Perovskite solar cell and preparation method thereof
By using bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium as a passivation material in perovskite solar cells, the problem of carrier recombination in perovskite solar cells is solved, and the photoelectric conversion efficiency and stability are improved.
Patent Information
- Application Number
- CN202510620864.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-14
- Publication Date
- 2025-09-09
AI Technical Summary
Perovskite solar cells have defects, and carriers are easily recombined, resulting in reduced photoelectric conversion efficiency.
A passivation layer is prepared between the hole transport layer and the perovskite active layer, and bis(4,6-difluorophenylpyridine-C2,N)picolinyl iridium is used as the passivation material. The interface defects are filled through chemical bonds or physical adsorption, the interface energy level is adjusted, and the carrier transport is promoted.
It improves the open-circuit voltage and fill factor of perovskite solar cells, enhances the stability and photoelectric performance of the device, and reduces the energy loss during carrier recombination.
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Figure CN120614966A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of perovskite solar cells, and in particular to a perovskite solar cell and a preparation method thereof. Background Art
[0002] Perovskite solar cells have excellent optoelectronic properties, including adjustable bandgap, high light absorption coefficient, high carrier mobility, and long carrier diffusion length. Their power conversion efficiency (PCE) has rapidly increased from 3.8% to 26.7%. Due to their high efficiency, low cost, and process-solution capabilities, perovskite solar cells have great potential to lead the next generation of photovoltaic technology.
[0003] However, perovskite solar cells produced using current processes often have numerous defects. These defects are unstable under external stimuli (light, heat, moisture, oxygen), particularly at unstable interfaces associated with the charge extraction layer. This can lead to the formation of numerous carrier recombination centers, ultimately resulting in a decrease in device performance. To reduce these defects, interface modification materials are often used. The introduction of these materials can aid in the formation of high-quality perovskite films, reduce interface defects, and thus improve device performance. Summary of the Invention
[0004] The main purpose of the present invention is to provide a perovskite solar cell and a preparation method thereof, so as to solve the technical problem that perovskite solar cells have defects and carriers are easily recombine, resulting in reduced photoelectric conversion efficiency.
[0005] To achieve the above object, the present invention provides a method for preparing a perovskite solar cell, comprising the following steps:
[0006] dissolving bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium in a solvent to obtain a bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution;
[0007] The bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution is coated on the surface of the hole transport layer to obtain a passivation layer, and a perovskite active layer is prepared on the surface of the passivation layer; or, the bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution is coated on the surface of the perovskite active layer to obtain a passivation layer, and a hole transport layer is prepared on the surface of the passivation layer.
[0008] In some embodiments of the present invention, the solvent includes at least one of isopropyl alcohol, ethanol, and chlorobenzene.
[0009] In some embodiments of the present invention, the concentration of bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium in the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution is (0.1-5) mg / ml.
[0010] In some embodiments of the present invention, the concentration of bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium in the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution is (2-4) mg / ml.
[0011] In some embodiments of the present invention, the thickness of the passivation layer is 0.1 nm to 10 nm.
[0012] In some embodiments of the present invention, the bis(4,6-difluorophenylpyridine-C2,N)picolinyl iridium solution is coated onto the surface of the hole transport layer or the surface of the perovskite active layer by spin coating, wherein the spin coating time is 10s to 60s; and / or the spin coating speed is 1000rpm to 6000rpm.
[0013] In some embodiments of the present invention, after the bis(4,6-difluorophenylpyridine-C2,N)picolinyliridium solution is coated on the surface of the hole transport layer or the surface of the perovskite active layer, an annealing treatment is further performed.
[0014] In some embodiments of the present invention, the annealing temperature is 100° C. to 150° C.; and / or the annealing time is 5 min to 10 min.
[0015] The present invention also provides a perovskite solar cell prepared by the above-mentioned method for preparing a perovskite solar cell.
[0016] In some embodiments of the present invention, the perovskite solar cell includes a transparent conductive oxide layer, the hole transport layer, the passivation layer, the perovskite active layer, the electron transport layer and the back electrode stacked in sequence; or, the perovskite solar cell includes a transparent conductive oxide layer, the electron transport layer, the perovskite active layer, the passivation layer and the hole transport layer stacked in sequence.
[0017] The beneficial effects that can be achieved by the present invention are:
[0018] The present invention uses bis(4,6-difluorophenylpyridine-C2,N) picolinyl iridium as a passivation material to prepare a passivation layer between a hole transport layer and a perovskite active layer. The bis(4,6-difluorophenylpyridine-C2,N) picolinyl iridium contains fluorophenyl and pyridine groups. The fluorophenyl and pyridine groups can form chemical bonds or physical adsorption with the perovskite active layer and the adjacent hole transport layer, thereby filling the defects at the interface between the perovskite active layer and the hole transport layer, reducing the non-radiative recombination of carriers, and improving the open circuit voltage and fill factor of the perovskite solar cell. The pyridine group can also promote the hole to hole transport by adjusting the surface potential of the film. The transport of electrons to the hole transport layer and the reverse transport of electrons to the hole transport layer are inhibited at the same time. The nitrogen atoms on the pyridine ring can form coordination bonds with metal ions such as lead ions in the perovskite active layer, thereby stabilizing the interface structure and reducing defects. Moreover, the pyridine ring can also participate in adjusting the interface energy level and promote the effective transport of carriers. As a metal center, the electronic structure of iridium can form a good energy level match with the perovskite active layer or transport layer. The formation of a good energy level match is conducive to the effective transport of carriers at the interface, reducing energy loss and carrier recombination process. In addition, the overall structure of the iridium complex also helps to form a more ordered and denser perovskite crystal structure.
[0019] The present invention utilizes bis(4,6-difluorophenylpyridine-C2,N) picolinyl iridium as a passivating agent to form an interface passivation layer between a hole transport layer and a perovskite active layer, thereby enabling the perovskite solar cell to obtain excellent photoelectric performance and stability. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.
[0021] Figure 1 This is a schematic diagram of the preparation process of the passivation layer of a perovskite solar cell according to one embodiment of the present invention.
[0022] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION
[0023] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.
[0025] In the present invention, descriptions such as "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions of various embodiments may be combined with each other, but this must be based on the fact that they can be implemented by a person of ordinary skill in the art. If the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.
[0026] The present invention provides a method for preparing a passivation layer of a perovskite solar cell, referring to Figure 1 , including the following steps:
[0027] S10, dissolving bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium to obtain a bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution;
[0028] S20. The bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution is applied to the surface of the hole transport layer to obtain a passivation layer, and a perovskite active layer is prepared on the surface of the passivation layer; or, the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution is applied to the surface of the perovskite active layer to obtain a passivation layer, and a hole transport layer is prepared on the surface of the passivation layer.
[0029] In the present invention, when a bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution is coated on the surface of a hole transport layer to obtain a passivation layer, and then a perovskite active layer is prepared on the surface of the passivation layer, an inverted perovskite solar cell can be prepared. When a bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution is coated on the surface of a perovskite active layer to obtain a passivation layer, and then a hole transport layer is prepared on the surface of the passivation layer, an upright perovskite solar cell can be prepared.
[0030] In the present invention, the hole transport layer is an important part of the perovskite solar cell, which prevents electrons from passing through and reduces the recombination of electrons and holes. The hole transport material can be dissolved in a solvent to obtain a hole transport layer precursor solution, and the hole transport layer precursor solution forms a hole transport layer on the surface of the substrate.
[0031] In some embodiments, the hole transport material includes at least one of MeO-2PACz, Spiro-OMeTAD, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS), and poly(triarylamine) (PTAA), which can be selected according to the type of perovskite solar cell.
[0032] In the present invention, the perovskite active layer is the core part of the perovskite solar cell, which is responsible for absorbing sunlight and generating charge carriers. The perovskite material can be dissolved in an organic solvent to obtain a perovskite precursor solution. The perovskite precursor solution forms a perovskite film on the surface of the substrate. The obtained perovskite film is the perovskite active layer.
[0033] In some embodiments, the perovskite material comprises a structural formula ABX3, wherein A comprises an organic cation or an inorganic cation, for example, MA + , FA + 、Cs + At least one of the B positions includes a metal cation, such as Pb 2+ 、Sn 2+ At least one of the X positions includes a halogen anion, such as Br - , I - 、Cl - At least one of .
[0034] In some embodiments, the organic solvent that dissolves the perovskite material includes at least one of anhydrous N,N-dimethylformamide (DMF) and anhydrous dimethyl sulfoxide (DMSO).
[0035] In some embodiments, the volume ratio of DMF to DMSO is 4:1.
[0036] In some embodiments, when the perovskite precursor solution is applied to the surface of the substrate by spin coating, the perovskite precursor solution is spin coated at a low speed of 1000 rpm and a high speed of 4000 rpm, respectively, with the spin coating time being 10 s and 40 s, respectively, and the anti-solvent chlorobenzene is added dropwise when the total time remains for 6 s.
[0037] In some embodiments, after the perovskite precursor solution is coated on the surface of the hole transport layer, an annealing treatment is performed, and the annealing temperature is 100° C. and the annealing time is 20 minutes.
[0038] The present invention dissolves bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium to obtain a bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution, and applies the bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution between a hole transport layer and a perovskite active layer to obtain a passivation layer. The passivation layer can improve the contact between the perovskite active layer and the adjacent hole transport layer to improve the performance of the perovskite solar cell. Iridium is the metal center of bis(4,6-difluorophenylpyridine-C2,N) pyridine carboxylate, which contains fluorophenyl and pyridine groups. Fluorophenyl and pyridine groups can form chemical bonds or physical adsorption between the perovskite active layer and the transport layer, fill the defects at the interface of the perovskite active layer, reduce the non-radiative recombination of carriers, and improve the open circuit voltage and fill factor of perovskite solar cells. The pyridine group can also promote the transmission of holes to the hole transport layer by adjusting the surface potential of the perovskite active layer, while inhibiting the reverse transmission of electrons to the hole transport layer. The nitrogen atoms on it can also form coordination bonds with metal ions such as lead ions in the perovskite active layer, thereby stabilizing the interface structure and reducing defects. Moreover, the pyridine ring can also participate in adjusting the interface energy level and promote the effective transport of carriers. As a metal center, iridium's electronic structure can form a good energy level match with the perovskite active layer and the hole transport layer, thereby facilitating the effective transport of carriers at the interface, reducing energy loss and carrier recombination processes. In addition, the overall structure of the iridium complex also helps to form a more ordered and dense perovskite crystal structure.
[0039] In the present invention, the passivation layer prepared by coating the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution on the surface of the hole transport layer or on the surface of the perovskite active layer can be understood as the same functional layer, that is, the description of the passivation layer of the present invention represents both the film layer obtained by coating the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution on the surface of the hole transport layer and the film layer obtained by coating the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution on the surface of the perovskite active layer.
[0040] In some embodiments, bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium is dissolved in an organic solvent to obtain a bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution, and the organic solvent includes isopropanol. Isopropanol can effectively disperse the iridium evenly, thereby facilitating the formation of a uniform passivation layer.
[0041] In some embodiments, after bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium is dissolved in the organic solvent, stirring is further performed to promote the dissolution of bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium.
[0042] In some embodiments, the concentration of bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium in the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution is (0.1-5) mg / ml, which can be 0.1 mg / ml, 0.3 mg / ml, 0.5 mg / ml, 0.8 mg / ml, 1 mg / ml, 1.5 mg / ml, 2 mg / ml, 2.5 mg / ml, 3 mg / ml, 4 mg / ml, 4.5 mg / ml, 5 mg / ml, etc. Within the above concentration range, it is beneficial to form a passivation layer on the surface of the hole transport layer to play a modifying role.
[0043] In some embodiments, the thickness of the passivation layer is 0.1 to 10 nm, which can be 0.1 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, etc., which is conducive to the role of the passivation layer on the perovskite active layer and the hole transport layer. In this embodiment, the limitation on the thickness of the passivation layer includes both the di(4,6-difluorophenylpyridine-C2, N) picolinyl iridium solution coated on the surface of the hole transport layer to obtain the passivation layer, and the di(4,6-difluorophenylpyridine-C2, N) picolinyl iridium solution coated on the surface of the perovskite active layer to obtain the passivation layer.
[0044] In some embodiments, the bis(4,6-difluorophenylpyridine-C2,N)picolinyl iridium solution is applied to the surface of the hole transport layer or the perovskite active layer by spin coating at a spin coating speed of 1000 rpm to 6000 rpm for a spin coating time of 10s to 60s.
[0045] In some embodiments, the spin coating time is 10s to 60s, which can be 10s, 20s, 30s, 40s, 50s, 60s, etc., and the spin coating speed is 1000rpm to 6000rpm, which can be 1000rpm, 2000rpm, 3000rpm, 3500rpm, 4500rpm, 5000rpm, 6000rpm, etc., so that it is easy to evenly coat the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution on the surface of the hole transport layer or the perovskite active layer, and the thickness of the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium can be controlled, so as to fully exert the effect of the passivation layer on the perovskite active layer and the hole transport layer.
[0046] In some embodiments, after the bis(4,6-difluorophenylpyridine-C2,N)picolinyl iridium solution is coated on the surface of the substrate, annealing treatment is also performed, the annealing temperature is 100°C to 150°C, which can be 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc., and the annealing time is 5min to 10min, which can be 5min, 6min, 7min, 8min, 9min, 10min, etc. The structure of the passivation layer can be improved by annealing treatment.
[0047] The present invention also provides a perovskite solar cell, which includes a passivation layer prepared by the above-mentioned method for preparing a passivation layer of a perovskite solar cell.
[0048] In some embodiments, a perovskite solar cell includes a transparent conductive oxide layer, a hole transport layer, the passivation layer, a perovskite active layer, an electron transport layer, and a back electrode stacked in sequence.
[0049] In some embodiments, a perovskite solar cell includes a transparent conductive oxide layer, an electron transport layer, a perovskite active layer, the above-mentioned passivation layer, a hole transport layer, and a back electrode stacked in sequence.
[0050] In the present invention, the preparation method of the perovskite solar cell includes not only the preparation process of the passivation layer, but also the preparation of the above-mentioned various functional layers, such as the pretreatment of the transparent conductive oxide, the preparation of the electron transport layer, the preparation of the hole transport layer, the preparation of the perovskite active layer and the preparation of the back electrode.
[0051] The present invention provides an embodiment of a method for preparing a perovskite solar cell. The perovskite solar cell prepared thereby is an inverted perovskite solar cell. The preparation method comprises at least the following steps:
[0052] The transparent conductive oxide coated glass is ultrasonically cleaned using glass cleaning agent, deionized water, ethanol and isopropyl alcohol in sequence, and then the transparent conductive oxide coated glass is blown dry with a nitrogen flow, and then subjected to ultraviolet ozone cleaning (UVO) treatment; a hole transport material is dissolved in a solvent to obtain a hole transport layer precursor solution, the hole transport precursor solution is deposited on the surface of the transparent conductive oxide coated glass, and a hole transport layer is obtained after annealing; bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium is dissolved in a solvent to obtain a bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution; the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution with a concentration of (0.1-5) mg / ml is spin-coated on the surface of the hole transport layer at a speed of 5000 rpm for a spin coating time of 10s-60s, and then annealed at 100°C-150°C for 5min-10m in to obtain a passivation layer; dissolving a perovskite material in an organic solvent to obtain a perovskite precursor solution, placing a transparent conductive oxide-coated glass containing a hole transport layer in a nitrogen glove box, coating the perovskite precursor solution on the surface of the hole transport layer, adding an anti-solvent chlorobenzene during the spin coating process, and then annealing to obtain a perovskite active layer; dissolving m-fluorophenylethylamine bromide (mF-PEABr) in a solvent to obtain a m-fluorophenylethylamine bromide (mF-PEABr) solution; spin-coating the m-fluorophenylethylamine bromide (mF-PEABr) solution with a concentration of 2 mg / ml on the surface of the perovskite active layer at a rotation speed of 5000 rpm for a spin coating time of 30 seconds, and then annealing at 100° C. for 5 minutes to obtain a second passivation layer; depositing an electron transport material on the surface of the second passivation layer to prepare an electron transport layer; preparing a modification layer on the surface of the electron transport layer; and depositing a back electrode material on the surface of the modification layer to prepare a back electrode.
[0053] In the present invention, the electron transport layer, the modification layer and the back electrode can be prepared by referring to common preparation methods in the art.
[0054] In some embodiments, the electron transport material comprises C 60 .
[0055] In some embodiments, the electron transport layer is prepared by vacuum thermal evaporation.
[0056] In some embodiments, the thickness of the electron transport layer is 20 nm to 22 nm.
[0057] In some embodiments, the material for preparing the modification layer includes bathocuproin, thereby preparing a bathocuproin modification layer.
[0058] In some embodiments, the modified layer is prepared by vacuum thermal evaporation.
[0059] In some embodiments, the thickness of the modification layer is 7 nm to 10 nm.
[0060] In some embodiments, the back electrode material includes a metal material, illustratively including at least one of Ag, Cu, and Au.
[0061] In some embodiments, the back electrode is prepared by vacuum thermal evaporation.
[0062] In some embodiments, the thickness of the back electrode is 100 nm to 110 nm.
[0063] In some embodiments, during the preparation of a perovskite solar cell, an electron transport layer, a perovskite active layer, a passivation layer, a hole transport layer, and a back electrode layer can be sequentially prepared on the surface of a transparent conductive oxide-coated glass to prepare an upright perovskite solar cell.
[0064] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not used to limit the present invention.
[0065] Example 1
[0066] Prepare the transparent conductive oxide layer: ultrasonically clean the TCO conductive glass using glass cleaner, deionized water, ethanol, and isopropyl alcohol for 15 minutes. Then, blow dry the TCO conductive glass with a nitrogen stream and perform ultraviolet ozone cleaning (UVO) for 15 minutes.
[0067] Preparation of the hole transport layer: MeO-2PACz with a concentration of 1 mg / mL was deposited on the surface of the TCO conductive substrate by spin coating, and the hole transport layer was obtained by annealing at 100°C for 10 min.
[0068] Preparation of passivation layer: Dissolve bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium in ethanol to obtain a bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution with a concentration of 1 mg / mL, and spin-coat the bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution with a concentration of 1 mg / mL on the surface of the perovskite active layer at a speed of 5000 rpm for 30 seconds. Then anneal at 100°C for 5 minutes to obtain a passivation layer with a thickness of 0.1 nm to 10 nm.
[0069] Preparation of the perovskite active layer: CsI, FAI, MABr, MACl, and PbI2 were dissolved in a 0.95:0.05:1 molar ratio in a mixture of DMF and DMSO (8:2 by volume) to prepare a 1.5M solution of FA0.95Cs0.05PbI3 containing additives. The solution was then stirred at room temperature for 12 hours to obtain the perovskite precursor solution. The sample with the prepared hole transport layer was spin-coated with 100 μL of the prepared perovskite precursor solution in a nitrogen glove box at a low speed of 1000 rpm and a high speed of 4000 rpm for 10 and 40 seconds, respectively. Chlorobenzene, the antisolvent, was added dropwise with 6 seconds remaining in the total spin-coating time. The sample was then annealed at 100°C for 20 minutes to obtain the perovskite active layer.
[0070] Preparation of the second passivation layer: Spin-coat a 2 mg / mL m-fluorophenylethylamine bromide (mF-PEABr) solution on the surface of the perovskite active layer at a rotation speed of 5000 rpm for 30 s, and then anneal at 100°C for 5 min to obtain the second passivation layer.
[0071] Preparation of electron transport layer: A C60 electron transport layer with a thickness of 20 nm was prepared on the surface of the second passivation layer by vacuum thermal evaporation.
[0072] Preparation of the modification layer: A 7 nm bathocuproine (BCP) modification layer was prepared on the surface of the C60 electron transport layer by vacuum thermal evaporation.
[0073] Preparation of back electrode: A 100 nm thick Ag back electrode was prepared on the surface of the bathocuproin (BCP) modified layer by vacuum thermal evaporation.
[0074] Example 2
[0075] The preparation method of Example 2 is basically the same as that of Example 1, except that the concentration of the passivating agent (4,6-difluorophenylpyridine-C2,N) picolinyl iridium is 0.1 mg / mL.
[0076] Example 3
[0077] The preparation method of Example 3 is basically the same as that of Example 1, except that the concentration of the passivating agent (4,6-difluorophenylpyridine-C2,N) picolinyl iridium is 0.5 mg / mL.
[0078] Example 4
[0079] The preparation method of Example 4 is basically the same as that of Example 1, except that the concentration of the passivating agent (4,6-difluorophenylpyridine-C2,N) picolinyl iridium is 1.5 mg / mL.
[0080] Example 5
[0081] The preparation method of Example 5 is basically the same as that of Example 1, except that the concentration of the passivating agent (4,6-difluorophenylpyridine-C2,N) picolinyl iridium is 2 mg / mL.
[0082] Example 6
[0083] The preparation method of Example 6 is basically the same as that of Example 1, except that the concentration of the passivating agent (4,6-difluorophenylpyridine-C2,N) picolinyl iridium is 3 mg / mL.
[0084] Example 7
[0085] Example 7 A perovskite active solar cell was prepared by referring to the preparation method of Example 1, except that Example 7 did not perform the preparation of the second passivation layer in step S5.
[0086] Example 8
[0087] The preparation method of the perovskite solar cell of Example 8 is as follows:
[0088] Prepare the transparent conductive oxide layer: ultrasonically clean the ITO conductive glass for 15 minutes using glass cleaner, deionized water, ethanol, and isopropyl alcohol in sequence. Then, blow dry the ITO conductive glass with a nitrogen stream and perform ultraviolet ozone cleaning (UVO) for 15 minutes.
[0089] Preparation of electron transport layer: A SnO2 hydrocolloid solution with a mass concentration of 15% and deionized water were mixed in a volume ratio of 2:1 to prepare an electron transport layer precursor solution, which was then spin-coated onto the surface of ITO at a speed of 5000 rpm for 10 seconds, and then annealed at 150°C for 10 minutes and UVO treated for 30 minutes to obtain the electron transport layer.
[0090] Preparation of perovskite active layer: CsI, FAI, MABr, MACl, and PbI2 were dissolved in a mixed solution of DMF and DMSO with a volume ratio of 8:2 at a molar ratio of 0.95:0.05:1 to prepare a 1.5 M concentration of FAI containing additives. 0.95 Cs 0.05 A PbI3 solution was then stirred at room temperature for 12 hours to obtain a perovskite precursor solution. The sample with the prepared hole transport layer was spin-coated with 100 μL of the prepared perovskite precursor solution in a nitrogen glove box at a low speed of 1000 rpm and a high speed of 4000 rpm for 10 seconds and 40 seconds, respectively. The anti-solvent chlorobenzene was added dropwise when the total spin-coating time remained for 6 seconds. The sample was then annealed at 100°C for 20 minutes to obtain the perovskite active layer.
[0091] Preparation of passivation layer: Dissolve bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium in ethanol to obtain a bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution with a concentration of 1 mg / mL, and spin-coat the bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution with a concentration of 1 mg / mL on the surface of the perovskite active layer at a speed of 5000 rpm for 30 seconds. Then anneal at 100°C for 5 minutes to obtain a passivation layer with a thickness of 0.1 nm to 10 nm.
[0092] Preparation of hole transport layer: Take 72.5 mg of Spiro-OMeTAD, add 1 mL of chlorobenzene, 28.5 uL of 4-tert-butylpyridine, and 18 μL of lithium bistrifluoromethanesulfonyl imide acetonitrile solution (concentration is 520 mg / mL), stir for 10 h to 15 h to prepare Spiro-OMeTAD solution, and spin-coat the Spiro-OMeTAD solution on the surface of the passivation layer at a speed of 4000 rpm for 20 s to obtain a hole transport layer.
[0093] Preparation of the back electrode layer: an Ag back electrode with a thickness of 80 nm was evaporated on the surface of the hole transport layer.
[0094] Comparative Example 1
[0095] The preparation methods of Comparative Example 1 are substantially the same as those of Example 1, except that the passivation material (4,6-difluorophenylpyridine-C2,N) iridium pyridine is not used to prepare the passivation layer.
[0096] Comparative Example 2
[0097] Comparative Example 2: A perovskite solar cell was prepared by referring to the preparation method of Example 8, except that no passivation layer was prepared in Comparative Example 2.
[0098] Table 1 Performance comparison of the products obtained from Examples 1 to 8 and Comparative Examples 1 and 2
[0099]
[0100] It can be seen from Table 1 that a passivation layer is prepared between the hole transport layer and the perovskite active layer in Examples 1 to 8. The passivation layer contains bis(4,6-difluorophenylpyridine-C2, N) pyridine carboxylic acid iridium. Bis(4,6-difluorophenylpyridine-C2, N) pyridine carboxylic acid iridium contains fluorophenyl and pyridine groups. The fluorophenyl and pyridine groups can form chemical bonds or physical adsorptions with the perovskite active layer and the adjacent hole transport layer, thereby filling the defects at the interface between the perovskite active layer and the adjacent transport layer, reducing the non-radiative recombination of carriers, and improving the open circuit voltage and fill factor of the perovskite solar cell. The pyridine group can also promote the transport of holes to the hole transport layer by adjusting the surface potential of the perovskite active layer, while inhibiting the reverse transport of electrons to the hole transport layer. The pyridine ring Nitrogen atoms can form coordination bonds with metal ions such as lead ions in the perovskite active layer, thereby achieving the purpose of stabilizing the interface structure and reducing defects. Moreover, the pyridine ring can also participate in adjusting the interface energy level and promote the effective transport of carriers. Iridium, as a metal center, has an electronic structure that may form a good energy level match with the perovskite active layer or the transport layer. The formation of a good energy level match contributes to the effective transport of carriers at the interface, reducing energy loss and the recombination process of carriers. In addition, the overall structure of the iridium complex also helps to form a more ordered and denser perovskite crystal structure. In summary, the perovskite solar cell has better photoelectric performance and stability. The photoelectric conversion efficiency of the perovskite solar cells of Example 1 and Example 8 is better than that of the perovskite solar cells of Comparative Example 1 and Comparative Example 2, respectively.
[0101] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A method for preparing a perovskite solar cell, characterized in that: The following steps are involved: dissolving bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium in a solvent to obtain a bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution; The bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution is coated on the surface of the hole transport layer to obtain a passivation layer, and a perovskite active layer is prepared on the surface of the passivation layer; or, the bis(4,6-difluorophenylpyridine-C2,N)picolinoyl iridium solution is coated on the surface of the perovskite active layer to obtain a passivation layer, and a hole transport layer is prepared on the surface of the passivation layer.
2. The method for preparing a perovskite solar cell according to claim 1, wherein: The solvent includes at least one of isopropyl alcohol, ethanol and chlorobenzene.
3. The method for preparing a perovskite solar cell according to claim 1, wherein: The concentration of bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium in the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution is (0.1-5) mg / ml.
4. The method for preparing a perovskite solar cell according to claim 3, wherein: The concentration of bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium in the bis(4,6-difluorophenylpyridine-C2,N)picolinoyliridium solution is (2-4) mg / ml.
5. The method for preparing a perovskite solar cell according to claim 1, wherein: The thickness of the passivation layer is 0.1 nm to 10 nm.
6. The method for preparing a perovskite solar cell according to claim 1, wherein: The bis(4,6-difluorophenylpyridine-C2,N)picolinyl iridium solution is coated on the surface of the hole transport layer or the surface of the perovskite active layer by spin coating, wherein the spin coating time is 10s to 60s; and / or the spin coating speed is 1000rpm to 6000rpm.
7. The method for preparing a perovskite solar cell according to claim 1, wherein: After the bis(4,6-difluorophenylpyridine-C2,N)picolinyliridium solution is coated on the surface of the hole transport layer or the surface of the perovskite active layer, an annealing treatment is further performed.
8. The method for preparing a passivation layer of a perovskite solar cell according to claim 7, wherein: The annealing temperature is 100° C. to 150° C.; and / or the annealing time is 5 min to 10 min.
9. A perovskite solar cell prepared by the method for preparing a perovskite solar cell according to any one of claims 1 to 8.
10. The perovskite solar cell according to claim 9, characterized in that The perovskite solar cell includes a transparent conductive oxide layer, the hole transport layer, the passivation layer, the perovskite active layer, the electron transport layer and the back electrode stacked in sequence; or, the perovskite solar cell includes a transparent conductive oxide layer, the electron transport layer, the perovskite active layer, the passivation layer and the hole transport layer stacked in sequence.