N-dansyl-DL-threonine cyclohexyl ammonium modified perovskite solar cell and preparation method thereof

Abstract

The invention discloses an N-dansyl-DL-threonine cyclohexylammonium modified perovskite solar cell and a preparation method thereof. The N-dansyl-DL-threonine cyclohexylammonium modified perovskite solar cell comprises a substrate layer, a conductive substrate, a hole transport layer, a composite perovskite light absorption layer, an electron transport layer and a top electrode layer, wherein a chiral additive N-dansyl-DL-threonine cyclohexyl ammonium is added into a perovskite precursor liquid for forming the composite perovskite light absorption layer. According to the invention, N-dansyl-DL-threonine cyclohexylammonium is adopted to inhibit bulk phase and interface defects of perovskite through triple synergistic effects, including passivation of lead-related defects, inhibition of formation of cation vacancies and blocking of migration of anion vacancies; the problems that in the prior art, most organic molecules are single in function and can only act on one or two charged defects in perovskite, and the device optimization effect is limited can be solved. And the formed composite light absorption layer can greatly improve the photoelectric conversion efficiency of the solar cell.

Description

Technical Field

[0001] This invention belongs to the field of perovskite solar cell technology, and relates to perovskite solar cells modified with N-dansyl-DL-threonine cyclohexylammonium and their preparation methods. Background Technology

[0002] Perovskite solar cells (PSCs) are considered one of the most promising solar photovoltaic technologies due to their low cost, high efficiency, and commercial potential. However, their limited lifetime and stability remain a major challenge to their commercialization. Perovskite crystals have a multi-ionic structure, and eliminating and passivating ionic defects in the perovskite bulk phase is crucial to the quality of perovskite thin films, as well as the efficiency and stability of perovskite cells.

[0003] Currently, various strategies have been developed to eliminate defects in perovskite solar cells, including interface treatment, optimization of the charge transport layer, and additive engineering. Among these, additive engineering, which can fabricate cells with high crystallinity and high photoelectric conversion efficiency without additional post-processing, is considered the most direct and effective strategy for passivating inherent defects in perovskite and pursuing high-performance photovoltaic devices. Furthermore, additives are crucial for the formation of small grain boundaries and large grains, and can also significantly improve the durability of perovskite cells.

[0004] Therefore, in recent years, scientists have developed many additives to passivate perovskite phases, grain boundaries, and surface defects, suppress non-radiative recombination losses, and improve the performance of battery devices. However, most small molecules can only passivate one or two of these defects, limiting the improvement in device performance.

[0005] Furthermore, while additives significantly enhance the performance of perovskite solar cells, excessive amounts can lead to a substantial decrease in performance. Therefore, it is not feasible to mix multiple additives in the perovskite precursor solution, making the development of single-molecule additives particularly important. Thus, introducing a multifunctional organic small molecule into the perovskite precursor solution that can simultaneously passivate multiple charged defects, reduce cell defects, suppress non-radiative recombination, improve cell efficiency and stability, and further promote the industrialization of perovskite has become an important research direction in the perovskite field. Summary of the Invention

[0006] The problem solved by this invention is to provide a perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium and its preparation method, so as to improve the photoelectric conversion efficiency of perovskite solar cells.

[0007] This invention is achieved through the following technical solution:

[0008] N-dansyl-DL-threonine cyclohexylammonium modified perovskite solar cells include a substrate layer, a conductive substrate, a hole transport layer, a composite perovskite light-absorbing layer, an electron transport layer, and a top electrode layer.

[0009] In this process, a chiral additive, N-dansyl-DL-threonine cyclohexylammonium, is added to the perovskite precursor solution that forms the composite perovskite light-absorbing layer; the concentration of the additive is 0.1–5.0 mg / mL.

[0010] The structural formula of the N-dansyl-DL-threonine cyclohexylammonium is:

[0011]

[0012] The solvent for the perovskite precursor fluid is a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide, and the chemical formula of the active ingredient is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3;

[0013] Using chlorobenzene as the antisolvent, a perovskite precursor liquid with added N-dansyl-DL-threonine cyclohexylammonium was deposited on the hole transport layer in a one-step process to form a perovskite film, which was then annealed.

[0014] Furthermore, the substrate layer is a soda-lime glass or borosilicate glass layer;

[0015] The conductive substrate is one or more of the following: F-doped tin oxide layer, In-doped tin oxide layer, and Al-doped zinc oxide layer;

[0016] The hole transport layer is formed by spin-coating a solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid onto a conductive substrate.

[0017] The composite perovskite light-absorbing layer is formed by depositing a perovskite precursor liquid containing N-dansyl-DL-threonine cyclohexylammonium on a hole transport layer in a one-step process using chlorobenzene as the antisolvent, thereby forming a perovskite film and annealing it.

[0018] The solvent for the perovskite precursor fluid is a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide, and the chemical formula of the active ingredient is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3;

[0019] The electron transport layer is formed by sequentially layering a C layer on a composite perovskite layer. 60 And a layer of BCP;

[0020] The top electrode layer is formed by evaporating Ag or Au onto the electron transport layer.

[0021] The present invention also provides a method for preparing the N-dansyl-DL-threonine cyclohexylammonium modified perovskite solar cell, comprising the following steps:

[0022] 1) Pretreatment of the conductive ITO substrate;

[0023] 2) Fabricate a hole transport layer on a conductive substrate;

[0024] 3) Using chlorobenzene as the antisolvent, the perovskite precursor liquid with added N-dansyl-DL-threonine cyclohexylammonium was deposited on the hole transport layer in one step to form a perovskite film and then annealed.

[0025] The solvent for the perovskite precursor fluid is a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide, and the chemical formula of the active ingredient is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3;

[0026] 4) An electron transport layer is prepared on the composite perovskite light-absorbing layer;

[0027] 5) A top electrode layer was fabricated on the electron transport layer to obtain an N-dansyl-DL-threonine cyclohexylammonium-doped perovskite solar cell.

[0028] Wherein, 1) includes the following operations:

[0029] The substrate with a conductive base is ultrasonically cleaned with a cleaning solution;

[0030] Then, sonicate twice with ultrapure water, 20 minutes each time. Place the cleaned ITO substrate in a 100°C oven to dry for 20 minutes. Place the dried substrate with conductive substrate in an ultraviolet ozone generator for 25 minutes and set aside.

[0031] Wherein, 2) includes the following operations:

[0032] [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid was mixed with anhydrous ethanol to obtain a solution with a concentration of 0.5–1.5 mmol / L. The solution was spin-coated onto the prepared ITO surface and annealed at 100–120 °C for 10–15 min.

[0033] Wherein, 3) includes the following operations:

[0034] Formamidinium hydroiodate, cesium iodide, methylamine hydrobromide, lead bromide, lead iodide, and N-dansyl-DL-threonine cyclohexylammonium were mixed and dissolved in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide to form the active ingredient with the chemical formula Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 The composite perovskite precursor solution of 3, wherein the volume ratio of N,N-dimethylformamide and dimethyl sulfoxide in the mixed solvent is 3 to 5:1, and the doping concentration of N-dansyl-DL-threonine cyclohexylammonium is 0.5 to 2 mg / mL;

[0035] A composite perovskite precursor solution was spin-coated onto a hole transport layer using a one-step spin-coating method to deposit a perovskite film, which was then annealed at 100–150 °C for 10–20 min.

[0036] Wherein, 4) includes the following operations:

[0037] A layer of C is sequentially deposited on the perovskite layer. 60 An electron transport layer was obtained by reacting 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0038] This invention also provides the application of N-dansyl-DL-threonine cyclohexylammonium as a chiral additive for composite perovskite precursor solutions in the preparation of perovskite solar cells.

[0039] Compared with the prior art, the present invention has the following beneficial technical effects:

[0040] This invention utilizes the chiral molecule N-dansyl-DL-threonine cyclohexylammonium to suppress perovskite bulk and interface defects in inverted perovskite solar cells through a triple synergistic effect:

[0041] 1) Defects related to passivated lead

[0042] C=O and S=O groups in the molecule and undercoordinated Pb 2+ Strong coordination eliminates deep-level trapped states and reduces nonradiative recombination;

[0043] 2) Inhibit the formation of cation vacancies

[0044] NH3 + Can occupy FA + The vacancies suppress the formation of negative charge defects (FA vacancies), and the O atom interacts with the FA. +Formation of NH···O hydrogen bonds, stabilizing the crystal lattice structure

[0045] It can also be used with I - Electrostatic interactions inhibit the formation of I vacancies;

[0046] 3) Blocking anion vacancy migration

[0047] NH3 + Can be with I - Electrostatic interactions are formed, which inhibit the diffusion of iodine vacancies and delay the performance degradation caused by ion migration.

[0048] This invention, by doping with N-dansyl-DL-threonine cyclohexylammonium, can solve the problems of most organic molecules in the prior art having single functions, only able to act on one or two charged defects in perovskites, and limited device optimization effects; the resulting composite light absorption layer can significantly improve the open-circuit voltage and photoelectric conversion efficiency of solar cells; the open-circuit voltage can be increased from 1.140V to 1.161-1.175V, and the photoelectric conversion efficiency can be increased from 25.22% to 25.93-26.40%. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the architecture of the perovskite solar cell of the present invention.

[0050] Figure 2 This is a comparison graph of the current density / voltage of the perovskite solar cell of this invention and a comparative example. Detailed Implementation

[0051] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with existing known technologies. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0052] like Figure 1 As shown, the organic small molecule doped perovskite solar cell includes, from bottom to top, a substrate layer, a conductive substrate, a hole transport layer, a composite perovskite light-absorbing layer, an electron transport layer, and a top electrode layer.

[0053] In this process, a chiral additive, N-dansyl-DL-threonine cyclohexylammonium, is added to the perovskite precursor solution that forms the composite perovskite light-absorbing layer; the concentration of the additive is 0.1–5.0 mg / mL.

[0054] The structural formula of the N-dansyl-DL-threonine cyclohexylammonium is:

[0055]

[0056] Furthermore, the solvent for the perovskite precursor liquid is a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide, with the chemical formula Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3;

[0057] Using chlorobenzene as the antisolvent, a perovskite precursor liquid with added N-dansyl-DL-threonine cyclohexylammonium was deposited on the hole transport layer in a one-step process to form a perovskite film, which was then annealed.

[0058] Specifically, the substrate layer is a soda-lime glass or borosilicate glass layer;

[0059] The conductive substrate is one or more of the following: F-doped tin oxide layer, In-doped tin oxide layer, and Al-doped zinc oxide layer;

[0060] The hole transport layer is formed by spin-coating a solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz) onto a conductive substrate.

[0061] The composite perovskite light-absorbing layer uses chlorobenzene as the anti-solvent. The perovskite precursor liquid with added N-dansyl-DL-threonine cyclohexylammonium is deposited on the hole transport layer in one step to form a perovskite film and then annealed.

[0062] The electron transport layer is formed by sequentially layering a C layer on a composite perovskite layer. 60 And a layer of BCP;

[0063] The top electrode layer is formed by evaporating Ag or Au onto the electron transport layer.

[0064] The method for preparing the N-dansyl-DL-threonine cyclohexylammonium modified perovskite solar cell includes the following steps:

[0065] 1) Pretreatment of the conductive ITO substrate;

[0066] 2) Fabricate a hole transport layer on a conductive substrate;

[0067] 3) Using chlorobenzene as the antisolvent, the perovskite precursor liquid with added N-dansyl-DL-threonine cyclohexylammonium was deposited on the hole transport layer in one step to form a perovskite film and then annealed.

[0068] 4) An electron transport layer is prepared on the composite perovskite light-absorbing layer;

[0069] 5) A top electrode layer was fabricated on the electron transport layer to obtain an N-dansyl-DL-threonine cyclohexylammonium-doped perovskite solar cell.

[0070] Specific implementation examples are given below.

[0071] Example 1:

[0072] 1) ITO Pretreatment: First, sonicate the ITO substrate in a 100:1 mixture of ultrapure water and glass cleaner for 25 minutes each time. Then sonicate twice more with ultrapure water, 20 minutes each time. Place the cleaned ITO substrate in a 100℃ oven to dry for 20 minutes. Finally, treat the dried ITO substrate in a UV ozone generator for 25 minutes.

[0073] 2) Preparation of hole transport layer: MeO-2PACz was mixed with anhydrous ethanol to obtain a mixed solution (1 mmol / L). 100 μl of the solution was spin-coated onto the prepared ITO surface and annealed at 100 °C for 10 min.

[0074] 3) Preparation of the light-absorbing layer: PbI2, MABr, PbBr, FAI, CsI, and N-dansyl-DL-threonine cyclohexylammonium were dissolved in a mixed solution of DMF:DMSO = 4:1 to form a layer with the chemical formula CsI. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3 Perovskite precursor solution (100 μl);

[0075] A perovskite film was deposited on the hole transport layer in one step using chlorobenzene as the antisolvent, and then annealed at 100°C for 10 min.

[0076] 4) Fabrication of the electron transport layer: A layer of C is sequentially deposited on the perovskite layer. 60 And BCP, to obtain the electron transport layer, where C 60 The thickness is 20nm, and the thickness of BCP is 3nm.

[0077] 5) Preparation of cathode layer: An Ag layer with a thickness of 100 nm is deposited on the electron transport layer.

[0078] In this embodiment, 0.5 mg / mL of N-dansyl-DL-threonine cyclohexylammonium-doped Cs was prepared. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3 perovskite solar cells.

[0079] Example 2:

[0080] In this example, a 1 mg / mL N-dansyl-DL-threonine cyclohexylammonium-doped Cs was prepared. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3 perovskite solar cells.

[0081] All parameters not mentioned in this embodiment are the same as those in Embodiment 1.

[0082] Example 3:

[0083] In this embodiment, 2 mg / mL of N-dansyl-DL-threonine cyclohexylammonium-doped Cs was prepared. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3 perovskite solar cells.

[0084] All parameters not mentioned in this embodiment are the same as those in Embodiment 1.

[0085] Comparative Example 1:

[0086] In this comparative example, no N-dansyl-DL-threonine cyclohexylammonium was added to the perovskite; all other materials, structures, and preparation methods were the same as in Example 1.

[0087] The performance parameters of various perovskite solar cells are shown in Table 1 below. Figure 2 As shown:

[0088] Figure 2 The intersection of the horizontal axis and the vertical axis represents the open-circuit voltage, and the intersection of the horizontal axis and the vertical axis represents the current density. The fill factor is the maximum power point in the JV curve divided by (open-circuit voltage multiplied by short-circuit current). The closer the JV curve is to a square, the larger the fill factor. The photoelectric conversion efficiency is the product of the first three factors.

[0089] Table 1. Comparison of performance parameters of perovskite solar cells

[0090]

[0091] As shown in Table 1 above, the composite light-absorbing layer formed by doping with N-dansyl-DL-threonine cyclohexylammonium can significantly improve the open-circuit voltage (from 1.140V to 1.161–1.175V) and photoelectric conversion efficiency (from 25.22% to 25.93–26.40%) of solar cells. The C=O and S=O atoms in the molecule can passivate undercoordinated Pb. 2+ Simultaneously, oxygen atoms can form hydrogen bonds with FA (NH···O), thereby inhibiting the formation of FA vacancies; NH3 + Can occupy FA + The vacancies further suppress the formation of negative charge defects (FA vacancies), and can also interact with I - Electrostatic interactions suppress the formation of I vacancies, ultimately improving the photoelectric conversion efficiency of perovskite solar cells.

[0092] Based on the above, this invention also proposes the application of N-dansyl-DL-threonine cyclohexylammonium as a chiral additive for composite perovskite precursor solutions in the preparation of perovskite solar cells.

[0093] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium, characterized in that, It includes a substrate layer, a conductive substrate, a hole transport layer, a composite perovskite light-absorbing layer, an electron transport layer, and a top electrode layer; In this process, a chiral additive, N-dansyl-DL-threonine cyclohexylammonium, is added to the perovskite precursor solution that forms the composite perovskite light-absorbing layer; the concentration of the additive is 0.1–5.0 mg / mL.

2. The perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium as described in claim 1, characterized in that, The structural formula of the N-dansyl-DL-threonine cyclohexylammonium is:

3. The perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium as described in claim 1, characterized in that, The solvent for the perovskite precursor fluid is a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide, and the chemical formula of the active ingredient is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3; Using chlorobenzene as the antisolvent, a perovskite precursor liquid containing N-dansyl-DL-threonine cyclohexylammonium was deposited onto the hole transport layer in a one-step process to form a perovskite layer, which was then annealed.

4. The perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium as described in claim 1, characterized in that, The substrate layer is a soda-lime glass or a borosilicate glass layer; The conductive substrate is one or more of the following: F-doped tin oxide layer, In-doped tin oxide layer, and Al-doped zinc oxide layer; The hole transport layer is formed by spin-coating a solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid onto a conductive substrate. The composite perovskite light-absorbing layer is formed by depositing a perovskite precursor liquid containing N-dansyl-DL-threonine cyclohexylammonium on a hole transport layer in a one-step process using chlorobenzene as the antisolvent, thereby forming a perovskite film and annealing it. The solvent for the perovskite precursor fluid is a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide, and the chemical formula of the active ingredient is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3; The electron transport layer is formed by sequentially layering a C layer on a composite perovskite layer. 60 And a layer of BCP; The top electrode layer is formed by evaporating Ag or Au onto the electron transport layer.

5. A method for preparing an N-dansyl-DL-threonine cyclohexylammonium modified perovskite solar cell, characterized in that, Includes the following operations: 1) Pretreatment of the conductive ITO substrate; 2) Fabricate a hole transport layer on a conductive substrate; 3) Using chlorobenzene as the antisolvent, the perovskite precursor liquid with added N-dansyl-DL-threonine cyclohexylammonium was deposited on the hole transport layer in one step to form a perovskite film and then annealed. The solvent for the perovskite precursor fluid is a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide, and the chemical formula of the active ingredient is Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 )3; 4) An electron transport layer is prepared on the composite perovskite light-absorbing layer; 5) A top electrode layer was fabricated on the electron transport layer to obtain an N-dansyl-DL-threonine cyclohexylammonium-doped perovskite solar cell.

6. The method for preparing the perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium as described in claim 5, characterized in that, The 1) includes the following operations: The substrate with a conductive base is ultrasonically cleaned with a cleaning solution; Then, sonicate twice with ultrapure water, 10-20 minutes each time. Place the cleaned ITO substrate in an oven at 100-150℃ and dry for 10-20 minutes. Place the dried substrate with conductive substrate in an ultraviolet ozone generator for 10-25 minutes and set aside.

7. The method for preparing the perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium as described in claim 5, characterized in that, The second step includes the following operations: [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid was mixed with anhydrous ethanol to obtain a solution with a concentration of 0.5–1.5 mmol / L. This solution was then spin-coated onto a prepared ITO surface and annealed at 100–120 °C for 10–15 min.

8. The method for preparing the perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium as described in claim 5, characterized in that, The third step includes the following operations: Formamidinium hydroiodate, cesium iodide, methylamine hydrobromide, lead bromide, lead iodide, and N-dansyl-DL-threonine cyclohexylammonium were mixed and dissolved in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide to form a compound with the chemical formula Cs. 0.05 (MA 0.05 FA 0.95 ) 0.95 Pb(Br 0.05 I 0.95 The composite perovskite precursor solution of 3, wherein the volume ratio of N,N-dimethylformamide and dimethyl sulfoxide in the mixed solvent is 3 to 5:1, and the concentration of N-dansyl-DL-threonine cyclohexylammonium is 0.5 to 2 mg / mL. A composite perovskite precursor solution was spin-coated onto a hole transport layer using a one-step spin-coating method to deposit a perovskite film, which was then annealed at 100–150 °C for 10–20 min.

9. The method for preparing the perovskite solar cell modified with N-dansyl-DL-threonine cyclohexylammonium as described in claim 5, characterized in that, 4) includes the following operations: A layer of C is sequentially deposited on the perovskite layer. 60 An electron transport layer was obtained by reacting 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

10. Application of N-dansyl-DL-threonine cyclohexylammonium as a chiral additive in composite perovskite precursor solutions in the preparation of perovskite solar cells.

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