Trans-perovskite solar cell and preparation method thereof

Abstract

The embodiment of the invention provides a trans-perovskite solar cell and a preparation method thereof. The trans-perovskite solar cell sequentially comprises a conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer and an electrode layer in the thickness direction, the electron transport layer comprises a first dielectric layer and a second dielectric layer, the second dielectric layer is located on the side, away from the perovskite light absorption layer, of the first dielectric layer, and the first dielectric layer comprises [6, 7]-dicyclopentadiene. The first dielectric layer comprises a 1, 6]-phenyl C61 methyl butyrate layer, and the second dielectric layer comprises a tin oxide layer. The [6, 6]-phenyl C61 methyl butyrate layer enables good interface contact between the electron transport layer and the perovskite light absorption layer, reduces interface defects between the electron transport layer and the perovskite light absorption layer, improves the carrier transport efficiency, and improves the photoelectric performance of the trans-perovskite solar cell. And meanwhile, the tin oxide layer enables the electron transport layer to have good stability, so that the stability and the service life of the trans-perovskite solar cell are effectively improved and prolonged.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the technical field related to solar cells, and specifically to an inverted perovskite solar cell and a method for preparing the same. Background Art

[0002] Perovskite solar cells have received extensive attention in the third generation of solar cells due to their excellent photoelectric performance, high photoelectric conversion efficiency, low production cost and simple preparation process. Perovskite solar cells can be divided into formal perovskite solar cells and inverted perovskite solar cells according to the device structure. Compared with formal perovskite solar cells, inverted perovskite solar cells have higher industrialization potential.

[0003] However, there are usually interface defects between the electron transport layer and the perovskite light absorption layer in the inverse perovskite solar cell, which will affect the carrier transmission efficiency, thereby affecting the photoelectric performance of the inverse perovskite solar cell. In addition, the stability of the electron transport layer is poor, which affects the stability and service life of the inverse perovskite solar cell. Summary of the invention

[0004] Embodiments of the present disclosure provide an inverted perovskite solar cell and a method for preparing the same that at least partially solves at least one of the above-mentioned problems or other problems in the prior art.

[0005] The first aspect of the embodiments of the present disclosure provides an inverted perovskite solar cell, which comprises a conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer and an electrode layer in sequence in the thickness direction, wherein the electron transport layer comprises a first dielectric layer and a second dielectric layer, the second dielectric layer is located on a side of the first dielectric layer away from the perovskite light absorption layer, and the first dielectric layer comprises [6,6]-phenyl C 61 The second dielectric layer comprises a methyl butyrate layer, and the second dielectric layer comprises a tin oxide layer.

[0006] In some embodiments, the second dielectric layer includes a tin oxide layer prepared by a reactive plasma deposition process; or, the second dielectric layer includes the tin oxide layer prepared by an atomic layer deposition process using ozone as an oxygen source.

[0007] In some embodiments, the thickness of the first dielectric layer is equal to or greater than 10 nm and less than or equal to 20 nm; and / or the thickness of the second dielectric layer is equal to or greater than 10 nm and less than or equal to 20 nm.

[0008] In some embodiments, the thickness of the first dielectric layer is equal to or greater than 10 nm and less than or equal to 15 nm; and / or the thickness of the second dielectric layer is equal to or greater than 10 nm and less than or equal to 15 nm.

[0009] In some embodiments, the perovskite light absorbing layer includes FA a MA b Cs c BX 3 , where B includes Pb 2+ and / or Sn 2+ , X includes F - ,I - Br - , Cl - and SCN - One or more of, wherein a+b+c=1, 0.8≤a<1, 0<b≤0.1, 0<c≤0.1.

[0010] In some embodiments, the perovskite light absorbing layer satisfies at least one of the following conditions:

[0011] 0.9≤a<1; 0<b≤0.05; 0<c≤0.05; 0<c / (a+b)<0.12; 0<b / a<0.13.

[0012] In some embodiments, the hole transport layer includes one or more of an organic hole transport material, an inorganic hole transport material, and a self-assembled monolayer material. The organic hole transport material includes poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and the inorganic hole transport material includes NiO x , 1≤x≤2. The self-assembled monolayer material includes one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid and [2-(9H-carbazole-9-yl)ethyl]phosphonic acid.

[0013] In some embodiments, the conductive substrate includes a first transparent conductive oxide, the first transparent conductive oxide includes one or more of indium tin oxide, indium zinc oxide, fluorine-doped tin oxide, tungsten-doped indium oxide, and cerium-doped indium oxide; and / or the electrode layer includes one of gold, silver, copper, aluminum, and a second transparent conductive oxide, the second transparent conductive oxide includes one or more of indium tin oxide, indium zinc oxide, fluorine-doped tin oxide, tungsten-doped indium oxide, and cerium-doped indium oxide.

[0014] The second aspect of the embodiments of the present disclosure provides a method for preparing an inverted perovskite solar cell, by which the inverted perovskite solar cell described in the first aspect can be prepared, the method comprising: sequentially forming a hole transport layer and a perovskite light absorption layer on a surface of one side of a conductive substrate; sequentially forming a first dielectric layer and a second dielectric layer on a side of the perovskite light absorption layer away from the hole transport layer, wherein the first dielectric layer and the second dielectric layer constitute an electron transport layer, and the first dielectric layer comprises [6,6]-phenyl C 61 A methyl butyrate layer, a second dielectric layer including a tin oxide layer; and an electrode layer formed on a side of the electron transport layer away from the perovskite light absorbing layer.

[0015] In some embodiments, a hole transport layer and a perovskite light absorption layer are sequentially formed on one side surface of a conductive substrate, comprising: forming a hole transport layer on one side surface of a conductive substrate; and mixing a FA source, an MA source, a Cs source, a B source and a solvent to obtain a precursor solution, and coating the precursor solution on the hole transport layer, removing the solvent and annealing to obtain a perovskite light absorption layer, wherein the perovskite light absorption layer comprises FA a MA b Cs c BX 3 , where B includes Pb 2+ and / or Sn 2+ , X includes F - ,I - Br - , Cl - and SCN - One or more of the following, a+b+c=1, 0.8≤a<1, 0<b≤0.1, 0<c≤0.1.

[0016] In some embodiments, a first dielectric layer and a second dielectric layer are sequentially formed on a side of the perovskite light absorbing layer away from the hole transport layer, including: forming the first dielectric layer on a side of the perovskite light absorbing layer away from the hole transport layer; and forming a tin oxide layer on the first dielectric layer using an atomic layer deposition process or a reactive plasma deposition process.

[0017] In some embodiments, an atomic layer deposition process is used to form a tin oxide layer on the first dielectric layer, including: using tetrakis(dimethylamino)tin as a tin source, using ozone as an oxygen source, and following a cycle of a tin source pulse of 0.05s-0.1s, an inert gas purge of 5s-10s, an oxygen source pulse of 0.05s-0.1s, and an inert gas purge of 5s-10s, the cycle is repeated 130 to 160 times to obtain a tin oxide layer, wherein the flow rate of the oxygen source is 20sccm-100sccm, the inert gas includes nitrogen and / or argon, and the operating temperature is 80°C-100°C.

[0018] In some embodiments, the conditions of the reactive plasma deposition process include: the evaporation target includes a tin oxide target, the process gas includes oxygen-doped argon, the operating current is 140A-160A, and the operating pressure is 2×10 -5 Pa-4×10 -5 Pa, wherein the oxygen content is 6 vt% to 10 vt% based on the total volume of the process gas.

[0019] In some embodiments of the present disclosure, the electron transport layer includes a first dielectric layer and a second dielectric layer, and the first dielectric layer includes [6,6]-phenyl C 61 The second dielectric layer includes a tin oxide layer. 61 The methyl butyrate layer is used as the first dielectric layer, which can achieve good interface contact between the electron transport layer and the perovskite light absorbing layer, reduce the interface defects between the electron transport layer and the perovskite light absorbing layer, improve the carrier transmission efficiency, and enhance the photoelectric performance of the trans-perovskite solar cell; at the same time, the tin oxide layer is used as the second dielectric layer, which can make the electron transport layer have good stability, thereby effectively improving the stability and service life of the trans-perovskite solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features, objects and advantages of the present disclosure will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings. In the drawings:

[0021] Figure 1 is a schematic structural diagram of an inverted perovskite solar cell according to some embodiments of the present disclosure; and

[0022] Figure 2 The present invention is a schematic flow chart of a method for preparing an inverse perovskite solar cell according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0023] In order to better understand the present disclosure, various aspects of the present disclosure will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present disclosure and are not intended to limit the scope of the present disclosure in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0024] It should be noted that in this specification, the expressions first, second, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features, especially do not represent any order of precedence. Therefore, without departing from the teaching of the present disclosure, the first dielectric layer discussed in the present disclosure may also be referred to as the second dielectric layer, and vice versa.

[0025] In the embodiments of the present disclosure, the orientation or state relationship indicated by the terms "upper", "lower", etc. is based on the orientation or state relationship shown in the drawings and is only for the convenience of description, and is not used to limit each element to have a specific orientation shown in the drawings.

[0026] In the embodiments of the present disclosure, when describing that a certain feature is located "above" or "below" another feature, it may mean that the two features are in direct contact or in indirect contact through an intermediate medium. In addition, when describing that a certain feature is located "above" or "below" another feature, it may mean that one feature is directly above or obliquely above the other feature, or simply means that the horizontal height of one feature is higher than the other feature. Similarly, when describing that a certain feature is located "below" or "below" another feature, it may mean that one feature is located directly below or obliquely below the other feature, or simply means that the horizontal height of one feature is lower than the other feature.

[0027] Unless otherwise defined, all terms (including technical and scientific terms) used in this disclosure have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be understood to have the same meaning as they have in the context of the relevant technology, and should not be interpreted in an idealized or overly formal sense, unless explicitly defined in this disclosure.

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other. In addition, unless explicitly limited or contradictory to the context, the specific steps included in the method described in the present disclosure are not necessarily limited to the order described, but can be performed in any order or in parallel. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] The electron transport layer in current inverse perovskite solar cells may include carbon 60 (C 60 ) layer and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) layer. 60 When the BCP layer contacts the perovskite light-absorbing layer, there are interface defects between the layer and the perovskite light-absorbing layer. The interface defects will increase the non-radiative recombination of carriers and also cause energy level mismatch at the interface, affecting the transmission efficiency of carriers at the interface, thereby affecting the photoelectric performance of the inverse perovskite solar cell, such as open circuit voltage, fill factor, photoelectric conversion efficiency, etc. In addition, the BCP layer has poor stability under the long-term effects of water, oxygen, light and heat, thus affecting the stability and service life of the inverse perovskite solar cell.

[0030] Based on this, some embodiments of the present disclosure provide an inverse perovskite solar cell and a method for preparing the same. Specifically, a method is provided in which the electron transport layer is set to [6,6]-phenyl C 61 The structural form of the methyl butyrate layer and the tin oxide layer is to achieve good interface contact between the electron transport layer and the perovskite light absorbing layer under the condition that the electron transport layer has good stability, and the inverted perovskite solar cell and the preparation method thereof.

[0031] Figure 1 FIG. 1 is a schematic diagram of the structure of an inverted perovskite solar cell 100 according to some embodiments of the present disclosure. Figure 1 The inverse perovskite solar cell 100 may include a conductive substrate 110, a hole transport layer 120, a perovskite light absorbing layer 130, an electron transport layer 140 and an electrode layer 150 in sequence in the thickness direction. The electron transport layer 140 may include a first dielectric layer 141 and a second dielectric layer 142. The second dielectric layer 142 may be located on a side of the first dielectric layer 141 away from the perovskite light absorbing layer 130. The first dielectric layer 141 may include [6,6]-phenyl C 61 The second dielectric layer 142 may include a tin oxide layer.

[0032] By using the PCBM layer as the first dielectric layer 141, the electron transport layer 140 and the perovskite light absorption layer 130 can achieve good interface contact, reduce interface defects between the electron transport layer 140 and the perovskite light absorption layer 130, and thus reduce non-radiative recombination of carriers, and match the energy levels at the interface, improve the carrier transmission efficiency, and improve the photoelectric performance of the inverted perovskite solar cell 100, such as open circuit voltage, fill factor, photoelectric conversion efficiency, etc. At the same time, the tin oxide layer has good stability. By using the tin oxide layer as the second dielectric layer 142, the electron transport layer 140 can have good stability, thereby effectively improving the stability and service life of the inverted perovskite solar cell 100.

[0033] In some embodiments, the conductive substrate 110 may include a transparent substrate and a first transparent conductive oxide. The transparent substrate may include a flexible substrate or a rigid substrate, the flexible substrate may be, for example, a flexible polyimide, and the rigid substrate may be, for example, a glass substrate. The first transparent conductive oxide may include one or more of indium tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), tungsten-doped indium oxide (IWO), and cerium-doped indium oxide (ICO). The thickness of the first transparent conductive oxide may be 300nm-400nm, for example, 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm, 390nm, 400nm, etc.

[0034] It should be understood that the thickness of the transparent substrate in the conductive substrate 110 can be any thickness that meets actual use requirements, and the present disclosure does not impose any specific limitation on the thickness of the transparent substrate.

[0035] In some embodiments, the hole transport layer 120 may include one or more of an organic hole transport material, an inorganic hole transport material, and a self-assembled monolayer material. The organic hole transport material may include poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA). The inorganic hole transport material may include NiO x , 1≤x≤2. The self-assembled monolayer material may include one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz) and [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2-PACz).

[0036] In some embodiments, the thickness of the hole transport layer 120 may be equal to or greater than 2 nm and less than or equal to 20 nm. When the hole transport layer 120 includes a self-assembled monolayer material, the thickness of the hole transport layer 120 may be 2 nm-5 nm, for example, 2 nm, 3 nm, 4 nm, 5 nm, etc. When the hole transport layer 120 includes an inorganic hole transport material or an organic hole transport material, the thickness of the hole transport layer 120 may be 10 nm-20 nm, for example, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, etc.

[0037] In some embodiments, the perovskite light absorbing layer 130 may include FA a MA b Cs c BX 3 , where B may include Pb 2+ and / or Sn 2+ , X may include F - ,I - Br - , Cl - and SCN - One or more of, wherein a+b+c=1, 0.8≤a<1, 0<b≤0.1, 0<c≤0.1. Further, 0.9≤a<1, 0<b≤0.05, 0<c≤0.05.

[0038] FA + MA is a formamidinium cation, which is used to adjust the band gap of the perovskite light absorbing layer 130. +It is a methylamine cation, which is used to adjust the lattice energy of the perovskite light absorbing layer 130, make the crystal structure more stable, reduce the sensitivity to water and oxygen, and improve the stability of the perovskite light absorbing layer 130. + Cesium cations are used to improve the crystal quality of the perovskite light absorbing layer 130, form larger and more uniform grains, and reduce defects and non-radiative recombination centers in the perovskite light absorbing layer 130. + 、MA + , Cs + The ratio of (such as a, b, c) can adjust the band gap, lattice energy and crystal quality of the perovskite light absorbing layer 130, thereby improving the photoelectric performance and stability of the inverted perovskite solar cell 100.

[0039] In some embodiments, the perovskite light absorbing layer 130 may satisfy: 0<b / a<0.13. Further, 0<b / a≤0.06. By adjusting the FA in the perovskite light absorbing layer 130 + and MA + The ratio of can adjust the band gap and stability of the perovskite light absorbing layer 130. The band gap of the perovskite light absorbing layer 130 can be 1.53eV-1.58eV, for example, 1.53eV, 1.54eV, 1.55eV, 1.56eV, 1.57eV, 1.58eV, etc.

[0040] In some embodiments, the perovskite light absorbing layer 130 may satisfy: 0<c / (a+b)<0.12. Further, 0<c / (a+b)≤0.06. By introducing Cs in this range into the perovskite light absorbing layer 130 + When the perovskite light absorbing layer 130 has a reasonable band gap and stability, the defects and non-radiative recombination centers of the perovskite light absorbing layer 130 can be reduced, thereby improving the filling factor and photoelectric conversion efficiency of the inverse perovskite solar cell 100.

[0041] In some embodiments, the thickness of the perovskite light absorbing layer 130 may be equal to or greater than 500 nm and less than or equal to 800 nm. For example, the thickness of the perovskite light absorbing layer 130 may be 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, etc.

[0042] In some embodiments, the second dielectric layer 142 may include a tin oxide layer prepared by a reactive plasma deposition (RPD) process. The tin oxide layer prepared by the RPD process may be referred to as RPD-SnO. 2 , RPD-SnO 2 It can have good density and uniformity, and has good stability under the long-term effects of water, oxygen, light and heat.

[0043] The PCBM layer will degrade to a certain extent when it comes into contact with water. Therefore, the stability of the PCBM layer in an environment with water is poor, which leads to the poor photoelectric performance of the inverse perovskite solar cell. 2 In the preparation process, the process gas is oxygen-doped argon. There is no water involved in the whole preparation process, which can avoid the failure of the PCBM layer due to water degradation as much as possible. In addition, when the PCBM layer has good stability, the RPD-SnO 2 As the second dielectric layer 142 , the stability and service life of the inverse perovskite solar cell 100 can be effectively improved.

[0044] In some embodiments, the second dielectric layer 142 may include a tin oxide layer formed by an atomic layer deposition (ALD) process using ozone as an oxygen source. The tin oxide layer formed by the ALD process may be referred to as ALD-SnO. 2 , ALD-SnO 2 It can have good density and uniformity, and has good stability under the long-term effects of water, oxygen, light and heat.

[0045] The PCBM layer will degrade to a certain extent when it comes into contact with water. Therefore, the stability of the PCBM layer in an environment with water is poor, which leads to the poor photoelectric performance of the inverse perovskite solar cell. 2 In the preparation process, the oxygen source is ozone, and there is no water involved in the whole preparation process, which can avoid the failure of the PCBM layer due to water degradation as much as possible, and when the PCBM layer has good stability, the ALD-SnO 2 As the second dielectric layer 142 , the stability and service life of the inverse perovskite solar cell 100 can be effectively improved.

[0046] In some embodiments, the thickness of the first dielectric layer 141 may be equal to or greater than 10 nm and less than or equal to 20 nm. For example, the thickness of the first dielectric layer 141 may be 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, or 20 nm.

[0047] In some embodiments, the thickness of the second dielectric layer 142 may be equal to or greater than 10 nm and less than or equal to 20 nm. For example, the thickness of the second dielectric layer 142 may be 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, or 20 nm.

[0048] In some embodiments, the electrode layer 150 may include one of gold, silver, copper, aluminum, and a second transparent conductive oxide, and the second transparent conductive oxide may include one or more of indium tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), tungsten-doped indium oxide (IWO), and cerium-doped indium oxide (ICO).

[0049] In some embodiments, the thickness of the electrode layer 150 may be equal to or greater than 500 nm and less than or equal to 700 nm. For example, the thickness of the electrode layer 150 may be 500 nm, 520 nm, 540 nm, 560 nm, 580 nm, 600 nm, 620 nm, 640 nm, 660 nm, 680 nm, or 700 nm.

[0050] In some embodiments, the inverse perovskite solar cell 100 may be, for example, an inverse single junction perovskite solar cell or an inverse tandem perovskite solar cell. The inverse tandem perovskite solar cell may include one or more of a perovskite / perovskite tandem solar cell, a perovskite / crystalline silicon tandem solar cell, and a perovskite / copper indium gallium tin (CIGS) tandem solar cell.

[0051] Figure 2 FIG. 1 is a flow chart of a method 1000 for preparing an inverse perovskite solar cell according to some embodiments of the present disclosure. The inverse perovskite solar cell may be, for example, Figure 1 An inverted perovskite solar cell 100 is shown.

[0052] like Figure 2 As shown, the method 1000 for preparing an inverse perovskite solar cell may include the following steps:

[0053] S100, forming a hole transport layer and a perovskite light absorption layer in sequence on one side surface of a conductive substrate.

[0054] In some embodiments, the conductive substrate 110 is sequentially placed in deionized water, anhydrous ethanol, isopropanol, and acetone for ultrasonic cleaning, and the ultrasonic cleaning time may be 10 min to 15 min, for example, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, etc. Then, the conductive substrate 110 after ultrasonic cleaning is nitrogen air-dried, and the air-dried conductive substrate 110 is stored for later use.

[0055] In some embodiments, before forming the hole transport layer 120, the conductive substrate 110 is placed in an ultraviolet ozone cleaning machine for cleaning for 15 minutes to 20 minutes, for example, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, 20 minutes, etc. The ultraviolet ozone cleaning machine utilizes the strong oxidizing effect of ultraviolet light and ozone to effectively remove organic pollutants and / or inorganic pollutants, such as grease, dust, etc., on the surface of the conductive substrate 110, thereby improving the surface wettability of the conductive substrate 110. The improvement of the surface wettability of the conductive substrate 110 is not only conducive to the uniform film formation of the hole transport layer 120, but also conducive to achieving good interface contact between the hole transport layer 120 and the conductive substrate 110, reducing the interface defects between the hole transport layer 120 and the conductive substrate 110, thereby improving the transmission efficiency of holes at the interface.

[0056] In some embodiments, the conductive substrate 110 may include a transparent substrate and a first transparent conductive oxide. The transparent substrate may include a flexible substrate or a rigid substrate, the flexible substrate may be, for example, a flexible polyimide, and the rigid substrate may be, for example, a glass substrate. The first transparent conductive oxide may include one or more of indium tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), tungsten-doped indium oxide (IWO), and cerium-doped indium oxide (ICO). The thickness of the first transparent conductive oxide may be 300nm-400nm, for example, 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm, 390nm, 400nm, etc.

[0057] It should be understood that the thickness of the transparent substrate in the conductive substrate 110 can be any thickness that meets the actual use requirements, and the present disclosure does not impose any specific restrictions on the thickness of the transparent substrate.

[0058] In some embodiments, a hole transport layer 120 is formed on one side surface of the conductive substrate 110. Specifically, a hole transport material is mixed with N,N-dimethylformamide (DMF) or anhydrous ethanol to obtain a hole transport material solution; the hole transport material solution is spin-coated on the conductive substrate 110, and annealed to obtain the hole transport layer 120. The spin coating speed may be 3000 rpm, the spin coating time may be 30 s, the annealing temperature may be 100° C., and the annealing time may be 10 min-15 min. The concentration of the hole transport material in the hole transport material solution may be 0.2 mg / mL-1 mg / mL, for example, 0.2 mg / mL, 0.4 mg / mL, 0.5 mg / mL, 0.6 mg / mL, 0.8 mg / mL, 1 mg / mL, etc.

[0059] In some embodiments, the hole transport layer 120 may include one or more of an organic hole transport material, an inorganic hole transport material, and a self-assembled monolayer material. The organic hole transport material may include PTAA. The inorganic hole transport material may include NiO x , where 1 ≤ x ≤ 2. The self-assembled monolayer material may include one or more of MeO-2PACz, Me-4PACz, and 2-PACz.

[0060] In some embodiments, the thickness of the hole transport layer 120 may be equal to or greater than 2 nm and less than or equal to 20 nm. When the hole transport layer 120 includes a self-assembled monolayer material, the thickness of the hole transport layer 120 may be 2 nm - 5 nm, for example, 2 nm, 3 nm, 4 nm, 5 nm, etc. When the hole transport layer 120 includes an inorganic hole transport material or an organic hole transport material, the thickness of the hole transport layer 120 may be 10 nm - 20 nm, for example, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, etc.

[0061] In some embodiments, an FA source, an MA source, a Cs source, a B source are mixed with a solvent (a solvent system with a volume ratio of DMF and dimethyl sulfoxide (DMSO) of 4:1) to obtain a precursor solution, and the precursor solution is coated on the hole transport layer 120, and after desolvation, annealing treatment is performed to obtain a perovskite light-absorbing layer 130. Among them, the precursor solution may be coated in a first stage and a second stage. In the first stage, spin coating is performed at 1000 rpm for 10 s, and in the second stage, spin coating is performed at 5000 rpm for 35 s; an antisolvent is dropped at the remaining 13 s in the second stage of coating to extract the solvent, and the antisolvent may include ethyl acetate or chlorobenzene; finally, annealing treatment is performed at 105 °C for 30 min - 40 min, for example, 30 min, 32 min, 34 min, 36 min, 38 min, 40 min, etc.

[0062] In some embodiments, MACl is added to the precursor solution, where the molar ratio of MACl in terms of the molar amount of MA element to the precursor solution in terms of the molar amount of MA element is 0.1:1 - 0.4:1, for example, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, etc. Adding MACl to the precursor solution can promote the crystallization of the perovskite light-absorbing layer 130, optimize the crystal structure and morphology, thereby improving the optoelectronic performance of the inverted perovskite solar cell 100; at the same time, it can also form a favorable interfacial layer between the perovskite light-absorbing layer 130 and other functional layers (such as the electron transport layer 140), reduce interfacial defects, and improve the carrier transport efficiency.

[0063] In some embodiments, the perovskite light-absorbing layer 130 may include FA a MAb Cs c BX 3 , where B may include Pb 2+ and / or Sn 2+ , X may include F - ,I - Br - , Cl - and SCN - One or more of, wherein a+b+c=1, 0.8≤a<1, 0<b≤0.1, 0<c≤0.1. Further, 0.9≤a<1, 0<b≤0.05, 0<c≤0.05.

[0064] In some embodiments, the perovskite light absorbing layer 130 may satisfy: 0<b / a<0.13. Further, 0<b / a≤0.06. By adjusting the FA in the perovskite light absorbing layer 130 + and MA + The ratio of can adjust the band gap and stability of the perovskite light absorbing layer 130. The band gap of the perovskite light absorbing layer 130 can be 1.53eV-1.58eV, for example, 1.53eV, 1.54eV, 1.55eV, 1.56eV, 1.57eV, 1.58eV, etc.

[0065] In some embodiments, the perovskite light absorbing layer 130 may satisfy: 0<c / (a+b)<0.12. Further, 0<c / (a+b)≤0.06. By introducing Cs in this range into the perovskite light absorbing layer 130 + When the perovskite light absorbing layer 130 has a reasonable band gap and stability, the defects and non-radiative recombination centers of the perovskite light absorbing layer 130 can be reduced, thereby improving the filling factor and photoelectric conversion efficiency of the inverse perovskite solar cell 100.

[0066] In some embodiments, the thickness of the perovskite light absorbing layer 130 may be equal to or greater than 500 nm and less than or equal to 800 nm. For example, the thickness of the perovskite light absorbing layer 130 may be 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, etc.

[0067] S200, forming a first dielectric layer and a second dielectric layer in sequence on a side of the perovskite light absorbing layer away from the hole transport layer, wherein the first dielectric layer and the second dielectric layer constitute an electron transport layer, and the first dielectric layer may include [6,6]-phenyl C 61 The methyl butyrate layer, the second dielectric layer may include a tin oxide layer.

[0068] In some embodiments, a first dielectric layer 141 is formed on a side of the perovskite light absorbing layer 130 away from the hole transport layer 120, and the first dielectric layer 141 may include a PCBM layer. Specifically, PCBM and chlorobenzene are mixed to obtain a PCBM solution, and then the PCBM solution is spin-coated on the perovskite light absorbing layer 130, and annealed to obtain a PCBM layer. The concentration of the PCBM solution may be 20 mg / mL, the spin coating speed may be 2000 rpm, the spin coating time may be 30 s, the annealing temperature may be 100° C., and the annealing time may be 5 min-10 min.

[0069] In some embodiments, the thickness of the first dielectric layer 141 may be equal to or greater than 10 nm and less than or equal to 20 nm. For example, the thickness of the first dielectric layer 141 may be 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc.

[0070] In some embodiments, the PCBM layer will degrade to a certain extent when it encounters water, so the stability of the PCBM layer in an environment with water is poor, which leads to the deterioration of the photoelectric performance of the inverse perovskite solar cell. The second dielectric layer 142 is formed on the first dielectric layer 141 by an atomic layer deposition process, and the second dielectric layer 142 may include a tin oxide layer. Specifically, tetrakis(dimethylamino)tin is used as a tin source, ozone is used as an oxygen source, and a cycle of 0.05s-0.1s tin source pulse, 5s-10s inert gas purge, 0.05s-0.1s oxygen source pulse, and 5s-10s inert gas purge is repeated 130 to 160 times to obtain a tin oxide layer (such as ALD-SnO 2 ). The flow rate of the oxygen source may be 20 sccm-100 sccm; the inert gas may include nitrogen and / or argon; the operating temperature may be 80°C-100°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, etc.

[0071] In ALD-SnO 2 In the preparation process, the oxygen source is ozone, and there is no water involved in the whole preparation process, which can avoid the failure of the PCBM layer due to water degradation as much as possible, and when the PCBM layer has good stability, the ALD-SnO 2 As the second dielectric layer 142 , the stability and service life of the inverse perovskite solar cell 100 can be effectively improved.

[0072] In some embodiments, the PCBM layer will degrade to a certain extent when it encounters water, so the stability of the PCBM layer in an environment with water is poor, resulting in poor photoelectric performance of the inverse perovskite solar cell. The second dielectric layer 142 is formed on the first dielectric layer 141 by a reactive plasma deposition process, and the second dielectric layer 142 may include a tin oxide layer. Specifically, a reactive plasma deposition device is used, with a tin oxide target as an evaporation target material, and oxygen-doped argon as a process gas. The working current can be 140A-160A, and the working pressure can be 2×10 -5 Pa-4×10 -5 Pa, the rotation speed of the carrier plate can be 80mm / s-100mm / s, and the tin oxide layer (such as RPD-SnO 2 ). Based on the total volume of the process gas, the oxygen content may be 6vt% to 10vt%. Further, the operating current may be 140A, 145A, 150A, 155A, 160A, etc.; the operating pressure may be 2×10 -5 Pa, 2.5×10 -5 Pa, 3×10 -5 Pa, 3.5×10 -5 Pa, 4×10 -5 Pa, etc.; the rotation speed of the carrier plate can be 80mm / s, 85mm / s, 90mm / s, 95mm / s, 100mm / s, etc.; based on the total volume of the process gas, the oxygen content can be 6vt%, 7vt%, 8vt%, 9vt%, 10vt%, etc.

[0073] In RPD-SnO 2 In the preparation process, the process gas is oxygen-doped argon. There is no water involved in the whole preparation process, which can avoid the failure of the PCBM layer due to water degradation as much as possible. In addition, when the PCBM layer has good stability, the RPD-SnO 2 As the second dielectric layer 142 , the stability and service life of the inverse perovskite solar cell 100 can be effectively improved.

[0074] In some embodiments, the thickness of the second dielectric layer 142 may be equal to or greater than 10 nm and less than or equal to 20 nm. For example, the thickness of the second dielectric layer 142 may be 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc.

[0075] S300 , forming an electrode layer 150 on a side of the electron transport layer 140 away from the perovskite light absorbing layer 130 .

[0076] In some embodiments, the electrode layer 150 is formed on the electron transport layer 140 by high vacuum evaporation. The evaporation rate may be 0.1nm / s-0.5nm / s, for example, 0.1nm / s, 0.2nm / s, 0.3nm / s, 0.4nm / s, 0.5nm / s, etc. The electrode layer 150 may include one of gold, silver, copper, aluminum and a second transparent conductive oxide, and the second transparent conductive oxide may include one or more of indium tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), tungsten-doped indium oxide (IWO) and cerium-doped indium oxide (ICO). The thickness of the electrode layer 150 may be equal to or greater than 500nm and less than or equal to 700nm. For example, the thickness of the electrode layer 150 may be 500nm, 520nm, 540nm, 560nm, 580nm, 600nm, 620nm, 640nm, 660nm, 680nm, 700nm, etc.

[0077] Hereinafter, embodiments of the present disclosure are described. The embodiments described below are exemplary and are only used to explain the present disclosure, and should not be construed as limiting the present disclosure. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in the art or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0078] Example 1

[0079] 1. Pretreatment of conductive substrate

[0080] The conductive substrate is ultrasonically cleaned in deionized water, anhydrous ethanol, isopropanol, and acetone in sequence, and the ultrasonic cleaning time can be 10 minutes. Then, the conductive substrate after ultrasonic cleaning is air-dried with nitrogen, and the air-dried conductive substrate is stored for later use. Before forming the hole transport layer, the conductive substrate is placed in a UV ozone cleaning machine for cleaning for 15 minutes to improve the surface wettability of the conductive substrate.

[0081] 2. Preparation of hole transport layer

[0082] MeO-2PACz is mixed with DMF or anhydrous ethanol to obtain a 0.5 mg / mL MeO-2PACz solution. Then, the MeO-2PACz solution is spin-coated on a conductive substrate and annealed to obtain a hole transport layer. The spin coating speed can be 3000 rpm, the spin coating time can be 30 s, the annealing temperature can be 100° C., and the annealing time can be 10 min-15 min. The thickness of the hole transport layer can be 2 nm-5 nm, for example, 2 nm, 3 nm, 4 nm, 5 nm, etc.

[0083] 3. Preparation of perovskite light-absorbing layer

[0084] FAI, MABr, CsI, PbI 2 Mix with a solvent (a solvent system in which the volume ratio of DMF and DMSO is 4:1) to obtain a precursor solution, and add MACl to the precursor solution, wherein the molar ratio of MACl measured in terms of the molar amount of the MA element to the precursor solution measured in terms of the molar amount of the MA element is 0.2:1. The precursor solution with MACl added can be coated on the hole transport layer according to the first stage and the second stage, with the first stage being spin coated at 1000 rpm for 10 seconds, and the second stage being spin coated at 5000 rpm for 35 seconds. When the second stage of coating has 13 seconds left, ethyl acetate is added dropwise to extract the solvent, and finally annealed at 105°C for 30 minutes to obtain a perovskite light-absorbing layer. The perovskite light-absorbing layer may include FA 0.9 MA 0.05 Cs 0.05 PbI 2.85 Br 0.15 The band gap of the perovskite light absorbing layer may be 1.55 eV. The thickness of the perovskite light absorbing layer may be 500 nm-800 nm. c / (a+b)=0.053. b / a=0.055.

[0085] 4. Preparation of the first dielectric layer

[0086] PCBM and chlorobenzene are mixed to obtain a 20 mg / mL PCBM solution, and then the PCBM solution is spin-coated on the perovskite light-absorbing layer, and annealed to obtain a PCBM layer. The spin-coating speed can be 2000 rpm, the spin-coating time can be 30 seconds, the annealing temperature can be 100° C., and the annealing time can be 5 minutes to 10 minutes. The PCBM layer can be the first dielectric layer, and the thickness of the first dielectric layer can be 15 nm.

[0087] 5. Preparation of the second dielectric layer

[0088] A tin oxide layer (such as ALD-SnO 2 Specifically, tetrakis(dimethylamino)tin was used as the tin source and ozone was used as the oxygen source. The cycle of 0.1s tin source pulse, 10s inert gas purge, 0.1s oxygen source pulse, and 10s inert gas purge was repeated 150 times to obtain a tin oxide layer (such as ALD-SnO 2 ). The flow rate of the oxygen source may be 20 sccm-100 sccm, the inert gas may include nitrogen and / or argon, and the operating temperature may be 85°C. Tin oxide layer (such as ALD-SnO 2 ) may be the second dielectric layer, and the thickness of the second dielectric layer may be 15 nm. The first dielectric layer (PCBM layer) and the second dielectric layer (tin oxide layer) together constitute an electron transport layer.

[0089] 6. Preparation of electrode layer

[0090] An electrode layer is formed on the electron transport layer by high vacuum evaporation. The electrode layer may include gold. The thickness of the electrode layer may be 600 nm. The evaporation rate may be 0.1 nm / s.

[0091] Example 2

[0092] The difference between Example 2 and Example 1 is that the preparation method of the second dielectric layer is different.

[0093] A tin oxide layer (such as RPD-SnO) is formed on the first dielectric layer by a reactive plasma deposition process. 2 ). Specifically, a reactive plasma deposition device is used, with a tin oxide target as the evaporation target material and oxygen-doped argon as the process gas. The working current can be 150A and the working pressure can be 3×10 -5 Pa, the rotation speed of the carrier plate can be 90 mm / s, and the tin oxide layer (such as RPD-SnO 2 ). The oxygen content may be 8vt% based on the total volume of the process gas. The tin oxide layer (such as RPD-SnO 2 ) may be a second dielectric layer, and the thickness of the second dielectric layer may be 15 nm.

[0094] Comparative Example 1

[0095] The only difference between Comparative Example 1 and Example 1 is that water is used as an oxygen source and an atomic layer deposition process is adopted to form a tin oxide layer, which is the second dielectric layer.

[0096] Comparative Example 2

[0097] The difference between Comparative Example 2 and Example 1 is that the first dielectric layer includes a PCBM layer, and the second dielectric layer includes a BCP layer.

[0098] Comparative Example 3

[0099] The difference between Comparative Example 3 and Example 1 is that the first dielectric layer includes C 60 layer, and the second dielectric layer includes a BCP layer.

[0100] Table 1 shows the thickness and resistivity of the tin oxide layer of Example 1, Example 2 and Comparative Example 1.

[0101] example Thickness(nm) Resistivity (Ω·cm) Example 1 15 <![CDATA[9×10 3 ]]> Example 2 15 <![CDATA[1.8×10 4 ]]> Comparative Example 1 15 <![CDATA[8.6×10 3 ]]>

[0102] Table 1

[0103] It can be seen from Table 1 that compared with the tin oxide layer formed by the atomic layer deposition process, the tin oxide layer formed by the reactive plasma deposition process has a higher resistivity.

[0104] Table 2 shows the photoelectric performance parameters and stability tracking data of the inverse perovskite solar cells of various embodiments and comparative examples. Wherein, Voc is the open circuit voltage, Jsc is the short circuit current, FF is the fill factor, and PCE is the photoelectric conversion efficiency. The stability tracking data can be the percentage of the residual efficiency of the inverse perovskite solar cell after being heated at 85°C and placed on an inert glove box hot stage for 1000 hours to the initial efficiency.

[0105] example Voc(V) <![CDATA[Jsc(mA / cm 2 )]]> FF PCE Stability Tracking Data Example 1 1.15 24.1 80.5％ 22.3％ 96％ Example 2 1.13 23.5 78％ 20.7％ 91％ Comparative Example 1 1.03 22.6 63％ 14.66％ 54％ Comparative Example 2 1.17 24.5 81.4％ 23.33％ 46％ Comparative Example 3 1.12 24.2 79.3％ 21.49％ 61％

[0106] Table 2

[0107] As shown in Table 2, in Comparative Example 1, water is involved in the process of preparing the tin oxide layer on the PCBM layer by atomic layer deposition process, and the PCBM layer and the perovskite light absorption layer are degraded to varying degrees, and the photoelectric conversion efficiency and stability tracking data of the inverse perovskite solar cell are poor. Comparative Example 2 uses the PCBM layer and the BCP layer to form the electron transport layer. Due to the poor stability of the BCP layer, after 85°C and 1000h stability tracking, the residual efficiency of the inverse perovskite solar cell is 46% of the initial efficiency. Comparative Example 3 uses C 60 The BCP layer and the electron transport layer constitute the C 60 There are interface defects between the layer and the perovskite light-absorbing layer. The filling factor and photoelectric conversion efficiency of the inverse perovskite solar cell are lower than those in Comparative Example 2, and the stability of the BCP layer is poor. After stability tracking at 85°C and 1000h, the residual efficiency of the inverse perovskite solar cell is 61% of the initial efficiency.

[0108] In Example 1 and Example 2, the PCBM layer is used as the first dielectric layer. Since the PCBM layer will degrade to a certain extent when it encounters water, different processes are used to prepare the tin oxide layer on the PCBM layer, and there is no water involved in the preparation process to avoid the PCBM layer from failing due to degradation when it encounters water, so that the trans-perovskite solar cell has good photoelectric conversion efficiency, and after 85°C and 1000h stability tracking, the trans-perovskite solar cell has a high residual efficiency. Therefore, the use of the PCBM layer and the anhydrous tin oxide layer to form the electron transport layer can reduce the interface defects between the electron transport layer and the perovskite light absorption layer, and improve the photoelectric performance of the trans-perovskite solar cell 100; at the same time, the anhydrous tin oxide layer has good stability, which can make the electron transport layer have good stability, thereby effectively improving the stability and service life of the trans-perovskite solar cell.

[0109] The above description is only an exemplary embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of protection involved in the present disclosure is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the technical concept. For example, the above features are replaced with the technical features with similar functions disclosed in this disclosure (but not limited to) by each other.

Claims

1. An inverted perovskite solar cell, characterized in that: The inverted perovskite solar cell comprises a conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer and an electrode layer in sequence in the thickness direction. The electron transport layer includes a first dielectric layer and a second dielectric layer, the second dielectric layer is located on a side of the first dielectric layer away from the perovskite light absorption layer, and the first dielectric layer includes [6,6]-phenyl C 61 The second dielectric layer comprises a methyl butyrate layer, and the second dielectric layer comprises a tin oxide layer.

2. The inverted perovskite solar cell according to claim 1, wherein: The second dielectric layer includes the tin oxide layer prepared by a reactive plasma deposition process; or, The second dielectric layer includes the tin oxide layer which is prepared by an atomic layer deposition process using ozone as an oxygen source.

3. The inverted perovskite solar cell according to claim 1, wherein: The thickness of the first dielectric layer is equal to or greater than 10 nm and less than or equal to 20 nm; and / or, The thickness of the second dielectric layer is equal to or greater than 10 nm and less than or equal to 20 nm.

4. The inverted perovskite solar cell according to claim 3, wherein: The thickness of the first dielectric layer is equal to or greater than 10 nm and less than or equal to 15 nm; and / or, The thickness of the second dielectric layer is equal to or greater than 10 nm and less than or equal to 15 nm.

5. The inverted perovskite solar cell according to any one of claims 1 to 4, wherein: The perovskite light absorbing layer includes FA a MA b Cs c BX3, where B includes Pb 2+ and / or Sn 2+ , X includes F - ,I - Br - , Cl - and SCN - One or more of Among them, a+b+c=1, 0.8≤a<1, 0<b≤0.1, 0<c≤0.

1.

6. The inverted perovskite solar cell according to claim 5, wherein: The perovskite light absorbing layer satisfies at least one of the following conditions: 0.9≤a＜1； 0＜b≤0.05； 0＜c≤0.05； 0<c / (a+b)<0.12; 0<b / a<0.

13.

7. The inverted perovskite solar cell according to any one of claims 1 to 4, wherein: The hole transport layer comprises one or more of an organic hole transport material, an inorganic hole transport material and a self-assembled monolayer material. Wherein, the organic hole transport material comprises poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; Wherein, the inorganic hole transport material comprises NiO x , 1≤x≤2; The self-assembled monolayer material includes one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid and [2-(9H-carbazole-9-yl)ethyl]phosphonic acid.

8. The inverted perovskite solar cell according to any one of claims 1 to 4, wherein: The conductive substrate comprises a first transparent conductive oxide, wherein the first transparent conductive oxide comprises one or more of indium tin oxide, indium zinc oxide, fluorine-doped tin oxide, tungsten-doped indium oxide, and cerium-doped indium oxide; and / or, The electrode layer includes one of gold, silver, copper, aluminum and a second transparent conductive oxide, and the second transparent conductive oxide includes one or more of indium tin oxide, indium zinc oxide, fluorine-doped tin oxide, tungsten-doped indium oxide and cerium-doped indium oxide.

9. A method for preparing an inverse perovskite solar cell as claimed in any one of claims 1 to 8, characterized in that: include: A hole transport layer and a perovskite light absorption layer are sequentially formed on one surface of the conductive substrate; A first dielectric layer and a second dielectric layer are sequentially formed on a side of the perovskite light absorbing layer away from the hole transport layer, wherein the first dielectric layer and the second dielectric layer constitute an electron transport layer, and the first dielectric layer includes [6,6]-phenyl C 61 methyl butyrate layer, the second dielectric layer comprises a tin oxide layer; and An electrode layer is formed on a side of the electron transport layer away from the perovskite light absorbing layer.

10. The method according to claim 9, wherein: A hole transport layer and a perovskite light absorption layer are sequentially formed on one side surface of a conductive substrate, comprising: forming the hole transport layer on one side surface of the conductive substrate; and The FA source, MA source, Cs source, B source and solvent are mixed to obtain a precursor solution, and the precursor solution is coated on the hole transport layer, and the solvent is removed and then annealed to obtain the perovskite light absorbing layer. Wherein, the perovskite light absorbing layer includes FA a MA b Cs c BX3, where B includes Pb 2+ and / or Sn 2+ , X includes F - ,I - Br - , Cl - and SCN - One or more of the following, a+b+c=1, 0.8≤a<1, 0<b≤0.1, 0<c≤0.

1.

11. The method according to claim 9 or 10, wherein: A first dielectric layer and a second dielectric layer are sequentially formed on a side of the perovskite light absorbing layer away from the hole transport layer, comprising: forming the first dielectric layer on a side of the perovskite light absorbing layer away from the hole transport layer; and The tin oxide layer is formed on the first dielectric layer by an atomic layer deposition process or a reactive plasma deposition process.

12. The method according to claim 11, wherein: The tin oxide layer is formed on the first dielectric layer by an atomic layer deposition process, comprising: Tetrakis(dimethylamino)tin is used as a tin source, ozone is used as an oxygen source, and a cycle of 0.05s-0.1s tin source pulse, 5s-10s inert gas purge, 0.05s-0.1s oxygen source pulse, and 5s-10s inert gas purge is repeated 130 to 160 times to obtain the tin oxide layer. Wherein, the flow rate of the oxygen source is 20 sccm-100 sccm, the inert gas includes nitrogen and / or argon, and the operating temperature is 80°C-100°C.

13. The method according to claim 11, wherein: The conditions of the reactive plasma deposition process include: The evaporation target material includes tin oxide target, the process gas includes oxygen-doped argon, the working current is 140A-160A, and the working pressure is 2×10 -5 Pa-4×10 -5 Pa, Wherein, based on the total volume of the process gas, the content of oxygen is 6vt% to 10vt%.

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