Perovskite solar cell and preparation method thereof

Abstract

The invention provides a perovskite solar cell and a preparation method thereof. The method comprises the following steps: preparing a first carrier transport layer on the surface of one side of a conductive surface of a transparent conductive substrate; performing laser treatment on the surface of one side, far away from the transparent conductive substrate, of the first carrier transport layer by adopting a surface laser source to obtain a modified first carrier transport layer; the projection area of the surface laser source is 1-10000 mm < 2 >; the first carrier transport layer is a hole transport layer or an electron transport layer; and sequentially preparing a perovskite active layer, a second carrier transport layer and a metal electrode layer on the surface of one side, far away from the transparent conductive substrate, of the modified first carrier transport layer to obtain the perovskite solar cell. The first carrier transport layer is subjected to laser processing, the surface structure of the first carrier transport layer can be improved, and the modified first carrier transport layer is obtained, so that the energy level matching and the carrier mobility between the modified first carrier transport layer and the perovskite active layer are improved, and the photoelectric conversion efficiency of the perovskite solar cell is further improved.

Description

Technical Field

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

[0002] In the field of perovskite solar cell technology, metal oxide materials are widely used as carrier transport layers due to their excellent stability, cost-effectiveness and environmental compatibility. However, metal oxide materials usually have surface defects in practical applications, which limits their application potential in high-performance devices. Specifically, the insufficiently coordinated atoms on the surface of metal oxides are the key factors leading to their surface defects and low conductivity. Their surface defects induce high-energy deep gap states. When metal oxides form an interface with perovskite semiconductors, these deep gap states will intensify the recombination of carriers, thereby reducing the collection efficiency and transmission speed of free charges (including electrons and holes), and ultimately affecting the photoelectric conversion efficiency of the battery.

[0003] The surface defects in metal oxide materials can also cause the Fermi level pinning effect, that is, the effect that the Fermi level does not change position with changes in conditions such as doping, thereby inducing the generation of a Schottky barrier, that is, an energy barrier formed at the interface between the metal oxide and the perovskite, which further restricts the flow of charge and has an adverse effect on the performance of perovskite solar devices. The interface defects between metal oxides and perovskites not only increase the probability of non-radiative recombination and reduce the charge transfer rate, but may also cause adverse chemical reactions (such as decomposition of perovskite components) and mechanical stratification during battery operation, resulting in reduced structural stability of perovskite solar cells, further affecting the long-term stability and performance of the battery.

[0004] In summary, developing and studying a method for preparing perovskite solar cells is of great significance for improving the surface defects of the carrier transport layer, improving its charge transfer efficiency, energy level matching and interface stability with the perovskite active layer, and improving the photoelectric conversion efficiency and stability of perovskite solar cells. Summary of the invention

[0005] The main purpose of the present invention is to provide a perovskite solar cell and a preparation method thereof, so as to solve the problems of low charge transfer efficiency and poor interface stability caused by surface defects of the metal oxide carrier transport layer in the prior art, as well as the problems of low photoelectric conversion efficiency and poor stability of the perovskite solar cell caused by the above problems.

[0006] In order to achieve the above-mentioned object, the present invention provides a method for preparing a perovskite solar cell, which comprises: step S1, preparing a first carrier transport layer on the surface of one side of the conductive surface of a transparent conductive substrate; step S2, using a surface laser source to perform laser treatment on the surface of the first carrier transport layer away from the transparent conductive substrate to obtain a modified first carrier transport layer; the projection area of ​​the surface laser source is 1 to 10000 mm 2 ; The first carrier transport layer is a hole transport layer or an electron transport layer; step S3, preparing a perovskite active layer on the surface of the modified first carrier transport layer away from the transparent conductive substrate; step S4, preparing a second carrier transport layer on the surface of the perovskite active layer away from the modified first carrier transport layer; step S5, preparing a metal electrode layer on the surface of the second carrier transport layer away from the perovskite active layer to obtain a perovskite solar cell.

[0007] Furthermore, the surface laser source is a continuous laser source; preferably, the surface laser source is visible light, and more preferably, its wavelength is 400nm, 450nm, 550nm, 580nm, 600nm or 650nm.

[0008] Furthermore, during the laser treatment, the surface laser source continuously irradiates the first carrier transport layer, the frequency of the surface laser source is 430 to 780 THz, and the power density is 1 to 100 mW / mm 2 , scanning rate is 1~200mm 2 / s.

[0009] Further, the first carrier transport layer is a hole transport layer, and the second carrier transport layer is an electron transport layer; or, the first carrier transport layer is an electron transport layer, and the second carrier transport layer is a hole transport layer.

[0010] Furthermore, the material of the first carrier transport layer is selected from one or more of the group consisting of tin oxide, titanium oxide, nickel oxide, copper oxide, vanadium oxide and tungsten oxide doped with doping elements, the frequency of the surface laser source is 430 to 670 THz, and the power density is 1 to 20 mW / mm 2 , scanning speed is 5~15mm 2 / s; preferably, the doping element is selected from one or more of the group consisting of Li, Mg, H and B; preferably, the doping concentration of the doping element is 1 to 15 at%, more preferably 1 to 5 at%.

[0011] Furthermore, the material of the first carrier transport layer is selected from one or more of the group consisting of tin oxide, titanium oxide, nickel oxide, copper oxide, vanadium oxide and tungsten oxide, the frequency of the surface laser source is 430 to 570 THz, and the power density is 1 to 20 mW / mm 2 , scanning speed is 5~15mm2 / s.

[0012] Furthermore, the material of the second carrier transport layer is selected from C 60 , 2,2',7,7'-tetrakis[n,n-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine].

[0013] Furthermore, the thickness of the first carrier transport layer and the second carrier transport layer are independently 10 to 70 nm; preferably, the thickness of the modified first carrier transport layer is 10 to 70 nm.

[0014] Further, step S1 includes: preparing a first carrier transport layer by spraying, spin coating, physical vapor deposition or chemical vapor deposition; preferably, the physical vapor deposition method is selected from magnetron sputtering or atomic layer deposition; preferably, step S1 adopts spraying, spin coating or physical vapor deposition to prepare the first carrier transport layer, and between step S1 and step S2, it also includes: performing a first annealing treatment on the first carrier transport layer; more preferably, the temperature of the first annealing treatment is 100-600°C, and the time is 1min-10h.

[0015] Further, step S4 includes: preparing a second carrier transport layer by spraying, spin coating, physical vapor deposition or chemical vapor deposition; preferably, the physical vapor deposition method is selected from magnetron sputtering or atomic layer deposition; preferably, step S4 prepares the second carrier transport layer by spraying, spin coating or physical vapor deposition, and between step S4 and step S5, it also includes: performing a second annealing treatment on the second carrier transport layer; more preferably, the temperature of the second annealing treatment is 100-600°C, and the time is 1min-10h.

[0016] In order to achieve the above object, another aspect of the present invention further provides a perovskite solar cell, which is prepared by the preparation method of the perovskite solar cell provided in the present application. The perovskite solar cell comprises a transparent conductive substrate, a modified first carrier transport layer, a perovskite active layer, a second carrier transport layer and a metal electrode layer stacked in sequence.

[0017] By applying the technical solution of the present invention, in order to improve the surface defects of the metal oxide carrier transport layer in the prior art, the present application provides a method for preparing a perovskite solar cell, by laser processing the surface of the first carrier transport layer, the laser energy can be injected into the material of the first carrier transport layer, the surface structure of the first carrier transport layer is improved, and a modified first carrier transport layer is obtained, thereby improving the energy level matching between the perovskite active layer and the modified first carrier transport layer, improving its carrier mobility and transmission efficiency, and at the same time, it can also suppress the occurrence of adverse interface chemical reactions and mechanical stratification problems, thereby improving the interface stability between the perovskite active layer and the modified first carrier transport layer. The above-mentioned preparation method provided by the present application can improve the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0018] Compared with a point laser source or a line laser source, the present application uses a surface laser source with a specific projection area to perform laser treatment on the surface of the first carrier transport layer, which can improve the uniformity and consistency of the laser treatment, reduce local performance differences, and improve the laser treatment efficiency of large-area materials, thereby helping to reduce production costs and improve the performance consistency of perovskite solar cells in large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic diagram of the stacked structure of a perovskite solar cell in one embodiment of the present application is shown.

[0021] The above drawings include the following reference numerals:

[0022] 10. Transparent conductive substrate; 20. Modified first carrier transport layer; 30. Perovskite active layer; 40. Second carrier transport layer; 50. Metal electrode layer. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0024] As described in the background art, the existing metal oxide carrier transport layer has problems of low charge transfer efficiency and poor interface stability due to surface defects, and the resulting perovskite solar cell has low photoelectric conversion efficiency and poor stability. In order to solve the above technical problems, the first aspect of the present application provides a method for preparing a perovskite solar cell, such as Figure 1As shown, the preparation method comprises: step S1, preparing a first carrier transport layer on the surface of one side of the conductive surface of the transparent conductive substrate 10; step S2, using a surface laser source to laser treat the surface of the first carrier transport layer away from the transparent conductive substrate 10 to obtain a modified first carrier transport layer 20; the projection area of ​​the surface laser source is 1 to 10000 mm 2 ; The first carrier transport layer is a hole transport layer or an electron transport layer; step S3, preparing a perovskite active layer 30 on the surface of the modified first carrier transport layer 20 away from the transparent conductive substrate 10; step S4, preparing a second carrier transport layer 40 on the surface of the perovskite active layer 30 away from the modified first carrier transport layer 20; step S5, preparing a metal electrode layer 50 on the surface of the second carrier transport layer 40 away from the perovskite active layer 30, to obtain a perovskite solar cell.

[0025] The above-mentioned preparation method of perovskite solar cells can obtain a perovskite solar cell with higher photoelectric conversion efficiency and better stability. In the above-mentioned preparation method, step S2 performs laser treatment on the surface of the first carrier transport layer, which can inject laser energy into the material of the first carrier transport layer, improve its surface structure, and obtain a modified first carrier transport layer 20, thereby improving the energy level matching between the perovskite active layer 30 and the modified first carrier transport layer 20, improving its carrier mobility and transmission efficiency, and at the same time, it can also suppress the occurrence of adverse interface chemical reactions and mechanical stratification problems, thereby improving the interface stability between the perovskite active layer 30 and the modified first carrier transport layer 20, and then improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0026] Compared with a point laser source or a line laser source, the surface of the first carrier transport layer is laser treated by a surface laser source with a specific projection area in the present application, which can improve the uniformity and consistency of the laser treatment, reduce local performance differences, and improve the efficiency of laser treatment of large-area materials, thereby helping to reduce production costs and improve the performance consistency of perovskite solar cells in large-scale industrial production.

[0027] It should be noted that the projection area of ​​the surface laser source in the present application refers to the area irradiated by the surface laser source on the surface of the first carrier transport layer.

[0028] In a preferred embodiment, the surface laser source is a continuous laser source. Compared with a pulsed laser or an intermittent laser source, the use of a continuous laser source for laser processing is conducive to providing stable and continuous laser energy output, improving the uniformity and consistency of laser processing, and suppressing the influence of instantaneous energy fluctuations on the microstructure of the first carrier transport layer material, thereby improving the surface structure of the first carrier transport layer, obtaining a modified first carrier transport layer 20, and further improving the energy level matching and interface stability between the perovskite active layer 30 and the modified first carrier transport layer 20.

[0029] In a preferred embodiment, the surface laser source is visible light. Compared with laser sources in other bands, laser sources in the visible light band have lower energy and less thermal effect on the material, which is beneficial to suppress the damage of the first carrier transport layer during the laser treatment process, and is also beneficial to carry out targeted laser treatment on the first carrier transport layer of different materials, thereby improving the effect of laser treatment and broadening the scope of application of laser treatment.

[0030] In order to further suppress damage to the first carrier transport layer during laser processing and further improve the effect of laser processing, preferably, the wavelength of the surface laser source includes but is not limited to 400nm, 450nm, 550nm, 580nm, 600nm or 650nm.

[0031] In a preferred embodiment, during the laser treatment, the surface laser source continuously irradiates the first carrier transport layer, the frequency of the surface laser source is 430 to 780 THz, and the power density is 1 to 100 W / mm 2 , scanning rate is 1~200mm 2 / s. The first carrier transport layer is continuously irradiated by a surface laser source, and the frequency, power density and scanning rate of the surface laser source include but are not limited to the above ranges. Limiting it within the above range is conducive to providing more stable and efficient laser energy, improving the uniformity and consistency of laser processing, and improving processing efficiency, thereby improving the surface structure of the first carrier transport layer, obtaining a modified first carrier transport layer 20, improving the energy level matching and interface stability between the perovskite active layer 30 and the modified first carrier transport layer 20, and improving the carrier mobility and transport efficiency of the modified first carrier transport layer 20, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0032] It should be noted that the laser processing in the present application adopts a single scanning method, and the laser processing is completed after all areas of the first carrier transport layer are irradiated at a scanning rate within the above range.

[0033] The above-mentioned laser processing method provided in the present application is not only applicable to the hole transport layer, but also to the electron transport layer. The perovskite solar cell provided in the present application can be a trans structure (pin) or a formal structure (nip). In a preferred embodiment, the first carrier transport layer is a hole transport layer, and the second carrier transport layer 40 is an electron transport layer; or, the first carrier transport layer is an electron transport layer, and the second carrier transport layer 40 is a hole transport layer.

[0034] In a preferred embodiment, the material of the first carrier transport layer includes but is not limited to one or more of the group consisting of tin oxide, titanium oxide, nickel oxide, copper oxide, vanadium oxide and tungsten oxide doped with doping elements, the frequency of the surface laser source is 430 to 670 THz, and the power density is 1 to 20 mW / mm 2 , scanning speed is 5~15mm 2 / s.

[0035] Compared with undoped single materials, the introduction of doping elements is conducive to the formation of regions with p-type and n-type semiconductor characteristics inside the material, thereby generating energy band bending at the junction of these regions, forming a built-in electric field, which is conducive to the separation and transmission of electrons and holes, thereby improving the conductivity and band structure of the carrier transport layer material, and improving its energy level matching and interface stability with the perovskite active layer 30. Compared with other ranges, limiting the frequency, power density and scanning rate of the surface laser source within the above range is conducive to further improving the surface structure of the first carrier transport layer of the above material, and is conducive to embedding laser energy into the pn homojunction of the material, thereby accelerating the transmission of carriers, reducing recombination, and improving the collection efficiency and transmission efficiency of carriers, thereby improving the energy level matching and interface stability between the modified first carrier transport layer 20 and the perovskite active layer 30, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0036] In order to further improve the conductivity and band structure of the first carrier transport layer, thereby further improving its energy level matching and interface stability with the perovskite active layer 30, and further improving the carrier transport efficiency and collection efficiency, preferably, the doping elements include but are not limited to one or more of the group consisting of Li, Mg, H and B.

[0037] In order to further improve the conductivity and band structure of the first carrier transport layer, thereby further improving its energy level matching and interface stability with the perovskite active layer 30, and further improving the carrier transport efficiency and collection efficiency, preferably, the doping concentration of the doping element is 1 to 15 at%, more preferably 1 to 5 at%.

[0038] In a preferred embodiment, the material of the first carrier transport layer includes but is not limited to one or more of the group consisting of tin oxide, titanium oxide, nickel oxide, copper oxide, vanadium oxide and tungsten oxide, the frequency of the surface laser source is 430 to 570 THz, and the power density is 1 to 20 W / mm 2 , scanning speed is 5~15mm 2 / s.

[0039] Compared with other ranges, limiting the frequency, power density and scanning rate of the surface laser source within the above range is conducive to more targeted improvement of the surface structure of the first carrier transport layer of the above material, thereby obtaining a modified first carrier transport layer 20, thereby facilitating improvement of the energy level matching and interface stability between the first carrier transport layer 20 and the perovskite active layer 30, thereby facilitating improvement of the carrier mobility and transport efficiency thereof, and thereby facilitating improvement of the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0040] In a preferred embodiment, the material of the second carrier transport layer 40 is selected from C 60 One or more of the group consisting of (footballene), 2,2',7,7'-tetrakis[n,n-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD) and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA). Compared with other materials, the use of the above materials is conducive to improving the carrier transport efficiency of the second carrier transport layer 40 and the energy level matching and interface stability between it and the perovskite active layer 30, thereby helping to improve the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0041] In a preferred embodiment, the thickness of the first carrier transport layer and the second carrier transport layer 40 are independently 10 to 70 nm. The thickness of the first carrier transport layer 20 and the second carrier transport layer 40 includes but is not limited to the above range, and limiting it within the above range is conducive to improving the carrier collection efficiency of the first carrier transport layer and the second carrier transport layer 40, and is conducive to reducing the recombination of carriers, thereby facilitating the improvement of the carrier transport efficiency, and further facilitating the improvement of the photoelectric conversion efficiency of the perovskite solar cell.

[0042] Laser treatment is used to modify the surface of the first carrier transport layer, and will not directly lead to a significant change in the thickness of the first carrier transport layer. In a preferred embodiment, the thickness of the modified first carrier transport layer 20 is 10 to 70 nm. The thickness of the modified first carrier transport layer 20 includes but is not limited to the above range. Limiting it within the above range is beneficial to improving the carrier collection efficiency of the modified first carrier transport layer 20, and is beneficial to reducing the recombination of carriers, thereby helping to improve the carrier transport efficiency, and further helping to improve the photoelectric conversion efficiency of the perovskite solar cell.

[0043] In a preferred embodiment, step S1 includes: preparing the first carrier transport layer by spraying, spin coating, physical vapor deposition or chemical vapor deposition; preferably, the physical vapor deposition method includes but is not limited to magnetron sputtering or atomic layer deposition. Compared with other methods, the above preparation method is conducive to obtaining a first carrier transport layer with better film quality.

[0044] In order to improve the crystallinity of the first carrier transport layer, reduce its surface defects, and improve its conductivity, in a preferred embodiment, step S1 adopts spraying, spin coating or physical vapor deposition to prepare the first carrier transport layer, and between step S1 and step S2 also includes a first annealing treatment of the first carrier transport layer.

[0045] In order to further improve the crystallinity of the first carrier transport layer, further reduce its surface defects, and further improve its conductive properties, preferably, the temperature of the first annealing treatment is 100-600° C., and the time is 1 min-10 h.

[0046] In a preferred embodiment, step S4 includes: preparing the second carrier transport layer 40 by spraying, spin coating, physical vapor deposition or chemical vapor deposition; preferably, the physical vapor deposition method includes but is not limited to magnetron sputtering, spraying or atomic layer deposition. Compared with other methods, the above preparation method is conducive to obtaining a second carrier transport layer 40 with better film quality.

[0047] In order to improve the crystallinity of the second carrier transport layer 40, reduce its surface defects, and improve its conductivity, in a preferred embodiment, step S4 adopts spraying, spin coating or physical vapor deposition to prepare the second carrier transport layer 40, and between step S4 and step S5, it also includes a second annealing treatment of the second carrier transport layer 40.

[0048] In order to further improve the crystallinity of the second carrier transport layer 40 , further reduce its surface defects, and further improve its conductive properties, preferably, the second annealing treatment is performed at a temperature of 100 to 600° C. and for a time of 1 min to 10 h.

[0049] The present application has no particular limitation on the type of the transparent conductive substrate 10, as long as it is conductive and has high light transmittance. In a preferred embodiment, the transparent conductive substrate 10 includes but is not limited to ITO conductive glass, FTO conductive glass or AZO conductive glass.

[0050] In a preferred embodiment, step S3 includes: preparing a perovskite active layer 30 on the surface of the modified first carrier transport layer 20 away from the transparent conductive substrate 10 by spin coating, blade coating or spray deposition, and obtaining the perovskite active layer 30 after a third annealing treatment; step S6 includes preparing a metal electrode layer 50 on the surface of the second carrier transport layer 40 away from the perovskite active layer 30 by screen printing or evaporation. Compared with other methods, the above method is conducive to improving the film forming properties and uniformity of the perovskite active layer 30 and the metal electrode layer 50, and is conducive to obtaining a higher quality film layer.

[0051] In order to improve the stability, durability and photoelectric conversion efficiency of the perovskite solar cell, in a preferred embodiment, the thickness of the perovskite active layer 30 is 10 to 1000 nm; the thickness of the metal electrode layer 50 is 10 to 500 nm.

[0052] In a preferred embodiment, the material of the perovskite active layer 30 is ABX3, wherein A includes but is not limited to CH3NH3 + NH=CHNH3 + and Cs + One or more of the group consisting of, B is Pb 2+ , X includes but is not limited to Cl - Br - and I - Compared with other types, the use of the above-mentioned types of materials for the perovskite active layer 30 is beneficial to improving the light absorption efficiency of the perovskite material, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0053] In a preferred embodiment, the material of the metal electrode layer 50 includes but is not limited to one or more of the group consisting of Ag, Cu and Au. Compared with other types, the use of the above types of metal electrode materials is conducive to improving the conductivity of the metal electrode layer 50, thereby facilitating the improvement of the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0054] The second aspect of the present application also provides a perovskite solar cell, which is prepared by the above-mentioned perovskite solar cell preparation method provided in the present application. Figure 1 As shown, the perovskite solar cell provided in the present application includes a transparent conductive substrate 10, a modified first carrier transport layer 20, a perovskite active layer 30, a second carrier transport layer 40 and a metal electrode layer 50 which are stacked in sequence.

[0055] The method for preparing the perovskite solar cell of the present application can obtain a perovskite solar cell with higher photoelectric conversion efficiency and better stability. The prepared perovskite solar cell has the following characteristics: Figure 1 The stacked structure shown. In the above preparation method, by laser processing the surface of the first carrier transport layer, laser energy can be injected into the material of the first carrier transport layer, improving its surface structure, and obtaining a modified first carrier transport layer 20, thereby improving the energy level matching between the perovskite active layer 30 and the modified first carrier transport layer 20, improving its carrier mobility and transport efficiency, and at the same time, it can also suppress the occurrence of adverse interface chemical reactions and mechanical stratification problems, thereby improving the interface stability between the perovskite active layer 30 and the modified first carrier transport layer 20, and further improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0056] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0057] Example 1

[0058] A method for preparing a trans (pin) perovskite solar cell specifically comprises the following steps:

[0059] (1) Providing a transparent conductive substrate 10: ultrasonically cleaning an ITO conductive glass with water and ethanol for 15 minutes, drying it for later use, and then plasma treating the cleaned ITO conductive glass for 30 minutes for later use;

[0060] (2) Preparation of hole transport layer: NiOx doped with Mg (Mg doping concentration is 3 at%) is sputtered and deposited on the conductive surface of the transparent conductive substrate 10 provided in step (1) to obtain a NiOx layer doped with Mg with a thickness of 30 nm, wherein the sputtering power is 80 W, the sputtering time is 3 min, and the vacuum degree is 3×10 -4 Pa, argon flow rate is 40 sccm;

[0061] (3) Preparation of modified hole transport layer: The surface of the hole transport layer obtained in step (2) away from the transparent conductive substrate 10 was laser treated for 1.5 min using a continuous surface laser source with a wavelength of 450 nm to obtain a modified hole transport layer with a thickness of 30 nm; wherein the projection area of ​​the surface laser source is 400 mm 2 , frequency is 667THz, power density is 3mW / mm 2 , scanning rate is 10mm 2 / s;

[0062] (4) Preparation of perovskite active layer 30: 0.6 g of PbI2 was weighed and dissolved in 900 μL of DMF (N,N-dimethylformamide) and 100 μL of DMSO (dimethyl sulfoxide) solution, and stirred at 70°C and 1500 rpm for 0.5 min to obtain a PbI2 precursor solution; 50 mg of FAI (formamidine iodine) and 10 mg of MAI (methylamine iodine) were weighed and dissolved in 1 mL of IPA (isopropyl alcohol) solution, stirred at 20°C and 1500rpm for 0.5h to obtain an organic salt solution; 60μL of PbI2 precursor solution was spin-coated on the surface of the modified hole transport layer prepared in step (3) away from the transparent conductive substrate 10 at a speed of 2300rpm by a glue spreader, the spin coating time was 30s, and then placed it on a 75°C hot plate for annealing for 1min to form an intermediate coating; 80μL of organic salt solution was spin-coated on the surface of the intermediate coating at a speed of 3000rpm by a glue spreader, the spin coating time was 30s, and then placed it on a 150°C hot plate for annealing for 15min to obtain a perovskite active layer 30 with a thickness of 450nm;

[0063] (5) Preparation of electron transport layer: The surface of the perovskite active layer 30 prepared in step (4) away from the modified hole transport layer is The deposition rate was 50 nm. 60 layer;

[0064] (6) Preparation of metal electrode layer 50: The C prepared in step (5) 60 The layer is away from the surface of the side of the perovskite active layer 30, A Cu electrode layer with a thickness of 100 nm was obtained by evaporation at a deposition rate of .

[0065] The laminated structure of the perovskite solar cell prepared in this embodiment is as follows: Figure 1 shown.

[0066] Example 2

[0067] The difference from Example 1 is that the material of the hole transport layer in step (2) is NiOx not doped with Mg element, and in step (3), the frequency of the surface laser source used for laser treatment is 500 THz and the power density is 3.5 W / mm 2 , scanning rate is 5mm 2 / s; the remaining steps are the same as those in Example 1.

[0068] Example 3

[0069] The difference from Example 1 is that the material of the hole transport layer in step (2) is NiOx doped with Li (the doping concentration of Li is 5at%), and in step (3), the frequency of the surface laser source used for laser treatment is 560THz and the power density is 4W / mm 2 , scanning rate is 7mm 2 / s; the remaining steps are the same as those in Example 1.

[0070] Example 4

[0071] The difference from Example 1 is that in step (2), the NiOx layer doped with Mg element obtained by sputtering deposition is annealed at 300° C. for 60 min to obtain a hole transport layer; the remaining steps are the same as Example 1.

[0072] Example 5

[0073] The difference from Example 1 is that in step (3), the frequency of the surface laser source used for laser treatment is 430 THz and the power density is 1 W / mm 2 , scanning rate is 1mm 2 / s; the remaining steps are the same as those in Example 1.

[0074] Example 6

[0075] The difference from Example 1 is that in step (3), the frequency of the surface laser source used for laser treatment is 780 THz and the power density is 100 W / mm 2 , scanning speed is 200mm 2 / s; the remaining steps are the same as those in Example 1.

[0076] Example 7

[0077] The difference from Example 1 is that in step (3), the frequency of the surface laser source used for laser treatment is 390 THz and the power density is 120 W / mm 2 , scanning speed is 210mm 2 / s; the remaining steps are the same as those in Example 1.

[0078] Example 8

[0079] A method for preparing a formal (nip) perovskite solar cell specifically comprises the following steps:

[0080] (1) Providing a transparent conductive substrate 10: ultrasonically cleaning an ITO conductive glass with water and an ethanol solution for 15 minutes, drying it for later use, and then plasma treating the cleaned ITO conductive glass for 30 minutes for later use;

[0081] (2) Preparation of electron transport layer: SnOx doped with Mg (Mg doping concentration is 3 at%) is sputtered and deposited on the conductive surface of the transparent conductive substrate 10 provided in step (1) to obtain a SnOx layer doped with Mg with a thickness of 30 nm, wherein the sputtering power is 30 W, the sputtering time is 15 min, and the vacuum degree is 3×10 -4 Pa, argon flow rate is 80 sccm;

[0082] (3) Preparation of modified electron transport layer: The surface of the electron transport layer obtained in step (2) away from the transparent conductive substrate 10 is subjected to surface laser treatment for 3 min using a continuous surface laser source with a wavelength of 600 nm to obtain a modified electron transport layer with a thickness of 30 nm; wherein the projection area of ​​the surface laser source is 400 mm 2 , frequency is 500THz, power density is 5mW / mm 2 , scanning rate is 8mm 2 / s;

[0083] (4) Preparation of perovskite active layer 30: 0.6 g of PbI2 was weighed and dissolved in 900 μL of DMF (N,N-dimethylformamide) and 100 μL of DMSO (dimethyl sulfoxide) solution, and stirred at 70°C and 1500 rpm for 0.5 min to obtain a PbI2 precursor solution; 50 mg of FAI (formamidine iodine) and 10 mg of MAI (methylamine iodine) were weighed and dissolved in 1 mL of IPA (isopropyl alcohol) solution, stirred at 20°C and 1500rpm for 0.5h to obtain an organic salt solution; 60μL of PbI2 precursor solution was spin-coated on the surface of the modified electron transport layer prepared in step (3) away from the transparent conductive substrate 10 at a rotation speed of 2300rpm by a glue spreader, the spin coating time was 30s, and then placed it on a 75°C hot plate for annealing for 1min to form an intermediate coating; 80μL of organic salt solution was spin-coated on the surface of the intermediate coating at a rotation speed of 3000rpm by a glue spreader, the spin coating time was 30s, and then placed it on a 150°C hot plate for annealing for 15min to obtain a perovskite active layer 30 with a thickness of 450nm;

[0084] (5) Preparation of hole transport layer: 100 μL of 3 mg / mL PTAA chlorobenzene solution was spin coated at 2000 rpm on the surface of the perovskite active layer 30 prepared in step (4) away from the modified electron transport layer. The spin coating time was 30 s, and then the layer was placed on a hot plate at 100° C. for annealing for 15 min to obtain a PTAA layer with a thickness of 30 nm.

[0085] (6) Preparing the metal electrode layer 50: The PTAA layer prepared in step (5) is placed on a surface away from the perovskite active layer 30. A Cu electrode layer with a thickness of 100 nm was obtained by evaporation at a deposition rate of .

[0086] The laminated structure of the perovskite solar cell prepared in this embodiment is as follows: Figure 1 shown.

[0087] Example 9

[0088] The difference from Example 8 is that the material for preparing the electron transport layer in step (2) is SnOx doped with Mg (the doping concentration of Mg is 5at%), and in step (3), the frequency of the surface laser source used for laser treatment is 500THz, and the power density is 5W / mm 2 , scanning rate is 8mm 2 / s; the remaining steps are the same as in Example 8.

[0089] Comparative Example 1

[0090] The difference from Example 1 is that step (3) is omitted, the hole transport layer prepared in step (2) is not laser treated, and the perovskite active layer 30 is directly prepared on the surface of the hole transport layer. The remaining steps are the same as in Example 1.

[0091] Comparative Example 2

[0092] The difference from Example 1 is that in step (3), a linear laser source with a wavelength of 450 nm is used to perform laser scanning on the hole transport layer obtained in step (2), wherein the frequency of the linear laser source is 667 THz, the power is 3 mW / mm, the scanning rate is 10 mm / s, and the processing time is 1.5 min; the remaining steps are the same as in Example 1.

[0093] Comparative Example 3

[0094] The difference from Example 8 is that step (3) is omitted, the electron transport layer prepared in step (2) is not laser treated, and the perovskite active layer 30 is directly prepared on the surface of the electron transport layer. The remaining steps are the same as those in Example 8.

[0095] Comparative Example 4

[0096] The difference from Example 8 is that in step (3), a point laser source with a wavelength of 600 nm is used to perform laser scanning on the electron transport layer obtained in step (2), wherein the frequency of the point laser source is 500 THz, the power is 5 mW / mm, the scanning rate is 8 mm / s, and the processing time is 3 min; the remaining steps are the same as Example 8.

[0097] A Hall effect tester (Ecopia, HMS-3000) was used to test the carrier mobility of the modified hole transport layer of the perovskite solar cell prepared in Examples 1 to 7 of the present application and Comparative Examples 1 and 2, and the carrier mobility of the modified electron transport layer of the perovskite solar cell prepared in Examples 8 and 9 and Comparative Examples 3 and 4 was tested. The test results are shown in Table 1.

[0098] Table 1

[0099] <![CDATA[Carrier mobility (cm 2 ·V -1 ·s -1 )]]> Example 1 70 Example 2 65 Example 3 71 Example 4 68 Example 5 80 Example 6 83 Example 7 50 Example 8 86 Example 9 90 Comparative Example 1 3 Comparative Example 2 4 Comparative Example 3 2 Comparative Example 4 5

[0100] The photovoltaic performance of the perovskite solar cells prepared in all the above embodiments and comparative examples of the present application was tested. The effective area of ​​the device was 9 mm 2 , at 100mW / cm 2 The JV curve of the perovskite solar cell was tested under simulated solar illumination using a solar simulator (Newport, OrielSol 3A Class AAA) and a Keithley 2400 digital source meter. The test results are shown in Table 2 below.

[0101] Table 2

[0102]

[0103] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0104] Comparing Example 1 and Comparative Examples 1 and 2, it can be seen that laser treatment of the hole transport layer of the inverted (pin) perovskite solar cell can inject laser energy into the material of the hole transport layer, improve its surface structure, and obtain a modified hole transport layer, thereby improving the energy level matching and interface stability between the perovskite active layer 30 and the modified hole transport layer, improving its carrier mobility and transmission efficiency, and thus improving the photoelectric conversion efficiency of the perovskite solar cell. Compared with a linear laser source, the use of a surface laser source with a specific projection area in the present application for laser treatment can improve the uniformity and consistency of the laser treatment, reduce local performance differences, thereby improving the laser treatment efficiency of large-area materials, and thus improving the carrier mobility of the modified hole transport layer and the photoelectric conversion efficiency of the perovskite solar cell prepared therefrom.

[0105] Comparing Example 8 with Comparative Examples 3 and 4, it can be seen that laser treatment of the electron transport layer of the formal (nip) perovskite solar cell can inject laser energy into the material of the electron transport layer, improve its surface structure, and obtain a modified electron transport layer, thereby improving the energy level matching and interface stability between the perovskite active layer 30 and the modified electron transport layer, improving its carrier mobility and transmission efficiency, and thus improving the photoelectric conversion efficiency of the perovskite solar cell. Compared with a point laser source, the use of a surface laser source with a specific projection area in the present application for laser treatment can improve the uniformity and consistency of the laser treatment, reduce local performance differences, thereby improving the laser treatment efficiency of large-area materials, and thus improving the carrier mobility of the modified electron transport layer and the photoelectric conversion efficiency of the perovskite solar cell prepared therefrom.

[0106] By comparing Examples 1 to 3, it can be seen that the material of the hole transport layer in the inverse perovskite solar cell can be nickel oxide or nickel oxide doped with doping elements. Limiting the type and concentration of the doping elements within the above-mentioned range of the present application is beneficial to improving the conductivity and band structure of the hole transport layer, thereby facilitating improving its energy level matching and interface stability with the perovskite active layer 30, and further facilitating improving its carrier mobility and transport efficiency, and thus improving the photoelectric conversion efficiency of the perovskite solar cell.

[0107] By comparing Examples 1 and 4, it can be seen that annealing the hole transport layer obtained by sputtering deposition before laser treatment and limiting the temperature and time of the annealing treatment within the above-mentioned range of the present application is beneficial to improving the crystallinity of the hole transport layer, reducing its surface defects, and thus improving its conductivity and carrier mobility.

[0108] By comparing Examples 1, 5 to 7, it can be seen that, compared with other ranges, limiting the frequency, power density and scanning rate of the surface laser source within the above range is beneficial to providing more stable and efficient laser energy, and is beneficial to improving the uniformity and consistency of laser processing, thereby helping to improve the surface structure of the first carrier transport layer to obtain a modified first carrier transport layer 20, which is beneficial to improving the energy level matching and interface stability between the perovskite active layer 30 and the modified first carrier transport layer 20, and is beneficial to improving the carrier mobility and transport efficiency of the modified first carrier transport layer 20, thereby helping to improve the photoelectric conversion efficiency of the perovskite solar cell.

[0109] By comparing Examples 8 and 9, it can be seen that the material of the electron transport layer in the formal perovskite solar cell can be tin oxide or tin oxide doped with a doping element. Limiting the type and concentration of the doping element within the above-mentioned range of the present application is beneficial to improving the conductivity and band structure of the electron transport layer, thereby facilitating improving its energy level matching and interface stability with the perovskite active layer 30, and further facilitating improving its carrier mobility and transmission efficiency, and thus improving the photoelectric conversion efficiency of the perovskite solar cell.

[0110] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a perovskite solar cell, characterized in that: The preparation method comprises: Step S1, preparing a first carrier transport layer on one side of the conductive surface of the transparent conductive substrate (10); Step S2, using a surface laser source to perform laser treatment on a side of the first carrier transport layer away from the transparent conductive substrate (10) to obtain a modified first carrier transport layer (20); the projection area of ​​the surface laser source is 1 to 10000 mm 2 ; The first carrier transport layer is a hole transport layer or an electron transport layer; Step S3, preparing a perovskite active layer (30) on a surface of the modified first carrier transport layer (20) that is away from the transparent conductive substrate (10); Step S4, preparing a second carrier transport layer (40) on a surface of the perovskite active layer (30) away from the modified first carrier transport layer (20); Step S5, preparing a metal electrode layer (50) on the surface of the second carrier transport layer (40) away from the perovskite active layer (30) to obtain a perovskite solar cell.

2. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The surface laser source is a continuous laser source; Preferably, the surface laser light source is visible light, and more preferably has a wavelength of 400 nm, 450 nm, 550 nm, 580 nm, 600 nm or 650 nm.

3. The method for preparing a perovskite solar cell according to claim 1 or 2, characterized in that: During the laser treatment, the surface laser source continuously irradiates the first carrier transport layer, the frequency of the surface laser source is 430-780 THz, and the power density is 1-100 mW / mm 2 , scanning rate is 1~200mm 2 / s.

4. The method for preparing a perovskite solar cell according to any one of claims 1 to 3, characterized in that: The first carrier transport layer is a hole transport layer, and the second carrier transport layer (40) is an electron transport layer; or the first carrier transport layer is an electron transport layer, and the second carrier transport layer (40) is a hole transport layer.

5. The method for preparing a perovskite solar cell according to any one of claims 1 to 4, characterized in that: The material of the first carrier transport layer is selected from one or more of the group consisting of tin oxide, titanium oxide, nickel oxide, copper oxide, vanadium oxide and tungsten oxide doped with doping elements, the frequency of the surface laser source is 430 to 670 THz, and the power density is 1 to 20 mW / mm 2 , scanning speed is 5~15mm 2 / s; Preferably, the doping element is selected from one or more of the group consisting of Li, Mg, H and B; Preferably, the doping concentration of the doping element is 1 to 15 at %, preferably 1 to 5 at %.

6. The method for preparing a perovskite solar cell according to any one of claims 1 to 4, characterized in that: The material of the first carrier transport layer is selected from one or more of the group consisting of tin oxide, titanium oxide, nickel oxide, copper oxide, vanadium oxide and tungsten oxide. The frequency of the surface laser source is 430-570 THz, and the power density is 1-20 mW / mm 2 , scanning speed is 5~15mm 2 / s.

7. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The material of the second carrier transport layer (40) is selected from C 60 , one or more of the group consisting of 2,2',7,7'-tetrakis[n,n-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; Preferably, the thickness of the first carrier transport layer and the second carrier transport layer (40) are independently 10 to 70 nm; Preferably, the modified first carrier transport layer (20) has a thickness of 10 to 70 nm.

8. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The step S1 comprises: preparing the first carrier transport layer by spraying, spin coating, physical vapor deposition or chemical vapor deposition; preferably, the physical vapor deposition method is selected from magnetron sputtering or atomic layer deposition; Preferably, the step S1 adopts the spray coating method, the spin coating method or the physical vapor deposition method to prepare the first carrier transport layer, and between the step S1 and the step S2, the step further includes: performing a first annealing treatment on the first carrier transport layer; More preferably, the temperature of the first annealing treatment is 100-600° C., and the time is 1 min-10 h.

9. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The step S4 comprises: preparing the second carrier transport layer (40) by spraying, spin coating, physical vapor deposition or chemical vapor deposition; preferably, the physical vapor deposition method is selected from magnetron sputtering or atomic layer deposition; Preferably, the step S4 adopts the spray coating method, the spin coating method or the physical vapor deposition method to prepare the second carrier transport layer (40), and between the step S4 and the step S5, further comprises: performing a second annealing treatment on the second carrier transport layer (40); More preferably, the temperature of the second annealing treatment is 100-600° C., and the time is 1 min-10 h.

10. A perovskite solar cell, characterized in that: The perovskite solar cell is prepared by the preparation method of the perovskite solar cell according to any one of claims 1 to 9; the perovskite solar cell comprises a transparent conductive substrate (10), a modified first carrier transport layer (20), a perovskite active layer (30), a second carrier transport layer (40) and a metal electrode layer (50) which are stacked in sequence.

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