TWI734564B - Perovskite solar cells and method for producing the same - Google Patents

Abstract

The present invention relates to a perovskite solar cells and a method for producing the same. The perovskite solar cells comprises a transparent electrode, a hole transporting layer, a photo-conversion layer, an electron transporting composite layer and a metal electrode. An electron transporting material and a polymer material in the electron transporting composite layer can enhance electron transporting ability of the perovskite solar cells and restrain moisture from permeating into the cells. Therefore, photo-conversion efficiency and stability of the perovskite solar cells can be efficiently improved.

Description

Perovskite solar cell and manufacturing method thereof

The invention relates to a solar cell, in particular to a perovskite solar cell and a manufacturing method thereof.

With the advancement of science and technology, the demand for energy is increasing day by day. However, with the rising awareness of environmental protection and the limited resources of the earth, the development of green energy has been paid more and more attention. Since the generation of green energy does not cause pollution, it does not cause additional burden on the environment. Furthermore, green energy technology generates energy by transforming renewable resources, so it can be used by users for a long time without the predicament of resource exhaustion. Among them, since organic solar cells can convert daily solar energy into electrical energy, solar cells are currently the most valued technology in green energy.

With the development of technology, organic solar cells have evolved from early dye-sensitized solar cells to perovskite solar cells. Perovskite solar cells have better photoelectric conversion efficiency by using perovskite materials as the photoelectric conversion layer, but perovskite materials have poor moisture stability, so perovskite solar cells are susceptible to environmental moisture , And reduce its photoelectric conversion efficiency.

In view of this, it is urgent to provide a perovskite solar cell and a manufacturing method thereof to improve the defects of the conventional perovskite solar cell.

Therefore, one aspect of the present invention is to provide a perovskite solar cell, wherein the perovskite solar cell contains an electron transport composite layer and has better device stability and photoelectric conversion efficiency.

Another aspect of the present invention is to provide a method for manufacturing a perovskite solar cell, which improves the element stability and photoelectric conversion efficiency of the solar cell by infiltrating a polymer material into the electron transport layer.

According to one aspect of the present invention, a perovskite solar cell is provided. The perovskite solar cell includes a transparent electrode, a hole transport layer, a photoelectric conversion layer, an electron transport composite layer, and a metal electrode layer. The hole transfer layer is arranged on the transparent electrode. The photoelectric conversion layer is arranged on the hole transfer layer. The electron transport composite layer is arranged on the photoelectric conversion layer, and the electron transport composite layer includes a first electron transport material as a first continuous phase and a mixed material as a second continuous phase. Wherein, the first continuous phase and the second continuous phase are combined to form a composite phase, and the mixed material includes a second electron transfer material and a polymer material. The metal electrode layer is arranged on the electron transfer composite layer.

According to some embodiments of the present invention, the aforementioned perovskite solar cell may optionally include a hole blocking material. The hole blocking material is located between the electron transfer composite layer and the metal electrode layer, and the hole blocking material includes a second electron transfer material and a polymer material.

According to some embodiments of the present invention, the aforementioned hole blocking material is combined with the second continuous phase.

According to some embodiments of the present invention, the ratio of the total weight of the aforementioned polymer material to the total weight of the second electron transport material is 0.01 to 0.4.

According to some embodiments of the present invention, the aforementioned first electron transport material includes a carbon ball derivative, and the second electron transport material includes 2,9-dimethyl-4,7-diphenylphenanthroline.

According to some embodiments of the present invention, the aforementioned polymer material includes polymethylmethacrylate and/or polyvinylpyrrolidone.

According to another aspect of the present invention, a manufacturing method of a perovskite solar cell is provided. In this manufacturing method, a hole transfer layer is first formed on the transparent electrode, and a photoelectric conversion layer is formed on the hole transfer layer. Then, an electron transport layer is formed on the photoelectric conversion layer, wherein the electron transport layer includes the first electron transport material, and the electron transport layer is the first continuous phase. Then, a second continuous phase is formed in the electron transport layer by a mixed material, wherein the first continuous phase and the second continuous phase are combined to form a composite phase, and the mixed material includes a second electron transport material and a polymer material. After forming the second continuous phase, a metal electrode layer is formed on the electron transport layer.

According to some embodiments of the present invention, the aforementioned mixed material forms a hole blocking layer, and the top surface of the hole blocking layer covers the top surface of the electron transport layer.

According to some embodiments of the present invention, the foregoing operation of forming the second continuous phase in the electron transport layer includes coating a solution on the electron transport layer, and the solution includes the second electron transport material and the polymer material.

According to some embodiments of the present invention, the aforementioned solution does not damage the surface morphology of the electron transport layer.

The perovskite solar cell and the manufacturing method thereof of the present invention can form an electron transport composite layer by infiltrating the interface modification material containing a polymer material into the electron transport layer, which can inhibit the water vapor penetrating into the element and improve The electron transfer efficiency of the device can improve the stability of the device and enhance the photoelectric conversion efficiency.

The manufacture and use of the embodiments of the present invention are discussed in detail below. However, it can be understood that the embodiments provide many applicable inventive concepts, which can be implemented in various specific contents. The specific embodiments discussed are for illustration only, and are not intended to limit the scope of the present invention.

Please refer to FIG. 1 and FIG. 2A at the same time, in which FIG. 1 is a schematic flowchart of a manufacturing method 100 of a perovskite solar cell according to some embodiments of the present invention, and FIG. 2A is a schematic view of some embodiments according to the present invention. The schematic diagram of the components of the perovskite solar cell 200a. In the method 100, a hole transport layer 230 is first formed on the transparent electrode 220, as shown in operation 110. The transparent electrode 220 can be disposed on the substrate 210 by sputtering or other suitable film forming methods. In some embodiments, the transparent electrode 220 may be indium tin oxide (ITO), other suitable conductive materials, or any mixture of the above materials. Preferably, in order to ensure that sunlight can pass through the substrate 210 and irradiate the solar cell 200a, the substrate 210 can be made of a light-transmitting material. In some specific examples, the light-transmitting material may be glass, polymer materials, other suitable light-transmitting materials, or any combination of the foregoing materials.

The hole transfer layer 230 can be formed on the transparent electrode 220 by spin coating or other appropriate methods. For example, the hole transport layer 230 may include PEDOT:PSS, other suitable hole transport materials, or any mixture of the above materials. It is understandable that although the solar cell 200a of FIG. 2A only has a single hole transport layer 230, the present invention is not limited thereto. In some embodiments, the solar cell 200a may include a plurality of hole transport layers, and the material of the hole transport layers can be selected according to the potential energy levels of adjacent layers to improve the hole transport capability of the device.

Then, a photoelectric conversion layer 240 is formed on the hole transfer layer 230, as shown in operation 120. The photoelectric conversion layer 240 is made of perovskite material. It should be noted that the present invention is not limited to perovskite solar cells. In other application examples, the photoelectric conversion layer 240 of the present invention can also be other photoelectric conversion materials.

After operation 120 is performed, step 130 is performed. Wherein, in step 130, an electron transport layer is first formed on the photoelectric conversion layer 240, and then the mixed material is infiltrated into the electron transport layer to form an electron transport composite layer 250a, as shown in operations 131 and 133. The electron transport layer can be formed on the photoelectric conversion layer 240 by spin coating or other appropriate methods. In some embodiments, the electron transport layer may include a continuous phase formed of the first electron transport material. Preferably, there is a gap between the stacked molecules of the first electron transport material in the electron transport layer, but the gap referred to in this case refers to the gap between the stacked molecules, which is caused by the molecular structure, and does not refer to poor film forming properties The resulting gap. In some embodiments, the first electron transport material may include carbon ball derivatives, other suitable electron transport materials, or any mixture of the foregoing materials. For example, the carbon ball derivative may be, for example, a fullerene derivative (carbon 60 derivative (PCBM)).

The aforementioned hybrid material may include a second electron transport material and a polymer material. Among them, the second electron transport material is different from the aforementioned first electron transport material. Preferably, the second electron transport material may be an organic small molecule material. For example, the second electron transport material may include 2,9-dimethyl-4,7-diphenylphenanthroline (BCP), other appropriate electron transport materials, or any mixture of the foregoing materials. The polymer material may include polymethylmethacrylate (PMMA), polyvinylpyrrolidone (PVP), other suitable polymer materials, or any mixture of the above materials. The second electron transfer material in the hybrid material helps to further improve the electron transfer capability of the solar cell 200a, and the polymer material can additionally improve the stability of the device and/or increase the electrical transfer efficiency.

In some embodiments, the weight ratio of the polymer material to the second electron transport material may be 0.01 to 0.4, preferably 0.1 to 0.4, and more preferably 0.1 to 0.3. When the weight ratio of the polymer material to the second electron transfer material is in the aforementioned range, an appropriate amount of the second transfer material and the polymer material can effectively improve the stability of the device and/or the photoelectric conversion efficiency, thereby enhancing the solar cell 200a The effectiveness of.

During operation 133, the mixed material may be first dissolved in an organic solvent to form an interface modification solution. Then, drop this interface modification solution on the electron transport layer, and use an appropriate film forming method (such as spin coating or other methods) and baking conditions to remove excess solvent. When the interface modification solution is dropped on the electron transport layer, the second electron transport material and the polymer material in the mixed material can penetrate into the gap between the stacked molecules of the first electron transport material through the solvent, and form after removing the solvent Another continuous phase, in which another continuous phase formed by the mixed material is combined with the continuous phase formed by the first electron transport material to form the electron transport composite layer 250a. As shown in FIG. 2A, the interface modification layer formed by the mixed material is combined with the electron transport layer to form a two-phase composite electron transport composite layer 250a. In other words, the top surface of the interface modification layer is not higher than (that is, lower than or coplanar with) the top surface of the electron transport layer. The selection of the aforementioned organic solvent is not particularly limited, as long as it can dissolve the mixed material and does not damage the surface morphology of the electron transport layer during operation 133. For example, the organic solvent can be isopropanol, other suitable organic solvents, or any combination of the above.

After step 130 is performed, a metal electrode layer 260 is formed on the electron transport composite layer 250a to prepare the perovskite solar cell 200a of the present invention, as shown in operation 140 and operation 150. Although the metal electrode layer 260 shown in FIG. 2A is only one layer, in other embodiments, the metal electrode layer 260 may be composed of multiple layers of metal. In some embodiments, the single-layer metal electrode layer 260 may be made of a single metal material, or may be composed of multiple metal materials. The metal electrode layer 260 can be formed by evaporation, other appropriate methods, or any combination of the above methods.

It should be noted that the thickness of each layer and the thickness ratio between the layers in the solar cell 200a shown in FIG. 2A are merely illustrative and not intended to limit the present invention. In order to obtain better photoelectric conversion efficiency, the technical field of the present invention belongs to Those with general knowledge can adjust the thickness of each layer according to the design.

Please refer to FIG. 2B, which is a schematic diagram of elements of a perovskite solar cell according to some embodiments of the present invention. The manufacturing method and device structure of the solar cell 200b are substantially the same as the manufacturing method and device structure of the solar cell 200a. The difference between the two is that the electron transport composite layer 250b of the solar cell 200b includes a composite interface layer 252b and a hole blocking layer 251b. Wherein, the composite interface layer 252b is formed by dropping an interface modification solution containing a mixed material on the electron transport layer as described above, so the composite interface layer 252b includes a continuous phase electron transport layer and a mixed material. In addition, the interface modification layer is separated from the electron transport layer, so the composite interface layer 252b is formed by combining the electron transport layer in a continuous phase and the interface modification layer in another continuous phase. In the solar cell 200b, by adjusting the thickness of the interface modification layer, the top surface of the interface modification layer formed by the interface modification solution can be higher than the top surface of the electron transport layer, and an interface modification layer is additionally formed on the composite interface layer 252b. Since the mixed material forming the interface modification layer includes the second electron transport material, the interface modification layer can also be used to block electric holes. Accordingly, the interface modification layer in the continuous phase on the composite interface layer 252b is also referred to as the hole blocking layer 251b.

Please refer to FIG. 2C, which is a schematic diagram of elements of a perovskite solar cell according to some embodiments of the present invention. The manufacturing method and device structure of the solar cell 200c and the device structure of the solar cell 200b are roughly the same. The difference between the two is that the electron transport composite layer 250c of the solar cell 200c includes a hole blocking layer 251c, an electron transport layer 253c, and a configuration The composite interface layer 252c between the hole blocking layer 251c and the electron transport layer 253c. By dripping the interface modification solution on the electron transport layer as described above, the mixed material in the interface modification solution can form another continuous phase in the electron transport layer, which is separated from the continuous phase of the electron transport layer. The composite interface layer 252c is formed by the method, and a continuous-phase interface modification layer is formed on the electron transport layer, and a hole blocking layer 251c is formed on the composite interface layer 252c. Similarly, by adjusting the thickness, the mixed material in the interface modification solution of the solar cell 200c does not penetrate to the bottom surface of the electron transport layer (that is, the bottom surface of the composite interface layer 252c is higher than the bottom surface of the electron transport layer). The electron transport layer 253c formed of the first electron transport material still remains under the composite interface layer 252c.

In some application examples, the electron transport composite layer of the present invention can effectively improve the electron transport efficiency of solar cells and improve the photoelectric conversion efficiency of the cells. Wherein, the second electron transport material and the polymer material used can be formed into another continuous phase and penetrate into the electron transport layer in the continuous phase, and combine with the electron transport layer in a phase separation manner to form a composite layer. The stability and/or photoelectric conversion efficiency of the solar cell can be further improved.

The following examples are used to illustrate the application of the present invention, but they are not intended to limit the present invention. Anyone who is familiar with the art can make various changes and modifications without departing from the spirit and scope of the present invention.

Preparation of perovskite solar cells

Example 1-1

First, drop PEDOT:PSS on indium tin oxide glass, and spin-coating to form a hole transfer layer. Then, methylammonium iodide (MAI) and lead iodide (PbI ₂ ) are dissolved in dimethyl sulfite (DMSO) to form a perovskite precursor solution. Drop the perovskite precursor liquid on the hole transfer layer, and spin coating to form the photoelectric conversion layer. Next, PCBM was dissolved in chlorobenzene and spin-coated as an electron transport layer. Then, 2,9-dimethyl-4,7-diphenyl o-phenanthroline and polymethyl methacrylate (weight ratio 1:0.1) were dissolved in isopropanol, and the mixed solution was added dropwise On the electron transport layer, and spin-coated to form an electron transport composite layer. After vapor-depositing the metal electrode on the electron transport composite layer, the perovskite solar cell of Example 1-1 can be prepared. The photovoltaic characteristics of Example 1-1 are as shown in Table 1, which will not be repeated here.

Examples 1-2 and 1-3 and Examples 2-1 to 2-3

Examples 1-2 and 1-3 use the same preparation method as the production method of the perovskite solar cell of Example 1-1, the difference is that Examples 1-2 and 1-3 are dripped and mixed separately. The proportion of the mixed solution is on the electron transport layer. Among them, the weight ratio of 2,9-dimethyl-4,7-diphenyl o-phenanthroline and polymethyl methacrylate of Example 1-2 is 1:0.2, and Example 1-3 of 2 The weight ratio of 9-dimethyl-4,7-diphenyl-phenanthroline to polymethyl methacrylate is 1:0.4.

Example 2-1 uses the same manufacturing method as the manufacturing method of the perovskite solar cell of Example 1-1, except that the mixed solution of Example 2-1 contains 2,9-dimethyl-4, The weight ratio of 7-diphenylphenanthroline to polyvinylpyrrolidone is 1:0.1.

Examples 2-2 and 2-3 use the same preparation method as the production method of the perovskite solar cell of Example 2-1, the difference is that Examples 2-2 and 2-3 are dripped and mixed separately. The proportion of the mixed solution is on the electron transport layer. Among them, the weight ratio of 2,9-dimethyl-4,7-diphenylphenanthroline to polyvinylpyrrolidone in Example 2-2 is 1:0.2, and that in Example 2-3, 2,9- The weight ratio of dimethyl-4,7-diphenyl-phenanthroline to polyvinylpyrrolidone is 1:0.4.

The photovoltaic characteristics of the foregoing Examples 1-2 and 1-3 and Examples 2-1 to 2-3 are as shown in Table 1, respectively, and will not be repeated here.

Comparative example 1

Comparative Example 1 uses the same manufacturing method as the manufacturing method of the perovskite solar cell of Example 1-1, except that Comparative Example 1 only drops 2,9-dimethyl-4,7-diphenyl Phenanthroline is on the electron transport layer. Its photovoltaic characteristics are shown in Table 1.

Please refer to FIGS. 3A and 3B, which respectively show scanning electron micrographs of perovskite solar cells according to Examples 1-1 and 2-1 of the present invention. The electron transport composite layer containing the mixed material is located on the photoelectric conversion layer of the perovskite material, and its thickness is about 52.5 nm and 69.4 nm, respectively. Obviously, the mixed material in the interface modification solution can penetrate into the electron transport layer to further improve the stability and/or photoelectric conversion efficiency of the solar cell.

In Examples 1-1 to 1-3, because polymethyl methacrylate is hydrophobic, it can effectively prevent water vapor from penetrating into the solar cell, and prevent the perovskite material of the photoelectric conversion layer from being damaged by water vapor. In turn, the stability of the battery can be improved. When the solar cell of Example 1-1 is placed in an environment with a relative humidity of 40%, and after 1000 hours, the decline in its photoelectric conversion efficiency is only 20%. If it is placed in an atmosphere with a relative humidity of 50% to 70%, and after 200 hours, the degradation of the photoelectric conversion efficiency is only 10%. Among them, when the weight ratio of 2,9-dimethyl-4,7-diphenylphenanthroline to polymethyl methacrylate is 1:0.2, the solar cell produced has better stability.

If the solar cell of Comparative Example 1 is placed at a relative humidity of 40%, and after 300 hours, the photoelectric conversion efficiency will decline by at least 50%. If it is placed in an atmosphere with a relative humidity of 50% to 70%, and after 200 hours, its photoelectric conversion efficiency will decline by 50%.

In Examples 2-1 to 2-3, since polyvinylpyrrolidone has good electron transfer ability, compared with Comparative Example 1, the solar cells of Examples 2-1 to 2-3 have better photoelectric conversion efficiency.

According to the foregoing description, the perovskite solar cell of the present invention can further improve the stability of the device and the photoelectric conversion efficiency by infiltrating the polymer material of the mixed material into the electron transport layer to form an electron transport composite layer.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Retouching, therefore, the scope of protection of the present invention shall be subject to the scope of the attached patent application.

100: method

110, 120, 131, 133, 140, 150: Operation

130: steps

200a, 200b, 200c: solar cell

210: Substrate

220: Transparent electrode

230: hole transfer layer

240: photoelectric conversion layer

250a, 250b, 250c: electron transport composite layer

251b, 251c: hole blocking layer

252b, 252c: composite interface layer

253c: electron transport layer

260: Metal electrode layer

In order to have a more complete understanding of the embodiments of the present invention and its advantages, please refer to the following description and the corresponding drawings. It must be emphasized that the various features are not drawn to scale and are for illustration purposes only. The contents of the relevant diagrams are described as follows: FIG. 1 is a schematic flowchart of a manufacturing method of a perovskite solar cell according to some embodiments of the present invention. 2A, 2B, and 2C are respectively schematic diagrams of elements of a perovskite solar cell according to some embodiments of the present invention. 3A and 3B respectively show scanning electron micrographs of perovskite solar cells according to Examples 1-1 and 2-1 of the present invention.

Domestic deposit information (please note in the order of deposit institution, date and number) none Foreign hosting information (please note in the order of hosting country, institution, date, and number) none

100: method

110, 120, 131, 133, 140, 150: Operation

130: steps

Claims (9)

A perovskite solar cell, comprising: a transparent electrode; a hole transfer layer arranged on the transparent electrode; a photoelectric conversion layer arranged on the hole transfer layer; an electron transfer composite layer arranged on the photoelectric On the conversion layer, and the electron transport composite layer includes a first electron transport material as a first continuous phase and a mixed material as a second continuous phase, wherein the first continuous phase and the second continuous phase are combined to form A composite phase, the mixed material includes a second electron transfer material and a polymer material, and the polymer material includes polymethylmethacrylate and/or polyvinylpyrrolidone; and a metal electrode layer disposed on the electron transfer material On the composite layer. The perovskite solar cell according to claim 1, further comprising a hole blocking material, wherein the hole blocking material is located between the electron transport composite layer and the metal electrode layer, and the hole blocking material includes the hole blocking material The second electron transfer material and the polymer material. The perovskite solar cell according to claim 2, wherein the hole blocking material is combined with the second continuous phase. The perovskite solar cell according to claim 1 or 2, wherein the ratio of the total weight of the polymer material to the total weight of the second electron transport material is 0.01 to 0.4. The perovskite solar cell according to claim 1 or 2, wherein the first electron transport material includes a carbon ball derivative, and the second electron transport material includes 2,9-dimethyl-4,7-diphenyl Phenanthroline. A manufacturing method of a perovskite solar cell includes: forming a hole transfer layer on a transparent electrode; forming a photoelectric conversion layer on the hole transfer layer; forming an electron transfer layer on the photoelectric conversion layer, wherein The electron transport layer includes a first electron transport material, and the electron transport layer is a first continuous phase; a second continuous phase is formed in the electron transport layer by a mixed material, wherein the first continuous phase and the The second continuous phase is combined into a composite phase, the mixed material includes a second electron transport material and a polymer material, and the polymer material includes polymethylmethacrylate and/or polyvinylpyrrolidone; and forming the second electron transport material After the two continuous phases, a metal electrode layer is formed on the electron transport layer. The method for manufacturing a perovskite solar cell according to claim 6, wherein the mixed material forms a hole blocking layer, and a top surface of the hole blocking layer covers a top surface of the electron transport layer. Production of perovskite solar cells as described in claim 6 The method, wherein the operation of forming the second continuous phase in the electron transport layer includes coating a solution on the electron transport layer, and the solution includes the second electron transport material and the polymer material. The manufacturing method of the perovskite solar cell according to claim 8, wherein the solution does not damage a surface morphology of the electron transport layer.

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