Perovskite solar cell with synergistically passivated buried interface and preparation method thereof

Abstract

The application discloses a perovskite solar cell with a buried interface of synergistic passivation and a preparation method thereof. The method comprises the following steps: adding ribose or deoxyribose as an additive into an electron (hole) transport layer solution to form an electron (hole) transport layer precursor solution; spin-coating the electron (hole) transport layer precursor solution on a conductive glass substrate to form a modified electron (hole) transport layer; and sequentially preparing a perovskite thin film layer, a hole (electron) transport layer and a metal electrode on the modified electron (hole) transport layer to obtain the perovskite solar cell. The method utilizes the unique three-dimensional space structure of the biological small molecule ribose or deoxyribose itself to produce a passivation effect with the electron transport layer or the hole transport layer, so that the defect state density is greatly reduced, the carrier separation and extraction efficiency is effectively increased, and the photoelectric performance of the perovskite solar cell is improved.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell technology, specifically to a perovskite solar cell with synergistic passivation of the buried interface and its fabrication method. Background Technology

[0002] Organic-inorganic hybrid perovskite solar cells have attracted widespread attention due to their excellent photoelectric conversion performance, with a current photoelectric conversion efficiency (PCE) reaching 25.7%. However, when preparing perovskite thin films using solution spin-coating, defects inevitably occur at grain boundaries and surfaces. These defects mainly include unpassivated Pb. 2+ The deep defect states formed, oxygen vacancies in electron transport materials, and defect sites in hole transport materials, etc., these defects are called nonradiative recombination centers. They easily trap photogenerated carriers, weaken the conductivity of carrier transport materials, reduce carrier transport efficiency, and seriously affect the short-circuit current (J) of perovskite solar cells. sc ), open circuit voltage (V) oc The presence of halogen anions and fill factor (FF) negatively impacts the photoelectric conversion efficiency and long-term stability of the device. Furthermore, continuous illumination typically leads to the segregation of halide anions, resulting in the formation of iodine vacancies within the perovskite structure, which also adversely affects the performance of perovskite solar cells.

[0003] Most currently proven effective passivating additives typically contain only a single type of functional group, thus only passivating a specific defect. There is an urgent need to explore methods that can simultaneously passivate defects in both the carrier transport layer and the perovskite buried interface. Summary of the Invention

[0004] To address the current technical problem of the inability to synergistically passivate the carrier transport layer and the perovskite buried interface, this invention proposes a perovskite solar cell with synergistic passivation of the buried interface and its fabrication method. The fabrication method of the perovskite solar cell with synergistic passivation of the buried interface includes the following steps:

[0005] Ribose or deoxyribose is added as an additive to a metal oxide solution to form an electron transport layer precursor solution;

[0006] The electron transport layer precursor solution is spin-coated onto a conductive glass substrate to form a modified electron transport layer;

[0007] A perovskite thin film layer, a hole transport layer, and a metal electrode were sequentially fabricated on a modified electron transport layer to obtain a perovskite solar cell.

[0008] Preferably, the specific steps for sequentially preparing a perovskite thin film layer, a hole transport layer, and a metal electrode on the modified electron transport layer are as follows:

[0009] A perovskite thin film layer was prepared by spin-coating a perovskite precursor solution onto the modified electron transport layer.

[0010] The perovskite thin film layer is subjected to heat annealing;

[0011] A hole transport layer is prepared by spin-coating a hole transport material onto a perovskite thin film layer after heating and annealing.

[0012] Metal electrodes are deposited on the hole transport layer using vacuum deposition.

[0013] Preferably, the concentration of the ribose or deoxyribose is 0.1 to 0.3 mg / mL.

[0014] Preferably, the electron transport layer solution is a SnO2 solution, ZnO solution, or TiO2 solution with a mass fraction of 2-3%.

[0015] Preferably, the specific preparation steps of the perovskite precursor solution are as follows: Pb salt or Sn salt is dissolved in an organic solvent with methylamine iodide, formamidinium iodide, or cesium salt in any proportion to obtain the perovskite precursor solution. The perovskite molecular structure of the perovskite precursor solution is ABX3, where A is FA. + MA + Cs + One or more of them, where B is Pb 2+ Sn 2+ One or more of them, where X is Cl-, Br- - I - One or more of them

[0016] Preferably, the specific preparation steps for spin-coating the hole transport material onto the perovskite thin film layer after heating and annealing are as follows: dissolving lithium bis(trifluoromethanesulfonyl)imide in anhydrous acetonitrile to obtain a lithium bis(trifluoromethanesulfonyl)imide solution; dissolving Spiro-OMeTAD in a mixed solution of chlorobenzene, tributyl phosphate, and the lithium bis(trifluoromethanesulfonyl)imide solution to obtain the hole transport material; and coating the hole transport material onto the perovskite thin film layer to prepare the hole transport layer.

[0017] The present invention also provides a perovskite solar cell with synergistic passivation of the buried interface, wherein the perovskite solar cell is prepared by the above method.

[0018] In addition to solar cells with a positive planar heterojunction (nip) structure, i.e., the perovskite solar cells with synergistic passivation of the buried interface mentioned above, the ribose or deoxyribose proposed in this invention can also be applied to perovskite solar cells with a negative planar heterojunction (pin) structure. Therefore, this invention also provides a method for preparing a negative planar heterojunction perovskite solar cell, comprising the following steps:

[0019] Ribose or deoxyribose is added as an interfacial additive to the hole transport layer precursor solution;

[0020] A modified hole transport layer is formed by spin-coating a hole transport layer precursor solution with additives onto an electron transport layer on a conductive glass substrate.

[0021] A perovskite thin film layer, an electron transport layer, and a metal electrode were sequentially fabricated on a modified hole transport layer to obtain a perovskite solar cell.

[0022] Preferably, the hole transport layer driver solution is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate or halogenated poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution.

[0023] The present invention also provides an inverted planar heterojunction perovskite solar cell, which is prepared by the above method.

[0024] This invention uses ribose or deoxyribose biomolecules as additives in an electron transport layer precursor solution, which is then spin-coated onto a conductive glass substrate to form a modified electron transport layer. The use of ribose or deoxyribose reduces the accumulation of charge at the interface between the electron transport layer and the perovskite thin film light-absorbing layer, achieving synergistic passivation on both sides of the electron transport layer and the perovskite thin film layer. The oxygen atom on the furan ring can react with Pb... 2+ Lewis acid-base interactions occur, and the functional groups on the lower side of the furan ring plane can react with Sn in substrates such as SnO2. 4+ Phase coordination can effectively suppress the hysteresis phenomenon during forward and reverse scanning, greatly reduce the defect state density, effectively increase the charge extraction rate, and thus enhance the photoelectric conversion efficiency and stability of the device. At the same time, the functional groups on the upper side of the ring plane form hydrogen bonds with the halide ions in the perovskite, which can effectively suppress the generation of iodine vacancies and further improve the photoelectric performance of the device.

[0025] In inverted planar heterojunction perovskite solar cells, the addition of ribose / deoxyribose effectively passivates defects at the hole transport layer interface and the perovskite interface, reduces nonradiative recombination of photogenerated carriers, and further improves the energy utilization of solar cells. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the fabrication method of upright / reverse perovskite solar cells with synergistic passivation of the buried interface in Examples 1 / 3.

[0027] Figure 2 This is a schematic diagram of the structure of ribose / deoxyribose used in the examples;

[0028] Figure 3This is a schematic diagram of the perovskite solar cell structure of Example 1 / 2 with synergistic passivation of the buried interface;

[0029] Figure 4 This is a schematic diagram of the structure of the inverted planar heterojunction perovskite solar cell in Examples 3 / 4;

[0030] Figure 5 A schematic diagram of the design of ribonucleic acid as a crosslinking agent at the interface between tin oxide and perovskite;

[0031] in, Figure 3 In this diagram, 101 is a metal electrode; 102 is a modified electron transport layer; 103 is a perovskite thin film layer; 104 is a hole transport layer; and 105 is conductive glass.

[0032] Figure 4 In this diagram, 201 is the electron transport layer; 202 is the perovskite thin film layer; 203 is the modified hole transport layer; and 204 is the conductive glass (metal electrodes are omitted).

[0033] Figure 5 501 in the text refers to a halide anion, such as Cl. - ,Br - Or I - 502 is an A-site cation, such as FA. + MA + or Cs + 503 is a divalent metal cation, such as Pb. 2+ or Sn 2+ ; 504 is a ribose molecule. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] This embodiment provides a method for fabricating a perovskite solar cell with synergistic passivation of the buried interface, such as... Figure 1 As shown, the specific steps are as follows:

[0037] S101. The FTO conductive glass is continuously ultrasonically washed in deionized water, acetone, ethanol and isopropanol for 15 min, then dried under nitrogen, and treated with ultraviolet / ozone for 20-30 min; 1.0 mL of 15% SnO2 solution is taken with a pipette, 4.6 mL of deionized water is added to dilute the SnO2 solution to 2.67%, and then 0.1 mg / mL ribose solution is added as an interface additive to the 2.67% SnO2 solution to form an electron transport layer precursor solution. The electron transport layer precursor solution can also be ZnO or TiO2 solution.

[0038] S102. After filtering the electron transport layer driving solution, spin-coat it onto FTO conductive glass at a speed of 4000 r / min for 30 s to form a modified electron transport layer.

[0039] S103. Methylamine iodide (1.25 mol) and lead iodide (1.25 mol) are dissolved in a mixed solvent of N,N-dimethylformamide:dimethyl sulfoxide = 8-10:1, and stirred at 60°C for 12 hours to form a perovskite precursor solution. The perovskite precursor solution is then spin-coated onto the modified electron transport layer to prepare a perovskite thin film. The perovskite structure of the perovskite precursor solution is MAPbI3 or MA. 0.8 FA 0.2 The specific spin-coating method for PbI3 is as follows: accelerate from 5000 r / min to 1500 r / min and rotate for 10 seconds, then accelerate from 1000 r / min to 4000 r / min and rotate for another 25 seconds, for a total spin-coating time of 30-40 seconds. In the last 5 seconds before the end of the spin coating, apply 300 μL of chlorobenzene to the perovskite film; anneal the perovskite film coated with chlorobenzene at 100°C for 10 minutes in a glove box to form a perovskite film layer.

[0040] Weigh 520 mg of lithium bis(trifluoromethanesulfonyl)imide and dissolve it in 1 mL of anhydrous acetonitrile to prepare a lithium bis(trifluoromethanesulfonyl)imide solution; dissolve 72.3 mg of Spiro-OMeTAD in 1 mL of chlorobenzene, then add 28.8 μL of tributyl phosphate solution and 17.5 μL of lithium bis(trifluoromethanesulfonyl)imide solution; pipette 75 μL of Spiro-OMeTAD precursor solution, set the rotation speed to 3000 r / min, the acceleration to 1000 r / min, and the time to 30 s, and coat the hole transport material onto a perovskite film to prepare a hole transport layer 102. The hole transport layer 102 is Spiro-OMeTAD with a thickness of approximately 100 nm; under a vacuum degree <1×10 -5 Under Tor conditions, metallic Au is deposited onto the hole transport layer at a rate of 0.1–0.3 A per second to form a 100 nm Au electrode.

[0041] In this embodiment, the structure of the solar cell is as follows: Figure 3 As shown: It includes Ag101 / modified electron transport layer 102 / perovskite thin film layer 103 / hole transport layer 104 / conductive glass substrate 105.

[0042] Example 2

[0043] This embodiment provides a method for preparing a perovskite solar cell with synergistic passivation of the buried interface. The difference from Example 1 is that the interface additive is a 0.1 mg / mL deoxyribose solution.

[0044] Example 3

[0045] This embodiment provides a method for fabricating an inverted planar heterojunction perovskite solar cell, such as... Figure 1 As shown, it includes the following steps:

[0046] S101. The ITO conductive glass is continuously ultrasonically washed in deionized water, acetone, ethanol and isopropanol for 15 min, and then treated with ultraviolet / ozone for 10-20 min.

[0047] S102. Spin-coat a poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate solution with 0.1 mg / mL ribose solution added as an interface additive onto ITO conductive glass. Spin-coat continuously at 4000 rpm for 45 s to prepare a modified hole transport layer. Then anneal the ITO conductive glass with the prepared modified hole transport layer at 120 °C for 20 min and immediately transfer it to a glove box (oxygen and humidity should be less than 0.01 ppm).

[0048] S103. Methylamine iodide (1.25 mol) and lead iodide (1.25 mol) are dissolved in a mixed solvent of N,N-dimethylformamide:dimethyl sulfoxide = 8-10:1, and stirred at 60°C for 12 hours to form a perovskite precursor solution. The perovskite precursor solution is then spin-coated onto a modified hole transport layer to prepare a perovskite thin film. The perovskite structure of the perovskite precursor solution is MAPbI3 or MA. 0.8 FA 0.2 The specific spin-coating procedure for PbI3 is as follows: Accelerate from 5000 r / min to 1500 r / min and rotate for 10 seconds, then accelerate from 1000 r / min to 4000 r / min and rotate for another 25 seconds, for a total spin-coating time of 30–40 seconds. In the last 5 seconds before the end of the spin coating, apply 300 μL of chlorobenzene to the perovskite film; anneal the chlorobenzene-coated perovskite film at 100°C for 10 minutes in a glove box; then apply PC at a concentration of 20 mg / mL. 61BM spin-coated the perovskite thin film at 2000 rpm for 60 seconds, depositing an electron transport layer on top of the perovskite layer; the device semi-finished product was then transferred to approximately 1×10 -6 Finally, in a vacuum thermal evaporation machine with an 80-meter bar, approximately 80 nm of Ag is deposited onto the perovskite film.

[0049] In this embodiment, the structure of the solar cell is as follows: Figure 4 As shown: It includes a conductive glass substrate 204, a modified hole transport layer 203, a perovskite thin film layer 202, an electron transport layer 201, and an Ag electrode.

[0050] Example 4

[0051] This embodiment provides a method for preparing a perovskite solar cell with synergistic passivation of the buried interface. The difference from Example 3 is that the interface additive is a 0.1 mg / mL deoxyribose solution.

[0052] This invention opens up new avenues for the application of biomolecules in the optoelectronic field, provides new inspiration for interdisciplinary exploration, and offers deeper insights into the rational use of the three-dimensional spatial structure of organic molecules for the synergistic passivation of perovskite solar cells.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for fabricating a perovskite solar cell with synergistic passivation of the buried interface, characterized in that, Includes the following steps: Ribose or deoxyribose is added as an additive to the electron transport layer solution to form an electron transport layer precursor solution; the concentration of ribose or deoxyribose is 0.1~0.3 mg / mL; the electron transport layer solution is a SnO2 solution, ZnO solution or TiO2 solution with a mass fraction of 2~3%; The electron transport layer precursor solution is spin-coated onto a conductive glass substrate to form a modified electron transport layer; A perovskite thin film layer, a hole transport layer, and a metal electrode were sequentially fabricated on a modified electron transport layer to obtain a perovskite solar cell.

2. The method for fabricating a perovskite solar cell with synergistic passivation of the buried interface as described in claim 1, characterized in that, The specific steps for sequentially preparing a perovskite thin film layer, a hole transport layer, and a metal electrode on the modified electron transport layer are as follows: A perovskite thin film layer was prepared by spin-coating a perovskite precursor solution onto the modified electron transport layer. The perovskite thin film layer is subjected to heat annealing; A hole transport layer is prepared by spin-coating a hole transport material onto a perovskite thin film layer after heating and annealing. Metal electrodes are deposited on the hole transport layer using vacuum deposition.

3. The method for preparing a perovskite solar cell with synergistic passivation of the buried interface as described in claim 2, characterized in that, The specific preparation steps of the perovskite precursor solution are as follows: Pb salt or Sn salt is dissolved in an organic solvent with methylamine iodide, formamidinium iodide, or cesium salt in any proportion to obtain the perovskite precursor solution. The perovskite molecular structure of the perovskite precursor solution is ABX3, where A is FA. + MA + Cs + One or more of them, where B is Pb 2+ Sn 2+ One or more of them, where X is Cl - ,Br - I - One or more of them.

4. The method for preparing a perovskite solar cell with synergistic passivation of the buried interface as described in claim 2, characterized in that, The specific preparation steps for preparing a hole transport layer by spin-coating a hole transport material onto a perovskite thin film layer after heating and annealing are as follows: A lithium bis(trifluoromethanesulfonyl)imide solution is prepared by dissolving lithium bis(trifluoromethanesulfonyl)imide in anhydrous acetonitrile; a hole transport material is prepared by dissolving Spiro-OMeTAD in a mixed solution composed of chlorobenzene, tributyl phosphate, and the lithium bis(trifluoromethanesulfonyl)imide solution; and the hole transport material is spin-coated onto a perovskite thin film layer to prepare a hole transport layer.

5. A perovskite solar cell with synergistic passivation of the buried interface, characterized in that, Perovskite solar cells are prepared by the method described in any one of claims 1 to 4.

6. A method for fabricating an inverted planar heterojunction perovskite solar cell, characterized in that, Includes the following steps: Ribose or deoxyribose is added as an additive to the hole transport layer precursor solution; the hole transport layer precursor solution is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate or halogenated poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution; A modified hole transport layer is formed by spin-coating a hole transport layer precursor solution with additives onto an electron transport layer on a conductive glass substrate. A perovskite thin film layer, an electron transport layer, and a metal electrode were sequentially fabricated on a modified hole transport layer to obtain a perovskite solar cell.

7. A reverse planar heterojunction perovskite solar cell, characterized in that, Perovskite solar cells were prepared using the method described in claim 6.

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