Interface and field passivation high efficiency perovskite solar cell and preparation method thereof

Abstract

An interface and field passivation high-efficiency perovskite solar cell and a preparation method thereof belong to the technical field of solar cell processing, and comprise 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 electron transport layer comprises an electron transport layer body, the electron transport layer body is in contact with the perovskite light absorption layer, and the electron transport layer body is doped with ferroelectric nanoparticles inside, the material of the ferroelectric nanoparticles is KNbO3, and the ferroelectric nanoparticles are field passivated by ferroelectric polarization; the KNbO3 ferroelectric nanoparticles modify the SnO2 electron transport layer, on the one hand, K+ ions are used to passivate defects at the interface of the electron transport layer, and the photoelectric conversion efficiency and stability of the perovskite solar cell are improved, on the other hand, the perovskite pin junction is field passivated by ferroelectric polarization, so that the photoelectric conversion efficiency of the perovskite solar cell is further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cell processing, and in particular relates to an interface and field passivation high-efficiency perovskite solar cell and a preparation method thereof. Background Art

[0002] Perovskite solar cells have attracted widespread attention due to their exceptional optoelectronic properties, including tunable band gaps, high light absorption coefficients, long carrier lifetimes and diffusion lengths, high defect tolerance, and low-cost, low-temperature liquid-phase fabrication methods. The efficiency of small-scale laboratory-fabricated photovoltaic devices has soared from 3.8% in 2009 to 25.8% in 2021 in just over a decade, making them a promising candidate for the next generation of novel photovoltaic materials.

[0003] Inverted (nip) perovskite cells have long been a research hotspot in the perovskite photovoltaic field due to their simple fabrication process and high photoelectric conversion efficiency. However, these cells suffer from significant hysteresis, poor device stability, and difficulty in fabricating flexible devices, hindering their large-scale commercialization. Inverted (pin) perovskite cells, with their negligible hysteresis, excellent interface stability, and low-temperature fabrication of flexible devices, have become a dominant force in the industrialization of perovskite cells.

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

[0005] The traditional electron transport layer material TiO2 is not suitable for inverted perovskite cells due to its high-temperature manufacturing process. Instead, the SnO2 electron transport layer has been replaced, which has higher carrier mobility, energy level matching, and is prepared at low temperature. However, the preparation process of the SnO2 electron transport layer introduces defects at the interface, which affects the photoelectric conversion efficiency and stability of the perovskite cell. For SnO2-based inverted perovskite cells, the mainstream method to improve the efficiency is to dope and modify the SnO2 electron transport layer to passivate the defects at the interface and improve the performance of the perovskite cell. However, few people have studied efficiency improvement methods other than passivation of defects. Summary of the Invention

[0006] The object of the present invention is to provide an interface and field passivation high-efficiency perovskite solar cell and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An interface and field-passivated high-efficiency perovskite solar cell comprises a transparent conductive substrate, on which a hole transport layer, a perovskite light absorption layer, an electron transport layer and an electrode layer are sequentially arranged from the inside to the outside; wherein the electron transport layer comprises an electron transport layer body, the electron transport layer body is in contact with the perovskite light absorption layer, and the electron transport layer body is doped with ferroelectric nanoparticles, the ferroelectric nanoparticle material is KNbO3, and the ferroelectric nanoparticles are field-passivated when ferroelectric polarization is applied.

[0009] Compared with the existing technology, this technical solution has the following effects:

[0010] By modifying the SnO2 electron transport layer with KNbO3 ferroelectric nanoparticles, on the one hand, K+ ions are used to passivate the defects at the interface of the electron transport layer, thereby improving the photoelectric conversion efficiency and stability of the perovskite battery. On the other hand, the perovskite pin junction is field-passivated through ferroelectric polarization, which not only enhances the built-in field of the perovskite material and promotes the separation and transmission of photogenerated electron-hole pairs, but also intensifies the splitting of the quasi-Fermi level of electrons and holes in the perovskite pin junction, thereby further improving the open circuit voltage of the battery and the photoelectric conversion efficiency of the perovskite battery.

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

[0012] The present invention also discloses a method for preparing an interface and field passivation high-efficiency perovskite solar cell, comprising the following steps:

[0013] Step 1: Deposit the hole transport layer, using NiO x As the material of the hole transport layer, a layer of NiO with a thickness of 80-100 nm is generated on the transparent conductive substrate by magnetron sputtering. x film;

[0014] Step 2: Deposit the perovskite light absorption layer, using FA 0.91 Cs 0.09 The PbI3 precursor solution was coated on the battery prepared by S1 and annealed at 160°C for 10-15 minutes;

[0015] Step 3: Depositing the electron transport layer: mixing the nanoparticle hydrosol with ionized water in a certain ratio, adding ferroelectric nanoparticles to a concentration of 3 mg / ml, dissolving the mixture, coating the mixture on the perovskite light absorption layer, and annealing the mixture;

[0016] Preferably, the nanoparticle material is SnO2.

[0017] Preferably, the nanoparticle hydrosol has a content of 15 wt %, and the nanoparticle hydrosol and the deionized water are mixed in a volume ratio of 1:4.

[0018] Preferably, the thickness of the electron transport layer is 50-80 nm, and the temperature of the annealing treatment of the electron transport layer during the preparation process is 100-150° C.

[0019] Preferably, the method further includes: Step 4: depositing an electrode layer on the battery cell prepared in Step 3.

[0020] Preferably, the method further includes: step five: applying a positive ferroelectric polarization; that is, using a constant current voltage source to apply a positive ferroelectric polarization from the electrode layer to the transparent conductive substrate and perpendicular to the surface of the perovskite cell prepared in step four, wherein the applied external electric field is greater than the ferroelectric coercive field of the ferroelectric material.

[0021] As a preference, in step 2, regarding FA 0.91 Cs 0.09 The preparation method of the PbI3 precursor solution is as follows: PbI2:FAI:CsI is added to a DMF / DM mixed solution with a volume ratio of 4.75:1 in a ratio of 1:0.91:0.09, and the concentration of the precursor solution is adjusted to 1.25 mol / L; then MaCl is added to the solution to obtain a MACl solution with a concentration of 23 mol%.

[0022] Preferably, a first groove is provided on the transparent conductive film for local embedding of the hole transport layer, a second groove is provided on the electron transport layer for embedding the electrode layer, the second groove extends downward to the upper surface of the transparent conductive film, and a third groove is provided on the electrode layer for downward extension to the upper surface of the transparent conductive film. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a schematic diagram of the overall structure of the first embodiment of the perovskite solar cell in the present invention;

[0024] Figure 2 Schematic diagram of the overall structure of the second embodiment of the perovskite solar cell in the present invention;

[0025] Figure 3 It is a schematic diagram of the J-V curve of the perovskite solar cell of the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] like Figure 1 The interface and field passivation high-efficiency perovskite solar cell shown in the figure includes a transparent conductive substrate 1, on which a hole transport layer 2, a calcium carbonate light absorption layer 3, an electron transport layer 4 and an electrode layer 5 are sequentially provided from the inside to the outside; wherein, the electron transport layer 4 includes an electron transport layer body 40, the electron transport layer body 40 is in contact with the calcium carbonate light absorption layer 3, and the electron transport layer body 40 is doped with ferroelectric nanoparticles 51, the material of the ferroelectric nanoparticles 51 is KNbO3, and the ferroelectric nanoparticles 51 are ferroelectrically polarized. Field passivation is performed; the SnO2 electron transport layer is modified with KNbO3 ferroelectric nanoparticles. On the one hand, K+ ions are used to passivate the defects at the interface of the electron transport layer, thereby improving the photoelectric conversion efficiency and stability of the perovskite battery. On the other hand, the perovskite pin junction is field passivated through ferroelectric polarization, which not only enhances the built-in field of the perovskite material and promotes the separation and transmission of photogenerated electron-hole pairs, but also intensifies the splitting of the quasi-Fermi level of electrons and holes in the perovskite pin junction, thereby further improving the open circuit voltage of the battery and the photoelectric conversion efficiency of the perovskite battery.

[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] Combine Figure 2 It can be seen that in another embodiment, a groove 7 is provided on the transparent conductive film 11 for local embedding of the hole transport layer 3, a groove 2 8 is provided on the electron transport layer 4 for embedding the electrode layer 5, the groove 2 8 extends downward to the upper surface of the transparent conductive film 11, and a groove 3 9 is provided on the electrode layer 4 extending downward to the upper surface of the transparent conductive film 11; wherein, the first groove 7 and the third groove 9 are both formed by laser scribing and cutting on the transparent conductive film 2 using a laser with a wavelength of 1064nm; the second groove 8 is formed by cutting using a laser with a wavelength of 532nm, thereby dividing the large-area perovskite cell into several sub-cells connected in series.

[0030] Furthermore, a method for preparing an interface and field passivated high-efficiency perovskite solar cell as described in any of the above solutions comprises the following steps:

[0031] Step 1: Deposit hole transport layer 2, using NiO x As the material of the hole transport layer 2, a layer of NiO with a thickness of 80-100 nm is formed on the transparent conductive substrate 1 by magnetron sputtering. x film;

[0032] Step 2: Deposit the perovskite light absorption layer 3, using FA 0.91 Cs 0.09The PbI3 precursor solution is coated on the battery prepared by S1 and annealed at 160°C for 10-15 minutes; wherein, in this embodiment, the step 2 regarding FA 0.91 Cs 0.09 The preparation method of the PbI3 precursor solution is as follows: PbI2:FAI:CsI is added to a DMF / DM mixed solution with a volume ratio of 4.75:1 in a ratio of 1:0.91:0.09, and the concentration of the precursor solution is adjusted to 1.25 mol / L; then MaCl is added to the solution to obtain a MACl solution with a concentration of 23 mol%.

[0033] Step 3: Deposit the electron transport layer 4, mix the nanoparticle hydrosol with ionized water in a certain proportion, add ferroelectric nanoparticles 51 to make its concentration 3 mg / ml, dissolve it and apply it on the perovskite light absorption layer 3, and anneal it; wherein the nanoparticle material is SnO2, the content of the nanoparticle hydrosol is 15wt%, and the nanoparticle hydrosol and the deionized water are mixed in a volume ratio of 1:4.

[0034] In this embodiment, the thickness of the electron transport layer 4 is 50-80 nm, and the temperature of the annealing treatment of the electron transport layer 4 during the preparation process is 100-150° C.

[0035] In this embodiment, the ferroelectric nanoparticles 51 are KNbO3.

[0036] Step 4: Deposit an electrode layer 5 on the cell prepared in Step 3. The electrode layer 5 is made of one of Ag, Au, Cu, and Al, with Ag being the preferred metal electrode material. A layer of Ag is deposited on the electron transport layer 6 using thermal evaporation. The thickness of the electrode is approximately 60 nm.

[0037] Step 5: applying a positive ferroelectric polarization; that is, using a constant current voltage source 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 cell prepared in step 4, wherein the applied external electric field is greater than the ferroelectric coercive field of the ferroelectric material.

[0038] It is worth noting that the preparation of ferroelectric KNbO3 nanoparticles in this embodiment is:

[0039] KNbO3 nanoparticles were synthesized using a hydrothermal method: 40 ml of a 6 mol / L KOH solution was placed in a beaker, and 0.5 g of Nb2O5 was added. The mixture was stirred with a magnetic stirrer for 2 hours to thoroughly mix the reactants. The mixture was then transferred to a polytetrafluoroethylene reactor and allowed to react at 180°C for 5 days. After the reaction was complete, the mixture was allowed to cool to room temperature and rinsed several times with deionized water and ethanol to remove impurities. The mixture was then dried in a drying oven at 70-80°C to obtain a white KNbO3 powder. Finally, the resulting white powder was ground in a ball mill to obtain KNbO3 nanoparticles.

[0040] In addition, in this embodiment, the transparent conductive substrate 1 needs to be cleaned before preparation. The specific cleaning steps are: first wipe the surface of the transparent conductive substrate 1 with dust-free paper dipped in ethanol, then ultrasonically clean it with detergent, deionized water, acetone, and ethanol for 15-20 minutes in sequence, and finally put it into a ventilated oven for drying.

[0041] The transparent conductive film layer 11 is made of a material selected from the group consisting of ITO (tin-doped indium oxide), FTO (fluorine-doped tin oxide), IWO (tungsten-doped indium oxide), and ICO (cerium-doped indium oxide).

[0042] The hole transport layer 2 is formed of a material selected from the group consisting of PTAA, PEDOT:PSS, Spiro-OMeTAD, Poly-TPD, NiOX, CuSCN, CuI, and V2O5.

[0043] The constituent material of the perovskite light absorption layer 3 is an organic-inorganic hybrid perovskite, whose 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-.

[0044] The constituent material of the electron transport layer 4 is at least one of PCBM, TiO2, ZnO, SnO2, H-PDI, and F-PDI.

[0045] In this embodiment, combined with Figure 3 It can be seen that the cell performance of the perovskite solar cell prepared by the present invention is compared with that of the traditional perovskite solar cell, and its open circuit voltage is significantly improved, and the short circuit current density is also slightly improved, which obviously shows that its efficiency is improved by 30%-50%.

[0046] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "several" means two or more. In addition, the term "including" and any variations thereof are intended to cover non-exclusive inclusions.

[0047] The present invention has been described in accordance with the embodiments. Without departing from the principles herein, the present invention may be modified and improved in several ways. It should be noted that any technical solution obtained by equivalent replacement or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. An interface and field passivation high-efficiency perovskite solar cell, comprising a transparent conductive substrate (1), characterized in that: The transparent conductive substrate (1) is provided with a hole transport layer (2), a calcium carbonate light absorption layer (3), an electron transport layer (4) and an electrode layer (5) in sequence from the inside to the outside; wherein the electron transport layer (4) includes an electron transport layer body (40), the electron transport layer body (40) is in contact with the calcium carbonate light absorption layer (3), and the electron transport layer body (40) is doped with ferroelectric nanoparticles (51), the ferroelectric nanoparticles (51) are made of KNbO3, and the ferroelectric nanoparticles (51) are field-passivated in the ferroelectric polarization, and the field passivation includes applying a positive ferroelectric polarization from the electrode layer (5) to the transparent conductive substrate (1) and perpendicular to the surface of the battery to the battery using a constant current voltage power supply, wherein the applied external electric field is greater than the ferroelectric coercive field of the ferroelectric material.

2. The interface and field passivation high-efficiency 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).

3. A method for preparing an interface and field passivation high-efficiency perovskite solar cell according to claim 1 or 2, characterized in that: The following steps are included: Step 1: Deposit the hole transport layer (2), select As the material of the hole transport layer (2), a layer with a thickness of 80-100 nm is generated on the transparent conductive substrate (1) by magnetron sputtering. Thin film; Step 2: Deposit the perovskite light absorbing layer (3), using The precursor solution is coated on the battery prepared by S1 and annealed at 160°C for 10-15 minutes; Step 3: Deposit the electron transport layer (4), mix the nanoparticle hydrosol with deionized water in a certain proportion, and add ferroelectric nanoparticles (51) to make the concentration of , after being dissolved, coated on the perovskite light absorption layer (3), and annealed; the nanoparticle material is selected from , the material of the ferroelectric nanoparticles (51) is KNbO3; Step 4: depositing an electrode layer (5) on the cell prepared in step 3; Step 5: applying a positive ferroelectric polarization; that is, applying a positive ferroelectric polarization from the electrode layer (5) toward the transparent conductive substrate (1) and perpendicular to the surface of the perovskite cell using a constant current voltage source, wherein the applied external electric field is greater than the ferroelectric coercive field of the ferroelectric material.

4. The method for preparing an interface and field passivation high-efficiency perovskite solar cell according to claim 3, wherein: The nanoparticle hydrosol has a content of 15 wt %, and the nanoparticle hydrosol and the deionized water are mixed in a volume ratio of 1:

4.

5. The method for preparing an interface and field passivation high-efficiency perovskite solar cell according to claim 4, characterized in that: The thickness of the electron transport layer (4) is 50-80 nm, and the temperature of the annealing treatment of the electron transport layer (4) during the preparation process is 100-150° C.

6. The method for preparing an interface and field passivation high-efficiency perovskite solar cell according to claim 3, characterized in that: Regarding the step 2 The preparation method of the precursor solution is as follows: Add 4.75:1 in a volume ratio of 1:0.91:0.09 In the mixed solution, the concentration of the precursor solution is adjusted to 1.25 ; Then add to the solution to The concentration of the solution is 23 .

7. The interface and field passivation high-efficiency perovskite solar cell according to claim 2, characterized in that: The transparent conductive film (11) further comprises a first groove (7) for partially embedding the hole transport layer (3), a second groove (8) for embedding the electrode layer (5) on the electron transport layer (4), the second groove (8) extending downward to the upper surface of the transparent conductive film (11), and a third groove (9) extending downward to the upper surface of the transparent conductive film (11) on the electrode layer (4).

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