Ferroelectric material modified composite perovskite solar cell and preparation method thereof

Abstract

The application discloses a ferroelectric material modified composite perovskite solar cell and a preparation method thereof, and belongs to the technical field of solar cell processing. The ferroelectric material modified composite perovskite solar cell comprises a transparent conductive substrate, and a hole transport layer, a perovskite light absorption layer, an electron transport layer and an electrode layer are sequentially arranged on the transparent conductive substrate from inside to outside. The perovskite light absorption layer comprises a perovskite light absorption layer body, a ferroelectric layer is deposited at the contact position of the perovskite light absorption layer body and the hole transport layer, the ferroelectric layer is composed of a plurality of ferroelectric nanocrystals, and the ferroelectric layer is field passivated in ferroelectric polarization. On one hand, the perovskite pin junction can be field passivated through ferroelectric polarization, and the photoelectric conversion efficiency of the perovskite solar cell is improved. On the other hand, unlike directly inserting a ferroelectric functional layer, the direct contact between the perovskite light absorption layer and the hole transport layer is not affected, and the extraction of holes by the hole transport layer is not affected.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solar cell processing, and particularly relates to a ferroelectric material modified composite perovskite solar cell and a preparation method thereof. BACKGROUND

[0002] Perovskite solar cells have attracted extensive attention due to their excellent photoelectric properties such as tunable band gap, high light absorption coefficient, long carrier lifetime and diffusion length, high defect tolerance, and low-cost low-temperature liquid-phase preparation method. The efficiency of small-area laboratory-prepared photovoltaic devices has soared from 3.8% in 2009 to 25.8% in 2021 in just a few years, and it is considered to be a strong contender for the next generation of new photovoltaic materials.

[0003] The upside-down structure planar heterojunction (nip type) perovskite cell has always been a research hotspot in the field of perovskite photovoltaics due to its simple preparation process and high photoelectric conversion efficiency. However, the perovskite cell with an upside-down structure has the disadvantages of obvious hysteresis effect, poor device stability, and difficulty in preparing flexible devices, making it difficult to achieve large-scale commercial application. The inverted structure (pin type) perovskite cell has negligible hysteresis effect, good interface stability, and the ability to prepare flexible devices at low temperature, making it the dominant force in the industrialization of perovskite cells.

[0004] The methods for improving the efficiency of inverted structure perovskite cells mainly include the following aspects: optimization of perovskite light absorption layer (including solvent engineering optimization of crystallization, bulk defect passivation, mixed component perovskite, surface defect passivation, etc.), optimization of perovskite functional layer (modification of electron / hole transport layer, defect passivation, new functional layer material, etc.), and interface engineering (interface defect passivation, interface energy level regulation, etc.).

[0005] Currently, the preparation of mainstream high-efficiency inverted structure perovskite cells starts from the optimization and modification of each functional layer of the cell itself, and has high requirements for the purity of the material and the preparation process. However, few people have studied the method of improving the efficiency of perovskite cells through field passivation. In addition, although a functional layer can be added between the perovskite and the electron / hole transport layer to achieve field passivation of the perovskite, the functional layer itself does not meet the band matching between the perovskite and the charge transport layer, thus inhibiting the extraction of electrons / holes in the perovskite to some extent, thereby affecting the efficiency of the perovskite cell. SUMMARY

[0006] The purpose of the present application is to provide a high-efficiency perovskite solar cell, a cell module, a cell device, and a preparation method thereof, to solve the problems raised in the background art.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0008] A ferroelectric material modified composite perovskite solar cell, comprising a transparent conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer and an electrode layer are sequentially arranged on the transparent conductive substrate from inside to outside; wherein the perovskite light absorption layer comprises a perovskite light absorption layer body, a ferroelectric layer is deposited at the contact between the perovskite light absorption layer body and the hole transport layer, the ferroelectric layer is composed of a plurality of ferroelectric nanocrystals, and the ferroelectric layer is field passivated in ferroelectric polarization.

[0009] Compared with the prior art, the technical scheme has the following effects:

[0010] The ferroelectric nanocrystals are dispersed at the contact between the hole transport layer and the perovskite light absorption layer body: on the one hand, the ferroelectric polarization can field passivate the perovskite pin junction, which not only enhances the built-in field of the perovskite material and promotes the separation and transmission of the photo-generated electron-hole pairs, but also intensifies the splitting of the electron and hole quasi-Fermi levels in the perovskite pin junction, so that the open circuit voltage of the cell is further improved, and finally the photoelectric conversion efficiency of the perovskite cell is improved; on the other hand, unlike directly inserting a ferroelectric functional layer, since the ferroelectric nanocrystals have small particle size and are relatively dispersed on the hole transport layer, the direct contact between the perovskite light absorption layer and the hole transport layer is not affected, and the extraction of holes by the hole transport layer is not affected.

[0011] Preferably, the transparent conductive substrate comprises a glass substrate and a transparent conductive film deposited on the glass substrate.

[0012] The application further discloses a method for preparing a ferroelectric material modified composite perovskite solar cell, comprising the following steps: step one: depositing a hole transport layer, selecting a ferroelectric nanocrystal dispersion liquid as the material of the hole transport layer, generating a layer of thin film with a thickness of 80-100 nm on the transparent conductive substrate by means of magnetron sputtering;

[0013] Step two: depositing a perovskite light absorption layer, specifically comprising the following two aspects: S1, depositing a ferroelectric layer, placing the transparent conductive substrate treated in step one into a culture dish containing a ferroelectric nanocrystal dispersion liquid, placing the culture dish in a constant temperature box with a temperature of 80 DEG C for 1.5 h, depositing the ferroelectric nanocrystals on the hole transport layer, taking out after deposition, cleaning with anhydrous ethanol and deionized water, and then placing in a drying box for drying; S2, depositing a perovskite light absorption layer body, selecting a perovskite precursor solution to coat the cell prepared in S1, and annealing at 160 DEG C for 10-15 min.

[0014] Step three: depositing an electron transport layer;

[0015] Step four: depositing an electrode layer on the cell piece prepared in step three;

[0016] Step five: applying a positive ferroelectric polarization; that is, applying a positive ferroelectric polarization from the electrode layer to the transparent conductive substrate and perpendicular to the surface of the perovskite solar cell by using a constant current voltage source, wherein the applied external electric field > ferroelectric coercive field of the ferroelectric material.

[0017] Preferably, the specific content of step three is that the nanoparticles are dissolved in ionized water in a certain proportion, and then coated on the perovskite light absorption layer after dissolution, and annealing treatment.

[0018] Preferably, the nanoparticle material is selected from , and the nanoparticles and the deionized water are dissolved in a volume ratio of 1:5.

[0019] Preferably, the thickness of the electron transport layer is 50-80 nm, and the annealing temperature of the electron transport layer during preparation is 100-150℃.

[0020] Preferably, the configuration method of the precursor solution in S2 is as follows: the is added to the mixed solution in a volume ratio of 4.75:1 in a proportion of 1:0.91:0.09, and the concentration of the precursor solution is adjusted to 1.25 ; then is added to the solution to a concentration of 23 .

[0021] Preferably, a groove one for locally embedding the hole transport layer is provided on the transparent conductive film, a groove two for embedding the electrode layer is provided on the electron transport layer, the groove two extends downward to the upper surface of the transparent conductive film, and a groove three extending downward to the upper surface of the transparent conductive film is provided on the electrode layer. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the schematic diagram of the overall structure of the first embodiment of the perovskite solar cell in the present application;

[0023] Figure 2 is the schematic diagram of the circuit principle of applying a positive ferroelectric polarization in the present application;

[0024] Figure 3 is the schematic diagram of the overall structure of the second embodiment of the perovskite solar cell in the present application;

[0025] Figure 4 is the J-V curve schematic diagram of the perovskite solar cell in the present application.​​​ Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] like Figure 1 A ferroelectric material-modified composite perovskite solar cell is shown, comprising a transparent conductive substrate 1. From the inside out, a hole transport layer 2, a perovskite light absorption layer 3, an electron transport layer 4, and an electrode layer 5 are sequentially disposed on the transparent conductive substrate 1. The perovskite light absorption layer 3 includes a perovskite light absorption layer body 30. A ferroelectric layer 31 is deposited at the contact point between the perovskite light absorption layer body 30 and the hole transport layer 2. The ferroelectric layer 31 is composed of ferroelectric nanocrystals, which are uniformly dispersed on the upper surface of the hole transport layer 2. The ferroelectric layer 31 undergoes field passivation during ferroelectric polarization. The ferroelectric nanocrystals are dispersed into the hole transport layer 2. At the contact point with the perovskite light-absorbing layer body 30: on the one hand, the perovskite pin junction can be passivated by ferroelectric polarization, which not only enhances the built-in field of the perovskite material to promote the separation and transport of photogenerated electron-hole pairs, but also intensifies the splitting of the electron and hole quasi-Fermi levels in the perovskite pin junction, thereby further improving the open-circuit voltage of the battery and ultimately improving the photoelectric conversion efficiency of the perovskite battery; on the other hand, unlike the direct insertion of the ferroelectric functional layer, since the ferroelectric nanocrystals are small in size and relatively dispersed on the hole transport layer 2, they will not affect the direct contact between the perovskite light-absorbing layer and the hole transport layer, and will not affect the extraction of holes by the hole transport layer.

[0028] In this embodiment, the transparent conductive substrate 1 includes a glass substrate 10 and a transparent conductive film 11 deposited on the glass substrate 10.

[0029] In another embodiment, combined Figure 3 It is known that the transparent conductive film 11 has a first groove 7 for the hole transport layer 3 to be partially embedded, the electron transport layer 4 has a second groove 8 for the electrode layer 5 to be embedded, the second groove 8 extends downward to the upper surface of the transparent conductive film 11, and the electrode layer 4 has a third groove 9 extending downward to the upper surface of the transparent conductive film 11. The first groove 7 and the third groove 9 are both formed by laser scribing on the transparent conductive film 2 with a wavelength of 1064nm; the second groove 8 is formed by laser cutting with a wavelength of 532nm, thereby dividing the large-area perovskite solar cell into several interconnected sub-cells.

[0030] The method for preparing the ferroelectric material-modified composite perovskite solar cell described above includes the following steps:

[0031] Step one: depositing a hole transport layer 2; selecting As the material of the hole transport layer 2, a layer of thin film with a thickness of 80-100 nm is generated on the transparent conductive substrate 1 by means of magnetron sputtering Step two: depositing a perovskite light absorption layer 3; in this embodiment,

[0032] S1, depositing a ferroelectric layer 31, placing the transparent conductive substrate 1 processed via step one into a culture dish containing a ferroelectric nanocrystal dispersion liquid, placing the culture dish in a thermostat with a temperature of 80℃ for 1.5h, depositing the ferroelectric nanocrystal onto the hole transport layer 2, taking it out after the deposition is completed, cleaning it with anhydrous ethanol and deionized water, and then placing it in a drying box for drying;

[0033] S2, depositing a perovskite light absorption layer body 30, selecting a precursor solution to coat the battery prepared in S1, and annealing at 160℃ for 10-15 minutes; wherein the configuration method of the precursor solution in S2 is as follows: adding , methylammonium iodide, and lead iodide into a mixed solution in a proportion of 1:0.91:0.09, and adding a volume ratio of 4.75:1, adjusting the concentration of the precursor solution to 1.25 ; then adding to the solution to a concentration of 23 .

[0034] Step three: depositing an electron transport layer 4; dissolving the nanoparticles in ionized water in a certain proportion, coating them on the perovskite light absorption layer 3 after dissolving, and annealing; the nanoparticle material is selected from , and the nanoparticles and the deionized water are dissolved in a volume ratio of 1:5;

[0035] Step four: depositing an electrode layer 5 on the battery piece prepared in step three;

[0036] Step five: applying a positive ferroelectric polarization; that is, applying a positive ferroelectric polarization from the electrode layer 5 to the transparent conductive substrate 1 and perpendicular to the surface of the perovskite battery by using a constant current voltage source, wherein the applied external electric field > the ferroelectric coercive field of the ferroelectric material, as shown in Figure 2 .

[0037] In this embodiment, the thickness of the electron transport layer 4 is 50-80 nm, and the temperature for annealing treatment during the preparation process of the electron transport layer 4 is 150℃.

[0038] ​​It is worth noting that the preparation of ferroelectric nanocrystals using the following method:

[0039] Preferably, the inorganic ferroelectric PZT is prepared into a ferroelectric nanocrystalline material by a metal organic thermal decomposition method (MOD).

[0040] S1: Synthesis of zirconium heptanoate (ZrO(C7H13O2)2).

[0041] Zirconium oxyheptanoate is prepared using zirconyl chloride octahydrate (ZrOCl2·8H2O) and heptanoic acid (CH3(CH2)5COOH) as raw materials. First, the crystallization water in the zirconyl chloride octahydrate is adsorbed using a desiccant. After adsorption is complete, the zirconyl chloride is dissolved in excess heptanoic acid to generate a zirconium oxyheptanoate solution. After the solution is prepared, the purity of the prepared zirconium oxyheptanoate solution is analyzed. The solution is tested for purity using the AgNO3 drop method to prevent Cl- in the solution from not reacting completely and thus generating impurities. If the solution does not become turbid after AgNO3 is added, the zirconium oxyheptanoate solution has a high purity. After obtaining the zirconium oxyheptanoate solution with high purity, the solution is heated and evaporated to precipitate zirconium oxyheptanoate powder. The powder is then washed with anhydrous ethanol and deionized water, and finally dried in a drying oven to synthesize zirconium oxyheptanoate powder with high purity.

[0042] S2: Preparation of MOD precursor solution.

[0043] A MOD precursor solution is synthesized using lead acetate trihydrate (Pb(CH3COO)2·3H2O), tetrabutyl titanate ((CH3CH2CH2CH2O)4Ti), and zirconium oxyheptanoate as raw materials, and ethylene glycol ether (CH3CH2OCH2CH2OH) as a solvent. A portion of the lead acetate ethylene glycol ether is heated to 124°C for 15 min to remove the crystallization water in the lead acetate. Zirconium oxyheptanoate is then added, and the mixture is stirred and heated to 130°C for 15 min. After natural cooling, a PZ solution is obtained. Another portion of the lead acetate ethylene glycol ether is heated to 124°C for 15 min to remove the crystallization water in the lead acetate. After the crystallization water is removed, the mixture is cooled to 110°C, tetrabutyl titanate is added, and the mixture is heated to 130°C for 15 min to obtain a PT solution. The PZ solution is added to the PT solution, and after stirring and filtration, a PZT precursor solution is obtained.

[0044] S3: Synthesis of PZT ferroelectric nanocrystalline powder.

[0045] The PZT precursor solution is placed in an oven and incubated at 70°C for 48 h. After that, it is dried in a box furnace. After grinding, PZT nanocrystalline powder is obtained.

[0046] S4: Preparation of PZT nanocrystalline dispersion.

[0047] The PZT nanocrystal powder is added into an acetone solvent, and ultrasonic dispersion is carried out for 30 min, so that a PZT ferroelectric nanocrystal dispersion liquid with a particle size of 20-40 nm is obtained.

[0048] In addition, in the embodiment, the transparent conductive substrate 1 needs to be cleaned before being prepared, and the specific cleaning steps are as follows: first, the surface of the transparent conductive substrate 1 is wiped with a dust-free paper dipped in ethanol, and then the transparent conductive substrate 1 is sequentially ultrasonically cleaned with a cleaning agent, deionized water, acetone and ethanol for 15-20 min, and finally dried in a ventilated oven.

[0049] The constituting material of the transparent conductive film layer 11 is one of ITO (tin-doped indium oxide), FTO (fluorine-doped tin oxide), IWO (tungsten-doped indium oxide) and ICO (cerium-doped indium oxide).

[0050] The constituting material of the hole transport layer 2 is one of PTAA, PEDOT:PSS, Spiro-OMeTAD, Poly-TPD, NiOX, CuSCN, CuI and V2O5.

[0051] The constituting material of the perovskite light absorption layer 3 is an organic-inorganic hybrid perovskite, and its general formula is ABX3, wherein A is at least one of CH3NH3+(MA+), CH(CH2)2+(FA+) and Cs+, B is one of Pb2+, Sn2+ and Ge2+, and X is at least one of Cl-, Br- and I-.

[0052] The constituting material of the electron transport layer 4 is at least one of 、 、 、 、 、 .

[0053] The constituting material of the conductive electrode layer 5 is one of Ag, Au, Cu and Al.

[0054] In the embodiment, the perovskite solar cell prepared by the method has the following advantages: Figure 4 It can be known that, compared with a conventional perovskite solar cell, the open-circuit voltage of the perovskite solar cell prepared by the method is significantly improved, and the short-circuit current density is slightly improved, so that the efficiency is obviously improved by 30%-50%.

[0055] In the description of the application, it should be understood that the terms "center", "transverse", "upper", "lower", "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 only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, unless otherwise stated, the meaning of "several" is two or more. In addition, the term "includes" and any variations thereof are intended to cover non-exclusive inclusion.

[0056] The application is described according to the embodiments, and the device can also be modified and improved in several ways without departing from the principles of the application. It should be noted that the technical solutions obtained by using equivalent replacement or equivalent transformation and the like fall within the scope of protection of the application.

Claims

1. A method for modifying a composite perovskite solar cell with a ferroelectric material, the ferroelectric material-modified composite perovskite solar cell comprising a transparent conductive substrate (1), wherein a hole transport layer (2), a carbonate perovskite light absorption layer (3), an electron transport layer (4) and an electrode layer (5) are sequentially arranged on the transparent conductive substrate (1) from inside to outside; wherein, The calcium carbonate mineral light absorption layer (3) comprises a calcium carbonate mineral light absorption layer body (30), a ferroelectric layer (31) is deposited at the contact position of the calcium carbonate mineral light absorption layer body (30) and the hole transport layer (2), the ferroelectric layer (31) is composed of ferroelectric nanocrystals, and the ferroelectric layer (31) is field passivated in ferroelectric polarization. Characterized in that: comprising the following steps: step one: depositing a hole transport layer (2); step two: depositing a perovskite light absorption layer (3); S1, depositing a ferroelectric layer (31), the transparent conductive substrate (1) treated by step one is put into a culture dish containing ferroelectric nanocrystal dispersion liquid, the culture dish is placed in a constant temperature oven with a temperature of 80℃ for 1.5h, the ferroelectric nanocrystal is deposited on the hole transport layer (2), after the deposition is completed, it is taken out, cleaned with anhydrous ethanol and deionized water, and then placed in a drying box for drying; S2, depositing a perovskite light absorption layer body (30), selecting The precursor solution is coated on the battery prepared by S1, annealed at 160℃ for 10-15 minutes; step three: depositing an electron transport layer (4); step four: depositing an electrode layer (5) on the battery piece prepared by step three; step five: applying a positive ferroelectric polarization; that is, a constant current voltage source is used to apply a positive ferroelectric polarization from the electrode layer (5) to the transparent conductive substrate (1) and perpendicular to the surface of the perovskite battery, wherein the applied external electric field > the ferroelectric coercive field of the ferroelectric material.

2. The method for preparing a ferroelectric material modified composite perovskite solar cell according to claim 1, characterized in that: The specific content of the step one is: selecting As the material of the hole transport layer (2), a layer of thin film with the thickness of 80-100nm is generated on the transparent conductive substrate (1) by the way of magnetron sputtering. Thin film.

3. The method for preparing a ferroelectric material modified composite perovskite solar cell according to claim 2, characterized in that: The specific content of the third step is that the nanoparticles are dissolved in ionized water at a certain ratio, and then coated on the perovskite light absorption layer (3) after dissolution and annealing treatment.

4. The method for preparing a ferroelectric material modified composite perovskite solar cell according to claim 3, characterized in that: The nanoparticle material is selected from , and the nanoparticles and the deionized water are dissolved at a volume ratio of 1:

5.

5. The method for preparing a ferroelectric material modified composite perovskite solar cell according to claim 4, characterized in that: The thickness of the electron transport layer (4) is 50-80 nm, and the annealing treatment temperature of the electron transport layer (4) during preparation is 150 DEG C.

6. The method for preparing a ferroelectric material modified composite perovskite solar cell according to claim 1, characterized in that: The transparent conductive substrate (1) comprises a glass substrate (10) and a transparent conductive film (11) deposited on the glass substrate (10).

7. The method for preparing a ferroelectric material modified composite perovskite solar cell according to claim 6, characterized in that: The transparent conductive film (11) is provided with a groove one (7) for locally embedding the hole transport layer (3), the electron transport layer (4) is provided with a groove two (8) for embedding the electrode layer (5), the groove two (8) extends downward to the upper surface of the transparent conductive film (11), and the electrode layer (4) is provided with a groove three (9) extending downward to the upper surface of the transparent conductive film (11).

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