Perovskite solar cell comprising carbon electrode infiltrated with charge transport material and manufacturing method therefor

Abstract

The present invention relates to a carbon-based perovskite solar cell and a manufacturing method therefor, wherein the perovskite solar cell exhibits improved performance by infiltrating a charge transport material into pores of a carbon electrode to form an effective perovskite-carbon electrode interface.

Description

Perovskite solar cell comprising a carbon electrode infiltrated with a charge transport material and a method for manufacturing the same

[0001] The present invention relates to a perovskite solar cell with improved performance by forming an effective perovskite-carbon electrode interface through the penetration of a charge transport material into the pores of the carbon electrode in a carbon electrode-based perovskite solar cell, and a method for manufacturing the same.

[0002]

[0003] Perovskite solar cells are solar cells that use a material with a perovskite structure as the light-absorbing layer. They can be manufactured using low-temperature solution processes with inexpensive materials, and are attracting attention as next-generation solar cells due to their very high light absorption rates even at thin thicknesses.

[0004] Typically, metals such as gold and silver are used for the top electrode of solar cells. These metal electrodes have the advantage of high conductivity and uniform application. However, metal electrodes have a high unit cost and involve significant manufacturing expenses. Additionally, they have the disadvantage of reduced photoelectric conversion efficiency due to rapid corrosion in high-humidity environments.

[0005] Meanwhile, carbon electrodes possess high conductivity, allowing them to be used as high-conductivity electrodes; furthermore, their hydrophobic properties enable effective moisture barrier operation. Additionally, they are lightweight and flexible, offering the advantage of being very easy to attach to solar cells.

[0006] However, the stacked structure of conventional perovskite solar cells faced difficulties in forming a dense interface with the charge transport layer due to the non-uniform interface and contact resistance of the carbon electrodes. This acted as a cause for the reduction in perovskite solar cell performance.

[0007] Accordingly, there is a need to develop technology for the effective interface formation of carbon electrodes in perovskite solar cells.

[0008]

[0009] The present invention provides a perovskite solar cell in which the interfacial contact between the carbon electrode and the perovskite layer is enhanced by infiltrating a charge transport material into the carbon electrode, and a method for manufacturing the same.

[0010]

[0011] A perovskite solar cell according to the present invention may comprise: a lower electrode stacked on a substrate; a first charge transport material stacked on the lower electrode; a perovskite layer stacked on the first charge transport material; and a carbon electrode stacked on the perovskite layer and infiltrated with a second charge transport material.

[0012] The carbon electrode may include one or more selected from the group comprising carbon nanotubes (CNT), graphite, carbon black, and polymeric binders.

[0013] The molecular weight of the second charge transport material may be 1,000 to 100,000 g / mol.

[0014] If the first charge transport material is an electron transport material, the second charge transport material is a hole transport material, and if the first charge transport material is a hole transport material, the second charge transport material may be an electron transport material.

[0015] The hole transport material may include one or more selected from the group comprising PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), P3HT (poly(3-hexylthiophene)), CuPc (copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine), and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate).

[0016] The above electron transport materials are titanium oxide, tin oxide, zinc oxide, PCBM (Phenyl-C61-Butyric Acid Methyl Ester), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)]) and Fullerene (C 60 It may include ).

[0017] A method for manufacturing a perovskite solar cell according to the present invention may include: S1) a step of stacking a lower electrode on a substrate; S2) a step of stacking a first charge transport material on the lower electrode; S3) a step of stacking a perovskite layer on the first charge transport material; S4) a step of stacking a carbon electrode on the perovskite layer; and S5) a step of infiltrating a second charge transport material into the carbon electrode.

[0018] Step S5) above may involve coating the carbon electrode with the second charge transport material dissolved in an organic solvent and heat treating it.

[0019] The above organic solvent may include one or more selected from the group comprising chloroform, ethyl acetate, diethyl ether, toluene, anisole, and butyl acetate.

[0020] The above heat treatment temperature may be 50 to 200 ℃.

[0021] The above heat treatment time may be 1 to 60 minutes.

[0022] The carbon electrode may include one or more selected from the group comprising carbon nanotubes (CNT), graphite, carbon black, and polymeric binders.

[0023] The molecular weight of the second charge transport material may be 1,000 to 100,000 g / mol.

[0024] If the first charge transport material is an electron transport material, the second charge transport material is a hole transport material, and if the first charge transport material is a hole transport material, the second charge transport material may be an electron transport material.

[0025] The hole transport material may include one or more selected from the group comprising PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), P3HT (poly(3-hexylthiophene)), CuPc (copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine), and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate).

[0026] The above electron transport materials are titanium oxide, tin oxide, zinc oxide, PCBM (Phenyl-C61-Butyric Acid Methyl Ester), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)]) and Fullerene (C 60 It may include one or more selected from a group including ).

[0027]

[0028] According to the present invention, a charge transport material can penetrate into the carbon electrode to fill the pores and penetrate into the perovskite layer to induce effective interface formation. In particular, by controlling the molecular weight of the charge transport material, a more effective interface between the perovskite and the carbon electrode can be formed. Accordingly, the conductivity of the electrode is improved due to the reduction of porosity in the carbon electrode, and the performance of the perovskite solar cell is enhanced by optimizing the interface with the charge transport material.

[0029] In addition, according to the present invention, a perovskite solar cell comprising a carbon electrode infiltrated with a charge transport material can be fabricated based on a solution process, making it suitable for large-area fabrication at low cost.

[0030]

[0031] FIG. 1 is a schematic diagram of a perovskite solar cell comprising a carbon electrode infiltrated with a charge transport material according to one embodiment of the present invention.

[0032] Figure 2 shows the current density-voltage measurement results of Example 1, Example 2 and Comparative Example 1 according to the present invention.

[0033] Figure 3 shows the current density-voltage measurement results of Example 1, Example 2 and Comparative Example 1 according to the present invention as a box plot.

[0034] Figure 4 shows the conductivity measurement results of Example 1, Example 2 and Comparative Example 1 according to the present invention.

[0035] Figure 5 shows the work functions of Example 1, Example 2 and Comparative Example 1 according to the present invention as a box plot.

[0036] Figure 6 shows Kelvin probe force microscope (KPFM) images of Example 1, Example 2 and Comparative Example 1 according to the present invention.

[0037] Figure 7 shows transmission electron microscope (TEM) images of Example 1, Example 2 and Comparative Example 1 according to the present invention.

[0038] FIG. 8 shows scanning electron microscope (SEM) images of Example 1, Example 2 and Comparative Example 1 according to the present invention.

[0039] Figure 9 shows the current density-voltage measurement results of Comparative Example 2 according to the PTAA concentration of the present invention.

[0040] Figure 10 shows the current density-voltage measurement results of Comparative Example 3 according to the PTAA concentration of the present invention.

[0041] Figure 11 shows the current density-voltage measurement results of Example 1 according to the PTAA concentration of the present invention.

[0042] Figure 12 shows the current density-voltage measurement results of Example 2 according to the PTAA concentration of the present invention.

[0043] Figure 13 shows the current density-voltage measurement results of Example 1 according to the heat treatment temperature of the present invention.

[0044] FIG. 14 shows the current density-voltage measurement results of Example 3 and Comparative Example 4 according to the present invention.

[0045]

[0046] The embodiments described in this specification may be modified in various different forms, and the technology according to one embodiment is not limited to the embodiments described below. Furthermore, the embodiments of one embodiment are provided to more fully explain the present disclosure to those with average knowledge in the relevant technical field. Unless otherwise defined, technical and scientific terms used herein have the meanings commonly understood by those with ordinary knowledge in the technical field to which this invention pertains, and descriptions of known functions and configurations that may unnecessarily obscure the essence of the present invention are omitted in the following description and accompanying drawings.

[0047] Additionally, the singular form used in this specification and the appended claims may be intended to include the plural form unless specifically indicated otherwise in the context.

[0048] Furthermore, in this specification and the appended claims, terms such as "first," "second," etc. are not used in a limiting sense but are used for the purpose of distinguishing one component from another.

[0049] Furthermore, in this specification and the appended claims, when a part such as a film (layer), region, or component is described as being located "on," "on top," "on the upper," "under," "on the lower," or "on the lower" of another part, this includes not only cases where a part is in contact with another part, but also cases where another part exists between the two parts.

[0050] Furthermore, terms such as "approximately" and "substantially" as used in this specification and the appended claims are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the said meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values ​​are mentioned to aid in understanding this specification and the appended claims.

[0051] Additionally, numeric ranges used in this specification include lower and upper limits and all values ​​within the range, increments logically derived from the shape and width of the defined range, all of which are limited values, and all possible combinations of upper and lower limits of numeric ranges limited in different forms.

[0052] Furthermore, in this specification and the appended claims, terms such as "comprising" or "having" mean that the features or components described in the specification exist, and unless specifically limited, do not preclude the possibility that one or more other features or components may be added.

[0053] Hereinafter, a perovskite solar cell comprising a carbon electrode infiltrated with a charge transport material according to the present invention and a method for manufacturing the same will be described in detail with reference to the attached drawings.

[0054]

[0055] FIG. 1 is a schematic diagram of a perovskite solar cell comprising a carbon electrode infiltrated with a charge transport material according to one embodiment of the present invention.

[0056] A perovskite solar cell according to the present invention may comprise: a lower electrode stacked on a substrate; a first charge transport material stacked on the lower electrode; a perovskite layer stacked on the first charge transport material; and a carbon electrode stacked on the perovskite layer and infiltrated with a second charge transport material.

[0057] In one embodiment, the carbon electrode infiltrated with the second charge transport material may be formed by the second charge transport material in a solution state seeping into the pores of the carbon electrode. Accordingly, as the second charge transport material seeping into the pores of the carbon electrode solidifies, it fills the pores, thereby reducing the pore size of the carbon electrode, and the second charge transport material penetrates through the pores of the carbon electrode to the perovskite layer, enabling more effective interface formation.

[0058] As one embodiment, the substrate is not particularly limited as long as it is one commonly used in the art. For example, it may comprise one or more selected from glass, plastic, metal, or composites thereof. Preferably, it may be a glass substrate, but is not limited thereto.

[0059] As an example, a lower electrode may be laminated on the substrate. The lower electrode is not particularly limited as long as it is one commonly used in the art. For example, as a transparent conductive electrode, it may include one or more selected from the group comprising indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO), and carbon (C). Preferably, it may be fluorine-doped tin oxide (FTO), but is not limited thereto.

[0060] In one embodiment, the thickness of the lower electrode may be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, 1000 nm, or within a range between any two of the values ​​listed herein. For example, it may be 10 to 1000 nm, 100 to 1000 nm, or 500 to 1000 nm, but is not limited thereto.

[0061] As an example, a first charge transport material may be laminated on the lower electrode. Typically, the charge transport layer has the function of transporting charge, and depending on the type of charge transported, it may be an electron transport layer (ETL) or a hole transport layer (HTL).

[0062] Perovskite solar cells can be manufactured into structures such as NIP and PIN depending on the arrangement of the electron transport layer (ETL), perovskite layer, and hole transport layer (HTL). The NIP structure is stacked in the order of electron transport layer, perovskite layer, and hole transport layer, while the PIN structure is stacked in the order of hole transport layer, perovskite layer, and electron transport layer. Although the NIP structure is generally widely used and offers the advantage of high efficiency, it has a critical disadvantage in that it requires a high-temperature heat treatment process because it primarily uses metal oxides for the electron transport layer, making it difficult to apply to large-area, flexible printed electronics processes. On the other hand, while the PIN structure exhibits lower efficiency than the NIP structure, it can be fabricated entirely using low-temperature solution processes, making it applicable to large-area, flexible printed electronics processes and suitable for mass production methods for future commercialization.

[0063] In one embodiment, in a perovskite solar cell of an NIP structure, the first charge transport material may be an electron transport material. The electron transport material is not particularly limited as long as it is commonly used in the art. For example, titanium oxide, tin oxide, zinc oxide, PCBM (Phenyl-C61-Butyric Acid Methyl Ester), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)]), and Fullerene (C 60 It may include one or more selected from the group including ). Preferably, it may be PCBM or titanium oxide (TiO2), but is not limited thereto.

[0064] As another embodiment, in a PIN-structured perovskite solar cell, the first charge transport material may be a hole transport material. The hole transport material is not particularly limited as long as it is commonly used in the art. For example, it may include one or more selected from the group comprising PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), P3HT (poly(3-hexylthiophene)), CuPc (copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine), and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate). Preferably, it may be PTAA, but is not limited thereto.

[0065] In one embodiment, the thickness of the stacked first charge transport material may be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, or within a range between any two of the values ​​described herein. For example, it may be 10 to 500 nm, 15 to 400 nm, or 20 to 300 nm, but is not limited thereto.

[0066] As one embodiment, a perovskite layer may be laminated on the first charge transport material. The perovskite layer may include a perovskite material represented by the following chemical formula 1.

[0067] [Chemical Formula 1]

[0068] ABX3

[0069] The above A may include one or more selected from the group including formamidinium (FA), methylammonium (MA), phenethylammonium (PEA), Cs, and Rb. Additionally, the above B may include one or more selected from the group including Pb, Sn, Ge, and Sb, and the above X may include one or more selected from the group including Cl, Br, and I.

[0070] As an example, the perovskite material represented by Formula 1 is not particularly limited as long as it is commonly used in the art. For example, it may include one or more selected from the group comprising FAPbBr3, FAPbI3, MAPbBr3, MAPbI3, CsPbBr3, CsPbI3, FAMAPbBr3, FAMAPbI3, and CsFAPb(I,Br)3. Preferably, it may be FAPbI3, MAPbBr3, or a mixture thereof, but is not limited thereto.

[0071] In one embodiment, the thickness of the perovskite layer may be 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, 1000 nm, or within a range between any two of the values ​​listed herein. For example, it may be 300 to 1000 nm, 400 to 800 nm, or 500 to 700 nm, but is not limited thereto.

[0072] In one embodiment, the perovskite layer may have many defects on its surface. The surface of the perovskite layer can be polished physically or chemically to create a smooth surface with reduced roughness. Physical polishing is a method of polishing by applying physical force to the surface of a material using an abrasive, while chemical polishing is a method of selectively removing surface material using chemicals. Preferably, the surface of the perovskite layer may be polished physically, but is not limited thereto.

[0073] In one embodiment, a polishing material larger than the substrate is fixed and brought into contact with the perovskite layer, and the surface of the perovskite layer can be physically polished by applying pressure and repeatedly pushing in one direction.

[0074] As an example, the polishing material is not particularly limited as long as it is commonly used in the industry. For example, it may be a polishing cloth having a particle size of 0.02 to 10 μm, preferably Chemomet (1 to 0.02 μm), MicroCloth (5 to 0.02 μm), or VelTex (9 to 1 μm), but is not limited thereto.

[0075] As one embodiment, the roughness (R) of the perovskite layer RMS ) can be measured, for example, using an atomic force microscope. The above R RMS Root-mean-square roughness is one of the indicators used to measure surface irregularity or roughness. In particular, it is useful for measuring roughness on non-uniform surfaces.

[0076] As one embodiment, the R RMS represents the square root of the mean of the squares of the measurements of curvature formed on the surface of the perovskite layer, and is calculated using the formula as in Equation 1 below.

[0077] [Equation 1]

[0078]

[0079] In the above Equation 1, N is the number of height data, and h i is the respective height value. R RMS The larger the value, the rougher the surface appears.

[0080] As one embodiment, the roughness (R) of the perovskite layer RMS) may be within the range of 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, 30 nm, 31 nm, 32 nm, 33 nm, 34 nm, 35 nm, 36 nm, 37 nm, 38 nm, 39 nm, 40 nm, 41 nm, 42 nm, 43 nm, 44 nm, 45 nm, 46 nm, 47 nm, 48 nm, 49 nm, 50 nm, 51 nm, 52 nm, 53 nm, 54 nm, 55 nm, or any two values ​​listed herein. There are. For example, it may be 10 to 55 nm, 30 to 50 nm, or 35 to 45 nm, but is not limited thereto.

[0081] As one embodiment, the thickness of the perovskite layer according to polishing may satisfy the following Equation 2.

[0082] [Equation 2]

[0083] 20 nm ≤ t0 - t1 ≤ 80 nm

[0084] In Equation 2 above, t0 is the thickness of the perovskite layer before polishing, and t1 is the thickness of the perovskite layer after polishing.

[0085] In one embodiment, the surface of the perovskite layer is smoothed through polishing, and due to the reduced surface roughness, an effective perovskite-carbon electrode interface is formed with the hole transport material, thereby improving the performance and stability of the perovskite solar cell.

[0086] In addition, as one embodiment, the perovskite layer may be surface-treated to improve the performance of the perovskite solar cell. For example, the surface treatment may be performed using a solution comprising one or more selected from 4MeO-PEAI (4-methoxy-phenethylammonium iodide), MABr (Methylammonium bromide), MACl (Methylammonium Chloride), Meo-4PACz ((4-(3,6-Dimethoxy-9H-carbazol-9-yl)butyl)phosphonic acid) and BCP (Bathocuproine). Preferably, it may be MeO-PEAI, but is not limited thereto.

[0087] As one embodiment, a carbon electrode may be laminated on the perovskite layer. The carbon electrode is not particularly limited as long as it is one commonly used in the art. For example, it may include one or more selected from the group comprising carbon nanotubes (CNT), graphite, carbon black, and polymeric binders. Preferably, it may be a carbon paste in the form of a slurry containing carbon nanotubes or a carbon nanotube film (CNT film), but is not limited thereto.

[0088] In one embodiment, the thickness of the carbon electrode may be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or within a range between any two of the values ​​listed herein. For example, in the case of carbon paste, it may be 1 to 100 μm, 5 to 70 μm, or 10 to 50 μm, and in the case of carbon nanotube thin film, it may be 0.1 to 50 μm, 0.1 to 10 μm, or 0.1 to 5 μm, but is not limited thereto.

[0089] In one embodiment, the carbon electrode has porosity, and a second charge transport material can be infiltrated to fill the porosity and form an effective perovskite-carbon electrode interface. Accordingly, the performance of the perovskite solar cell can be improved due to interface optimization.

[0090] In one embodiment, in a perovskite solar cell with an NIP structure, the second charge transport material may be a hole transport material, and in a perovskite solar cell with a PIN structure, the second charge transport material may be an electron transport material. The hole transport material or the electron transport material may include all the details described above regarding the first charge transport material.

[0091] In one embodiment, the second charge transport material may be a low-molecular-weight substance rather than a high-molecular-weight substance that can effectively penetrate into the pores of the carbon electrode, but is not particularly limited as long as the effects of the present invention are achieved.

[0092] In one embodiment, the molecular weight of the second charge transport material may be 1,000 g / mol, 2,000 g / mol, 3,000 g / mol, 4,000 g / mol, 5,000 g / mol, 6,000 g / mol, 7,000 g / mol, 8,000 g / mol, 9,000 g / mol, 10,000 g / mol, 20,000 g / mol, 30,000 g / mol, 40,000 g / mol, 50,000 g / mol, 60,000 g / mol, 70,000 g / mol, 80,000 g / mol, 90,000 g / mol, 100,000 g / mol, or within a range between any two of the values ​​listed herein. For example, in the case of low molecular weight, it may be 1,000 to 10,000 g / mol, 2,000 to 8,000 g / mol, or 3,000 to 6,000 g / mol, and in the case of high molecular weight, it may be 10,000 to 100,000 g / mol, 50,000 to 100,000 g / mol, or 70,000 to 100,000 g / mol, but is not limited thereto.

[0093] A method for manufacturing a perovskite solar cell according to the present invention may include: S1) a step of stacking a lower electrode on a substrate; S2) a step of stacking a first charge transport material on the lower electrode; S3) a step of stacking a perovskite layer on the first charge transport material; S4) a step of stacking a carbon electrode on the perovskite layer; and S5) a step of infiltrating a second charge transport material into the carbon electrode.

[0094] The above step S1) is a step of stacking a lower electrode on a substrate.

[0095] As one embodiment, the substrate is not particularly limited as long as it is one commonly used in the art. For example, it may comprise one or more selected from glass, plastic, metal, or composites thereof. Preferably, it may be a glass substrate, but is not limited thereto.

[0096] As an example, the lower electrode is not particularly limited as long as it is one commonly used in the art. For example, as a transparent conductive electrode, it may include one or more selected from the group comprising indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO), and carbon (C). Preferably, it may be fluorine-doped tin oxide (FTO), but is not limited thereto.

[0097] As an example, the deposition of the lower electrode in step S1) is not particularly limited as long as it is a method commonly used in the art. For example, it may be performed using one or more methods selected from sputtering, physical vapor deposition (PVD), chemical vapor deposition (CVD), etc. Preferably, it may be sputtering, but is not limited thereto.

[0098] In one embodiment, the thickness of the lower electrode may be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, 1000 nm, or within a range between any two of the values ​​listed herein. For example, it may be 10 to 1000 nm, 100 to 1000 nm, or 500 to 1000 nm, but is not limited thereto.

[0099] The above step S2) is a step of stacking a first charge transport material on the lower electrode.

[0100] In one embodiment, depending on the structure of the perovskite solar cell, the first charge transport material may be an electron transporting material or a hole transporting material. In a perovskite solar cell with an NIP structure, the first charge transport material may be an electron transporting material, and in a perovskite solar cell with a PIN structure, the first charge transport material may be a hole transporting material.

[0101] As an example, the electron transport material is not particularly limited as long as it is commonly used in the art. For example, titanium oxide, tin oxide, zinc oxide, PCBM (Phenyl-C61-Butyric Acid Methyl Ester), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)]), and Fullerene (C 60 It may include one or more selected from the group including ). Preferably, it may be PCBM or titanium oxide (TiO2), but is not limited thereto.

[0102] As an example, the hole transport material is not particularly limited as long as it is commonly used in the art. For example, it may include one or more selected from the group comprising PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), P3HT (poly(3-hexylthiophene)), CuPc (copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine), and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate). Preferably, it may be PTAA, but is not limited thereto.

[0103] As an example, the deposition of the first charge transport material in step S2) is not particularly limited as long as it is a method commonly used in the art. For example, it may be performed using one or more methods selected from spin coating, spray coating, dip coating, blade coating, etc. Preferably, it may be spin coating, but is not limited thereto.

[0104] In one embodiment, the thickness of the stacked first charge transport material may be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, or within a range between any two of the values ​​described herein. For example, it may be 10 to 500 nm, 15 to 400 nm, or 20 to 300 nm, but is not limited thereto.

[0105] Step S3) above is a step of depositing a perovskite layer on the first charge transport material.

[0106] As one embodiment, the perovskite layer may include a perovskite material represented by the following chemical formula 1.

[0107] [Chemical Formula 1]

[0108] ABX3

[0109] The above A may include one or more selected from the group including formamidinium (FA), methylammonium (MA), phenethylammonium (PEA), Cs, and Rb. Additionally, the above B may include one or more selected from the group including Pb, Sn, Ge, and Sb, and the above X may include one or more selected from the group including Cl, Br, and I.

[0110] As an example, the perovskite material represented by Formula 1 is not particularly limited as long as it is commonly used in the art. For example, it may include one or more selected from the group comprising FAPbBr3, FAPbI3, MAPbBr3, MAPbI3, CsPbBr3, CsPbI3, FAMAPbBr3, FAMAPbI3, and CsFAPb(I,Br)3. Preferably, it may be FAPbI3, MAPbBr3, or a mixture thereof, but is not limited thereto.

[0111] As an example, the deposition of the perovskite layer in step S3) is not particularly limited as long as it is a method commonly used in the art. For example, it may be performed using a printing process using equipment such as a doctor blade, inkjet, or slot die; or one or more methods selected from spin coating, sputtering, physical vapor deposition (PVD), chemical vapor deposition (CVD), etc. Preferably, it may be a printing process or physical vapor deposition, but is not limited thereto.

[0112] In one embodiment, the thickness of the perovskite layer may be 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, 1000 nm, or within a range between any two of the values ​​listed herein. For example, it may be 300 to 1000 nm, 400 to 800 nm, or 500 to 700 nm, but is not limited thereto.

[0113] In one embodiment, the perovskite layer may have many defects on its surface. The surface of the perovskite layer can be polished physically or chemically to create a smooth surface with reduced roughness. Preferably, the surface of the perovskite layer may be polished physically, but is not limited thereto.

[0114] In one embodiment, a polishing material larger than the substrate is fixed and brought into contact with the perovskite layer, and the surface of the perovskite layer can be physically polished by applying pressure and repeatedly pushing in one direction.

[0115] As an example, the polishing material is not particularly limited as long as it is commonly used in the industry. For example, it may be a polishing cloth having a particle size of 0.02 to 10 μm, preferably Chemomet (1 to 0.02 μm), MicroCloth (5 to 0.02 μm), or VelTex (9 to 1 μm), but is not limited thereto.

[0116] As one embodiment, the roughness (R) of the perovskite layer RMS) may be within the range of 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, 30 nm, 31 nm, 32 nm, 33 nm, 34 nm, 35 nm, 36 nm, 37 nm, 38 nm, 39 nm, 40 nm, 41 nm, 42 nm, 43 nm, 44 nm, 45 nm, 46 nm, 47 nm, 48 nm, 49 nm, 50 nm, 51 nm, 52 nm, 53 nm, 54 nm, 55 nm, or any two values ​​listed herein. There are. For example, it may be 10 to 55 nm, 30 to 50 nm, or 35 to 45 nm, but is not limited thereto.

[0117] As one embodiment, the thickness of the perovskite layer according to polishing may satisfy the following Equation 2.

[0118] [Equation 2]

[0119] 20 nm ≤ t0 - t1 ≤ 80 nm

[0120] In Equation 2 above, t0 is the thickness of the perovskite layer before polishing, and t1 is the thickness of the perovskite layer after polishing.

[0121] In one embodiment, the surface of the perovskite layer is smoothed through polishing, and due to the reduced surface roughness, an effective perovskite-carbon electrode interface is formed with the hole transport material, thereby improving the performance and stability of the perovskite solar cell.

[0122] In addition, as one embodiment, the perovskite layer may be surface-treated to improve the performance of the perovskite solar cell. For example, the surface treatment may be performed using a solution comprising one or more selected from 4MeO-PEAI (4-methoxy-phenethylammonium iodide), MABr (Methylammonium bromide), MACl (Methylammonium Chloride), Meo-4PACz ((4-(3,6-Dimethoxy-9H-carbazol-9-yl)butyl)phosphonic acid) and BCP (Bathocuproine). Preferably, it may be MeO-PEAI, but is not limited thereto.

[0123] Step S4) above is the step of depositing a carbon electrode on the perovskite layer.

[0124] As an example, the carbon electrode is not particularly limited as long as it is commonly used in the art. For example, it may include one or more selected from the group comprising carbon nanotubes (CNT), graphite, carbon black, and polymeric binders. Preferably, it may be a carbon paste in the form of a slurry containing carbon nanotubes or a carbon nanotube film (CNT film), but is not limited thereto.

[0125] As an example, the deposition of carbon electrodes in step S4) is not particularly limited as long as it is a method commonly used in the art. For example, in the case of carbon paste, it can be performed using one or more methods selected from spin coating, spray coating, dip coating, blade coating, etc., and in the case of carbon nanotube thin films, it can be attached to the perovskite layer using a two-roller laminator in accordance with a 4-electrode mask, but is not limited thereto.

[0126] In one embodiment, the thickness of the carbon electrode may be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or within a range between any two of the values ​​listed herein. For example, in the case of carbon paste, it may be 1 to 100 μm, 5 to 70 μm, or 10 to 50 μm, and in the case of carbon nanotube thin film, it may be 0.1 to 50 μm, 0.1 to 10 μm, or 0.1 to 5 μm, but is not limited thereto.

[0127] Step S5) above is a step of infiltrating a second charge transport material into the carbon electrode. The carbon electrode stacked on the perovskite layer has porosity, and by infiltrating the charge transport material into the carbon electrode, the porosity is filled, and an effective perovskite-carbon electrode interface can be formed. Accordingly, the performance of the perovskite solar cell can be improved due to interface optimization.

[0128] In one embodiment, the second charge transport material in step S5) may be an electron transporting material or a hole transporting material depending on the structure of the perovskite solar cell. In a perovskite solar cell with an NIP structure, the second charge transport material may be a hole transporting material, and in a perovskite solar cell with a PIN structure, the second charge transport material may be an electron transporting material. The hole transporting material or electron transporting material may include all the details described above regarding the first charge transport material.

[0129] In one embodiment, the second charge transport material may be a low-molecular-weight substance rather than a high-molecular-weight substance that can effectively penetrate into the pores of the carbon electrode, but is not particularly limited as long as the effects of the present invention are achieved.

[0130] In one embodiment, the molecular weight of the second charge transport material may be 1,000 g / mol, 2,000 g / mol, 3,000 g / mol, 4,000 g / mol, 5,000 g / mol, 6,000 g / mol, 7,000 g / mol, 8,000 g / mol, 9,000 g / mol, 10,000 g / mol, 20,000 g / mol, 30,000 g / mol, 40,000 g / mol, 50,000 g / mol, 60,000 g / mol, 70,000 g / mol, 80,000 g / mol, 90,000 g / mol, 100,000 g / mol, or within a range between any two of the values ​​listed herein. For example, in the case of low molecular weight, it may be 1,000 to 10,000 g / mol, 2,000 to 8,000 g / mol, or 3,000 to 6,000 g / mol, and in the case of high molecular weight, it may be 10,000 to 100,000 g / mol, 50,000 to 100,000 g / mol, or 70,000 to 100,000 g / mol, but is not limited thereto.

[0131] As one embodiment, the penetration of the second charge transport material in step S5) is not particularly limited as long as it is a method commonly used in the art. For example, it may be performed using one or more methods selected from spin coating, spray coating, dip coating, blade coating, etc. Preferably, it may be spin coating, but is not limited thereto.

[0132] As one embodiment, the second charge transport material dissolved in an organic solvent can be coated onto the carbon electrode and heat-treated to penetrate into the carbon electrode.

[0133] In one embodiment, the organic solvent may comprise one or more selected from the group comprising chloroform, ethyl acetate, diethyl ether, toluene, anisole, and butyl acetate. Preferably, it may be toluene, but is not limited thereto.

[0134] As an example, the heat treatment conditions are not particularly limited as long as they are those commonly used in the art. The heat treatment temperature may be 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, 200 ℃, or within a range between any two of the values ​​listed herein. For example, it may be 50 to 200 ℃, 60 to 180 ℃, or 70 to 150 ℃, but is not limited thereto. In addition, the heat treatment time may be 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, or within a range between any two of the values ​​listed herein. For example, it may be 1 to 60 minutes, 1 to 30 minutes, or 1 to 10 minutes, but is not limited thereto.

[0135] According to the present invention, a charge transport material can penetrate into the carbon electrode to fill the pores and penetrate into the perovskite layer to induce effective interface formation. In particular, by controlling the molecular weight of the charge transport material, a more effective interface between the perovskite and the carbon electrode can be formed. Accordingly, the conductivity of the electrode is improved due to the reduction of porosity in the carbon electrode, and the performance of the perovskite solar cell is enhanced by optimizing the interface with the charge transport material.

[0136] In addition, according to the present invention, a perovskite solar cell comprising a carbon electrode infiltrated with a charge transport material can be fabricated based on a solution process, making it suitable for large-area fabrication at low cost.

[0137]

[0138] Examples and experimental examples are described below with specific examples. However, the examples and experimental examples described below are merely illustrative of some aspects, and the technology described in this specification is not limited thereto. Furthermore, for the same example, each experimental example may be performed independently and there may be some differences in the measured values, but this is not specifically limited as long as the purpose of the present invention is achieved.

[0139]

[0140] <Example 1> NIP Structure

[0141] 2.5×2.5 cm 2 Fluorine-doped tin oxide (FTO) was deposited on a glass substrate by sputtering to form a lower electrode. Subsequently, the substrate was cleaned by ultrasonically treating it with detergent, acetone, and ethanol for 10 minutes, and then heat-treated in an argon plasma cleaner at 100°C for 10 minutes.

[0142] A solution of 20 mM Titanium diisopropoxide bis(acetylacetonate) and ethanol mixed in a volume ratio of 1:10 was coated onto the bottom electrode by spray pyrolysis at 450 °C. Subsequently, a Mesoporous TiO2 slurry was diluted in a solvent of 2-methoxyethanol and Terpineol mixed in a volume ratio of 3.5:1, spin-coated at 500 rpm for 50 seconds, and heat-treated at 500 °C for 1 hour to form a first charge transport material (electron transport layer).

[0143] FAPbI 3800 mg, MAPbBr 330 mg, and MACl 30 mg were dissolved in a solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) mixed in a volume ratio of 8:1 and spin-coated onto the first charge transport material at 1000 rpm for 8 seconds and at 5000 rpm for 15 seconds. After 12 seconds at 5000 rpm, 1 mL of diethyl ether was dropped, and the material was heat-treated at 150 °C for 10 minutes to form a dark brown perovskite layer. Additionally, a solution of 3.63 mg of 4MeO-PEAI dissolved in 1 mL of isopropyl alcohol was spin-coated onto the perovskite layer at 5000 rpm for 30 seconds and heat-treated at 100 °C for 1 minute to perform surface treatment.

[0144] A carbon nanotube aerogel was prepared by injecting methane as a carbon source, ferrocene as a catalyst, and thiophene as a co-catalyst into a vertical reactor heated to 1,200 °C along with a carrier gas mixture of hydrogen and argon in a 3:1 ratio. The ratio of methane to ferrocene was set to 200:1, the ratio of methane to thiophene to 60:1, and the ratio of the carrier gas to methane to 15:1. Subsequently, a carbon nanotube thin film was prepared by slowly winding the carbon nanotube aerogel onto a stainless steel winder at a speed of 3–5 m / min. The carbon nanotube thin film was placed on a perovskite layer, cut according to a 4-electrode mask, and then attached to the perovskite layer using a two-roller laminator to form a carbon electrode.

[0145] A perovskite solar cell was fabricated by spin-coating 60 µl of a solution containing 10 mg of low molecular weight PTAA (Mw: 3,000~6,000 g / mol), a hole transport material, dissolved in 1 mL of toluene as a second charge transport material, onto a carbon electrode at 3000 rpm for 30 seconds to allow sufficient penetration, and then heat-treating at 120 ℃.

[0146]

[0147] <Example 2> NIP Structure

[0148] A perovskite solar cell was prepared by carrying out the same procedure as in Example 1 above, except that high molecular weight PTAA (Mw: 90,000 g / mol) was used instead of low molecular weight PTAA.

[0149]

[0150] <Example 3> PIN structure

[0151] 2.5×2.5 cm 2 Fluorine-doped tin oxide (FTO) was deposited on a glass substrate by sputtering to form a lower electrode. Subsequently, the substrate was cleaned by ultrasonically treating it with detergent, acetone, and ethanol for 10 minutes, and then heat-treated in an argon plasma cleaner at 100°C for 10 minutes.

[0152] PTAA (Mw: 6,000~18,000 g / mol) was diluted in toluene to 2 mg / mL, spin-coated onto the lower electrode at 4000 rpm, and heat-treated at 80 ℃ for 5 minutes to form a first charge transport material (hole transport layer).

[0153] FAPbI 3800 mg, MAPbBr 330 mg, and MACl 30 mg were dissolved in a solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) mixed in a volume ratio of 8:1 and spin-coated onto the first charge transport material at 1000 rpm for 8 seconds and at 5000 rpm for 15 seconds. After 12 seconds at 5000 rpm, 1 mL of diethyl ether was dropped, and the material was heat-treated at 150 °C for 10 minutes to form a dark brown perovskite layer. Additionally, a solution of 3.63 mg of 4MeO-PEAI dissolved in 1 mL of isopropyl alcohol was spin-coated onto the perovskite layer at 5000 rpm for 30 seconds and heat-treated at 100 °C for 1 minute to perform surface treatment.

[0154] A carbon nanotube aerogel was prepared by injecting methane as a carbon source, ferrocene as a catalyst, and thiophene as a co-catalyst into a vertical reactor heated to 1,200 °C along with a carrier gas mixture of hydrogen and argon in a 3:1 ratio. The ratio of methane to ferrocene was set to 200:1, the ratio of methane to thiophene to 60:1, and the ratio of the carrier gas to methane to 15:1. Subsequently, a carbon nanotube thin film was prepared by slowly winding the carbon nanotube aerogel onto a stainless steel winder at a speed of 3–5 m / min. The carbon nanotube thin film was placed on a perovskite layer, cut according to a 4-electrode mask, and then attached to the perovskite layer using a two-roller laminator to form a carbon electrode.

[0155] A perovskite solar cell was fabricated by diluting PCBM, an electron transport material, in chlorobenzene to 20 mg / mL as a second charge transport material and spin-coating it onto a carbon electrode at 2000 rpm to allow sufficient penetration.

[0156]

[0157] <Comparative Example 1> NIP Structure

[0158] 2.5×2.5 cm 2 Fluorine-doped tin oxide (FTO) was deposited on a glass substrate by sputtering to form a bottom electrode. Afterward, it was cleaned by ultrasonically treating with detergent, acetone, and ethanol for 10 minutes, and then heat-treated in an oven at 100°C for 10 minutes.

[0159] A solution of 20 mM Titanium diisopropoxide bis(acetylacetonate) and ethanol mixed in a volume ratio of 1:10 was coated onto the bottom electrode by spray pyrolysis at 450 °C. Subsequently, a Mesoporous TiO2 slurry was diluted in a solvent of 2-methoxyethanol and Terpineol mixed in a volume ratio of 3.5:1, spin-coated at 500 rpm for 50 seconds, and heat-treated at 500 °C for 1 hour to form a first charge transport material (electron transport layer).

[0160] FAPbI 3800 mg, MAPbBr 330 mg, and MACl 30 mg were dissolved in a solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) mixed in a volume ratio of 8:1 and spin-coated onto the first charge transport material at 1000 rpm for 8 seconds and at 5000 rpm for 15 seconds. After 12 seconds at 5000 rpm, 1 mL of diethyl ether was dropped, and the material was heat-treated at 150 °C for 10 minutes to form a dark brown perovskite layer. Additionally, a solution of 3.63 mg of 4MeO-PEAI dissolved in 1 mL of isopropyl alcohol was spin-coated onto the perovskite layer at 5000 rpm for 30 seconds and heat-treated at 100 °C for 1 minute to perform surface treatment.

[0161] A carbon nanotube aerogel was prepared by injecting methane as a carbon source, ferrocene as a catalyst, and thiophene as a co-catalyst into a vertical reactor heated to 1,200 °C along with a carrier gas mixture of hydrogen and argon in a 3:1 ratio. The ratio of methane to ferrocene was set to 200:1, the ratio of methane to thiophene to 60:1, and the ratio of the carrier gas to methane to 15:1. Subsequently, a carbon nanotube thin film was prepared by slowly winding the carbon nanotube aerogel onto a stainless steel winder at a speed of 3–5 m / min. A perovskite solar cell was fabricated by placing the carbon nanotube thin film onto a perovskite layer, cutting it according to a 4-electrode mask, and then attaching it to the perovskite layer using a two-roller laminator to form a carbon electrode.

[0162]

[0163] <Comparative Example 2> NIP Structure

[0164] 2.5×2.5 cm 2 Fluorine-doped tin oxide (FTO) was deposited on a glass substrate by sputtering to form a bottom electrode. Afterward, it was cleaned by ultrasonically treating with detergent, acetone, and ethanol for 10 minutes, and then heat-treated in an oven at 100°C for 10 minutes.

[0165] A solution of 20 mM Titanium diisopropoxide bis(acetylacetonate) and ethanol mixed in a volume ratio of 1:10 was coated onto the bottom electrode by spray pyrolysis at 450 °C. Subsequently, a Mesoporous TiO2 slurry was diluted in a solvent of 2-methoxyethanol and Terpineol mixed in a volume ratio of 3.5:1, spin-coated at 500 rpm for 50 seconds, and heat-treated at 500 °C for 1 hour to form a first charge transport material (electron transport layer).

[0166] FAPbI 3800 mg, MAPbBr 330 mg, and MACl 30 mg were dissolved in a solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) mixed in a volume ratio of 8:1 and spin-coated onto the first charge transport material at 1000 rpm for 8 seconds and at 5000 rpm for 15 seconds. After 12 seconds at 5000 rpm, 1 mL of diethyl ether was dropped, and the material was heat-treated at 150 °C for 10 minutes to form a dark brown perovskite layer. Additionally, a solution of 3.63 mg of 4MeO-PEAI dissolved in 1 mL of isopropyl alcohol was spin-coated onto the perovskite layer at 5000 rpm for 30 seconds and heat-treated at 100 °C for 1 minute to perform surface treatment.

[0167] A 60 µl solution of 10 mg of low molecular weight PTAA (Mw: 3,000~6,000 g / mol) dissolved in 1 mL of toluene was spin-coated onto a perovskite layer at 3000 rpm and heat-treated at 120 ℃ for 5 minutes to form a second charge transport material (hole transport layer).

[0168] A carbon nanotube aerogel was prepared by injecting methane as a carbon source, ferrocene as a catalyst, and thiophene as a co-catalyst into a vertical reactor heated to 1,200 °C along with a carrier gas mixture of hydrogen and argon in a 3:1 ratio. The ratio of methane to ferrocene was set to 200:1, the ratio of methane to thiophene to 60:1, and the ratio of the carrier gas to methane to 15:1. Subsequently, a carbon nanotube thin film was prepared by slowly winding the carbon nanotube aerogel onto a stainless steel winder at a speed of 3–5 m / min. A perovskite solar cell was fabricated by placing the carbon nanotube thin film on a second charge transport material, cutting it according to a 4-electrode mask, and then attaching it to a perovskite layer using a two-roller laminator to form a carbon electrode.

[0169]

[0170] <Comparative Example 3> NIP Structure

[0171] A perovskite solar cell was manufactured by carrying out the same procedure as in Comparative Example 2 above, except that high molecular weight PTAA (Mw: 90,000 g / mol) was used instead of low molecular weight PTAA.

[0172]

[0173] <Comparative Example 4> PIN Structure

[0174] 2.5×2.5 cm 2 Fluorine-doped tin oxide (FTO) was deposited on a glass substrate by sputtering to form a lower electrode. Subsequently, the substrate was cleaned by ultrasonically treating it with detergent, acetone, and ethanol for 10 minutes, and then heat-treated in an argon plasma cleaner at 100°C for 10 minutes.

[0175] PTAA (Mw: 6,000~18,000 g / mol) was diluted in toluene to 2 mg / mL, spin-coated onto the lower electrode at 4000 rpm, and heat-treated at 80 ℃ for 5 minutes to form a first charge transport material (hole transport layer).

[0176] FAPbI 3800 mg, MAPbBr 330 mg, and MACl 30 mg were dissolved in a solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) mixed in a volume ratio of 8:1 and spin-coated onto the first charge transport material at 1000 rpm for 8 seconds and at 5000 rpm for 15 seconds. After 12 seconds at 5000 rpm, 1 mL of diethyl ether was dropped, and the material was heat-treated at 150 °C for 10 minutes to form a dark brown perovskite layer. Additionally, a solution of 3.63 mg of 4MeO-PEAI dissolved in 1 mL of isopropyl alcohol was spin-coated onto the perovskite layer at 5000 rpm for 30 seconds and heat-treated at 100 °C for 1 minute to perform surface treatment.

[0177] PCBM was diluted to 20 mg / mL in chlorobenzene and spin-coated onto a perovskite layer at 2000 rpm to form a second charge transport material (electron transport layer).

[0178] A carbon nanotube aerogel was prepared by injecting methane as a carbon source, ferrocene as a catalyst, and thiophene as a co-catalyst into a vertical reactor heated to 1,200 °C along with a carrier gas mixture of hydrogen and argon in a 3:1 ratio. The ratio of methane to ferrocene was set to 200:1, the ratio of methane to thiophene to 60:1, and the ratio of the carrier gas to methane to 15:1. Subsequently, a carbon nanotube thin film was prepared by slowly winding the carbon nanotube aerogel onto a stainless steel winder at a speed of 3–5 m / min. A perovskite solar cell was fabricated by placing the carbon nanotube thin film on a second charge transport material, cutting it according to a 4-electrode mask, attaching it to a perovskite layer using a two-roller laminator, and forming a carbon electrode.

[0179]

[0180] <Experimental Example 1>

[0181] Perovskite solar cells of Example 1 (w / L-PTAA), Example 2 (w / H-PTAA), and Comparative Example 1 (TWCNT) manufactured with an NIP structure were compared.

[0182]

[0183] V OC (V)J SC (mA cm -2 )FF (%) PCE (%) Example 1 1.05 2 2.9 28 1.2 19.53 Example 2 1.02 2 2.5 27 8.1 17.93 Comparative Example 10.98 2 3.2 06 7.9 15.50

[0184]

[0185] Table 1 and Figure 2 show the current density-voltage measurement results of Example 1, Example 2, and Comparative Example 1 according to the present invention, and Figure 3 shows the current density-voltage measurement results of Example 1, Example 2, and Comparative Example 1 according to the present invention as a box plot. The perovskite solar cells of Example 1 and Example 2 showed a significant improvement in photoelectric conversion efficiency compared to Comparative Example 1. This indicates that the performance of the perovskite solar cell was enhanced because the hole transport material penetrated into the carbon electrode, reducing voids while simultaneously forming an effective interface between the perovskite layer and the carbon electrode. Furthermore, Example 1 exhibited the highest photoelectric conversion efficiency by using low molecular weight PTAA as the hole transport material, which allowed for better penetration into the carbon electrode.

[0186] Figure 4 shows the conductivity measurement results of Example 1, Example 2, and Comparative Example 1 according to the present invention. As conductivity increases, charge transport becomes smoother, thereby improving the performance of the perovskite solar cell. The conductivity of Comparative Example 1 was measured to be 995 S / cm, the conductivity of Example 1 to be 1139 S / cm, and the conductivity of Example 2 to be 1073 S / cm. Therefore, it was confirmed that Examples 1 and 2 have higher conductivity compared to Comparative Example 1. This indicates that the conductivity of the electrode was improved due to the reduction of voids caused by the penetration of a hole transport material into the carbon electrode.

[0187] Figure 5 shows a box plot of the work functions of Example 1, Example 2, and Comparative Example 1 according to the present invention, and Figure 6 shows Kelvin probe force microscopy (KPFM) images of Example 1, Example 2, and Comparative Example 1 according to the present invention. Kelvin probe force microscopy is equipment used to characterize the surface potential and work function of metal materials. The work function of Comparative Example 1 was measured to be approximately 4.46 eVm, the work function of Example 1 to be 4.64 eV, and the work function of Example 2 to be 4.62 eV. Therefore, compared to Comparative Example 1, the work function of Example 1 and Example 2 increased as the hole transport material was infiltrated into the carbon electrode, which can contribute to the improvement of the overall performance of the perovskite solar cell by forming a stable interface and favorable energy levels.

[0188]

[0189] <Experimental Example 2>

[0190] Perovskite solar cells of Example 1 (w / L-PTAA), Example 2 (w / H-PTAA), and Comparative Example 1 (TWCNT) manufactured with an NIP structure were compared.

[0191] Figure 7 shows transmission electron microscope (TEM) images of Example 1, Example 2, and Comparative Example 1 according to the present invention. Compared to Comparative Example 1, Example 1 and Example 2 exhibited a planar shape, indicating that a PTAA interface was formed between the carbon electrode and the perovskite layer. In particular, in Example 1, low molecular weight PTAA, a hole transport material, effectively penetrated into the carbon electrode to form the most uniform interface.

[0192] Figure 8 shows scanning electron microscope (SEM) images of Example 1, Example 2, and Comparative Example 1 according to the present invention. The lower surface of the carbon electrode separated in the perovskite solar cell was measured by SEM. (A) and (D) are Comparative Example 1, (B) and (E) are Example 1, and (C) and (F) are Example 2. Compared to Comparative Example 1, it was confirmed that in Example 1 and Example 2, the hole transport material penetrated into the carbon electrode and the voids were reduced. In particular, it was confirmed that the hole transport material penetrated better in Example 1.

[0193]

[0194] <Experimental Example 3>

[0195] Perovskite solar cells according to the concentration of PTAA were compared in Example 1 (w / L-PTAA), Example 2 (w / H-PTAA), Comparative Example 2 (TWCNT), and Comparative Example 3 (TWCNT).

[0196]

[0197] Hole transporter concentration (mg / ml)V OC (V)J SC (mA cm -2 )FF (%) PCE (%) Comparative Example 2 Low molecular weight PTAA 10.97 23.14 2.09.43 0.93 21.72 4.14.95 0.93 21.72 0.64.21 0.93 18.11 6.72.8 Comparative Example 3 High molecular weight PTAA 10.99 22.34 9.01 0.83 1.02 22.03 5.37.95 0.97 22.22 5.35.11 0.90 8.31 3.51.0

[0198]

[0199] Table 2, Figure 9, and Figure 10 show the current density-voltage measurement results of Comparative Examples 2 and 3 according to the PTAA concentration of the present invention. In Comparative Examples 2 and 3, the photoelectric conversion efficiency decreased as the PTAA concentration increased.

[0200]

[0201] Hole transporter concentration (mg / ml)V OC (V)JSC (mA cm -2 )FF (%) PCE (%) Example 1 Low molecular weight PTAA 5 1.00 23.5 6 8.9 16.2 10 1.0 22 3.4 7 3.7 17.6 15 1.00 23.3 7 8.9 18.4 20 1.0 5 23.4 7 8.3 19.3 25 1.0 22 3.0 8 0.3 18.8 30 1.0 23.1 7 9.6 18.4 Example 2 High molecular weight PTAA 10.90 22 2.8 7 4.2 15.2 30 9 22 2.8 7 3.7 16.3 5 1.0 22 2.5 7 8.1 17.9 10 0.9 22 3.1 7 4.4 15.8 15 0.8 82 3.4 7 4.5 15.4 20 0.9 22 2.7 7 3.7 15.3

[0202]

[0203] Table 3, Figure 11, and Figure 12 show the current density-voltage measurement results of Example 1 and Example 2 according to the PTAA concentration of the present invention. In Example 1, no significant change in photoelectric conversion efficiency was observed according to the PTAA concentration. However, in Example 2, the photoelectric conversion efficiency decreased as the PTAA concentration increased. This was confirmed to be because, as the concentration of the polymer PTAA used as a hole transport material in Example 2 increased, the hole transport material penetrating into the carbon electrode decreased, leading to a decrease in performance.

[0204]

[0205] <Experimental Example 4>

[0206] In Example 1, perovskite solar cells were compared according to the heat treatment temperature of carbon electrodes infiltrated with low molecular weight PTAA.

[0207]

[0208] Heat treatment temperature (°C)V OC (V)J SC (mA cm -2 )FF (%)PCE (%) Heat Treatment X1.0223.777.918.8851.0223.179.618.71201.0522.881.219.51500.9922.774.716.7

[0209]

[0210] Table 4 and Figure 13 show the current density-voltage measurement results of Example 1 according to the heat treatment temperature of the present invention. V OC It was confirmed that heat treatment of a carbon electrode infiltrated with a hole transport material at 120°C is the best condition, as the highest photoelectric conversion efficiency (PCE) was obtained through the increase in FF.

[0211]

[0212] <Experimental Example 5>

[0213] Perovskite solar cells of Example 3 (penetration structure) and Comparative Example 4 (conventional structure), manufactured with a PIN structure, were compared.

[0214]

[0215] V OC (V)J SC (mA cm -2 )FF (%) PCE (%) Example 3 0.8 2 2 0.9 4 7.8 8.21 Comparative Example 4 0.6 2 1 7.4 3 6.1 3.88

[0216]

[0217] Table 5 and Figure 14 show the current density-voltage measurement results of Example 3 and Comparative Example 4 according to the present invention. Compared to Comparative Example 4, the photoelectric conversion efficiency of the perovskite solar cell of Example 3 was significantly improved to about 4.3%. This indicates that the performance of the perovskite solar cell was improved because the electron transport material penetrated into the carbon electrode, reducing the voids and simultaneously forming an effective interface between the perovskite layer and the carbon electrode.

[0218]

[0219] As described above, the present invention has been explained in this specification by specific details and limited embodiments, but this is provided only to aid in a more comprehensive understanding of the invention, and the invention is not limited to the above embodiments. A person skilled in the art to which the invention pertains can make various modifications and variations from this description. Accordingly, the concept described in this specification should not be limited to the described embodiments, and all things equivalent to or having equivalent variations to the claims set forth below, as well as the claims themselves, shall be considered to fall within the scope of the concept described in this specification.

Claims

1. Lower electrode stacked on a substrate; A first charge transport material stacked on the lower electrode above; A perovskite layer stacked on the first charge transport material; and A carbon electrode laminated on the above perovskite layer and infiltrated with a second charge transport material; A perovskite solar cell comprising 2. In Paragraph 1, The above carbon electrode comprises one or more selected from the group including carbon nanotubes (CNT), graphite, carbon black, and polymeric binders, in a perovskite solar cell.

3. In Paragraph 1, A perovskite solar cell in which the molecular weight of the second charge transport material is 1,000 to 100,000 g / mol.

4. In Paragraph 1, A perovskite solar cell in which if the first charge transport material is an electron transport material, the second charge transport material is a hole transport material, and if the first charge transport material is a hole transport material, the second charge transport material is an electron transport material.

5. In Paragraph 4, A perovskite solar cell comprising one or more hole transport materials selected from the group including PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), P3HT (poly(3-hexylthiophene)), CuPc (copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine), and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate).

6. In Paragraph 4, The above electron transport materials are titanium oxide, tin oxide, zinc oxide, PCBM (Phenyl-C61-Butyric Acid Methyl Ester), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)]) and Fullerene (C 60 A perovskite solar cell comprising one or more selected from the group including ). 7.S1) Step of stacking a lower electrode on a substrate; S2) A step of stacking a first charge transport material on the lower electrode; S3) A step of depositing a perovskite layer on the first charge transport material; S4) A step of depositing a carbon electrode on the perovskite layer; and S5) A step of infiltrating a second charge transport material into the carbon electrode; A method for manufacturing a perovskite solar cell comprising 8. In Paragraph 7, The above step S5) is a method for manufacturing a perovskite solar cell, wherein the second charge transport material dissolved in an organic solvent is coated onto the carbon electrode and heat-treated.

9. In Paragraph 8, A method for manufacturing a perovskite solar cell comprising one or more organic solvents selected from the group including chloroform, ethyl acetate, diethyl ether, toluene, anisole, and butyl acetate.

10. In Paragraph 8, A method for manufacturing a perovskite solar cell in which the heat treatment temperature is 50 to 200 ℃.

11. In Paragraph 8, A method for manufacturing a perovskite solar cell in which the heat treatment time is 1 to 60 minutes.

12. In Paragraph 7, A method for manufacturing a perovskite solar cell wherein the carbon electrode comprises one or more selected from the group including carbon nanotubes (CNT), graphite, carbon black, and polymeric binders.

13. In Paragraph 7, A method for manufacturing a perovskite solar cell in which the molecular weight of the second charge transport material is 1,000 to 100,000 g / mol.

14. In Paragraph 7, A method for manufacturing a perovskite solar cell in which if the first charge transport material is an electron transport material, the second charge transport material is a hole transport material, and if the first charge transport material is a hole transport material, the second charge transport material is an electron transport material.

15. In Paragraph 14, A method for manufacturing a perovskite solar cell comprising one or more hole transport materials selected from the group including PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), P3HT (poly(3-hexylthiophene)), CuPc (copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine), and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate).

16. In Paragraph 14, The above electron transport materials are titanium oxide, tin oxide, zinc oxide, PCBM (Phenyl-C61-Butyric Acid Methyl Ester), PCDTBT (Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)]) and Fullerene (C 60 A method for manufacturing a perovskite solar cell comprising one or more selected from the group including ).

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