Passivating agent for solar cell, application of passivating agent and solar cell

Abstract

The invention discloses a passivator for a solar cell, application of the passivator and the solar cell, and belongs to the technical field of solar cells. The passivator comprises one or more of compounds shown in the formula (I) and derivatives of the compounds, wherein R1-R10 are independently selected from hydrogen and fluorine; and Z is a monovalent anion of one of iodine, bromine, chlorine, fluorine, thiocyanate and trifluoromethanesulfonic acid ions. According to the passivator for the solar cell, the application of the passivator and the solar cell, the crystallization rate of a perovskite thin film can be effectively adjusted, the crystallization process is optimized, segregation of A-site cations in a perovskite layer is restrained, and the stability and performance of the cell are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a passivator for solar cells and application and a solar cell. BACKGROUND

[0002] In the process of seeking sustainable energy solutions, perovskite solar cells have emerged as a landmark innovation in the field of photovoltaic technology. Although the current perovskite solar cells have high photoelectric conversion efficiency, their limited device lifetime is still a major challenge to commercialization. Among them, the material of the perovskite layer of the perovskite solar cell is represented as ABX3, then the performance and stability of the perovskite solar cell is the key to the homogenization of the A-site cation in the perovskite structure, which significantly affects its photoelectric properties. From the perspective of structure, the A-site cation occupies the central position of the perovskite framework, determines the dimension of the structure, and directly affects its stability, especially the phase stability. The size and geometry of the A-site cation will affect the bond length and bond angle between the B-site cation and the halogen species, thereby changing the arrangement mode of the surrounding [BX6 ]4- octahedron, ultimately affecting the crystal symmetry and phase of the perovskite. SUMMARY

[0003] The purpose of the present application is to overcome the deficiencies in the prior art, provide a passivator for solar cells and application and a solar cell, the passivator for solar cells can effectively adjust the crystallization rate of the perovskite thin film, optimize the crystallization process, thereby inhibiting the segregation of the A-site cation in the perovskite layer, and improving the stability and performance of the cell.

[0004] To achieve the above purpose, the present application adopts the following technical scheme:

[0005] In a first aspect, the present application provides a passivator for solar cells, comprising one or more of the compounds and derivatives represented by formula (I):

[0006]

[0007] Wherein:

[0008] R1~R10 are each independently selected from hydrogen, fluorine;

[0009] Z is a monovalent anion of one of iodine, bromine, chlorine, fluorine, thiocyanate, triflate.

[0010] In a second aspect, the present application provides the use of the passivator for solar cells in a trans-form perovskite solar cell.

[0011] In a third aspect, the present application provides a solar cell, which is a transverse structure perovskite solar cell, comprising a passivation layer, wherein the raw material for preparing the passivation layer comprises the passivator for solar cells according to the first aspect.

[0012] Further, the solar cell further comprises an electrically conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer.

[0013] The electrically conductive substrate, the hole transport layer, the perovskite layer, the passivation layer, the electron transport layer and the electrode layer are sequentially stacked.

[0014] Further, the material of the electrically conductive substrate comprises at least one of ITO, FTO, AZO and GZO.

[0015] Further, the material of the hole transport layer comprises at least one of SAM, NiO x , PEDOT:PSS, PTAA, CuSCN and CuO x .

[0016] Further, the material of the perovskite layer is ABX3, and the band gap of the perovskite layer is 0.9eV-3.0eV.

[0017] Wherein:

[0018] The A-site ion comprises a monovalent cation of at least one of cesium, rubidium, methylamine group and formamidine group.

[0019] The B-site ion comprises a divalent cation of at least one of lead, copper, zinc, gallium, tin and calcium.

[0020] The X-site ion comprises a monovalent anion of at least one of iodine, bromine, chlorine, fluorine and thiocyanate ion.

[0021] Further, the material of the electron transport layer comprises at least one of C 60 , PCBM, SnO2 and ZnO.

[0022] Further, the material of the electrode layer comprises at least one of silver, gold, copper and aluminum.

[0023] Further, the thickness of the electrically conductive substrate is 100nm-200nm.

[0024] Further, the thickness of the hole transport layer is 1nm-60nm.

[0025] Further, the thickness of the perovskite layer is 10nm-100μm.

[0026] Further, the thickness of the passivation layer is 1-100nm.

[0027] And / or, the thickness of the electron transport layer is 1nm-100nm.

[0028] And / or, the thickness of the electrode layer is 50nm-1μm.

[0029] Further, a buffer layer is arranged on the surface of the electron transport layer away from the passivation layer.

[0030] Further, the material of the buffer layer comprises at least one of SnO2, PCBM, BCP, LiF, MoO x

[0031] And / or, the thickness of the buffer layer is 5nm-30nm.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] The passivation agent for solar cells provided by the present application changes the coordination environment of the perovskite precursor liquid through its own lower pKa (0.78), adjusts the perovskite crystallization rate, optimizes the perovskite crystallization process, reduces the pores of the buried interface of the perovskite layer, realizes the function of inhibiting the segregation of A-site cations in the perovskite layer, and improves the stability and performance of the perovskite solar cell. At the same time, the passivation agent will form a passivation layer on the surface of the perovskite, reduce the carrier recombination on the surface of the perovskite, and improve the extraction ability of the carriers. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a structural schematic diagram of a solar cell provided by an embodiment of the present application;

[0035] Figure 2 is an X-ray diffraction pattern of the perovskite thin film prepared in Example 1, Example 2 and Comparative Example 1 of the present application;

[0036] Figure 3 is a surface scanning electron microscope pattern of the perovskite thin film prepared in Example 1, Example 2 and Comparative Example 1 of the present application;

[0037] Figure 4 is a scanning electron microscope pattern of the buried interface of the perovskite thin film prepared in Example 1, Example 2 and Comparative Example 1 of the present application;

[0038] Figure 5 is a time-of-flight secondary ion mass spectrometer (TOF-SIMS) Cs + resulting pattern of the perovskite thin film prepared in Example 1 and Comparative Example 1 of the present application.

[0039] In the figure: 1, electrode layer; 2, buffer layer; 3, electron transport layer; 4, passivation layer; 5, perovskite layer; 6, hole transport layer; 7, conductive substrate. ​DETAILED DESCRIPTION

[0040] The application will be further described below with reference to the drawings. The following examples are only used to more clearly illustrate the technical solutions of the application, and cannot be used to limit the protection scope of the application.

[0041] Example 1

[0042] The present embodiment provides a passivation agent for a solar cell and a solar cell.

[0043] The passivation agent provided by the present embodiment includes a compound shown in formula (II):

[0044]

[0045] The solar cell provided by the present embodiment is a perovskite solar cell in a trans structure, as shown in formula (III), which includes an electrically conductive substrate 7, a hole transport layer 6, a perovskite layer 5, a passivation layer 4, an electron transport layer 3, a buffer layer 2 and an electrode layer 1 which are sequentially stacked, wherein the raw material for preparing the passivation layer 4 includes the passivation agent for a solar cell provided by the present embodiment. Figure 1

[0046] The preparation method of the solar cell includes:

[0047] S1, etching an ITO conductive glass with a size of 1.5*1.5 cm 2 and sequentially cleaning it with detergent, deionized water, acetone, ethanol and isopropanol by ultrasonic cleaning, the time for each step of ultrasonic cleaning being 15 min, and then placing it in an oven for drying for standby;

[0048] S2, performing oxygen plasma treatment on the ITO conductive glass for 3-5 min;

[0049] S3, spin coating a 10 mg / mL NiO x (x: 0.5-1.5) dispersion liquid (solvent: deionized water) prepared in advance onto the ITO glass substrate treated in S2, the spin coating speed being 3000 rpm and the spin coating time being 30 s, and then annealing it on a 100℃ hot table for 10 min to obtain a hole transport layer;

[0050] ​S4, preparation of 500 nm perovskite layer by solution method: CsI (38.9 mg), FAI (232.1 mg), PbI2(691.2 mg) and the compound shown in formula (II) (1 mg) were weighed and dissolved in 1 mL of DMF and DMSO mixed solvent, the solvent ratio was DMF / DMSO (v:v = 4:1), and it was completely dissolved by stirring at room temperature. The perovskite thin film was prepared by one-step spin coating, and the spin coating process was divided into two stages, the first stage was 1000 rpm for 10 s, and the second stage was 4000 rpm for 40 s. 300 μL of anti-solvent ethyl acetate was added at the last 15 s of the second stage of spin coating. After spin coating, it was transferred to the annealing table for 100°C annealing for 30 min. The above process was completed in a nitrogen glove box environment;

[0051] S5, preparation of passivation layer by solution method: 0.5 mg of the compound shown in formula (II) was dissolved in isopropyl alcohol (IPA), and stirred for 3 hours to completely dissolve, then filtered, and 50 μL of the solution was spin coated on the surface of the perovskite active layer at 4000 rpm, the spin coating time was 30 s, and the acceleration was 1000 rpm / s; After spin coating, the wet film was annealed at 100°C for 10 min, and the above process was completed in a nitrogen glove box environment;

[0052] S6, the above sample was transferred to a vacuum evaporation system, and an electron transport layer C 60 was prepared by vacuum evaporation, and the thickness of the electron transport layer was 20 nm;

[0053] S7, preparation of buffer layer BCP by vacuum evaporation method, and the thickness of the buffer layer was 7 nm;

[0054] S8, preparation of 120 nm silver electrode by vacuum evaporation method.

[0055] Example 2

[0056] The present embodiment provides a passivation agent for solar cells and a solar cell, which is different from example 1, the passivation agent provided in the present embodiment includes a compound shown in formula (III):

[0057]

[0058] The preparation method of the solar cell provided in the present embodiment is different from example 1, in steps S4 and S5, the compound shown in formula (III) is used instead of the compound shown in formula (II).

[0059] Comparative example 1

[0060] This comparative example provides a passivating agent for solar cells and a solar cell. Unlike Example 1, the passivating agent provided in this example is phenylethylamine hydroiodide, as shown in formula (IV):

[0061]

[0062] The method for preparing the solar cell provided in this comparative example differs from that in Example 1 in that, in steps S4 and S5, the compound shown in formula (IV) is used instead of the compound shown in formula (II).

[0063] The samples provided in Examples 1-2 and Comparative Example 1 were analyzed:

[0064] Figure 2 These are X-ray diffraction patterns of the perovskite thin films prepared in Examples 1, 2, and Comparative Example 1 of the present invention. Figure 1 As shown, the diffraction peak intensities of Examples 1 and 2 are higher than those of Comparative Example 1, indicating that the crystallinity of the perovskites in Examples 1 and 2 is better than that in Comparative Example 1.

[0065] Figure 3 These are scanning electron microscope images of the surface of the perovskite thin films prepared in Examples 1, 2, and Comparative Example 1 of the present invention. Figure 3 As shown, the cell volume of Examples 1 and 2 is larger than that of Comparative Example 1, and there are no obvious pores.

[0066] Figure 4 These are scanning electron microscope images of the buried interface of the perovskite thin films prepared in Examples 1, 2, and Comparative Example 1 of the present invention. Figure 4 As shown, obvious holes appeared in Comparative Example 1, while no obvious holes appeared in Example 1 and Example 2.

[0067] Figure 5 Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to measure the perovskite thin films prepared in Example 1 and Comparative Example 1. + Result figure. The figure shows that Cs in Comparative Example 1... + The distribution of Cs on the surface of the perovskite film is relatively small, and it is concentrated at the bottom of the perovskite film. In Example 1, Cs... + The distribution of the perovskite film is more uniform than that of Comparative Example 1.

[0068] The photoelectric performance of the solar cells provided in the embodiments and comparative examples was tested, and the specific steps were as follows:

[0069] (1) Photoelectric conversion test:

[0070] Photovoltaic data were obtained by measuring the current-voltage curves of the perovskite solar cells prepared in the above embodiments and comparative examples. The measured light intensity was 100 mW / cm².2 AM 1.5G standard light intensity, test temperature is room temperature, and test environment is nitrogen atmosphere.

[0071] (2) Battery stability test:

[0072] Under nitrogen atmosphere, the perovskite solar cell was placed in 100 mW / cm 2 Under AM 1.5G standard light intensity, the maximum power point was tracked for light aging test.

[0073] The relevant test data are shown in Table 1, wherein Jsc refers to short-circuit current density, Voc refers to open-circuit voltage, FF refers to fill factor, Eff refers to conversion efficiency, and T80 refers to the time when the efficiency decreases to 80% of the initial value.

[0074] Table 1

[0075] Physical property parameters Jsc(mA / cm2) Voc(V) FF(%) Eff(%) T80(h) Example 1 25.80 1.145 82.93 24.49 217 Example 2 25.29 1.131 81.00 23.16 191 Comparative Example 1 24.96 1.119 81.19 22.68 169

[0076] The test results are shown in Table 1. Compared with Example 1, 2 and Comparative Example 1, the photoelectric performance and battery stability are obviously improved. As can be seen from the results, the introduced passivator can effectively improve the stability and performance of the perovskite solar cell.

[0077] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are used only to explain the relative position relationship, movement condition and the like between the components in a certain specific posture. If the specific posture changes, the directional indication also changes accordingly. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0078] In the description of the present application, it should be noted that unless specifically stated and limited otherwise, the terms "mounting", "connected", "connecting" should be construed broadlyly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0079] The embodiments of the present application are described above with reference to the drawings, but the present application is not limited to the specific embodiments described above, and the specific embodiments described above are only illustrative, but not restrictive, and those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which are all within the protection of the present application.

Claims

1. A passivating agent for solar cells, characterized in that: Includes one or more of the compounds shown in formula (I) and their derivatives: in: R1 to R10 are each independently selected from hydrogen and fluorine; Z is a monovalent anion of one of the following ions: iodine, bromine, chloride, fluorine, thiocyanate, or trifluoromethanesulfonate.

2. The application of the passivating agent for solar cells as described in claim 1 in inverted perovskite solar cells.

3. A solar cell, characterized in that: The solar cell is an inverted perovskite solar cell, including a passivation layer, the raw materials for preparing the passivation layer including the passivating agent for solar cells as described in claim 1.

4. The solar cell according to claim 3, characterized in that: It also includes a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer; The conductive substrate, hole transport layer, perovskite layer, passivation layer, electron transport layer, and electrode layer are stacked sequentially.

5. The solar cell according to claim 3, characterized in that: The conductive substrate is made of at least one of ITO, FTO, AZO, and GZO. And / or, the material of the hole transport layer includes SAM, NiO x , PEDOT: PSS, PTAA, CuSCN, CuO x At least one of them; And / or, the perovskite layer is made of ABX3, and the band gap of the perovskite layer is 0.9eV - 3.0eV; in: The A-site ion includes at least one monovalent cation selected from cesium, rubidium, methylamino, and formamidinium. B-site ions include divalent cations of at least one of lead, copper, zinc, gallium, tin, and calcium; The X-site ion includes at least one monovalent anion selected from iodine, bromine, chloride, fluorine, and thiocyanate ions; And / or, the material of the electron transport layer includes C 60 At least one of PCBM, SnO2, and ZnO; And / or, the electrode layer is made of at least one of silver, gold, copper, and aluminum.

6. The solar cell according to claim 3, characterized in that: The thickness of the conductive substrate is 100nm-200nm; And / or, the thickness of the hole transport layer is 1nm-60nm; And / or, the thickness of the perovskite layer is 10 nm-100 μm; And / or, the thickness of the passivation layer is 1-100 nm; And / or, the thickness of the electron transport layer is 1nm-100nm; And / or, the thickness of the electrode layer is 50 nm-1 μm.

7. The solar cell according to claim 3, characterized in that: It also includes a buffer layer, located on the surface of the electron transport layer away from the passivation layer.

8. The solar cell according to claim 7, characterized in that: The buffer layer is made of materials including SnO2, PCBM, BCP, LiF, and MoO. x At least one of them; And / or, the thickness of the buffer layer is 5nm-30nm.

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