite layer but can also penetrate deep into the grain boundaries, thereby simultaneously passivating both the grain boundaries and the surface, achieving omnidirectional passivation. In this way, the recombination of electrons and holes at the grain boundaries and the surface can be more effectively prevented. Furthermore, even when the grain boundaries are small, the method of the present invention allows a passivating agent with a large molecular volume to penetrate deep into the grain boundaries. Moreover, since the passivating agent exists only in poor solvents, it does not affect the formation of the perovskite structure. This is difficult to achieve with conventional techniques.

[0062] 2.1 Perovskite precursor solution A perovskite precursor solution contains a perovskite precursor and a solvent. Specifically, the perovskite precursor is a substance containing A ions, B ions, and X ions. Examples of perovskite precursor solutions include mixtures of BX2 and AX in a solvent. Here, A may be selected from alkali metals such as cesium or nitrogen-containing small organic molecules such as methylamine and formamidine, B is Sn or Pb, and X is a halogen.

[0063] Regarding the solvent in the perovskite precursor solution, it is sufficient that it can dissolve BX2 and AX, is compatible with poor solvents, and can be removed by heating. A suitable solvent from those currently in common use may be selected. Those skilled in the art can produce the perovskite precursor solution by selecting any appropriate combination from the prior art.

[0064] When considering the molar ratio of BX2 to AX (BX2 / AX) from the perspective of being able to sufficiently form the structure of the perovskite layer, the ratio should be 1 or more, 1.01 or more, 1.02 or more, 1.03 or more, 1.04 or more, and 1.05 or more. When considering it from the perspective of cost saving, the ratio should be 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, and 1.1 or less.

[0065] In the perovskite precursor solution, the concentration of the perovskite precursor is used to adjust the thickness of the perovskite layer formed. Ideal concentrations are 0.2–5 mmol / mL, 0.3–4 mmol / mL, 0.4–3 mmol / mL, and 0.5–2 mmol / mL, based on the concentration of BX2. These concentrations are favorable for the formation of a desirable perovskite structure.

[0066] It should be explained that the tolerance factor for A ions must be between 0.8 and 1.2. If the ion volume is too large and the tolerance factor exceeds 1.2, it may cause lattice deformation or make it difficult to fill the BX octahedral structure, raising concerns that a perovskite structure cannot be formed. Even if the structure can be formed, the perovskite crystallization process is blocked, leading to a decrease in perovskite crystal quality, the formation of excessive grain boundaries, the occurrence of deep level defects, carrier trapping, and concerns that photoelectric conversion efficiency and stability will decrease.

[0067] When two or more A ions are present, the tolerance factors for each are preferably 0.8 to 1.2. This is because the presence of large molecules disrupts the crystal structure, as described above. Even when used as an additive, the large structure leads to poor crystal quality, making it difficult to achieve good stability.

[0068] 2.2 Solution containing a passivation agent In this method, the solution containing the passivation agent comprises a poor solvent and the passivation agent.

[0069] A poor solvent is a solvent used to transform a perovskite precursor into a perovskite structure. In the present invention, the poor solvent is a solvent with low solubility of the perovskite precursor and is selected from at least one of toluene, chlorobenzene, dichlorobenzene, ethyl acetate, ethyl ether, benzene, anhydrous ethanol, isopropanol, butanol, chloroform, methyl butyrate, anisole, xylene, and mesitylene. Preferably, the poor solvent is a mixed solvent formed by adding at least one second poor solvent selected from ethyl ether, benzene, anhydrous ethanol, isopropanol, butanol, chloroform, methyl butyrate, anisole, xylene, and mesitylene to at least one first poor solvent selected from toluene, chlorobenzene, dichlorobenzene, and ethyl acetate.

[0070] By adjusting the ratio of the first poor solvent to the second poor solvent in the poor solvent, the solubility of the precursor in the poor solvent can be controlled. This allows for control over the precipitation rate of the perovskite structure and the crystal size when the poor solvent comes into contact with the precursor in the precursor solution.

[0071] In a poor solvent, the ratio (by volume) of the first poor solvent to the second poor solvent is 100:0 to 100:50, preferably 100:0 to 100:10. When poor solvents are mixed in such a ratio for production, the precipitation rate of the perovskite structure and the crystal size can be advantageously controlled.

[0072] The poor solvent of the present invention contains the passivating agent of the present invention, and its description is omitted here. It should be explained that passivating agents from the prior art can also be used in the method for forming the passivated layer of the present invention. This refers to a passivating agent from the prior art.

[0073] In a poor solvent, the concentration of the passivating agent is 0.1 to 10 mmol / mL, and may also be 0.5 to 8 mmol / mL, 1 to 5 mmol / mL, or 2 to 3 mmol / mL. When within these ranges, the content of the passivating agent in the passivation layer can be easily controlled without affecting the precipitation of the perovskite structure.

[0074] The molar ratio (R) of the perovskite precursor in the perovskite precursor solution to the passivator in the poor solvent is 200 to 8000, and may be 800 to 1600 or 1000 to 1200. If the amount of passivator is too small relative to the perovskite precursor, the defects in the perovskite structure cannot be sufficiently passed through, and ideal hydrophobicity cannot be imparted. If the amount of passivator is too large, the passivation effect reaches saturation, the cost-effectiveness ratio decreases, and adverse effects such as interference with carrier transport, increased internal resistance, and ultimately battery failure may occur.

[0075] 2.3 annealing In this invention, a perovskite precursor solution and a poor solvent are applied, followed by an annealing treatment. During the annealing treatment, the solvent and poor solvent in the precursor solution volatilize, the precursor precipitates and forms a perovskite structure, creating a perovskite layer and a passivation layer. At the same time, the passivating agent passivates the grain boundaries and surface of the perovskite structure.

[0076] The conditions for the annealing process can be appropriately set according to the type of solvent used and the parameters of the annealing equipment, and there are no particular restrictions. However, from the perspective of obtaining a well-ordered perovskite structure, annealing may be performed at 80°C to 200°C for 10 minutes to 2 hours. For example, the annealing conditions in the examples described later may be adopted.

[0077] 3 Power generation equipment The power generation device of the present invention is a power generation device including the perovskite solar cell, which may be one or more. The power generation device further includes a control system and a transport system. The power generation device of the present invention adjusts the electrical energy generated from the solar cell to electrical energy suitable for power-consuming equipment via the control system and the transport system. It should be noted that "including" here refers to the case where the power generation device and the solar cell are electrically connected.

[0078] 4 power consumption equipment The power consumption device of the present invention is a power consumption device that includes the perovskite solar cell, which may be one or more. The power consumption device further includes a system that utilizes the electrical energy generated from the perovskite solar cell. Examples of such systems that utilize electrical energy include systems that convert electrical energy into kinetic energy, internal energy, light energy, or chemical energy. It should be noted that "includes" here refers to the case where the power consumption device and the solar cell are electrically connected.

[0079] Examples The following describes in detail embodiments of the technical invention of this application. The following embodiments are provided to more clearly illustrate the technical invention of this application and are merely illustrative; they do not limit the scope of protection of this application.

[0080] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art, and the terms used herein are used solely to describe specific embodiments and are not intended to limit this application. The terms “contains” and “has” and any variations thereof in the description of the specification, claims and drawings of this application are intended to cover the non-exclusive “contains.”

[0081] In the description of the embodiments of this application, terms such as "first," "second," etc., are used solely for the purpose of distinguishing different subjects and should not be understood as explicitly or implicitly indicating relative importance, or the number, specific order, or primary / secondary relationship of the technical features indicated. In the description of the embodiments of this application, "multiple" means two or more unless otherwise specified.

[0082] Where the “Examples” are referred to herein, it means that certain features, structures, or characteristics described in conjunction with the Examples may be included in at least one Example of this Application. The appearance of this phrase in each part of the Specification does not necessarily all refer to the same Example, nor do they represent mutually exclusive or alternative Examples. As those skilled in the art will understand both clearly and implicitly, the Examples described herein can be combined with other Examples.

[0083] In the description of the embodiments of this application, the term "and / or" merely describes the relationship between related objects and indicates that three relationships may exist. For example, A and / or B can represent three cases: A alone, a combination of A and B, or B alone. In this specification, the letter " / " generally indicates that the preceding and succeeding related objects are in an "or" relationship.

[0084] In the description of the embodiments of this application, the orientations or positional relationships indicated by technical terms such as "inside" and "outside" are based on the orientations or positional relationships shown in the drawings and are for the convenience or simplification of the description of the embodiments of this application. They do not indicate or imply that the mentioned devices or elements have a specific orientation or are constructed and operated in a specific orientation, and should not be understood as limiting the embodiments of this application.

[0085] Although only perovskite solar cells with a general structure are shown in the embodiments of this application, the present invention may also be used in perovskite solar cells with an inverted structure. [Examples]

[0086] Manufacturing of perovskite solar cells Example 1 [Manufacturing of electron transport layers] A 15% tin oxide solution and deionized water were mixed in a 1:3 ratio, stirred at room temperature for 1 hour, and 70 μL was taken and spatula-coated onto a conductive glass surface. The mixture was then heated at 150°C for 15 minutes.

[0087] [Fabrication of perovskite layers and passivation layers] Formamidine iodide and chloromethylamine as AX, and lead iodide as BX2 were added to a mixed solution of DMF and DMSO (DMF:DMSO=4:1) at a ratio of (BX2 / AX=1.05) to prepare a perovskite solution. The solution was magnetically stirred at room temperature for 1 hour, filtered, and prepared for use. The final concentration of the perovskite precursor in the solution was 1.5 mmol / mL of lead iodide. The passivation materials shown in Tables 1 and 2 below were dissolved in a poor solvent. UV light was irradiated onto conductive glass with the electron transport layer applied by rotation for 15 minutes. 60 μL of perovskite solution was added dropwise to the glass, and 600 μL of the poor solvent containing the dissolved passivation material was added. Annealing was performed at 150°C for 1 hour, thereby simultaneously forming a perovskite layer and a passivation layer. Finally, a perovskite layer with a thickness of 500 nm and a passivation layer with a thickness of 2 nm were formed. The ratio (molar ratio) of perovskite to passivation agent was 300.

[0088] [Manufacturing of hole transport layers] Li-TFSI, tBP, and FK209 were added to spiro, stirred for 1 hour, filtered, and prepared for use. 60 μL of spiro was dropped onto conductive glass with a perovskite layer and passivation layer formed on it, and the mixture was rotated to form a hole transport layer.

[0089] [Manufacturing of back electrode] On the hole transport layer formed by rotary coating, silver with a deposition thickness of 80 nm was deposited using a vacuum deposition apparatus by a general method to obtain a complete perovskite solar cell.

[0090] Examples 2-16 A perovskite solar cell was manufactured in the same manner as in Example 1, except that the formation conditions for the perovskite layer and passivation layer were replaced with those shown in Tables 1 and 2.

[0091] Comparative Examples 1-3 Perovskite solar cells were manufactured in the same manner as in Example 1, except that the passivating agents shown in Tables 1 and 2 were added to the perovskite precursor solution, and no passivating agent was added to the poor solvent.

[0092] Comparative Example 4 A perovskite solar cell was manufactured in the same manner as in Example 1, except that a passivating agent was not added.

[0093] [Table 1]

[0094] [Table 2]

[0095] Battery characteristics test (IV test) For each of the 20 solar cells obtained in the above-described examples and comparative examples, an IV test was performed at 25°C with a single irradiation intensity using ENLITECH's solar simulator. The average test results for the solar cells in each example and comparative example are shown in Table 3 below.

[0096] [Table 3]

[0097] Stability testing Twenty solar cells from each example and comparative example obtained using the above method were stored in a humidity-controlled glove box and subjected to a 30-day aging treatment under constant temperature of 25 degrees Celsius and constant humidity of 60% RH for stability testing. The average values ​​of the IV test results, efficiency retention rate, number of damaged cells, and damage rate for each example, comparative example, and reference example after the stability test are shown in Table 4 below.

[0098] [Table 4]

[0099] As can be seen from the results in Tables 3 and 4 above, perovskite solar cells using the passivating agent of the present invention have a more significant effect in improving device efficiency and stability compared to those that do not use the passivating agent of the present invention. Batteries that have not undergone passivation show a significant decrease in battery efficiency after being left for a certain period of time. When the cations are the same, using organic acids containing elements such as O, S, P, and N as acid ions results in a higher passivation effect. Furthermore, the battery damage rate of perovskite solar cells using the passivating agent of the present invention after being left for a certain period of time is significantly suppressed.

[0100] Furthermore, the following was also discovered: Perovskite solar cells obtained using the method for producing the passivation layer and perovskite layer of the present invention avoid the need for double heating and annealing of the perovskite compared to those not using the method of the present invention, resulting in higher device stability. Additionally, by adding the passivation material under wet film conditions and controlling the crystal structure, the passivation material can be better filled into the grain boundaries and surface, better protecting the perovskite and increasing its stability. [Industrial applicability]

[0101] This invention provides a perovskite solar cell with high energy conversion efficiency and excellent stability, as well as a method for manufacturing the solar cell. This has significant importance in addressing climate change and building an ecological civilization. [Explanation of symbols]

[0102] 1: Base, 2: First electrode, 3: Electron / Hole transportation Layer 4: Perovskite layer, 5: Passivation layer, 6: Hole / electron transportation Layer 7: Second electrode

Claims

1. Perovskite solar cells, The material comprises at least an electrode, an electron transport layer, a hole transport layer, a perovskite layer, a passivation layer, and an optional base layer, wherein the passivation layer contains a passivating agent, the passivating agent comprises an organic salt formed from an aza-condensed bicyclic compound and an acid, each condensed ring of the aza-condensed bicyclic compound is independently a five-membered or six-membered saturated ring, an unsaturated ring, or an aromatic ring, and each condensed ring of the aza-condensed bicyclic compound contains 1 to 5 nitrogen atoms. The fused ring is an unsubstituted ring, or a ring substituted with one or two substituents having 1 to 3 carbon atoms. The acid ion in the aforementioned organic salt is selected from one of the acid ions including O, P, N, F, I, Br, Cl, C, and H, and A perovskite solar cell characterized in that the acid ion is selected from an acid ion derived from one of the following: acetic acid, phosphoric acid, nitric acid, chloric acid, sulfonic acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, and hydroiodic acid.

2. The perovskite solar cell according to claim 1, characterized in that the aza-condensed bicyclic compound is selected from one of pteridine, 1,5,7-triazidobicyclo(4.4.0)deca-5-ene, quinazoline, quinoline, 1,5-diazabicyclo[4.3.0]-5-nonene, imidazo[1,2-a]pyrimidine, 5,6,7,8-tetrahydroindolidine, 1-methyl-2,3-dihydro-1H-pyrrolidine, and 2,4-dimethylquinoline.

3. The perovskite solar cell according to claim 1 or 2, characterized in that the ratio of the molar amount of perovskite in the perovskite layer to the molar amount of the passivating agent in the passivation layer is 100 to 800.

4. A power generation device characterized by including a perovskite solar cell according to any one of claims 1 to 3.

5. A power consumption device characterized by including a perovskite solar cell according to any one of claims 1 to 3.

6. A method for manufacturing a perovskite solar cell, The process includes the steps of coating a perovskite precursor solution onto a layer supporting a perovskite layer, directly coating a solution obtained by dissolving a passivating agent in a poor solvent, and then performing annealing to form a passivation layer. The poor solvent is a solvent in which the perovskite precursor has low solubility. The passivating agent comprises an organic salt formed from the aza-condensed bicyclic compound and an acid. Each condensed ring of the aza-condensed bicyclic compound is independently a five-membered or six-membered saturated ring, unsaturated ring, or aromatic ring, and each condensed ring of the aza-condensed bicyclic compound contains 1 to 5 nitrogen atoms. The fused ring is an unsubstituted ring, or a ring substituted with one or two substituents having 1 to 3 carbon atoms. The acid ion in the aforementioned organic salt is selected from one of the acid ions including O, P, N, F, I, Br, Cl, C, and H, and A method for manufacturing a perovskite solar cell, characterized in that the acid ion is selected from an acid ion derived from one of acetic acid, phosphoric acid, nitric acid, chloric acid, sulfonic acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, and hydroiodic acid.

7. The method for producing the aza-condensed bicyclic compound according to claim 6, characterized in that the aza-condensed bicyclic compound is selected from one of pteridine, 1,5,7-triazidobicyclo(4.4.0)deca-5-ene, quinazoline, quinoline, 1,5-diazabicyclo[4.3.0]-5-nonene, imidazo[1,2-a]pyrimidine, 5,6,7,8-tetrahydroindolidine, 1-methyl-2,3-dihydro-1H-pyrrolidine, and 2,4-dimethylquinoline.

8. The manufacturing method according to claim 6 or 7, characterized in that the poor solvent is selected from at least one of toluene, chlorobenzene, dichlorobenzene, ethyl acetate, ethyl ether, benzene, anhydrous ethanol, isopropanol, butanol, chloroform, methyl butyrate, anisole, xylene, and mesitylene.

9. The manufacturing method according to any one of claims 6 to 8, characterized in that, in the solution obtained by dissolving the passivating agent in the poor solvent, the concentration of the passivating agent is 0.1 to 10 mmol / mL.

10. The manufacturing method according to any one of claims 6 to 9, characterized in that the ratio of the molar amount of the perovskite precursor in the perovskite precursor solution to the molar amount of the passivator in the solution obtained by dissolving the passivator in the poor solvent is 200 to 8000.

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