A perovskite light-absorbing layer passivation liquid and applications thereof

Abstract

The application belongs to the field of photovoltaic materials, and specifically provides a perovskite light-absorbing layer passivation solution and application thereof in solar cells. The solute in the perovskite light-absorbing layer passivation solution comprises an amino-substituted nitrogen-containing heterocyclic compound and a benzoic acid derivative. A honeycomb structure passivation layer is formed on the surface of the light-absorbing layer through molecular self-assembly. The structure simultaneously realizes deep passivation of defects and inhibition of ion migration to reduce interface loss; a dynamic ultraviolet shielding layer is formed through an exciton coupling effect, high-energy photons are non-radiatively converted into heat energy to block perovskite photo-damage, and finally the photoelectric conversion efficiency and long-term operation stability of the solar cell are synergistically improved.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology and relates to a perovskite light-absorbing layer passivation liquid and its application. Background Technology

[0002] Perovskite solar cells (PSCs) have become a preferred solution for next-generation photovoltaic technology due to their high photoelectric conversion efficiency (PCE) and low manufacturing cost. This makes them extremely attractive in a variety of application areas, especially in space photovoltaics.

[0003] However, perovskite materials face severe challenges in the high-radiation and extreme temperature-varying environment of space. Even with encapsulated perovskite silicon solar cells, the high-energy radiation and temperature variations in space can easily induce halogen and lead vacancies within the perovskite material, negatively impacting cell performance. These vacancies act as non-radiative recombination centers, leading to a significant reduction in open-circuit voltage (Voc) and fill factor (FF). This adverse effect ultimately results in a significant decrease in the device's photoelectric conversion efficiency.

[0004] Furthermore, perovskite silicon solar cells operating in space are also subject to high-intensity ultraviolet (UV) radiation. This high-energy UV exposure is known to damage the perovskite crystal structure, leading to a significant decrease in cell efficiency.

[0005] Therefore, developing a novel interface passivation strategy that simultaneously possesses the functions of interface defect passivation, ion migration suppression, and ultraviolet protection is of significant scientific importance and engineering application value for improving the operational stability and lifespan of perovskite-silicon tandem solar cells in outer space environments. Summary of the Invention

[0006] This invention provides a perovskite light-absorbing layer passivation solution and its application. It utilizes a pre-assembly of an amino-substituted nitrogen-containing heterocyclic compound and a benzoic acid derivative to spontaneously form a hydrogen-bonded structure. This structure not only effectively eliminates deep-level defects in the perovskite layer, inhibits ion migration, and reduces interfacial recombination to minimize losses; more importantly, the pre-assembly-induced charge transfer and exciton coupling effect between the carboxyl group and the heterocyclic nitrogen molecule enable the passivation layer to form a strong absorption state in the ultraviolet band. Through efficient ultraviolet absorption, it fundamentally avoids lattice damage caused by ultraviolet radiation. The synergistic effect of these multiple functions significantly improves the photoelectric conversion efficiency (PCE) and long-term stability of solar cells.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a perovskite light-absorbing layer passivation solution, the perovskite light-absorbing layer passivation solution comprising a solvent and a solute, the solute comprising an amino-substituted nitrogen-containing heterocyclic compound and a benzoic acid derivative.

[0009] In the perovskite light-absorbing layer passivation solution of this invention, an amino-substituted nitrogen-containing heterocyclic compound and a benzoic acid derivative pre-assemble through intermolecular forces to form a honeycomb structure with a hydrogen bond network. In this structure, the amino group (-NH2) acts as a Lewis base, using lone pair electron coordination to passivate uncoordinated divalent cations in the perovskite, eliminating deep-level defects. Simultaneously, the electron-deficient nitrogen atoms of the nitrogen-containing heterocyclic compound (such as pyridine-N=) anchor free halide anions (X-) through electrostatic attraction, inhibiting ion migration and reducing the interfacial recombination rate. Furthermore, the pre-assembly-induced carboxyl group (-COOH) undergoes intermolecular charge transfer with the heterocyclic nitrogen (-N=), and through periodic arrangement, generates an exciton coupling effect, forming a strong absorption state in the ultraviolet band (300-400 nm), achieving a high ultraviolet interception effect. The absorbed high-energy photons are converted into thermal energy through non-radiative relaxation, avoiding perovskite lattice damage. These three factors synergistically improve the open-circuit voltage and stability of the device.

[0010] In the perovskite light-absorbing layer passivation solution of this invention, the honeycomb structure pre-assembled by amino-substituted nitrogen-containing heterocyclic compounds and benzoic acid derivatives has an ultrathin hydrogen bond self-assembly network with a thickness of less than 5 nm. This allows for efficient transmission of visible light in the 400-1200 nm band while exhibiting high ultraviolet light absorption in the 250 nm-320 nm band. This reduces the perovskite lattice decomposition caused by ultraviolet photons while maintaining the intrinsic light absorption of perovskite. When used in perovskite-silicon tandem solar cells, it can ensure the generation of photocurrent in the bottom cell.

[0011] Preferably, the molar ratio of the amino-substituted nitrogen-containing heterocyclic compound to the benzoic acid derivative is (0.3 to 3):1, for example: 0.3:1, 0.5:1, 1:1, 2:1 or 3:1, etc.

[0012] Preferably, the amino-substituted nitrogen-containing heterocyclic compound includes any one or a combination of at least two of 4-aminopyridine, 3-aminopyridine, 2-aminopyridine, 2,4-diaminopyrimidine, 3-amino-1,2,4-triazole, 4-amino-1,2,3-triazole, 2-aminopyrazine, 3-aminopyridazine or melamine, preferably 4-aminopyridine;

[0013] Preferably, the benzoic acid derivative includes any one or a combination of at least two of terephthalic acid, isophthalic acid, trimesic acid, 5-hydroxyisophthalic acid, or 2-aminoterephthalic acid, with trimesic acid being the most preferred.

[0014] Preferably, the solvent includes any one or a combination of at least two of isopropanol, chlorobenzene, methanol, acetone or ethanol, and is more preferably isopropanol and chlorobenzene.

[0015] Preferably, the volume ratio of isopropanol to chlorobenzene is (0.5 to 1.5):1, for example: 0.5:1, 0.8:1, 1:1, 1.2:1 or 1.5:1, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] Preferably, the total mass percentage concentration of amino-substituted nitrogen-containing heterocyclic compounds and benzoic acid derivatives in the perovskite light-absorbing layer passivation solution is 0.1% to 0.5%, for example: 0.1%, 0.2%, 0.3%, 0.4% or 0.5%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Secondly, the present invention provides a method for preparing a perovskite solar cell, the method comprising the following steps:

[0018] A first carrier transport layer and a perovskite light-absorbing layer are sequentially prepared on a substrate. The perovskite light-absorbing layer passivation liquid as described in the first aspect is coated on the perovskite light-absorbing layer, and the passivation layer is obtained by annealing.

[0019] The perovskite solar cell is obtained by sequentially fabricating a second carrier transport layer and a top electrode layer on the passivation layer.

[0020] Preferably, the substrate includes a conductive glass substrate and / or a conductive silicon cell substrate.

[0021] Preferably, the conductive glass substrate comprises ITO conductive glass and / or FTO conductive glass.

[0022] Preferably, the conductive silicon cell substrate includes a crystalline silicon cell and ITO and / or FTO disposed on one side surface of the crystalline silicon cell.

[0023] Preferably, the first carrier transport layer and the second carrier transport layer independently include a hole transport layer or an electron transport layer, and the first carrier transport layer and the second carrier transport layer are not simultaneously hole transport layers or electron transport layers.

[0024] Preferably, the material of the hole transport layer includes any one or a combination of at least two of nickel oxide, 2PACz, MeO-2PACz, PTAA, PEDOT:PSS, or Spiro-MeOTA.

[0025] Preferably, the self-assembled monolayer material includes carbazole-based self-assembled monolayer materials;

[0026] Preferably, the carbazole-based self-assembled monolayer material includes any one or a combination of at least two of 2PACz, MeO-2PACz, or Me-4PACz;

[0027] Preferably, the thickness of the hole transport layer is 10nm to 25nm, for example: 10nm, 11nm, 15nm, 20nm or 25nm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0028] Preferably, the electron transport layer comprises C layers stacked sequentially. 60 Layer and tin oxide buffer layer.

[0029] The tin oxide buffer layer described in this invention is deposited on C by atomic layer deposition. 60 Surface layer.

[0030] Preferably, the C 60 The layer is located on the side close to the perovskite light-absorbing layer.

[0031] Preferably, the C 60 The thickness of the layer is 10nm to 20nm, for example: 15nm, 18nm, 20nm, 22nm or 25nm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0032] Preferably, the thickness of the tin oxide buffer layer is 8nm to 20nm, for example: 8nm, 9nm, 10nm, 15nm or 20nm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0033] Preferably, the perovskite light-absorbing layer comprises a perovskite material with the chemical formula ABX3, wherein A is a monovalent cation, B is a divalent cation, and X is a monovalent anion. The A comprises any one or a combination of at least two of methylamine cation, formamidinium cation, cesium ion, or rubidium ion, the B comprises lead ion and / or tin ion, and the X comprises any one or a combination of at least two of iodide ion, bromide ion, or chloride ion.

[0034] Preferably, the thickness of the perovskite light-absorbing layer is 400nm to 1500nm, for example: 400nm, 500nm, 600nm, 1000nm or 1500nm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the coating method of the perovskite light-absorbing layer passivation liquid includes spin coating, slot coating, blade coating, and inkjet printing.

[0036] Preferably, the annealing temperature is 80℃~120℃, for example: 80℃, 90℃, 100℃, 110℃ or 120℃.

[0037] Preferably, the annealing time is 5 min to 15 min, for example: 5 min, 8 min, 10 min, 12 min or 15 min.

[0038] Preferably, the thickness of the passivation layer is 1nm to 5nm, for example: 1nm, 2nm, 3nm, 4nm or 5nm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Preferably, the top electrode layer comprises a metal electrode or a composite metal electrode.

[0040] Preferably, the metal electrode includes any one or a combination of at least two of copper, silver, or gold electrodes.

[0041] Preferably, the composite metal electrode includes an ITO transparent electrode and a silver electrode disposed on the ITO transparent electrode on the side away from the second carrier transport layer.

[0042] Preferably, the composite metal electrode is prepared by the following method: depositing an ITO transparent electrode on the second carrier transport layer by magnetron sputtering, and then preparing a silver electrode on the ITO transparent electrode using a mask by thermal evaporation or screen printing to obtain the composite metal electrode.

[0043] Preferably, the thickness of the ITO transparent electrode is 50nm to 100nm, for example: 50nm, 60nm, 80nm, 90nm or 100nm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] Preferably, the thickness of the silver electrode is 200nm to 500nm, for example: 200nm, 250nm, 300nm, 400nm or 500nm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] Thirdly, the present invention provides a solar cell, which is manufactured by the method described in the second aspect.

[0046] Preferably, the solar cell includes a perovskite solar cell and / or a perovskite-silicon tandem solar cell.

[0047] In the fabrication process of the solar cell described in this invention, if a conductive silicon battery substrate is used and a composite metal electrode is employed, the resulting solar cell is a perovskite-silicon tandem solar cell; if a conductive glass substrate is used and a metal electrode is employed, the resulting solar cell is a single-junction perovskite solar cell.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The perovskite light-absorbing layer passivation liquid of the present invention forms a honeycomb structure through the pre-assembly of amino-substituted nitrogen-containing heterocyclic compounds and benzoic acid derivatives. It can not only effectively passivate defects in the perovskite layer, but also inhibit ion migration, reduce interface loss, absorb ultraviolet photons, reduce their damage to perovskite materials, and synergistically improve the efficiency and stability of solar cells.

[0050] (2) The perovskite light-absorbing layer passivation solution described in this invention can produce a perovskite-silicon tandem solar cell with a Voc of over 1.834V and a Jsc of 18.54mA / cm. 2 The above results show that the FF (Factor Flow Rate) can reach over 81.23%, and the PCE (Potential Component Efficiency) can reach over 27.23%. Specifically, using 4-aminopyridine and trimesic acid as solutes, the Voc (Volume Oc) of the perovskite-silicon tandem solar cell can reach over 1.846V, and the Jsc (Junctional Component Efficiency) can reach 19.01 mA / cm². 2 The above results show that FF can reach over 82.53% and PCE can reach over 28.16%. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the perovskite-silicon tandem solar cell described in Example 1 of this invention. 1 is a crystalline silicon bottom cell with an ITO thin film on its surface; 2 is a nickel oxide layer; 3 is a self-assembled monolayer; 4 is a perovskite light-absorbing layer; 5 is a passivation layer; 6 is a C… 60 The layers are: 7 is a tin oxide buffer layer, 8 is an ITO electrode, and 9 is a silver electrode. Detailed Implementation

[0052] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0053] Example 1

[0054] This embodiment provides a perovskite light-absorbing layer passivation solution. The solute of the perovskite light-absorbing layer passivation solution is 4-aminopyridine and trimellitic acid, and the solvent is isopropanol and chlorobenzene in a volume ratio of 1:1. The molar ratio of 4-aminopyridine and trimellitic acid is 1:1, and the total mass concentration of 4-aminopyridine and trimellitic acid is 0.3%.

[0055] Example 2

[0056] This embodiment provides a perovskite light-absorbing layer passivation solution. The solute of the perovskite light-absorbing layer passivation solution is 4-aminopyridine and trimellitic acid, and the solvent is isopropanol and chlorobenzene in a volume ratio of 0.5:1. The molar ratio of 4-aminopyridine to trimellitic acid is 0.3:1, and the total mass concentration of 4-aminopyridine and trimellitic acid is 0.1%.

[0057] Example 3

[0058] This embodiment provides a perovskite light-absorbing layer passivation solution. The solute of the perovskite light-absorbing layer passivation solution is 4-aminopyridine and trimellitic acid, and the solvent is isopropanol and chlorobenzene in a volume ratio of 1.5:1. The molar ratio of 4-aminopyridine to trimellitic acid is 3:1, and the total mass concentration of 4-aminopyridine and trimellitic acid is 0.5%.

[0059] Example 4

[0060] The only difference between this embodiment and Example 1 is that 4-aminopyridine is replaced with an equimolar amount of 3-aminopyridine; all other conditions and parameters are exactly the same as in Example 1.

[0061] Example 5

[0062] The only difference between this embodiment and Example 1 is that 4-aminopyridine is replaced with an equimolar amount of 2,4-diaminopyrimidine; all other conditions and parameters are exactly the same as in Example 1.

[0063] Example 6

[0064] The only difference between this embodiment and Example 1 is that pyromellitic acid is replaced with an equimolar amount of 5-hydroxyisophthalic acid; all other conditions and parameters are exactly the same as in Example 1.

[0065] Example 7

[0066] The only difference between this embodiment and Example 1 is that the pyromellitic acid is replaced with an equimolar amount of isophthalic acid; all other conditions and parameters are exactly the same as in Example 1.

[0067] Example 8

[0068] The only difference between this embodiment and Example 1 is that pyromellitic acid is replaced with an equimolar amount of 2-aminoterephthalic acid; all other conditions and parameters are exactly the same as in Example 1.

[0069] Example 9

[0070] The only difference between this embodiment and Example 1 is that the molar ratio of 4-aminopyridine to pyromellitic acid is 0.1:1, while the other conditions and parameters are exactly the same as in Example 1.

[0071] Example 10

[0072] The only difference between this embodiment and Example 1 is that the molar ratio of 4-aminopyridine to pyromellitic acid is 5:1; all other conditions and parameters are exactly the same as in Example 1.

[0073] Example 11

[0074] The only difference between this embodiment and Example 1 is that the total mass concentration of 4-aminopyridine and pyromellitic acid is 0.05%, while the other conditions and parameters are exactly the same as in Example 1.

[0075] Example 12

[0076] The only difference between this embodiment and Example 1 is that the total mass concentration of 4-aminopyridine and pyromellitic acid is 1%, while the other conditions and parameters are exactly the same as in Example 1.

[0077] Comparative Example 1

[0078] The only difference between this comparative example and Example 1 is that pyromellitic acid is not added; all other conditions and parameters are exactly the same as in Example 1.

[0079] Comparative Example 2

[0080] The only difference between this comparative example and Example 1 is that 4-aminopyridine is not added; all other conditions and parameters are exactly the same as in Example 1.

[0081] Comparative Example 3

[0082] The only difference between this comparative example and Example 1 is that 4-aminopyridine is replaced with an equimolar amount of pyridine; all other conditions and parameters are exactly the same as in Example 1.

[0083] Comparative Example 4

[0084] The only difference between this comparative example and Example 1 is that 4-aminopyridine is replaced with an equimolar amount of aniline; all other conditions and parameters are exactly the same as in Example 1.

[0085] Application Example 1

[0086] This application example provides a perovskite-silicon tandem solar cell, the structural schematic of which is shown below. Figure 1 As shown, the perovskite-silicon tandem solar cell is prepared by the following method:

[0087] A crystalline silicon bottom cell 1 with an ITO thin film on its surface is provided. A 10 nm thick nickel oxide layer 2 is sputtered onto the ITO thin film using magnetron sputtering. Then, a 1 mg / mL Me-4PACz solution is spin-coated, with ethanol as the solvent, to form a 2 nm thick self-assembled monolayer 3, thus obtaining a hole transport layer. Cs is then coated onto the self-assembled monolayer 3. 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3 After drying and annealing, a perovskite light-absorbing layer 4 with a thickness of 900 nm is formed. The perovskite light-absorbing layer passivation solution described in Example 1 is spin-coated onto the perovskite light-absorbing layer 4 at a speed of 5000 rpm for 30 s. After annealing at 100 °C for 10 min, a passivation layer 5 with a thickness of 2 nm is obtained.

[0088] C with a thickness of 20 nm was sequentially deposited on passivation layer 5. 60 After layer 6, a 10 nm thick tin oxide buffer layer 7 is formed to obtain an electron transport layer. A 50 nm thick ITO electrode 8 is then magnetron sputtered onto the tin oxide buffer layer 7. Subsequently, a 200 nm thick silver electrode 9 is fabricated on the ITO electrode 8 using a photomask via thermal evaporation to obtain the perovskite-silicon tandem solar cell.

[0089] Application Example 2

[0090] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 2. All other conditions and parameters are exactly the same as in application example 1.

[0091] Application Example 3

[0092] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 3. All other conditions and parameters are exactly the same as in application example 1.

[0093] Application Example 4

[0094] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 4. All other conditions and parameters are exactly the same as in application example 1.

[0095] Application Example 5

[0096] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 5. All other conditions and parameters are exactly the same as in application example 1.

[0097] Application Example 6

[0098] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 6. All other conditions and parameters are exactly the same as in application example 1.

[0099] Application Example 7

[0100] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 7. All other conditions and parameters are exactly the same as in application example 1.

[0101] Application Example 8

[0102] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 8. All other conditions and parameters are exactly the same as in application example 1.

[0103] Application Example 9

[0104] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 9. All other conditions and parameters are exactly the same as in application example 1.

[0105] Application Example 10

[0106] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 10. All other conditions and parameters are exactly the same as in application example 1.

[0107] Application Example 11

[0108] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 11. All other conditions and parameters are exactly the same as in application example 1.

[0109] Application Example 12

[0110] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in example 12. All other conditions and parameters are exactly the same as in application example 1.

[0111] Comparative Application Example 1

[0112] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in comparative example 1. All other conditions and parameters are exactly the same as in application example 1.

[0113] Comparative Application Example 2

[0114] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in comparative example 2. All other conditions and parameters are exactly the same as in application example 1.

[0115] Comparative Application Example 3

[0116] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in comparative example 3. All other conditions and parameters are exactly the same as in application example 1.

[0117] Comparative Application Example 4

[0118] The only difference between this application example and application example 1 is that the perovskite light-absorbing layer passivation solution described in example 1 is replaced with the perovskite light-absorbing layer passivation solution described in comparative example 4. All other conditions and parameters are exactly the same as in application example 1.

[0119] Performance testing:

[0120] The open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and device conversion efficiency (PCE) of perovskite-silicon tandem solar cells fabricated for the corresponding use cases and comparative application examples were tested. The test results are shown in Table 1.

[0121] Table 1

[0122]

[0123]

[0124] As shown in Table 1, based on Application Examples 1-8, the perovskite light-absorbing layer passivation solution described in this invention can produce perovskite-silicon tandem solar cells with a Voc of over 1.834V and a Jsc of 18.54mA / cm. 2 The above results show that the FF (Factor Flow Rate) can reach over 81.23%, and the PCE (Potential Component Efficiency) can reach over 27.23%. Specifically, using 4-aminopyridine and trimesic acid as solutes, the Voc (Volume Oc) of the perovskite-silicon tandem solar cell can reach over 1.846V, and the Jsc (Junctional Component Efficiency) can reach 19.01 mA / cm². 2 The above results show that FF can reach over 82.53% and PCE can reach over 28.16%.

[0125] A comparison of Application Examples 1 and 9-10 shows that the ratio of amino-substituted nitrogen-containing heterocyclic compounds to benzoic acid derivatives in the perovskite light-absorbing layer passivation solution of the present invention affects its performance. Controlling the molar ratio of amino-substituted nitrogen-containing heterocyclic compounds to benzoic acid derivatives at (0.3–3):1 results in better performance of the perovskite light-absorbing layer passivation solution. If the proportion of amino-substituted nitrogen-containing heterocyclic compounds is too high, the excess compounds tend to form linear polymer chains, losing the advantages of the porous structure, leading to uneven distribution of passivation sites, reduced coverage efficiency for perovskite surface / grain boundary defects, and the formation of an insulating layer on the perovskite surface, increasing interfacial resistance and hindering carrier extraction. If the proportion of benzoic acid derivatives is too high, amorphous aggregates may form, reducing passivation uniformity.

[0126] A comparison of Application Examples 1 and 11-12 reveals that the concentrations of amino-substituted nitrogen-containing heterocyclic compounds and benzoic acid derivatives in the perovskite light-absorbing layer passivation solution of this invention significantly affect device performance. When the total concentration is controlled within the range of 0.1% to 0.5% by mass, the resulting passivation layer effectively covers perovskite surface defects without affecting carrier extraction, resulting in optimal overall performance. For example, the device with a concentration of 0.3% in Application Example 1 exhibits the highest PCE value (28.46%). When the concentration is too high (e.g., 1% in Application Example 12), the resulting passivation layer is too thick, easily increasing the device's series resistance, limiting charge transport, and leading to a decrease in device performance. Conversely, when the concentration is too low (e.g., 0.05% in Application Example 11), the passivation layer coverage is insufficient, interface defects cannot be effectively suppressed, non-radiative recombination increases, and open-circuit voltage and efficiency decrease significantly. Therefore, this invention achieves a balance between passivation layer thickness, interface quality, and charge transport performance by optimizing molecular concentration, ensuring that the device maintains high efficiency while possessing excellent stability.

[0127] A comparison of the experimental results of Application Example 1 and Comparative Application Examples 1 to 4 shows that the amino-substituted nitrogen-containing heterocyclic compound introduced into the passivation solution of the present invention forms an ordered honeycomb-like self-assembled network structure with the benzoic acid derivative through hydrogen bonding, exerting multiple synergistic functions. Specifically, the carboxyl group (–COOH) provided by the benzoic acid derivative can form an intermolecular charge transfer state with the nitrogen (–N=) in the heterocyclic molecule, exhibiting significant ultraviolet absorption in the 250–320 nm wavelength range, effectively blocking the destruction of the perovskite lattice by high-energy ultraviolet light; the amino group can react with uncoordinated metal ions (such as Pb) in the perovskite. 2The +) coordination reaction occurs, thereby passivating defects; in addition, the heterocyclic nitrogen atoms can also capture free halide ions in the perovskite, inhibiting ion migration. These effects significantly reduce the recombination rate at the device interface, and significantly improve the open-circuit voltage (Voc) and fill factor (FF). Compared with the control group lacking the above components, the battery prepared by the passivation solution of the present invention exhibits excellent performance in key properties such as Voc, Jsc, FF, and PCE. For example, the device in Application Example 1 achieves a Voc of 1.859V and a PCE as high as 28.46%, while the highest PCE in the control group is only 25.82%, which fully verifies the effectiveness of the synergistic passivation and interface stabilization of the two types of components in the present invention.

[0128] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A perovskite light-absorbing layer passivation solution, characterized in that, The perovskite light-absorbing layer passivation solution includes a solvent and a solute, wherein the solute includes an amino-substituted nitrogen-containing heterocyclic compound and a benzoic acid derivative; The amino-substituted nitrogen-containing heterocyclic compound includes any one or a combination of at least two of 4-aminopyridine, 3-aminopyridine, 2-aminopyridine, or 2,4-diaminopyrimidine, and the benzoic acid derivative includes any one or a combination of at least two of terephthalic acid, isophthalic acid, trimesic acid, 5-hydroxyisophthalic acid, or 2-aminoterephthalic acid.

2. The perovskite light-absorbing layer passivation solution as described in claim 1, characterized in that, The molar ratio of the amino-substituted nitrogen-containing heterocyclic compound to the benzoic acid derivative is (0.3~3):

1.

3. The perovskite light-absorbing layer passivation solution as described in claim 1, characterized in that, The solvent includes any one or a combination of at least two of isopropanol, chlorobenzene, methanol, acetone or ethanol.

4. The perovskite light-absorbing layer passivation solution as described in claim 1, characterized in that, The solvents include isopropanol and chlorobenzene.

5. The perovskite light-absorbing layer passivation solution as described in claim 4, characterized in that, The volume ratio of isopropanol to chlorobenzene is (0.5~1.5):

1.

6. The perovskite light-absorbing layer passivation solution as described in claim 1, characterized in that, The total mass percentage concentration of amino-substituted nitrogen-containing heterocyclic compounds and benzoic acid derivatives in the perovskite light-absorbing layer passivation solution is 0.1% to 0.5%.

7. A method for preparing a solar cell, characterized in that, The preparation method includes the following steps: A first carrier transport layer and a perovskite light-absorbing layer are sequentially prepared on a substrate. The perovskite light-absorbing layer passivation liquid as described in any one of claims 1-6 is coated on the perovskite light-absorbing layer, and the passivation layer is obtained by annealing. The second carrier transport layer and the top electrode layer are sequentially fabricated on the passivation layer to obtain the solar cell.

8. The preparation method according to claim 7, characterized in that, The substrate includes a conductive glass substrate or a conductive silicon cell substrate.

9. The preparation method according to claim 8, characterized in that, The conductive glass substrate includes ITO conductive glass or FTO conductive glass.

10. The preparation method according to claim 8, characterized in that, The conductive silicon cell substrate includes a crystalline silicon cell and ITO and / or FTO disposed on one side surface of the crystalline silicon cell.

11. The preparation method according to claim 7, characterized in that, The first carrier transport layer and the second carrier transport layer independently include a hole transport layer or an electron transport layer, and the first carrier transport layer and the second carrier transport layer are not simultaneously hole transport layers or electron transport layers.

12. The preparation method according to claim 11, characterized in that, The material of the hole transport layer includes any one or a combination of at least two of the following: self-assembled monomolecule materials, nickel oxide, PTAA, and PEDOT:PSS.

13. The preparation method according to claim 12, characterized in that, Self-assembled monolayer materials include carbazole-based self-assembled monolayer materials.

14. The preparation method according to claim 13, characterized in that, The carbazole-based self-assembled monolayer material includes any one or a combination of at least two of 2PACz, MeO-2PACz, or Me-4PACz.

15. The preparation method according to claim 11, characterized in that, The thickness of the hole transport layer is 10nm~25nm.

16. The preparation method according to claim 11, characterized in that, The electron transport layer comprises C layers stacked sequentially. 60 Layer and tin oxide buffer layer.

17. The preparation method according to claim 16, characterized in that, The C 60 The thickness of the layer is 10nm~20nm.

18. The preparation method according to claim 16, characterized in that, The thickness of the tin oxide buffer layer is 8nm~20nm.

19. The preparation method according to claim 7, characterized in that, The perovskite light-absorbing layer comprises a perovskite material with the chemical formula ABX3, wherein A is a monovalent cation, B is a divalent cation, and X is a monovalent anion.

20. The preparation method according to claim 19, characterized in that, A includes any one or a combination of at least two of the following: methylamine cation, formamidinium cation, cesium ion, or rubidium ion; and B includes lead ion and / or tin ion.

21. The preparation method according to claim 19, characterized in that, X includes any one or a combination of at least two of iodide ions, bromide ions, or chloride ions.

22. The preparation method according to claim 7, characterized in that, The thickness of the perovskite light-absorbing layer is 400 nm to 1500 nm.

23. The preparation method according to claim 7, characterized in that, The thickness of the passivation layer is 1 nm to 5 nm.

24. The preparation method according to claim 7, characterized in that, The annealing temperature is 80℃~120℃.

25. The preparation method according to claim 7, characterized in that, The annealing process takes 5 to 15 minutes.

26. The preparation method according to claim 7, characterized in that, The top electrode layer includes a metal electrode or a composite metal electrode.

27. The preparation method according to claim 26, characterized in that, The metal electrode includes any one or a combination of at least two of the following: copper electrode, silver electrode, or gold electrode.

28. The preparation method according to claim 26, characterized in that, The composite metal electrode includes an ITO transparent electrode and a silver electrode disposed on the ITO transparent electrode on the side away from the second carrier transport layer.

29. The preparation method according to claim 26, characterized in that, The composite metal electrode is prepared by the following method: depositing an ITO transparent electrode on the second carrier transport layer by magnetron sputtering, and then preparing a silver electrode on the ITO transparent electrode using a mask by thermal evaporation or screen printing to obtain the composite metal electrode.

30. A solar cell, characterized in that, The solar cell is prepared by the method according to any one of claims 7-29; The solar cells include perovskite solar cells and / or perovskite-silicon tandem solar cells.

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