Preparation method and application of unijunction perovskite solar cell

Abstract

The invention relates to a preparation method and application of a unijunction perovskite solar cell. The method includes preparing a first organic semiconductor thin film (P3HT) and a second organic semiconductor thin film (PCBM), and connecting the two thin films by a thin film transfer method to form a double-layer structure, and depositing a surface separation monolayer (SSM) on one of the thin films at the same time for adjusting the surface dipole moment and improving the open-circuit voltage of the double-layer structure. The SSM is deposited through chemical vapor deposition, spin coating and other technologies, and the influence of the SSM on the surface dipole moment is detected through X-ray photoelectron spectroscopy (XPS). According to the invention, by regulating and controlling interface characteristics, not only are experimental steps optimized, but also the open-circuit voltage of the organic photovoltaic device is remarkably improved.

Description

Technical Field

[0001] The technical field of the present invention is organic photovoltaic device (OPVs) technology, and in particular, relates to a preparation method and application of a single-junction perovskite solar cell. Background Art

[0002] Organic solar cells have attracted widespread attention in the field of renewable energy due to their thinness, flexibility and low cost. In order to improve the performance of such cells, researchers have been exploring various methods to optimize their structure and materials. One important direction is to form self-organized multilayer structures in organic solar cells, which can improve the photoelectric conversion efficiency of the cells.

[0003] Despite the progress made in the above research, the performance of organic solar cells is still limited by several factors, including:

[0004] Interface characteristics, material compatibility, and structural optimization. Therefore, further research is needed to improve the performance of organic solar cells by improving interface characteristics and structure. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a single-junction perovskite solar cell and its application in view of the deficiencies of the prior art. The present invention aims to solve the problem of low open circuit voltage in organic photovoltaic devices due to unsatisfactory interface characteristics. Specifically, existing organic photovoltaic devices often have low open circuit voltage due to misaligned energy levels at the interface and weak surface dipole moment, thereby affecting the overall photoelectric conversion efficiency.

[0006] The technical solution of the present invention is achieved through the following technical solutions:

[0007] A method for preparing a single-junction perovskite solar cell, the method comprising the following steps:

[0008] (1) preparing a first organic semiconductor thin film, wherein the first organic semiconductor is poly(3-hexylthiophene) (P3HT);

[0009] (2) preparing a second organic semiconductor thin film, wherein the second organic semiconductor is [6,6]-phenyl-C61-butyric acid methyl ester (PCBM);

[0010] (3) connecting the first and second organic semiconductor films to form a double-layer structure by a thin film transfer method, wherein the thin film connection process does not damage the flatness of the film surface;

[0011] (4) Depositing a surface separation monolayer (SSM) between the first organic semiconductor film and the second organic semiconductor film, wherein the SSM is used to adjust the surface dipole moment of the film and further adjust the open circuit voltage of the double-layer structure.

[0012] Furthermore, the preparation of the first organic semiconductor film and the preparation of the second organic semiconductor film specifically include the following steps:

[0013] (a) dissolving a poly(3-hexylthiophene) P3HT solution and a [6,6]-phenyl-C61-butyric acid methyl ester PCBM solution in a chlorobenzene solution, wherein the volume mass ratio of the chlorobenzene solution to the P3HT poly(3-hexylthiophene) P3HT solution is 1 ml:4-6 mg, and the volume mass ratio of the chlorobenzene solution to the [6,6]phenyl-C61-butyric acid methyl ester PCBM solution is 1 ml:6-8 mg;

[0014] (b) A PCBM film is prepared by a two-step spin coating method, i.e., first, a P3HT film, i.e., a first organic semiconductor film, is prepared by maintaining a rotation speed of 900 to 1800 r / min for 5 to 15 s; and then a PCBM film, i.e., a second organic semiconductor film, is prepared by maintaining a rotation speed of 4500 to 5500 r / min for 25 to 35 s.

[0015] Furthermore, step (4) is implemented by the following sub-steps:

[0016] (4.1) selecting P3HT and PCBM as the surface separation monolayer to adjust the surface dipole moment of the film;

[0017] (4.2) depositing the surface separation monolayer on the first or second organic semiconductor film by surface modification technology;

[0018] (4.3) The existence of the surface separated monolayer and its influence on the surface dipole moment were detected by X-ray photoelectron spectroscopy XPS.

[0019] Specifically, the formation of the surface separated monolayer increases the open circuit voltage of the double-layer structure by at least 0.36 volts compared to the unmodified double-layer structure.

[0020] Specifically, the surface modification technology used for the deposition of the surface separation monolayer is any one of chemical vapor deposition, spin coating or other suitable surface modification technologies.

[0021] Specifically, the deposition process of the surface separation single layer also includes a thermal annealing treatment to promote material mixing inside the double-layer structure, thereby stabilizing the performance of the double-layer structure.

[0022] Specifically, the thermal annealing treatment is to place the double-layer structure with SSM on a heating table and heat it to 100° C. for 30 minutes.

[0023] Specifically, the material of the surface separation monolayer is selected from P3DDFT or FC8, which is used to adjust the direction and strength of the surface dipole moment of the double-layer structure.

[0024] The second aspect of the present invention: application of the method for preparing a single-junction perovskite solar cell in preparing a double-layer structure for improving the open-circuit voltage of an organic photovoltaic device.

[0025] The beneficial effects of the present invention are as follows:

[0026] The beneficial effect of the present invention is that the surface dipole moment at the interface of the organic photovoltaic device can be effectively adjusted, thereby improving the energy level alignment. The open circuit voltage of the organic photovoltaic device is significantly improved, thereby improving the overall photoelectric conversion efficiency of the device. The preparation of the double-layer structure can be achieved through a simple and mild thin film transfer method, which is conducive to large-scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the full XPS spectrum of the present invention;

[0028] Figure 2 It is a structural schematic diagram of the present invention.

[0029] Figure 3 It is a voltage test curve diagram of the present invention. DETAILED DESCRIPTION

[0030] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0031] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0032] The present invention relates to a preparation method and application of a single-junction perovskite solar cell, which comprises: preparing a first organic semiconductor film (P3HT) and a second organic semiconductor film (PCBM), connecting the two films by a film transfer method to form a double-layer structure, and depositing a surface separation monolayer (SSM) on one of the films to adjust the surface dipole moment and improve the open circuit voltage of the double-layer structure. The method mainly achieves an effective improvement in the open circuit voltage by regulating the interface characteristics of the organic photovoltaic device. The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0033] Example 1: Tuning the interfacial dipole moment using a surface separated monolayer (SSM)

[0034] Preparation of the first organic semiconductor film: a poly(3-hexylthiophene) (P3HT) film is prepared by a spin coating method (solution processing method or vacuum evaporation method).

[0035] Preparation of the second organic semiconductor film: The [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) film is prepared by the solution processing method or the vacuum evaporation method.

[0036] The specific preparation process is as follows: poly (3-hexylthiophene) P3HT solution and [6,6]-phenyl-C61-butyric acid methyl ester PCBM solution are dissolved in chlorobenzene solution, wherein the volume mass ratio of chlorobenzene solution to P3HT poly (3-hexylthiophene) P3HT solution is 1 ml: 4-6 mg, and the volume mass ratio of chlorobenzene solution to [6,6]phenyl-C61-butyric acid methyl ester PCBM solution is 1 ml: 6-8 mg; then a two-step spin coating method is used to prepare a PCBM film, that is, firstly maintaining a rotation speed of 900-1800 r / min for 5-15s to prepare a P3HT film, that is, a first organic semiconductor film; and then maintaining a rotation speed of 4500-5500 r / min for 25s-35s to prepare a PCBM film, that is, a second organic semiconductor film.

[0037] Film connection: The P3HT film and PCBM film were connected using the contact film transfer (CFT) method, ensuring that the surfaces of the two films remained flat.

[0038] Surface detached monolayer deposition:

[0039] Materials containing fluorinated alkyl chains, such as perfluorooctane carboxylic acid (FC8), were selected as surface separation monolayer (SSM) materials.

[0040] A layer of FC8 with a thickness of about 1 nm was deposited on the P3HT or PCBM film using a spin coating technique.

[0041] X-ray photoelectron spectroscopy (XPS) tests confirmed the presence of FC8 and its effect on the surface dipole moment, such as Figure 1 shown.

[0042] Example 2: Further improving the performance of the double-layer structure by thermal annealing

[0043] Implementation steps: Prepare a double-layer structure with SSM according to the steps of Example 1.

[0044] Thermal annealing treatment: The double-layer structure with SSM was placed on a heating stage and heated to 100 °C for 30 min to promote slight mixing between the materials and improve the interface properties.

[0045] Example 3: Evaluating the effect of different SSMs on open circuit voltage

[0046] Implementation steps: According to the steps of Example 1, a double-layer structure with different SSMs was prepared, including perfluorooctane carboxylic acid (FC8) and poly (3,3′-di(dodecafluoroheptyl)-2,2′-bithiophene) (P3DDFT).

[0047] Evaluation of open circuit voltage change: The open circuit voltage of the double-layer structure with different SSMs was measured to evaluate the effect of the SSM on the open circuit voltage.

[0048] Furthermore, the preparation method of the present invention is applied to the double-layer structure for improving the open circuit voltage of an organic photovoltaic device, and the specific process is as follows:

[0049] Thin film preparation: P3HT and PCBM thin films were prepared on pretreated ITO glass substrates using spin coating technology.

[0050] Thin film connection: P3HT and PCBM thin films are stacked upside down using the CFT method, such as Figure 2 shown.

[0051] SSM deposition: FC8 was deposited on the PCBM film with a thickness of about 1 nm.

[0052] XPS test: XPS was used to detect the distribution of FC8 on the PCBM film, and the results showed that the F / C atomic ratio was 0.053. As shown in the following table:

[0053] Table 1

[0054]

[0055] Thermal annealing: The bilayer structure with SSM was placed on a heating stage and heated to 100 °C for 30 min.

[0056] Performance evaluation: After thermal annealing, the open circuit voltage of the double-layer structure is significantly improved.

[0057] SSM selection: Use FC8 and P3DDFT as SSM respectively.

[0058] Open circuit voltage evaluation: The open circuit voltages of the double-layer structure with FC8 and P3DDFT after thermal annealing are 0.52V and 0.51V, respectively, which are higher than that of the untreated double-layer structure (0.50V). The voltage test curves before and after thermal treatment are shown in Figure 2. Figure 3 shown in Figure 3 The specific data summary is shown in Table 2.

[0059]

[0060] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the contents disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application.

[0061] It should be understood that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A method for preparing a single-junction perovskite solar cell, characterized in that: The method comprises the following steps: (1) preparing a first organic semiconductor thin film, wherein the first organic semiconductor is poly(3-hexylthiophene) (P3HT); (2) preparing a second organic semiconductor thin film, wherein the second organic semiconductor is [6,6]-phenyl-C61-butyric acid methyl ester (PCBM); (3) connecting the first and second organic semiconductor films to form a double-layer structure by a thin film transfer method, wherein the thin film connection process does not damage the flatness of the film surface; (4) Depositing a surface separation monolayer (SSM) between the first organic semiconductor film and the second organic semiconductor film, wherein the SSM is used to adjust the surface dipole moment of the film and further adjust the open circuit voltage of the double-layer structure.

2. The preparation method according to claim 1, characterized in that: The preparation of the first organic semiconductor film and the preparation of the second organic semiconductor film specifically include the following steps: (a) dissolving a poly(3-hexylthiophene) P3HT solution and a [6,6]-phenyl-C61-butyric acid methyl ester PCBM solution in a chlorobenzene solution, wherein the volume mass ratio of the chlorobenzene solution to the P3HT poly(3-hexylthiophene) P3HT solution is 1 ml:4-6 mg, and the volume mass ratio of the chlorobenzene solution to the [6,6]phenyl-C61-butyric acid methyl ester PCBM solution is 1 ml:6-8 mg; (b) A PCBM film is prepared by a two-step spin coating method, i.e., first, a P3HT film, i.e., a first organic semiconductor film, is prepared by maintaining a rotation speed of 900 to 1800 r / min for 5 to 15 s; and then a PCBM film, i.e., a second organic semiconductor film, is prepared by maintaining a rotation speed of 4500 to 5500 r / min for 25 to 35 s.

3. The preparation method according to claim 1, characterized in that: The step (4) is implemented by the following sub-steps: (4.1) selecting P3HT and PCBM as the surface separation monolayer to adjust the surface dipole moment of the film; (4.2) depositing the surface separation monolayer on the first or second organic semiconductor film by surface modification technology; (4.3) The existence of the surface separated monolayer and its influence on the surface dipole moment were detected by X-ray photoelectron spectroscopy XPS.

4. The preparation method according to claim 3, characterized in that: The formation of the surface separated monolayer increases the open circuit voltage of the double-layer structure by at least 0.36 volts compared to the unmodified double-layer structure.

5. The preparation method according to claim 3, characterized in that: The surface modification technology used for the deposition of the surface separation monolayer is any one of chemical vapor deposition, spin coating or other suitable surface modification technologies.

6. The preparation method according to claim 3, characterized in that: The deposition process of the surface separation monolayer also includes a thermal annealing process to promote material mixing inside the double-layer structure, thereby stabilizing the performance of the double-layer structure.

7. The preparation method according to claim 3, characterized in that: The thermal annealing treatment is to place the double-layer structure with SSM on a heating table and heat it to 100° C. for 30 minutes.

8. The preparation method according to claim 3, characterized in that: The material of the surface separation monolayer is selected from P3DDFT or FC8, which is used to adjust the direction and strength of the surface dipole moment of the double-layer structure.

9. Use of the method for preparing a single-junction perovskite solar cell according to any one of claims 1 to 8 in preparing a double-layer structure for improving the open-circuit voltage of an organic photovoltaic device.

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