Perovskite solar cell, preparation method thereof and power utilization device

Abstract

The invention discloses a perovskite solar cell, a preparation method thereof and an electric device. The perovskite solar cell comprises a first electrode, a first charge transport layer, a perovskite absorption layer, a second charge transport layer and a second electrode, the first charge transport layer is arranged on one side of the first electrode; the perovskite absorption layer is arranged on one side of the first charge transport layer; the second charge transport layer is arranged on one side of the perovskite absorption layer; the second electrode is arranged on one side of the charge transport layer, the first charge transport layer, the first electrode and the perovskite absorption layer simultaneously meet the following relational expressions: d = (2k + 1) lambda / 4n1 and n12 = an2 * n0, d represents the thickness of the first charge transport layer, and the unit is nm; k is an integer not less than 0; lambda represents the wavelength of a main light absorption band of the perovskite absorption layer, and the unit is nm; n0 is the refractive index of the first electrode; n1 is the refractive index of the first charge transport layer; n2 is the refractive index of the perovskite absorption layer; a is a correction coefficient, and the value of a ranges from 0.5 to 1.5.

Description

Perovskite solar cell, preparation method thereof, and electrical device Technical Field

[0001] The present application relates to the field of solar cells, and in particular to a perovskite solar cell, a preparation method thereof, and an electrical device thereof. Background Art

[0002] Perovskite solar cells have attracted widespread attention due to their excellent optoelectronic properties, including adjustable band gap, high light absorption coefficient, long carrier lifetime and diffusion length, high defect tolerance, and low-cost, low-temperature liquid-phase fabrication methods. However, as incident light passes through the various functional layers of perovskite solar cells, it inevitably reflects and scatters at various interfaces, resulting in light loss.

[0003] Public content

[0004] In view of the technical problems existing in the background technology, the present application provides a perovskite solar cell, which aims to alleviate the problem of large light loss caused by reflection of incident light at various interfaces during the use of existing perovskite solar cells.

[0005] In order to achieve the above objectives, the first aspect of the present application provides a perovskite solar cell, comprising:

[0006] a first electrode;

[0007] a first charge transport layer, the first charge transport layer being disposed on one side of the first electrode;

[0008] a perovskite absorption layer, the perovskite absorption layer being provided on a side of the first charge transport layer away from the first electrode;

[0009] a second charge transport layer, the second charge transport layer being arranged on a side of the perovskite absorption layer away from the first charge transport layer;

[0010] a second electrode, the second electrode being disposed on a side of the second charge transport layer away from the perovskite absorption layer;

[0011] The first charge transport layer, the first electrode and the perovskite absorption layer simultaneously satisfy the following relationship:

[0012] d=(2k+1)λ / 4n1 and n1 2 =an2×n0,

[0013] d represents the thickness of the first charge transport layer, in nm;

[0014] k is an integer not less than 0;

[0015] λ represents the wavelength of the main wavelength band of light absorbed by the perovskite absorption layer, in nm;

[0016] n0 is the refractive index of the first electrode;

[0017] n1 is the refractive index of the first charge transport layer;

[0018] n2 is the refractive index of the perovskite absorption layer;

[0019] a is the correction coefficient, which ranges from 0.5 to 1.5.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects: the first charge transport layer, the first electrode and the perovskite absorption layer in the perovskite solar cell of the present invention simultaneously satisfy the relationship d=(2k+1)λ / 4n1 and n1 2 =an2×n0, which makes the first charge transport layer in the perovskite solar cell have an excellent anti-reflection effect, thereby reducing the reflection of the incident light, allowing more incident light to pass through the first charge transport layer and enter the perovskite absorption layer, thereby improving the energy conversion efficiency of the perovskite solar cell.

[0021] In some embodiments of the present application, the refractive index n0 of the first electrode is 0.5-3.

[0022] In some embodiments of the present application, the refractive index n1 of the first charge transport layer is 0.5-3.

[0023] In some embodiments of the present application, the refractive index n2 of the perovskite absorption layer is 0.5-3.

[0024] In some embodiments of the present application, the first charge transport layer includes a radioactive material. This allows, on the one hand, to adjust the refractive index of the first charge transport layer, and, on the other hand, the radioactive material is radioactive, and its high-energy radiation particles can self-excite to generate carriers, thereby increasing the number of carriers and thus improving the battery current.

[0025] In some embodiments of the present application, based on the total mass of the first charge transport layer, the content of the radioactive material is no more than 30 wt%, and may be 3 wt%-15 wt%, thereby increasing carriers and improving battery current.

[0026] In some embodiments of the present application, the radioactive material includes at least one of an α-type radiation source material and a β-type radiation source material, thereby increasing carriers and improving battery current.

[0027] In some embodiments of the present application, the α-type radiation source material includes 210 Po and its compounds, 228 Th and its compounds,235 U and its compounds, 238 Pu and its compounds, 241 Am and its compounds, 242 Cm and its compounds, 244 At least one of Cm and its compounds. This can increase carriers and improve battery current.

[0028] In some embodiments of the present application, the β-type radiation source material includes (C4H3 3 H5 - )n、 3 H2、Ti 3 H4, 14 C and its compounds, 35 S and its compounds, 63 Ni and its compounds, 90 Sr and its compounds, 99 Tc and its compounds, 106 Ru and its compounds, 137 Cs and its compounds, 144 Ce and its compounds, 147 Pm and its compounds, 151 Sm and its compounds, 226 At least one of Ra and its compounds. This can increase carriers and improve battery current.

[0029] In some embodiments of the present application, the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, and the electron transport material in the electron transport layer includes at least one of imide compounds, quinone compounds, fullerenes and their derivatives, metal oxides, silicon oxide, strontium titanate, calcium titanate, lithium fluoride and calcium fluoride, wherein the metal element in the metal oxide includes at least one of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr.

[0030] In some embodiments of the present application, the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, and the hole transport material in the hole transport layer includes at least one of 2,2',7,7'-tetrakis(N,N-p-methoxyanilino)-9,9'-spirobifluorene, methoxytriphenylamine-fluoroformamidine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene): polystyrenesulfonic acid, poly3-hexylthiophene, triphenylamine with triptycene as the core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-phenylamino)carbazole-spirobifluorene, polythiophene, phosphate-based monomers, carbazole-based monomers, sulfonic acid-based monomers, triphenylamine-based monomers, aromatic monomers, metal oxides and cuprous thiocyanate, wherein the metal element in the metal oxide includes at least one of Ni, Mo and Cu.

[0031] In some embodiments of the present application, the perovskite solar cell further comprises a buffer layer disposed between the first charge transport layer and the perovskite absorption layer, thereby reducing the risk of high-energy particles radiated by radioactive materials in the first charge transport layer damaging the perovskite absorption layer.

[0032] In some embodiments of the present application, the distance between the valence band top and the conduction band bottom of the buffer layer material is not less than 2.5 eV. Thus, the buffer layer can absorb high-energy particles radiated by the radioactive material in the first charge transport layer, thereby reducing damage to the perovskite absorption layer.

[0033] In some embodiments of the present application, the material of the buffer layer includes at least one of an inorganic wide bandgap semiconductor material and an organic wide bandgap semiconductor material, thereby reducing damage to the perovskite absorption layer.

[0034] In some embodiments of the present application, the inorganic wide bandgap semiconductor material includes at least one of a II-VI compound semiconductor, a III-V compound semiconductor, a transition metal oxide, a transition metal halide, and a silicon-based wide bandgap semiconductor. This can reduce damage to the perovskite absorber layer.

[0035] In some embodiments of the present application, the organic wide bandgap semiconductor material includes at least one of C60, PC61BM ((6,6)-phenyl-C61-butyric acid methyl ester), PC71BM ((6,6)-phenyl-C71-butyric acid methyl ester), P3HT (3-hexyl-substituted polythiophene), PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]), and PEDOT:PSS (poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid)). This can reduce damage to the perovskite absorber layer.

[0036] In some embodiments of the present application, the refractive index n3 of the buffer layer satisfies the relationship between the refractive index n1 of the first charge transport layer and the refractive index n0 of the first electrode: n1 2 =bn3×n0, where b is the correction coefficient and is set to 0.5-1.5. This can increase the transmittance of incident light and improve the energy conversion efficiency of the battery.

[0037] In some embodiments of the present application, the refractive index n2 of the buffer layer is 0.5-3. This can increase the transmittance of incident light and improve the energy conversion efficiency of the battery.

[0038] In some embodiments of the present application, the thickness of the buffer layer is no greater than 10 nm, thereby increasing the transmittance of incident light and improving the energy conversion efficiency of the battery.

[0039] A second aspect of the present application provides a method for preparing a perovskite solar cell, comprising:

[0040] forming a first charge transport layer on one side of the first electrode;

[0041] forming a perovskite absorption layer on a side of the first charge transport layer away from the first electrode;

[0042] forming a second charge transport layer on a side of the perovskite absorption layer away from the first charge transport layer;

[0043] forming a second electrode on a side of the second charge transport layer away from the perovskite absorption layer;

[0044] The first charge transport layer, the first electrode and the perovskite absorption layer simultaneously satisfy the following relationship:

[0045] d=(2k+1)λ / 4n1 and n1 2 =an2×n0,

[0046] d represents the thickness of the first charge transport layer, in nm;

[0047] k is an integer not less than 0;

[0048] λ represents the wavelength of the main wavelength band of light absorbed by the perovskite absorption layer, in nm;

[0049] n0 is the refractive index of the first electrode;

[0050] n1 is the refractive index of the first charge transport layer;

[0051] n2 is the refractive index of the perovskite absorption layer;

[0052] a is the correction coefficient, which ranges from 0.5 to 1.5.

[0053] Therefore, the method of the present application can be used to prepare the above-mentioned perovskite solar cell with excellent energy conversion efficiency.

[0054] In some embodiments of the present application, the method for preparing a perovskite solar cell further includes forming a buffer layer between the first charge transport layer and the perovskite absorption layer. This can reduce the risk of high-energy particles radiated by radioactive materials in the first charge transport layer damaging the perovskite absorption layer.

[0055] A third aspect of the present application provides an electrical device, which includes the perovskite solar cell of the embodiment of the first aspect or the perovskite solar cell manufactured by the method of the embodiment of the second aspect, and the perovskite solar cell is used to provide electrical energy.

[0056] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0058] FIG1 is a schematic structural diagram of a perovskite solar cell in the prior art.

[0059] FIG2 is a schematic structural diagram of a perovskite solar cell according to an embodiment of the present application.

[0060] FIG3 is a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application.

[0061] FIG4 is a diagram showing the working principle of a perovskite solar cell according to another embodiment of the present application.

[0062] Description of reference numerals:

[0063] 1000: Perovskite solar cell; 100: First electrode; 200: First charge transport layer; 300: Perovskite absorption layer; 400: Charge transport layer; 500: Second electrode; 600: Buffer layer. DETAILED DESCRIPTION

[0064] The following embodiments of the technical solution of the present application are described in detail. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only used as examples and are not intended to limit the scope of protection of the present application.

[0065] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0066] For the sake of clarity, only some numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, each individually disclosed point or single value may itself serve as a lower limit or upper limit and be combined with any other point or single value, or with other lower limits or upper limits, to form an unspecified range.

[0067] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0068] 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.

[0069] Perovskite solar cells have attracted widespread attention due to their excellent optoelectronic properties, such as adjustable band gap, high light absorption coefficient, long carrier lifetime and diffusion length, high defect tolerance, and low-cost low-temperature liquid phase preparation method.

[0070] As shown in Figure 1, the existing perovskite solar cell includes an upper electrode, a charge transfer layer, a perovskite layer, a charge transfer layer and a lower electrode. The incident light is incident from above the upper electrode. In the process of acting on each functional layer, the incident light is inevitably emitted and scattered at each interface, thereby reducing the light incident on the perovskite absorption layer and reducing the energy conversion efficiency of the battery.

[0071] Therefore, the first aspect of the present application discloses a perovskite solar cell. Referring to Figure 2, the perovskite solar cell 1000 includes: a first electrode 100, a first charge transport layer 200, a perovskite absorption layer 300, a second charge transport layer 400 and a second electrode 500, wherein the first charge transport layer 200 is arranged on one side of the first electrode 100; the perovskite absorption layer 300 is arranged on the side of the first charge transport layer 200 away from the first electrode 100; the second charge transport layer 400 is arranged on the side of the perovskite absorption layer 300 away from the first charge transport layer 200; the second electrode 500 is arranged on the side of the second charge transport layer 400 away from the perovskite absorption layer 300, and the first charge transport layer 200, the first electrode 100 and the perovskite absorption layer 300 simultaneously satisfy the following relationship: d = (2k+1)λ / 4n1 and n1 2 =an2×n0, d represents the thickness of the first charge transport layer, in nm; k is an integer not less than 0; λ represents the wavelength of the main band of light absorbed by the perovskite absorption layer, in nm; n0 is the refractive index of the first electrode; n1 is the refractive index of the first charge transport layer; n2 is the refractive index of the perovskite absorption layer; a is a correction coefficient, with a value of 0.5-1.5, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5.

[0072] The inventors have found through extensive research that the first charge transport layer 200, the first electrode 100 and the perovskite absorption layer 300 in the perovskite solar cell of the present application simultaneously satisfy the relationship d=(2k+1)λ / 4n1 and n1 2 =an2×n0, so that the first charge transport layer 200 in the perovskite solar cell 1000 has an excellent anti-reflection effect, thereby reducing the reflection of the incident light, allowing more incident light to pass through the first charge transport layer 200 and enter the perovskite absorption layer 300, thereby improving the energy conversion efficiency of the perovskite solar cell.

[0073] According to some examples, a method for testing "the wavelength λ of the main band of light absorbed by the perovskite absorption layer 300" includes: at room temperature, using an ultraviolet-visible spectrophotometer (Shimadzu UV-Vis 3200) to test a perovskite solid film sample to obtain its absorption spectrum in the visible light band, and taking the wavelength corresponding to the band with the largest absorption value in the absorption spectrum as the wavelength λ value of the main band of the absorbed light; a method for testing the refractive index n0 of the first electrode 100", the refractive index n1 of the first charge transport layer 200" and the refractive index n2 of the perovskite absorption layer 300 includes: at room temperature, using a refractive index tester (Mettler Toledo R5) to measure the solid film samples respectively, which can be directly obtained.

[0074] After in-depth research, the inventors of the present application found that when the perovskite solar cell of the present application satisfies the above conditions and optionally satisfies one or more of the following conditions, the energy conversion efficiency of the battery can be further improved.

[0075] In some embodiments, the refractive index n0 of the first electrode 100 is 0.5-3, such as 0.7-2.8, 1-2.5, 1.2-2.2, 1.5-2, or 1.5-1.7, thereby increasing the transmittance of incident light in the first electrode 100 and improving the energy conversion efficiency of the battery.

[0076] In some embodiments, the electrode materials of the first electrode 100 and the second electrode 500 may include organic conductive materials, inorganic conductive materials, or organic-inorganic hybrid conductive materials. For example, organic conductive materials include, but are not limited to, PEDOT (polymer of 3,4-ethylenedioxythiophene), polythiophene, and polyacetylene; inorganic conductive materials include, but are not limited to, FTO (fluorine-doped SnO2 conductive glass), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide transparent conductive glass), metals, carbon derivatives, and the like.

[0077] In some embodiments, the refractive index n1 and thickness d of the first charge transport layer 200 satisfy the relationship d=(2k+1)λ / 4n1, where k is an integer such as 0, 1, 2, 3, or 4. In other embodiments, k is 0, and the refractive index n1 and thickness d of the first charge transport layer 200 satisfy the relationship d=λ / 4n1. Under the same refractive index and incident light, the thickness of the first charge transport layer 200 is lower, and the anti-reflection effect of the corresponding first charge transport layer 200 is also higher.

[0078] In some embodiments, the refractive index n1 of the first charge transport layer 200 is 0.5-3, for example, 0.7-2.8, 1-2.5, 1.2-2.2, 1.5-2, or 1.5-1.7.

[0079] In some embodiments, the refractive index n1 of the first charge transport layer 200 can be regulated by doping the first charge transport layer 200 with a radioactive material, and the thickness of the first charge transport layer 200 can be regulated at the same time, so that the refractive index n1 and thickness d of the first charge transport layer 200 satisfy the relationship d=(2k+1)λ / 4n1 and n1 2=an2×n0. The inventors discovered that by doping the first charge transport layer 200 with a radioactive material, not only can the refractive index of the first charge transport layer be adjusted, but also the radioactive material in the first charge transport layer 200 is radioactive, and its high-energy radiation particles can self-excite to generate carriers, thereby increasing the number of carriers in the perovskite solar cell 1000 and improving the battery current.

[0080] In some embodiments, based on the total mass of the first charge transport layer 200, the content of the radioactive material is not greater than 30 wt%, for example, 1 wt%-30 wt%, 2 wt%-29 wt%, 3 wt%-28 wt%, 3 wt%-25 wt%, 3 wt%-22 wt%, 3 wt%-20 wt%, 3 wt%-18 wt%, 3 wt%-15 wt%, 3 wt%-12 wt%, or 3 wt%-10 wt%. Specifically, the refractive index of the first charge transport layer 200 is regulated by adjusting the content of the radioactive material in the first charge transport layer 200, so that the refractive index n1 and thickness d of the first charge transport layer 200 satisfy the relationship d=(2k+1)λ / 4n1 and n1 2 =an2×n0, thereby achieving the anti-reflection effect of the first charge transport layer 200. However, if the content of the radioactive material is too high, the high-energy particles radiated by it will damage the perovskite absorption layer 300. In other embodiments, based on the total mass of the first charge transport layer 200, the content of the radioactive material is 3wt%-15wt%.

[0081] In some embodiments, the radioactive material in the first charge transport layer 200 includes at least one of an α-type radiation source material and a β-type radiation source material. For example, the α-type radiation source material includes 210 Po and its compounds, 228 Th and its compounds, 235 U and its compounds, 238 Pu and its compounds, 241 Am and its compounds, 242 Cm and its compounds, 244 At least one of Cm and its compounds; the β-type radiation source material includes (C4H3 3 H5 - )n、 3 H2、Ti 3 H4, 14 C and its compounds, 35 S and its compounds, 63 Ni and its compounds, 90 Sr and its compounds, 99 Tc and its compounds, 106 Ru and its compounds, 137Cs and its compounds, 144 Ce and its compounds, 147 Pm and its compounds, 151 Sm and its compounds, 226 At least one of Ra and its compounds.

[0082] In some embodiments, the refractive index n2 of the perovskite absorption layer 300 is 0.5-3, for example, 0.7-2.8, 1-2.5, 1.2-2.2, 1.5-2, or 1.5-1.7.

[0083] The perovskite solar cell 1000 described in the present application may be a regular perovskite solar cell or an inverted perovskite solar cell.

[0084] In some embodiments, the perovskite solar cell 1000 is a formal perovskite solar cell, the first charge transport layer 200 is an electron transport layer, the second charge transport layer 400 is a hole transport layer, and the electron transport material in the electron transport layer includes at least one of imide compounds, quinone compounds, fullerenes and their derivatives, metal oxides, silicon oxide, strontium titanate, calcium titanate, lithium fluoride and calcium fluoride, wherein the metal element in the metal oxide includes at least one of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr, and further the electron transport material in the electron transport layer includes poly (3,4-ethylenedioxythiophene), polystyrene sulfonate, poly (bis (4-phenyl) (2,4,6-trimethylphenyl) amine), NiO x 、MoO x , at least one of 2,2',7,7'-tetrakis(N,N-p-anisyl)-9,9'-spirobifluorene, WO3, polyethoxyethyleneimine, polyethyleneimine, ZnO, TiO2, [6,6]-phenyl-C61-butyric acid isomethyl ester and SnO2. The hole transport material in the hole transport layer includes at least one of 2,2',7,7'-tetrakis(N,N-p-methoxyanilino)-9,9'-spirobifluorene, methoxytriphenylamine-fluoroformamidine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene):polystyrenesulfonic acid, poly3-hexylthiophene, triphenylamine with triptycene as the core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-phenylamino)carbazole-spirobifluorene, polythiophene, a phosphate-based single molecule, a carbazole-based single molecule, a sulfonic acid-based single molecule, a triphenylamine-based single molecule, an aromatic single molecule, a metal oxide and cuprous thiocyanate, wherein the metal element in the metal oxide includes at least one of Ni, Mo and Cu.

[0085] In some embodiments, the perovskite solar cell 1000 is an inverted perovskite solar cell, the first charge transport layer 200 is a hole transport layer, the second charge transport layer 400 is an electron transport layer, and the hole transport material in the hole transport layer includes 2,2',7,7'-tetrakis(N,N-p-methoxyanilino)-9,9'-spirobifluorene, methoxytriphenylamine-fluoroformamidine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly (3,4-ethylenedioxythiophene): at least one of polystyrene sulfonic acid, poly-3-hexylthiophene, triphenylamine with triptycene as the core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-phenylamino)carbazole-spirobifluorene, polythiophene, phosphate-based monomers, carbazole-based monomers, sulfonic acid-based monomers, triphenylamine-based monomers, aromatic monomers, metal oxides and cuprous thiocyanate, wherein the metal element in the metal oxide includes at least one of Ni, Mo and Cu. The electron transport material in the electron transport layer includes at least one of imide compounds, quinone compounds, fullerenes and their derivatives, metal oxides, silicon oxide, strontium titanate, calcium titanate, lithium fluoride and calcium fluoride, wherein the metal element in the metal oxide includes at least one of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr, and further the electron transport material in the electron transport layer includes poly 3,4-ethylenedioxythiophene, polystyrene sulfonate, poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine], NiO x 、MoO x , at least one of 2,2',7,7'-tetrakis(N,N-p-anisyl)-9,9'-spirobifluorene, WO3, polyethoxyethyleneimine, polyethyleneimine, ZnO, TiO2, [6,6]-phenyl-C61-butyric acid isomethyl ester and SnO2.

[0086] In some embodiments, the chemical formula of the perovskite material in the perovskite absorber layer 300 is ABX3, wherein A is an inorganic or organic or organic-inorganic mixed cation, B is a metal cation, and X is an inorganic or organic or organic-inorganic mixed anion, for example, A is an organic amine cation, B is a divalent metal cation, and X is a halogen anion or SCN. - In some examples, A in ABX3 may include CH3NH3 + and HC(NH2)2 + In other words, A can be CH3NH3 + 、HC(NH2)2 + Or a mixture of the two in any proportion. It is understood that A may also include metal ions, such as Cs + , Rb + and K+ At least one of the following. B in ABX3 can be Pb 2+ 、Sn 2+ and Ge 2+ For example, ABX3 can be CH3NH3PbI3, CH3NH3SnI3, CH3NH3PbI2Cl, CH3NH3PbI2Br, CH3NH3Pb(I 1-x Br x )3(where 0 <x<1)。

[0087] In some embodiments, since high-energy radiation particles in the radioactive material in the first charge transport layer 200 may damage the perovskite absorption layer 300, in order to reduce damage to the perovskite absorption layer 300, with reference to FIG3 , a buffer layer 600 is provided between the first charge transport layer 200 and the perovskite absorption layer 300. The distance between the valence band top and the conduction band bottom of the material of the buffer layer 600 is not less than 2.5 eV. Thus, the buffer layer 600 that meets this condition can absorb high-energy particles radiated from the radioactive material, causing energy deposition and converting the kinetic energy of the high-energy particles into charge energy, thereby effectively reducing damage to the perovskite absorption layer 300.

[0088] According to some examples, a method for testing the energy band information (valence band top, conduction band bottom, etc.) of the material of the buffer layer 600 includes: using an Escalab 250Xi (from Thermo Scientific) X-ray photoelectron spectrometer (XPS) at room temperature and pressure to obtain the energy band distribution of the material, and the valence band top position and the conduction band bottom position can be obtained from the XPS spectrum.

[0089] In some embodiments, the material of the buffer layer 600 includes at least one of an inorganic wide bandgap semiconductor material and an organic wide bandgap semiconductor material, wherein the inorganic wide bandgap semiconductor material includes at least one of a II-VI compound semiconductor, a III-V compound semiconductor, an oxide of a transition metal, a halide of a transition metal, and a silicon-based wide bandgap semiconductor. Specifically, the II-VI compound semiconductor refers to a compound semiconductor composed of elements of Group IIB (Zn, Cd, Hg) and elements of Group VIA (S, Se, Te, O) in the periodic table, such as ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe; the III-V compound semiconductor refers to a compound semiconductor composed of elements of Group IIIA (B, Al, Ga, In) and elements of Group VA (N, P, As, Sb) in the periodic table, such as BN, BP, BAs, BSb, AlN, AlP, AlAs, As lSb, GaN, GaP, GaAs, GaSb, InAs, InN, InP and InSb; oxides of transition metals include but are not limited to chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, palladium oxide, silver oxide, platinum oxide, etc.; halides of transition metals include but are not limited to chromium chloride, manganese chloride, iron chloride, cobalt chloride, nickel chloride, copper chloride, zinc chloride, palladium chloride, silver chloride, platinum chloride, chromium bromide, manganese bromide, iron bromide, cobalt bromide, nickel bromide, copper bromide, zinc bromide, palladium bromide, silver bromide, platinum bromide; silicon-based wide bandgap semiconductors include SiC, Si3N4, etc. The organic wide bandgap semiconductor material includes at least one of C60, PC61BM ((6,6)-phenyl-C61-butyric acid methyl ester), PC71BM ((6,6)-phenyl-C71-butyric acid methyl ester), P3HT (3-hexyl substituted polythiophene), PTAA (poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine]) and PEDOT:PSS (poly (3,4-ethylenedioxythiophene) -poly (styrene sulfonic acid)).

[0090] In some embodiments, the thickness of the buffer layer 600 is not greater than 10 nm, for example, 2 nm-10 nm, 2 nm-8 nm, 2 nm-6 nm, 2 nm-4 nm, 2 nm-3 nm, etc. This can improve the transmittance of incident light and the energy conversion efficiency of the battery.

[0091] In some embodiments, the refractive index n3 of the buffer layer 600, the refractive index n1 of the first charge transport layer 200, and the refractive index n0 of the first electrode 100 satisfy the relationship: n1 2=bn3×n0, where b is a correction coefficient and is 0.5-1.5, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5. The refractive index n3 of the buffer layer 600 is 0.5-3, for example, 0.7-2.8, 1-2.5, 1.2-2.2, 1.5-2, and 1.5-1.7. The inventors have discovered that the refractive index n3 of the buffer layer 600 satisfies the above relationship with the refractive index n1 of the first charge transport layer 200 and the refractive index n0 of the first electrode 100. The system consisting of the first electrode 100, the first charge transport layer 200, and the buffer layer 600 can improve the transmittance of the first charge transport layer 200, thereby increasing the amount of light incident on the perovskite absorption layer 300 and improving the energy conversion efficiency of the battery.

[0092] According to some examples, a method for testing the refractive index n3 of the buffer layer 600 includes: directly obtaining the refractive index n3 by measuring solid film samples using a refractive index meter (Mettler Toledo R5) at room temperature.

[0093] Specifically, referring to FIG4 , the perovskite solar cell includes a first electrode 100, a first charge transport layer 200, a buffer layer 600, a perovskite absorption layer 300, a second charge transport layer 400, and a second electrode 500, and taking the first charge transport layer 200 as an electron transport layer and the electron transport layer including a radioactive material, and the second charge transport layer 400 as a hole transport layer as an example, and the first charge transport layer 200, the first electrode 100 and the perovskite absorption layer 300 and the buffer layer 600 satisfy the following relationship: d = (2k+1)λ / 4n1 and n1 2 =an2×n0 and n1 2 =bn3×n0, the incident light is incident from the side of the first electrode 100 and passes through the first charge transport layer 200. Since the first charge transport layer 200 has an excellent anti-reflection effect, the reflection of the incident light in the first charge transport layer 200 can be reduced. The buffer layer 600 can reduce the damage of the high-energy particles radiated by the radioactive material in the first charge transport layer 200 to the perovskite absorption layer 300. The incident light passing through the buffer layer 600 is incident on the perovskite absorption layer 300. The perovskite material in the perovskite absorption layer 300 absorbs the incident photons to generate electron-hole pairs, which are dissociated to form free carriers. The free electrons are transmitted to the first positive electrode 100 through the first charge transport layer 200, and the free holes are transmitted to the second electrode 500 through the second charge transport layer 400. In addition, the radioactive material in the first charge transport layer 200 is radioactive, and its high-energy radiation particles can self-excite to generate carriers, thereby increasing the number of carriers and thus increasing the battery current.

[0094] A second aspect of the present application provides a method for preparing a perovskite solar cell, comprising:

[0095] S1: forming a first charge transport layer on one side of the first electrode.

[0096] S2: forming a perovskite absorption layer on a side of the first charge transport layer away from the first electrode.

[0097] S3: forming a second charge transport layer on a side of the perovskite absorption layer away from the first charge transport layer.

[0098] S4: forming a second electrode on a side of the charge transport layer away from the perovskite absorption layer.

[0099] In some embodiments, the first charge transport layer, the first electrode, and the perovskite absorption layer satisfy the following relationship: d = (2k + 1) λ / 4n1 and n1 2 =an2×n0, where d represents the thickness of the first charge transport layer in nm; k is an integer not less than 0; λ represents the wavelength of the main wavelength band of light absorbed by the perovskite absorption layer in nm; n0 is the refractive index of the first electrode; n1 is the refractive index of the first charge transport layer; n2 is the refractive index of the perovskite absorption layer; and a is a correction factor, ranging from 0.5 to 1.5, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5. Thus, the first charge transport layer in the perovskite solar cell has an excellent anti-reflection effect, thereby reducing the reflection of incident light, allowing more incident light to pass through the first charge transport layer and enter the perovskite absorption layer, thereby improving the energy conversion efficiency of the perovskite solar cell.

[0100] In some embodiments, the formation of the first charge transport layer on one side of the first electrode in S1, the formation of the perovskite absorption layer in S2, the formation of the charge transport layer in S3, and the formation of the second electrode in S4 can be carried out by chemical bath deposition, electrochemical deposition, chemical vapor deposition, physical epitaxial growth, thermal evaporation co-evaporation, atomic layer deposition, magnetron sputtering, precursor liquid spin coating, precursor liquid slit coating, precursor liquid scraping, mechanical pressing, etc.; among them, thermal evaporation co-evaporation and precursor liquid coating (spin coating) are preferred.

[0101] In some embodiments, the refractive index n1 of the first charge transport layer can be regulated by doping the first charge transport layer with a radioactive material, and the thickness of the first charge transport layer can be regulated at the same time, so that the refractive index n1 and the thickness d of the first charge transport layer satisfy the relationship d=(2k+1)λ / 4n1 and n1 2=an2×n0. The inventors discovered that by doping the first charge transport layer with a radioactive material, not only can the refractive index of the first charge transport layer be adjusted, but the radioactive material in the first charge transport layer is also radioactive, and its high-energy radiation particles can self-excite to generate carriers, thereby increasing the number of carriers in the perovskite solar cell and improving the battery current.

[0102] As an example, a first charge transport layer including a radioactive material and a charge transport layer material may be formed on one side of the first electrode by co-evaporation or magnetron sputtering.

[0103] Therefore, the method of the present application can be used to prepare the above-mentioned perovskite solar cell with excellent energy conversion efficiency.

[0104] In some embodiments of the present application, since high-energy radiation particles in the radioactive material in the first charge transport layer may damage the perovskite absorber layer, a buffer layer is formed between the first charge transport layer and the perovskite absorber layer to reduce damage to the perovskite absorber layer. The distance between the valence band top and the conduction band bottom of the buffer layer material is no less than 2.5 eV. Thus, a buffer layer that meets this condition can absorb high-energy particles radiated from the radioactive material, causing energy deposition and converting the kinetic energy of the high-energy particles into charge energy, thereby effectively reducing damage to the perovskite absorber layer.

[0105] As an example, the buffer layer may be formed between the first charge transport layer and the perovskite absorption layer by an evaporation method.

[0106] It should be noted that the first electrode, radioactive material, charge transport material, buffer layer, and second electrode used in the method for preparing a perovskite solar cell are the same as those described above and will not be repeated here.

[0107] In a third aspect, the present application provides an electrical device comprising a perovskite solar cell according to an embodiment of the first aspect, or a perovskite solar cell produced using a method according to an embodiment of the second aspect, wherein the perovskite solar cell is configured to provide electrical energy. By way of example, the electrical device may be a lighting element, a display element, or an automobile.

[0108] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0109] Example 1

[0110] The method for preparing a perovskite solar cell comprises:

[0111] 1) A 2.0 cm × 2.0 cm FTO conductive glass surface was cleaned twice with acetone and isopropyl alcohol, immersed in deionized water and ultrasonically treated for 10 min, dried in a forced air drying oven, and placed in a glove box (N2 atmosphere) to serve as the first electrode. Its refractive index n0 was 1.98.

[0112] 2) Preparation of an electron transport layer: A 3 wt% SnO2 nanocolloid aqueous solution was spin-coated on the first electrode at a speed of 4000-6500 rpm, and then heated at 150°C on a constant temperature hot plate for 15 minutes. The resulting electron transport layer had a thickness of d = 87.5 nm and a refractive index n1 of 2;

[0113] 3) Preparing a perovskite absorption layer: spin coating a 1.5 mol / L FAPbI3 solution in DMF on the electron transport layer obtained in step 2) at a rotation speed of 3000 rpm to 4500 rpm, then moving the coating to a constant temperature hot plate and heating at 100°C for 30 minutes. After cooling to room temperature, a perovskite absorption layer with a thickness of 500 nm and an n2 of 2.59 was formed on the electron transport layer. The main absorption wavelength λ of the perovskite absorption layer was 700 nm.

[0114] 4) Preparation of a hole transport layer: Spin-coat a 73 mg / mL solution of Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene) in chlorobenzene on the perovskite absorber layer at a speed of 3000-4000 rpm to form a hole transport layer with a thickness of 150 nm on the perovskite absorber layer;

[0115] 5) Preparation of the second electrode: Place the sample from step 4) into a vacuum coating machine and -4 An Ag electrode was evaporated on the surface of the hole transport layer obtained under a vacuum condition of 1.5 Pa at a deposition rate of 0.1 angstroms / s. The thickness of the Ag electrode was 80 nm and was used as the second electrode.

[0116] The method for preparing the perovskite solar cell in Example 2-3 is the same as that in Example 1, with the differences as shown in Table 1.

[0117] Table 1

[0118]

[0119] Example 4

[0120] The method for preparing a perovskite solar cell comprises:

[0121] 1) A 2.0 cm × 2.0 cm FTO conductive glass surface was cleaned twice with acetone and isopropyl alcohol, immersed in deionized water and ultrasonically treated for 10 min, dried in a forced air drying oven, and placed in a glove box (N2 atmosphere) to serve as the first electrode. Its refractive index n0 was 1.98.

[0122] 2) Preparation of electron transport layer: Place the first electrode into a vacuum coating machine and -4 Pa under vacuum conditions on the surface of the first electrode 63 NiCl x (X≥2) and SnO2, forming an electron transport layer, wherein, 63 NiCl x The mass ratio in the electron transport layer is 5 wt%, the thickness of the electron transport layer is d=85.4 nm, and the refractive index n1 is 2.05;

[0123] 3) Preparation of buffer layer: Place the sample obtained in step 2) into a vacuum coating machine and -4 Pa under vacuum conditions, ZrO2 was evaporated on the surface of the obtained electron transport layer with a thickness of 3 nm and a refractive index n3 of 2.14;

[0124] 4) Preparing a perovskite absorber layer: Spin coating a 1.5 mol / L FAPbI3 solution in DMF on the buffer layer obtained in step 2) at a rotation speed of 3000 rpm to 4500 rpm, then moving the solution to a constant temperature hot plate and heating it at 100°C for 30 minutes. After cooling to room temperature, a perovskite absorber layer with a thickness of 500 nm and an n2 of 2.59 was formed on the buffer layer. The main absorption band λ of the perovskite absorber layer was 700 nm.

[0125] 5) Preparation of a hole transport layer: Spin-coat a 73 mg / mL solution of Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene) in chlorobenzene on the perovskite absorber layer at a speed of 3000-4000 rpm to form a hole transport layer with a thickness of 150 nm on the perovskite absorber layer;

[0126] 6) Preparation of the second electrode: Place the sample from step 5) into a vacuum coating machine and -4 An Ag electrode was evaporated on the surface of the hole transport layer obtained under a vacuum condition of 1.5 Pa at a deposition rate of 0.1 angstroms / s. The thickness of the Ag electrode was 80 nm and was used as the second electrode.

[0127] The method for preparing the perovskite solar cell in Examples 5-21 is the same as that in Example 4, with the differences shown in Table 2.

[0128] The preparation of the first electrode, perovskite absorption layer, hole transport layer and second electrode in the comparative example of the perovskite solar cell is the same as that in Example 1, except that the step of preparing the electron transport layer includes: spin coating a SnO2 nanocolloid aqueous solution with a concentration of 3wt% on the first electrode at a speed of 4000rpm-6500rpm, and then heating it at 150°C on a constant temperature hot stage for 15min, and the thickness of the obtained electron transport layer is 50nm.

[0129] Table 2

[0130]

[0131]

[0132] The performance of the perovskite solar cells of Examples 1-21 and the comparative example was tested.

[0133] Energy conversion efficiency test: Under atmospheric conditions, the solar light source used was an AM1.5G standard light source. A four-channel digital source meter (Keithley 2440) was used to measure the battery's volt-ampere characteristic curve under the light source. The battery's open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF) were obtained, from which the battery's energy conversion efficiency (Eff) was calculated.

[0134] The energy conversion efficiency is calculated as follows: Eff = Pout / Popt = Voc×Jsc×(Vmpp×Jmpp) / (Voc×Jsc) = Voc×Jsc×FF

[0135] Among them, Pout, Popt, Vmpp, and Jmpp are the battery operating output power, incident light power, battery maximum power point voltage, and maximum power point current, respectively.

[0136] Damage to the perovskite absorber layer: This is characterized by tracking and evaluating the long-term (100-hour) PCE (power conversion efficiency) degradation of the battery device. Specifically, the battery is stored in an atmospheric environment without packaging, and the PCE change of the battery is recorded from 0 to 100 hours, with a collection interval of 10 hours. The decrease (%) of the PCE at 100 hours compared to the initial PCE is taken, that is, the damage to the perovskite absorber layer = (initial PCE - 100-hour PCE) / initial PCE.

[0137] The energy conversion efficiency of the perovskite solar cells of Examples 1-21 and the comparative example and the damage of the perovskite absorption layer are shown in Table 3.

[0138] Table 3

[0139]

[0140]

[0141] As shown in Table 3, the energy conversion efficiency of the perovskite solar cells of Examples 1-21 is significantly higher than that of the perovskite solar cells of the comparative example, indicating that the first charge transport layer, the first electrode and the perovskite absorption layer satisfy the following relationship: d = (2k + 1) λ / 4n1 and n1 2 =an2×n0, which can improve the anti-reflection effect of the first charge transport layer in the perovskite solar cell, thereby reducing the reflection of the incident light, so that more incident light can pass through the electron transport layer and enter the perovskite absorption layer, thereby improving the energy conversion efficiency of the perovskite solar cell. At the same time, the energy conversion efficiency of the perovskite solar cell of Example 4-21 is higher than that of Example 1-3, indicating that by doping the first charge transport layer with radioactive materials and the buffer layer meeting n1 2 =bn3×n0, which can further improve the energy conversion efficiency of the perovskite solar cell. Furthermore, the damage to the perovskite absorber layer of the perovskite solar cell of Example 4-20 was less than that of Example 21, indicating that by providing a buffer layer between the first charge transport layer and the perovskite absorber layer, damage to the perovskite absorber layer caused by radioactive materials in the first charge transport layer can be reduced.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A perovskite solar cell, wherein: include: a first electrode; a first charge transport layer, wherein the first charge transport layer is disposed on one side of the first electrode; a perovskite absorption layer, wherein the perovskite absorption layer is disposed on a side of the first charge transport layer away from the first electrode; a second charge transport layer, wherein the second charge transport layer is disposed on a side of the perovskite absorption layer away from the first charge transport layer; a second electrode, the second electrode being disposed on a side of the second charge transport layer away from the perovskite absorption layer, in, Wherein, the first charge transport layer, the first electrode and the perovskite absorption layer simultaneously satisfy the following relationship: d=(2k+1)λ / 4n1,n1 2 =an2×n0, d represents the thickness of the first charge transport layer, in nm; k is an integer not less than 0; λ represents the wavelength of the main wavelength band of light absorbed by the perovskite absorption layer, in nm; n0 is the refractive index of the first electrode; n1 is the refractive index of the first charge transport layer; n2 is the refractive index of the perovskite absorption layer; a is the correction coefficient, and its value is 0.5-1.

5.

2. The perovskite solar cell according to claim 1, wherein: The refractive index n0 of the first electrode is 0.5-3.

3. The perovskite solar cell according to claim 1 or 2, wherein: The refractive index n1 of the first charge transport layer is 0.5-3.

4. The perovskite solar cell according to any one of claims 1 to 3, wherein The refractive index n2 of the perovskite absorption layer is 0.5-3.

5. The perovskite solar cell according to any one of claims 1 to 4, wherein: The first charge transport layer includes a radioactive material.

6. The perovskite solar cell according to any one of claims 1 to 5, wherein: Based on the total mass of the first charge transport layer, the content of the radioactive material is no more than 30 wt %, and may be 3 wt %-15 wt %.

7. The perovskite solar cell according to any one of claims 1 to 6, wherein: The method further includes: a buffer layer, wherein the buffer layer is disposed between the first charge transport layer and the perovskite absorption layer.

8. The perovskite solar cell according to any one of claims 1 to 7, wherein: The distance between the valence band top and the conduction band bottom of the material of the buffer layer is not less than 2.5 eV.

9. The perovskite solar cell according to any one of claims 1 to 8, wherein: The refractive index n3 of the buffer layer satisfies the refractive index n1 of the first charge transport layer and the refractive index n0 of the first electrode: n1 2 =bn3×n 00 , b is the correction coefficient, and its value is 0.5-1.

5.

10. The perovskite solar cell according to any one of claims 1 to 9, wherein: The refractive index n3 of the buffer layer is 0.5-3.

11. The perovskite solar cell according to any one of claims 1 to 10, wherein: The thickness of the buffer layer is not greater than 10 nm.

12. A method for preparing a perovskite solar cell, wherein: include: forming a first charge transport layer on one side of the first electrode; forming a perovskite absorption layer on a side of the first charge transport layer away from the first electrode; forming a second charge transport layer on a side of the perovskite absorption layer away from the first charge transport layer; forming a second electrode on a side of the second charge transport layer away from the perovskite absorption layer, Wherein, the first charge transport layer satisfies the following relationship: d = (2k + 1)λ / 4n1 and n1 2 = an2 × n0, d represents the thickness of the first charge transport layer, in nm; k is an integer not less than 0; λ represents the wavelength of the main band of light absorbed by the perovskite absorption layer, in nm n0 is the refractive index of the first electrode; n1 is the refractive index of the first charge transport layer; n2 is the refractive index of the perovskite absorption layer; a is the correction coefficient, and its value is 0.5-1.

5.

13. The method according to claim 12, wherein: Also includes: A buffer layer is formed between the first charge transport layer and the perovskite absorption layer.

14. An electrical device, comprising the perovskite solar cell according to any one of claims 1 to 11 or a perovskite solar cell prepared by the method according to claim 12 or 13, wherein the perovskite solar cell is used to provide electrical energy.

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