Perovskite ultraviolet protection layer and preparation method and application thereof

Abstract

The invention provides a perovskite ultraviolet protection layer and a preparation method and application thereof, the perovskite ultraviolet protection layer comprises amino acid molecule modified polydopamine, and the perovskite ultraviolet protection layer is located on the surface of one side, receiving incident sunlight, of a perovskite active layer. The perovskite ultraviolet protection layer provided by the invention can effectively reduce the incidence amount of ultraviolet light reaching the perovskite active layer, fundamentally improve the irradiation stability of perovskite, and reduce the defect formation of an interface under illumination, thereby inhibiting the escape of iodide ions, overcoming the phase segregation of broadband gap perovskite, and improving the performance of the perovskite. Therefore, the open-circuit voltage loss of the wide-band-gap perovskite caused by the open-circuit voltage loss is avoided, and the battery life and the overall performance of the battery are improved.

Description

Technical Field

[0001] The present invention belongs to the field of perovskite cells and relates to a perovskite ultraviolet protection layer and a preparation method and application thereof. Background Art

[0002] Crystalline silicon solar cells dominate the photovoltaic market with their high efficiency, mature manufacturing technology, and excellent stability. However, the power conversion efficiency (PCE) of crystalline silicon solar cells has reached saturation over the years, with the current certified efficiency at 26.8%. The certified efficiency of perovskite single-junction cells has reached 27%, an efficiency value close to the Shockley-Queisser limit for single-junction solar cells. Because perovskite tandem solar cells can minimize thermal losses and broaden the utilization of the solar spectrum, their theoretical photoelectric conversion efficiency can reach over 40%. Furthermore, perovskite materials are inexpensive, can be processed in low-temperature solutions, and are compatible and flexible, showing greater application potential than crystalline silicon solar cells.

[0003] However, perovskite solar cells have problems such as insufficient water, oxygen and radiation stability. Among them, the problem of poor radiation stability is particularly serious. Under long-term irradiation, the highly active ion radicals at the interface of the perovskite photoactive layer will aggravate non-radiative recombination, promote the formation of deep energy level defects, and thus lead to phase segregation of perovskite and further component decomposition.

[0004] An international research team at King Abdullah University of Science and Technology in Saudi Arabia has increased the photoelectric conversion efficiency of perovskite solar cells from 20% to approximately 25%, while also extending their lifespan. Song Yanlin's research group at the Institute of Chemistry introduced 2-hydroxy-4-methoxybenzophenone as an additive into the perovskite active layer, achieving both improved photoelectric conversion efficiency and UV stability.

[0005] However, all of the above solutions use additive processes, introducing impurities into the perovskite precursor solution. These processes optimize the structure of the perovskite active layer to reduce UV damage, but they fail to fundamentally reduce the amount of UV light reaching the perovskite active layer. Therefore, improving the radiation stability of perovskite cells by reducing the amount of UV light reaching the perovskite active layer is a pressing technical issue. Summary of the Invention

[0006] In response to the shortcomings of the prior art, the present invention aims to provide a perovskite UV protection layer, its preparation method, and its application. The perovskite UV protection layer provided by the present invention, when applied to a perovskite cell, can effectively reduce the amount of UV light incident on the perovskite active layer, fundamentally improving the radiation stability of the perovskite. Furthermore, when the adjacent carrier transport layer is made of a metal oxide, the two can interact, further optimizing the interface.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a perovskite UV protection layer, which includes polydopamine modified with amino acid molecules, and the perovskite UV protection layer is located on the surface of the perovskite active layer that receives incident sunlight.

[0009] In the present invention, the molecular structure of polydopamine contains a large number of catechol groups and indole structural units, so it itself has significant ultraviolet light absorption properties. When it is combined with amino acids, different types of amino acids can enhance the ultraviolet blocking ability of polydopamine through different mechanisms such as aromatic ring conjugation, charge interaction, hydrogen bond network or free radical scavenging. Therefore, by setting it on the side of the perovskite active layer that receives incident sunlight, the amount of ultraviolet light reaching the perovskite active layer can be effectively reduced, thereby fundamentally improving the radiation stability of the perovskite.

[0010] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0011] Preferably, the amino acid molecule includes any one of phenylalanine, glutamic acid, tryptophan or arginine, or a combination of at least two of them, preferably tryptophan.

[0012] In the present invention, the indole ring of tryptophan is similar in structure to that of polydopamine, and has the strongest conjugation effect. In addition, the phenolic hydroxyl group of tryptophan can form hydrogen bonds with polydopamine, thereby enhancing the photostability of the perovskite layer and the corresponding device. Therefore, using tryptophan to modify polydopamine is beneficial for shielding more ultraviolet light and reducing the amount of ultraviolet light incident on the perovskite layer to a greater extent.

[0013] Preferably, the average particle size of the polydopamine is 100 nm to 200 nm, for example, 100 nm, 120 nm, 140 nm, 160 nm, 180 nm or 200 nm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] In the present invention, polydopamine acts as a scaffold to provide more nucleation sites, thereby promoting the crystal growth process of the film. When the average particle size of polydopamine is 100 nm to 200 nm, it is more conducive to the close stacking of amino acid molecules and the crystal growth of the perovskite film. The conjugated system of the aromatic ring structure is more complete, which can further enhance the absorption capacity of ultraviolet rays.

[0015] Preferably, the mass ratio of the polydopamine to the amino acid molecule is 100:(0.1-10), more preferably 100:(3-7), for example, 100:0.1, 100:1, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9 or 100:10, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0016] In the present invention, by controlling the mass ratio of polydopamine to amino acid molecules within the above preferred range, it is more conducive to the synergistic effect of the two.

[0017] Preferably, the thickness of the perovskite UV protection layer is 4 nm to 6 nm, for example, 4 nm, 4.5 nm, 5 nm, 5.5 nm or 6 nm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In the present invention, by controlling the thickness of the ultraviolet protection layer within the above preferred range, it is more conducive to taking into account both the ultraviolet shielding effect and the photoelectric performance of the perovskite cell.

[0019] In a second aspect, the present invention provides a method for preparing a perovskite UV protection layer as described in the first aspect, the preparation method comprising: mixing an amino acid, polydopamine and a solvent to obtain a mixed solution, coating the mixed solution on the surface of a first carrier transport layer, and heating to obtain a perovskite UV protection layer; the perovskite UV protection layer is located on the surface of the perovskite active layer that receives incident sunlight.

[0020] In the present invention, a perovskite UV protection layer with excellent anti-ultraviolet radiation effect can be obtained only through simple coating. The preparation method is simple and suitable for industrial application.

[0021] Preferably, the solvent comprises dimethyl sulfoxide.

[0022] Preferably, the concentration of the mixed solution is 0.1 mg / mL to 5 mg / mL, preferably 1 mg / mL to 3 mg / mL, for example, 0.1 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, or 5 mg / mL, but is not limited to the listed values, and other values ​​not listed within this numerical range are also applicable.

[0023] Preferably, the coating method includes spin coating.

[0024] Preferably, the spin coating speed is 3000 rpm to 5000 rpm, such as 3000 rpm, 3500 rpm, 4000 rpm, 4500 rpm or 5000 rpm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] Preferably, the spin coating time is 20s to 40s, such as 20s, 25s, 30s, 35s or 40s, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the heating temperature is 80°C to 100°C, such as 80°C, 85°C, 90°C, 95°C or 100°C, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0027] Preferably, the heating time is 3 min to 7 min, for example, 3 min, 4 min, 5 min, 6 min or 7 min, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] In a third aspect, the present invention further provides a perovskite battery, comprising the perovskite ultraviolet protection layer as described in the first aspect.

[0029] In the present invention, as long as the perovskite cell contains the perovskite UV protection layer provided by the present invention, the radiation resistance of the perovskite cell can be greatly improved.

[0030] Preferably, the perovskite cell comprises a single-junction perovskite cell or a stacked perovskite cell.

[0031] Preferably, the tandem perovskite cell includes a perovskite / crystalline silicon tandem cell, a perovskite / perovskite tandem cell or a perovskite / organic tandem cell, and more preferably a perovskite / organic tandem cell.

[0032] Preferably, the single-junction perovskite cell includes a substrate, a first carrier transport layer, an ultraviolet protection layer, a perovskite active layer, a second carrier transport layer and a first metal electrode stacked in sequence from bottom to top.

[0033] Preferably, the perovskite / organic stack cell includes a substrate, a first carrier transport layer, a UV protection layer, a perovskite active layer, a second carrier transport layer, a first metal electrode, a third carrier transport layer, an organic active layer, a fourth carrier transport layer and a second metal electrode stacked in sequence from bottom to top.

[0034] Preferably, the first carrier transport layer is a first hole transport layer or a first electron transport layer.

[0035] Preferably, the first carrier transport layer comprises metal oxide.

[0036] In the present invention, when the first carrier transport layer includes a metal oxide, polydopamine can be anchored on the surface of the metal oxide through strong interfacial interactions to form a polymer coating layer, preventing the metal oxide particles from approaching each other. After the introduction of amino acids, the electrostatic environment and spatial structure of the polydopamine layer can be optimized by introducing charge, steric hindrance or strong coordination groups, thereby effectively inhibiting the agglomeration of metal oxides and optimizing interfacial charge transfer.

[0037] Preferably, when the first carrier transport layer is a first hole transport layer, the metal oxide comprises NiO x .

[0038] Preferably, the NiO x Including NiO, Ni2O3 and NiOOH.

[0039] In the present invention, although NiO has excellent p-type semiconductor properties, its solubility is poor and cannot be solution processed. x On the one hand, it can ensure the hole transport ability, and on the other hand, it can solve the problem of poor solubility of NiO.

[0040] Preferably, when the first carrier transport layer is a first electron transport layer, the metal oxide includes SnO2.

[0041] Preferably, when the first carrier transport layer is a first hole transport layer, the second carrier transport layer is a first electron transport layer; when the first carrier transport layer is a first electron transport layer, the second carrier transport layer is a first hole transport layer.

[0042] Preferably, when the second carrier transport layer is the first electron transport layer, a buffer layer is further included between the second carrier transport layer and the first metal electrode.

[0043] Preferably, when the third carrier transport layer is the second hole transport layer, the fourth carrier transport layer is the second electron transport layer; when the third carrier transport layer is the second electron transport layer, the fourth carrier transport layer is the second hole transport layer.

[0044] Preferably, when the first carrier transport layer is a first hole transport layer, the third carrier transport layer is a second hole transport layer; when the first carrier transport layer is a first electron transport layer, the third carrier transport layer is a second electron transport layer.

[0045] Preferably, the organic active layer includes PM6, Y6 and PC 61 BM.

[0046] The present invention does not limit the material composition of the substrate, perovskite active layer, second carrier transport layer, buffer layer, first metal electrode, third carrier transport layer, fourth carrier transport layer and second metal electrode, and materials commonly used in the art are applicable to the present invention. For example, the substrate includes any one of an indium-doped tin oxide (ITO) glass substrate, a fluorine-doped tin oxide (FTO) glass substrate, a silicon wafer or polyethylene terephthalate (PET); the perovskite active layer includes ABX3 type perovskite, A includes Cs + 、Ru + 、MA + or FA + Any one or a combination of at least two of the following: 2+ or Sn 2+ Any one or a combination of at least two of, X includes Br - , I - or Cl - Any one or a combination of at least two of the following: When the second carrier transport layer is an electron transport layer, it includes C 60 , TiO2, SnO2, ZnO or (6,6)-phenyl-C61-butyric acid methyl ester (PC 61 BM) any one or a combination of at least two, when the second carrier transport layer is a hole transport layer, including NiO x, CuSCN, poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)(PTAA), (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz), (2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl)phosphonic acid (Me-2PACz), 2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl)phosphonic acid (MeO-2PACz), (4-(9H-carbazol-9-yl)butyl)phosphonic acid (4PACz), (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid (Me-4PACz), (4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl)phosphonic acid (MeO-4PACz), poly(3-hexylthiophene)(P3 HT) or 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) or any one or a combination of at least two thereof; the buffer layer includes 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP); the first metal electrode and the second metal electrode each independently include any one of Au, Ag, Cu or Pt; when the third carrier transport layer is the second hole transport layer, it includes any one of MoO3, 2PACz, PTAA or (poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid))(PEDOT:PSS) or any one or a combination of at least two thereof; when the third carrier transport layer is the second electron transport layer, it includes ZnO, C 60 When the fourth carrier transport layer is the second electron transport layer, it includes (poly (diketopyrrolopyrrole-naphthalene diimide)) (PDINN), 3,3'-(1,3,8,10-tetraanthrone and (2,1,9-def:6,5,10-d'e'f') diisoquinoline-2,9 (1H,3H,8H,10H) -diyl) bis (N,N-dimethylpropane-1-amine oxide) (PDINO) or C 60 When the fourth carrier transport layer is the second hole transport layer, it includes MoO3, PTAA or 2PACz.

[0047] At the same time, the present invention does not limit the preparation method of the perovskite battery, and conventional preparation methods in the field are applicable to the present invention. For example, the present invention provides a preparation method of a perovskite / organic stacked battery: first, a first carrier transport layer is prepared on a pretreated substrate by a solution method, and then a perovskite UV protection layer is prepared by the method provided by the present invention, followed by a solution method to prepare a perovskite active layer, and then a thermal evaporation method is used to sequentially prepare a second carrier transport layer, a buffer layer, a first metal electrode and a third carrier transport layer, and then a solution method is used to sequentially prepare an organic active layer and a fourth carrier transport layer on the surface of the third carrier transport layer, and finally a thermal evaporation method is used to prepare a second metal electrode on the surface of the fourth carrier transport layer.

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

[0049] The perovskite UV protection layer provided by the present invention can effectively reduce the amount of UV light incident on the perovskite active layer. Furthermore, when the adjacent carrier transport layer is made of a metal oxide, it can further optimize the interface. The perovskite provided by the present invention can fundamentally reduce the formation of interface defects under light, thereby inhibiting iodide ion escape, overcoming the phase segregation of wide-bandgap perovskites, and avoiding the resulting open-circuit voltage loss of wide-bandgap perovskites, thereby improving battery life and overall performance.

[0050] The perovskite UV protection layer provided by the present invention is applied to a single-junction perovskite cell, and the open circuit voltage of the single-junction perovskite cell reaches 1.30V, which is the highest open circuit voltage achieved by nickel oxide-based wide-bandgap perovskite solar cells without self-assembled monolayers. At the same time, the device efficiency is improved to 19.04%. The perovskite UV protection layer provided by the present invention is applied to perovskite / organic tandem solar cells, and its performance in small-area devices (0.04cm 2 ) has a photoelectric conversion efficiency of 24.30% and an open circuit voltage of 2.09 V. 2 ) is 22.87% with negligible hysteresis. The unpackaged device still maintains 80% of its initial efficiency after 500h of UV irradiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a schematic structural diagram of the perovskite / organic tandem cell provided in Example 1.

[0052] Figure 2 1 is an SEM image of the first hole transport layer in the perovskite / organic tandem cell provided in Example 1 and Comparative Example 1.

[0053] Figure 3 1 is a graph showing the photoelectric conversion efficiency attenuation curves of the perovskite / organic tandem cells provided in Example 1 and Comparative Example 1 under ultraviolet irradiation of different durations.

[0054] Figure 1 Middle: 1-substrate; 2-first carrier transport layer; 3-ultraviolet protection layer; 4-perovskite active layer; 5-second carrier transport layer; 6-buffer layer; 7-first metal electrode; 8-third carrier transport layer; 9-organic active layer; 10-fourth carrier transport layer; 11-second metal electrode. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0057] Example 1

[0058] This embodiment provides a perovskite / organic tandem battery, such as Figure 1 As shown, it includes a base layer 1, a first carrier transport layer 2, a UV protection layer 3, a perovskite active layer 4, a second carrier transport layer 5, a buffer layer 6, a first metal electrode 7, a third carrier transport layer 8, an organic active layer 9, a fourth carrier transport layer 10 and a second metal electrode 11 stacked in sequence from bottom to top. Among them, the first carrier transport layer is made of NiO x The first hole transport layer is composed of tryptophan-modified polydopamine (the mass ratio of polydopamine to tryptophan is 100:5, and the average particle size of polydopamine is 150 nm). The thickness of the ultraviolet protection layer is 5 nm. The preparation process is as follows:

[0059] (1) The patterned ITO glass substrate was cleaned in a ultrasonic bath with detergent, deionized water, and ethanol for 20 min each. Before spin coating the first hole transport layer (HTL), the ITO glass substrate was dried with a nitrogen stream and then treated with UV ozone for 20 min.

[0060] (2) Add 20 mg / mL NiO x Dissolved in distilled water, spin-coated on the treated ITO glass substrate for 30 seconds, and then heated at 100 °C for 10 minutes;

[0061] (3) Tryptophan-modified polydopamine was dissolved in dimethyl sulfoxide (DMSO) at a total concentration of 2 mg / mL and a mass ratio of 100:5, and the mixture was spin-coated at 4000 rpm for 30 s and heated at 90°C for 5 min.

[0062] (4) 0.24 M CsI, 0.96 M formamidinium lead iodide (FAI), 0.72 M PbBr and 0.48 M PbI2 were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide (DMF) and DMSO with a volume ratio of 3:1, and the stoichiometric ratio of FAI was prepared. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3 perovskite precursor solution was first spin-coated at 500 rpm for 2 seconds, then at 3000 rpm for 60 seconds. Finally, 35 seconds before the end of spin coating, 180 μL of chlorobenzene (CB) was added to the substrate as an antisolvent. After spin coating, the perovskite precursor solution was annealed at 100°C for 10 minutes to form a perovskite active layer.

[0063] (5) When the vacuum degree is 5×10 -4 The second carrier transport layer C with a thickness of 20 nm was thermally evaporated in the evaporation chamber of Pa. 60 , a 5nm thick buffer layer of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), a 1nm thick Ag electrode and a 30nm thick third carrier transport layer of MoO3;

[0064] (6) According to the mass ratio PM6:Y6:PC 61 BM=1:1.1:0.1, the organic active layer solution was spin-coated onto the third carrier transport layer at a speed of 3000 rpm, and then annealed at 100°C for 10 min;

[0065] (7) After cooling, 30 μL of a 2 mg / mL methanol solution of poly(3,4-ethylenedioxythiophene)-poly(4,4′-nonyldimethylindolinium) (PDINN) was spin-coated on the organic active layer at 4000 rpm for 30 seconds to form the fourth carrier transport layer;

[0066] (8) In 1×10 -6 A 100 nm thick Ag electrode was evaporated under a vacuum of 10 mbar.

[0067] Example 2

[0068] This embodiment provides a perovskite / organic tandem cell, comprising a substrate layer, a first carrier transport layer, a UV protection layer, a perovskite active layer, a second carrier transport layer, a first metal electrode, a third carrier transport layer, an organic active layer, a fourth carrier transport layer, and a second metal electrode, stacked in order from bottom to top. The first carrier transport layer is a first electron transport layer composed of SnO2, and the UV protection layer is arginine-modified polydopamine (the mass ratio of polydopamine to arginine is 100:3, and the average particle size of polydopamine is 100 nm). The UV protection layer has a thickness of 4 nm.

[0069] (1) The patterned ITO glass substrate was cleaned in a ultrasonic bath with detergent, deionized water, and ethanol for 20 min each. Before spin coating the first hole transport layer (HTL), the ITO glass substrate was dried with a nitrogen stream and then treated with UV ozone for 20 min.

[0070] (2) 20 mg / mL SnO2 was dissolved in distilled water, spin-coated on the treated ITO glass substrate for 30 seconds, and then heated at 100 °C for 10 minutes;

[0071] (3) Arginine-modified polydopamine was dissolved in dimethyl sulfoxide (DMSO) at a total concentration of 1 mg / mL and a mass ratio of 100:3, and the mixture was spin-coated at 3000 rpm for 40 s and heated at 80°C for 7 min.

[0072] (4) 0.24 M CsI, 0.96 M formamidinium lead iodide (FAI), 0.72 M PbBr and 0.48 M PbI2 were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) with a volume ratio of 3:1, and the stoichiometric ratio was FAI. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3 perovskite precursor solution. First, spin-coat at 500rpm for 2s, then spin-coat at 3000rpm for 60s, and finally, at 35s countdown to the end of spin-coating, add 180μL of chlorobenzene (CB) as an anti-solvent to the substrate. After the perovskite precursor solution is spin-coated, anneal at 100°C for 10min to form a perovskite active layer; then, spin-coat 72.3mg of Spiro-OMeTAD solution (72.3mg of Spiro-OMeTAD is dissolved in 1mL of chlorobenzene, to which 17uL of lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) and 28.8uL of tri-tert-butylphenol (2,4,6-tri-tert-butylphenol) (tBP)) on the perovskite surface at 3000rpm for 30s, and then place it in a drying cabinet for oxidation for 6 hours.

[0073] (5) When the vacuum degree is 5×10 -4 A 1 nm thick Ag electrode and a 20 nm thick third carrier transport layer ZnO were thermally evaporated in Pa’s evaporation chamber;

[0074] (6) According to the mass ratio PM6:Y6:PC 61 BM=1:1.1:0.1, the organic active layer solution was spin-coated onto the third carrier transport layer at a speed of 3000 rpm, and then annealed at 100°C for 10 min;

[0075] (7) After cooling, the vacuum degree is 5×10 -4 The fourth carrier transport layer is formed by thermally evaporating 30 nm thick MoO3 in the Pa evaporation chamber;

[0076] (8) In 1×10 -6 A 100 nm thick Ag electrode was evaporated under a vacuum of 10 mbar.

[0077] Example 3

[0078] This embodiment provides a perovskite / organic stacked cell, comprising a substrate layer, a first carrier transport layer, an ultraviolet protection layer, a perovskite active layer, a second carrier transport layer, a buffer layer, a first metal electrode, a third carrier transport layer, an organic active layer, a fourth carrier transport layer, and a second metal electrode stacked in sequence from bottom to top. x The hole transport layer is composed of glutamic acid-modified polydopamine (the mass ratio of polydopamine to glutamic acid is 100:7, and the average particle size of polydopamine is 200 nm), and the thickness of the ultraviolet protection layer is 6 nm.

[0079] Steps (1), (2) and (4) to (9) in the preparation process are consistent with those in Example 1. Step (3) is as follows: glutamate-modified polydopamine is dissolved in DMSO at a total concentration of 3 mg / mL and a mass ratio of 100:7 of polydopamine and tryptophan, and the mixture is spin-coated at 5000 rpm for 20 s and heated at 100°C for 3 min.

[0080] Example 4

[0081] This embodiment provides a perovskite single-junction cell, comprising a substrate layer, a first carrier transport layer, a UV protection layer, a perovskite active layer, a second carrier transport layer, and a metal electrode stacked in sequence from bottom to top. In the preparation method, steps (6) to (8) are not performed, and thermal evaporation of the third carrier transport layer is not performed in step (5);

[0082] The rest of the preparation methods and parameters were the same as those in Example 1.

[0083] Example 5

[0084] The difference between this embodiment and embodiment 1 is that, in this embodiment, the amino acid is lysine;

[0085] The rest of the preparation methods and parameters were the same as those in Example 1.

[0086] Example 6

[0087] The difference between this embodiment and embodiment 1 is that, in this embodiment, the amino acid is phenylalanine;

[0088] The rest of the preparation methods and parameters were the same as those in Example 1.

[0089] Example 7

[0090] The difference between Example 1 and Example 1 is that, in this example, the mass ratio of amino acid to polydopamine is 100:2;

[0091] The rest of the preparation methods and parameters were the same as those in Example 1.

[0092] Example 8

[0093] The difference between Example 1 and Example 1 is that, in this example, the mass ratio of polydopamine to amino acid is 100:10;

[0094] The rest of the preparation methods and parameters were the same as those in Example 1.

[0095] Example 9

[0096] The difference between this embodiment and embodiment 1 is that, in this embodiment, the average particle size of polydopamine is 250 nm;

[0097] The rest of the preparation methods and parameters were the same as those in Example 1.

[0098] Example 10

[0099] The difference between this embodiment and embodiment 1 is that, in this embodiment, the thickness of the ultraviolet protection layer is 2 nm;

[0100] The rest of the preparation methods and parameters were the same as those in Example 1.

[0101] Example 11

[0102] The difference between this embodiment and embodiment 1 is that, in this embodiment, the first hole transport layer is composed of Me-2PACz, and in step (2) of the preparation method, 0.5 mg / mL of Me-2PACz is dissolved in ethanol, spin-coated on the treated ITO glass substrate at a speed of 4000 rpm for 30 seconds, and then heated at 100°C for 10 minutes;

[0103] The rest of the preparation methods and parameters were the same as those in Example 1.

[0104] Example 12

[0105] The difference between this embodiment and embodiment 1 is that in this embodiment, the first carrier transport layer is a hole transport layer composed of NiO, and in step (2) of the preparation method, NiO is x Replaced with NiO;

[0106] The rest of the preparation methods and parameters were the same as those in Example 1.

[0107] Comparative Example 1

[0108] The difference between this comparative example and Example 1 is that in this comparative example, the perovskite / organic stacked cell includes a substrate layer, a first carrier transport layer, a perovskite active layer, a second carrier transport layer, a buffer layer, a first metal electrode, a third carrier transport layer, an organic active layer, a fourth carrier transport layer, and a second metal electrode stacked in sequence from bottom to top, and step (3) is not performed during the preparation process;

[0109] The rest of the preparation methods and parameters were the same as those in Example 1.

[0110] Comparative Example 2

[0111] The difference between this comparative example and Example 1 is that in this comparative example, the UV protection layer only includes polydopamine and does not include amino acids;

[0112] The rest of the preparation methods and parameters were the same as those in Example 1.

[0113] Comparative Example 3

[0114] The difference between this comparative example and Example 4 is that in this comparative example, the perovskite battery includes a base layer, a first carrier transport layer, a perovskite active layer, a UV protection layer, a second carrier transport layer and a first metal electrode stacked in sequence from bottom to top;

[0115] The rest of the preparation methods and parameters were the same as those in Example 4.

[0116] Performance Testing

[0117] The first hole transport layer in the perovskite / organic stacked cells prepared in Example 1 and Comparative Example 1 was subjected to SEM testing. The test results are as follows: Figure 2As shown; The initial photoelectric conversion efficiency test of the perovskite cells prepared in Examples 1-12 and Comparative Examples 1-3 was performed, and the photoelectric conversion efficiency test was performed again after 500 hours of ultraviolet light irradiation. The stability was expressed as the percentage ((η / η0)%) of the photoelectric conversion efficiency (η) of the cell after 500 hours of light irradiation to the initial photoelectric conversion efficiency (η0). The test results are shown in Tables 1 and Figure 3 shown.

[0118] Table 1

[0119]

[0120]

[0121] Depend on Figure 2 It can be seen that after a UV protection layer is introduced on the surface of the first carrier transport layer, the metal oxide in the first carrier transport layer is distributed more evenly and the occurrence of agglomeration is significantly reduced, thereby optimizing the interface, accelerating the charge transfer rate at the interface, and improving the photoelectric conversion efficiency and stability of the perovskite.

[0122] Depend on Figure 3 As can be seen from the comparison of the data of Examples 1-3 and Comparative Examples 1-2 in Table 1, by introducing a layer of amino acid-modified polydopamine as a UV protection layer on the surface of the perovskite active layer that receives incident sunlight, the battery life and overall performance of the perovskite battery are significantly improved.

[0123] From the comparison of the data of Example 4 and Comparative Example 3 in Table 1, it can be seen that if the ultraviolet protection layer is located on the surface of the perovskite active layer away from the incident sunlight, it cannot effectively reduce the amount of ultraviolet light reaching the perovskite active layer, and thus cannot effectively improve the radiation resistance of the perovskite cell.

[0124] From the data comparison of Example 1 and Examples 5-6, it can be seen that when phenylalanine or tryptophan is used to modify polydopamine, the effect is better than that of lysine modification; from the data comparison of Example 1 and Examples 7-10, it can be seen that the mass ratio of polydopamine to amino acids, the particle size of polydopamine and the thickness of the ultraviolet protection layer will also affect the performance and stability of the perovskite battery. By controlling them within the preferred range of the present invention, better effects can be achieved; from the data comparison of Example 1 and Examples 11-12, it can be seen that when the first carrier transport layer is a metal oxide, the ultraviolet protection layer can also inhibit the agglomeration of the metal oxide, thereby further improving the performance and stability of the perovskite battery, and NiO x As a hole transport layer, it is more effective than NiO.

[0125] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A perovskite UV protection layer, characterized in that: The perovskite ultraviolet protection layer includes polydopamine modified with amino acid molecules, and the perovskite ultraviolet protection layer is located on the surface of the perovskite active layer on the side that receives incident sunlight.

2. The perovskite UV protection layer according to claim 1, characterized in that The amino acid molecule includes any one or a combination of at least two of phenylalanine, glutamic acid, tryptophan or arginine, preferably tryptophan; Preferably, the average particle size of the polydopamine is 100 nm to 200 nm.

3. The perovskite UV protection layer according to claim 1 or 2, characterized in that: The mass ratio of the polydopamine to the amino acid molecules is 100:(0.1-10), and more preferably 100:(3-7).

4. The perovskite UV protection layer according to any one of claims 1 to 3, characterized in that: The thickness of the perovskite ultraviolet protection layer is 4nm to 6nm.

5. A method for preparing a perovskite UV protection layer according to any one of claims 1 to 4, characterized in that: The preparation method comprises: mixing amino acids, polydopamine and a solvent to obtain a mixed solution, coating the mixed solution on the surface of the first carrier transport layer, and heating to obtain a perovskite ultraviolet protection layer; The perovskite ultraviolet protection layer is located on the surface of the perovskite active layer that receives incident sunlight.

6. The method for preparing a perovskite UV protection layer according to claim 5, characterized in that: The solvent includes dimethyl sulfoxide; Preferably, the concentration of the mixed solution is 0.1 mg / mL to 5 mg / mL, more preferably 1 mg / mL to 3 mg / mL; Preferably, the coating method includes spin coating; Preferably, the spin coating speed is 3000 rpm to 5000 rpm; Preferably, the spin coating time is 20s to 40s; Preferably, the heating temperature is 80°C to 100°C; Preferably, the heating time is 3 minutes to 7 minutes.

7. A perovskite battery, characterized in that: The perovskite cell comprises the perovskite ultraviolet protection layer according to any one of claims 1 to 4.

8. The perovskite cell according to claim 7, characterized in that The perovskite cell includes a single-junction perovskite cell or a stacked perovskite cell; Preferably, the tandem perovskite cell includes a perovskite / crystalline silicon tandem cell, a perovskite / perovskite tandem cell or a perovskite / organic tandem cell, and more preferably a perovskite / organic tandem cell.

9. The perovskite cell according to claim 8, characterized in that The single-junction perovskite cell comprises a substrate, a first carrier transport layer, an ultraviolet protection layer, a perovskite active layer, a second carrier transport layer and a first metal electrode stacked in sequence from bottom to top; Preferably, the perovskite / organic stacked cell comprises a substrate, a first carrier transport layer, an ultraviolet protection layer, a perovskite active layer, a second carrier transport layer, a first metal electrode, a third carrier transport layer, an organic active layer, a fourth carrier transport layer and a second metal electrode stacked in sequence from bottom to top; Preferably, the first carrier transport layer is a first hole transport layer or a first electron transport layer; Preferably, the first carrier transport layer comprises a metal oxide; Preferably, when the first carrier transport layer is a first hole transport layer, the metal oxide comprises NiO x ; Preferably, the NiO x Including NiO, Ni2O3 and NiOOH; Preferably, when the first carrier transport layer is a first electron transport layer, the metal oxide includes SnO2.

10. The perovskite cell according to claim 9, characterized in that When the first carrier transport layer is a first hole transport layer, the second carrier transport layer is a first electron transport layer; when the first carrier transport layer is a first electron transport layer, the second carrier transport layer is a first hole transport layer; Preferably, when the second carrier transport layer is the first electron transport layer, a buffer layer is further included between the second carrier layer and the first metal electrode; Preferably, when the third carrier transport layer is the second hole transport layer, the fourth carrier transport layer is the second electron transport layer; when the third carrier transport layer is the second electron transport layer, the fourth carrier layer is the second hole transport layer; Preferably, when the first carrier transport layer is a first hole transport layer, the third carrier transport layer is a second hole transport layer; when the first carrier transport layer is a first electron transport layer, the third carrier transport layer is a second electron transport layer; Preferably, the organic active layer includes PM6, Y6 and PC 61 BM.

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