Perovskite cell, preparation method thereof and photovoltaic module

Abstract

The invention discloses a perovskite cell, a preparation method thereof and a photovoltaic module, and belongs to the technical field of solar cells. The perovskite cell comprises a substrate, a hole transport layer, a perovskite layer and an electron transport layer, wherein the hole transport layer, the perovskite layer and the electron transport layer are sequentially arranged on the substrate; the electron transport layer comprises a C60 layer; the perovskite layer comprises a perovskite material and dimethyl biguanide hydrochloride; and / or the perovskite cell further comprises a passivation layer, the passivation layer is arranged between the perovskite layer and the electron transport layer, and the passivation layer comprises dimethyl biguanide hydrochloride. According to the invention, by adding the dimethyl biguanide hydrochloride and / or adding the passivation layer containing the dimethyl biguanide hydrochloride on the perovskite layer and combining other layers, non-radiative recombination is inhibited, the electron transport layer can cover the perovskite layer more uniformly, meanwhile, a good passivation effect is achieved, the device filling of the obtained solar cell rises, and the performance of the solar cell is improved. Open-circuit voltage loss is reduced, and photoelectric conversion efficiency is improved.

Description

Technical Field

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

[0002] Perovskite solar cells are a type of solar cell with good application prospects. However, in current perovskite solar cells, there are significant problems with the quality of the perovskite layer, showing phenomena such as low fill factor and energy level mismatch in perovskite solar cells, which in turn affect the performance improvement of perovskite solar cells. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a perovskite solar cell, a preparation method thereof, and a photovoltaic module. By adding dimethylbiguanide hydrochloride to the perovskite layer or increasing a passivation layer containing dimethylbiguanide hydrochloride and combining with other layers, non-radiative recombination is inhibited. The electron transport layer can more evenly cover the perovskite layer, and at the same time has a good passivation effect. The fill factor of the obtained solar cell device increases, the open-circuit voltage loss decreases, and the photoelectric conversion efficiency increases, which can effectively improve problems such as small grains, rough surface, poor crystallinity, low fill factor, and insufficient energy level matching of the perovskite layer.

[0004] The technical solution of the present invention is as follows: In a first aspect of the present invention, a perovskite solar cell is provided. The perovskite solar cell includes a substrate, a hole transport layer, a perovskite layer, and an electron transport layer sequentially disposed on the substrate. The electron transport layer includes layer C; 60 layer; The perovskite layer includes a perovskite material and dimethylbiguanide hydrochloride; and / or, The perovskite solar cell further includes a passivation layer disposed between the perovskite layer and the electron transport layer, and the passivation layer includes dimethylbiguanide hydrochloride.

[0005] Preferably, the substrate is a transparent conductive substrate, and the hole transport layer is disposed on the transparent conductive substrate; The perovskite solar cell further includes a positive electrode and a negative electrode. The positive electrode is in ohmic contact with the electron transport layer, and the negative electrode is in ohmic contact with the transparent conductive substrate; The thickness of the electron transport layer is 20 nm to 30 nm; The passivation layer has a single-molecule layer thickness; The thickness of the perovskite layer is 450 nm to 550 nm; The hole transport layer is a nickel oxide layer with a thickness of 100 nm to 150 nm; The positive electrode and / or the negative electrode is silver, copper or aluminum, and the thickness of the positive electrode and / or the negative electrode is 250 nm to 300 nm.

[0006] Preferably, the substrate includes a bottom cell and an electron-hole recombination layer, and the electron-hole recombination layer is disposed between the bottom cell and the hole transport layer; The perovskite solar cell further includes a transparent conductive layer; the transparent conductive layer is disposed on a side of the electron transport layer away from the perovskite layer; The perovskite solar cell further includes a positive electrode and a negative electrode; The positive electrode is in ohmic contact with the transparent conductive layer, and the negative electrode is in ohmic contact with the bottom cell.

[0007] Preferably, a self-assembled monolayer is further disposed between the hole transport layer and the perovskite layer; and / or, The electron transport layer includes a first electron transport layer disposed close to the perovskite layer and a second electron transport layer disposed away from the perovskite layer, and the first electron transport layer is a C60 layer; The transparent conductive layer is disposed on a side of the second electron transport layer away from the first electron transport layer; The bottom cell includes at least one of a HJT silicon cell and a TopCon silicon cell; and / or, The electron-hole recombination layer includes at least one of an indium tin oxide composite layer, an indium zinc oxide composite layer, and an aluminum zinc oxide composite layer; and / or, The thickness of the electron-hole recombination layer is 100 nm to 180 nm; and / or, The hole transport layer is a nickel oxide layer; and / or, The thickness of the hole transport layer is 100 nm to 150 nm; and / or, The self-assembled monolayer is a MeO-2PACz layer; and / or, The thickness of the perovskite layer is 450 nm to 550 nm; and / or, The passivation layer is the thickness of a monolayer; and / or, The thickness of the first electron transport layer is 20 nm to 30 nm; and / or, The second electron transport layer is a SnO 2 layer; and / or, The thickness of the second electron transport layer is 20 nm to 30 nm; and / or, The transparent conductive layer is an IZO layer; and / or, The thickness of the transparent conductive layer is 80 nm to 120 nm; and / or, The positive electrode and / or the negative electrode is silver, copper or aluminum, and the thickness of the positive electrode and / or the negative electrode is 250 nm to 300 nm.

[0008] In a second aspect of the present invention, there is provided a method for preparing the perovskite solar cell described in the first aspect above, the preparation method comprising: Forming the hole transport layer on the substrate; Successively forming the perovskite layer and the electron transport layer on the hole transport layer, the perovskite layer comprising dimethylguanidine hydrochloride; and / or, Successively forming the perovskite layer, the passivation layer and the electron transport layer on the hole transport layer, the passivation layer comprising dimethylguanidine hydrochloride.

[0009] Preferably, the preparation method comprises: Forming the hole transport layer on the substrate; Forming the perovskite layer on the hole transport layer; Spin-coating a solution containing dimethylguanidine hydrochloride on the perovskite layer and annealing to obtain the passivation layer; Forming the electron transport layer on the passivation layer; Preferably, the preparation of the perovskite layer comprises: (1) Preparing a perovskite cation solution for standby; (2) Preparing a lead skeleton layer on the hole transport layer by co-evaporation; (3) Then spin-coating the perovskite cation solution on the lead skeleton layer and annealing to obtain the perovskite layer; In step (1), the perovskite cation solution is obtained by dissolving FAI, MABr, and MACl in a solvent; the mass ratio of FAI, MABr, and MACl is 35:8:5.

[0010] In step (2), the thickness of the lead skeleton layer is 300 nm to 340 nm; In step (3), the rotation speed of the spin-coating is 3000 rpm to 4000 rpm; the time is 25 s to 35 s; and / or, The annealing temperature is 100°C to 150°C; the time is 25 min to 35 min; and / or, The relative humidity of the annealing is 4% to 10%; In the preparation of the passivation layer, the concentration of the solution containing dimethylguanidine hydrochloride is 0.1 mg / mL to 1.0 mg / mL, and the solution containing dimethylguanidine hydrochloride is obtained by dissolving dimethylguanidine hydrochloride in an ethanol solution; and / or, The rotation speed of the spin coating is 3000 rpm to 4000 rpm, the acceleration is 3000 rpm / s to 4000 rpm / s, and the spin coating time is 20 s to 40 s; the air humidity during the spin coating is 4% to 6%; and / or, The annealing temperature is 130°C to 150°C, and the annealing time is 15 min to 25 min; The preparation method further includes performing a texturing treatment on the substrate; Preferably, the hole transport layer, the perovskite layer, and the electron transport layer are sequentially formed on the substrate and are consistent with the shape of the texture.

[0011] Preferably, the preparation method includes: Forming the hole transport layer on the substrate; Dissolving FAI, MABr, MACl, and dimethylbiguanide hydrochloride in a solvent to obtain a perovskite cation solution for standby; Forming a lead skeleton layer on the hole transport layer by co-evaporation; Spin-coating the perovskite cation solution on the lead skeleton layer and annealing to obtain the perovskite layer; Forming the electron transport layer on the perovskite layer; The mass ratio of FAI, MABr, MACl to dimethylbiguanide hydrochloride is 35:8:5:0.01 - 1.0; The mass-volume ratio of dimethylbiguanide hydrochloride to the solvent is 0.01 - 1.0:1 mg / mL.

[0012] Preferably, before forming the electron transport layer on the perovskite layer, a passivation layer is first formed on the perovskite layer, that is, a solution containing dimethylbiguanide hydrochloride is spin-coated on the perovskite layer by the spin coating method, and after annealing, a single molecular layer of dimethylbiguanide hydrochloride layer is obtained as the passivation layer; then the electron transport layer is formed on the passivation layer; It also includes performing a texturing treatment on the substrate; Preferably, the hole transport layer, the perovskite layer, and the electron transport layer are sequentially formed on the substrate and are consistent with the shape of the texture.

[0013] Preferably, the preparation method includes: Providing a bottom cell with a texture, after annealing treatment, forming an electron-hole recombination layer on the bottom cell; Magnetron sputtering to form a hole transport layer on the electron-hole recombination layer; Spin-coating a self-assembled monolayer on the hole transport layer and annealing; A lead skeleton layer is co-evaporated on the self-assembled monolayer, and the perovskite cation solution is spin-coated on the lead skeleton layer and annealed to form the perovskite layer; and / or, A solution containing dimethylbiguanide hydrochloride is spin-coated on the perovskite layer and annealed to form the passivation layer; A first electron transport layer is evaporated on the passivation layer; A second electron transport layer is deposited on the first electron transport layer by ALD; A transparent conductive layer is deposited on the second electron transport layer by PVD; A positive electrode is deposited on the transparent conductive layer to make an ohmic contact between the positive electrode and the transparent conductive layer, and a negative electrode is deposited on the bottom cell to make an ohmic contact between the negative electrode and the bottom cell; Preferably, in the step of providing the bottom cell with a matte surface, the annealing temperature is 140 °C to 160 °C, and the annealing time is 10 min to 20 min; and / or, In the preparation step of the hole transport layer, NiO with a content of 99.99% is used x Rotating the target, the process pressure is 0.5 Pa to 0.6 Pa, the process atmosphere is Ar:O 2 = 500:5 to 700:5, and the number of reciprocating movements of the carrier plate in the magnetron sputtering equipment is 10 to 15 times; and / or, When the first electron transport layer is evaporated, the evaporation rate < 0.5 Å / s.

[0014] The third aspect of the present invention provides a photovoltaic module, which includes the perovskite battery described in the first aspect above, or the perovskite battery prepared by the preparation method described in the second aspect above.

[0015] The beneficial technical effects of the present invention are as follows: By incorporating dimethylbiguanide hydrochloride material into the perovskite layer, or by adding a passivation layer containing dimethylbiguanide hydrochloride material between the perovskite layer and the electron transport layer, the present invention can effectively improve the problem of poor compatibility between the perovskite layer and the electron transport layer. Dimethylbiguanide hydrochloride effectively guides the crystallization growth of the perovskite thin film, further combines with the defects in the perovskite bulk phase, inhibits non-radiative recombination, promotes the more uniform coverage of the electron transport layer on the perovskite layer, and has a good passivation effect, resulting in an increase in the device fill factor of the solar cell, a reduction in the open-circuit voltage loss, and an improvement in the photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of the perovskite battery of Embodiment 1 of the present invention.

[0017] Figure 2 It is a schematic structural diagram of the perovskite solar cell of Embodiment 2 of the present invention.

[0018] Figure 3 It is a schematic structural diagram of the perovskite solar cell of Embodiment 3 of the present invention.

[0019] Figure 4 It is an SEM image of the effect of dimethylbiguanide hydrochloride on perovskite provided in Embodiment 1 of the present application.

[0020] Reference numerals: 11, bottom cell; 12, electron-hole recombination layer; 21, hole transport layer; 22, self-assembled monolayer; 3, perovskite layer; 4, passivation layer; 5, electron transport layer; 51, first electron transport layer; 52, second electron transport layer; 6, transparent conductive layer; 7, positive electrode; 8, negative electrode. Detailed implementation manners

[0021] The present invention will be specifically described below in conjunction with embodiments.

[0022] In a perovskite / silicon tandem solar cell, a silicon bottom cell with a textured structure is often used as a substrate. When the perovskite layer grows on such an irregular substrate, many problems will occur, specifically manifested in aspects such as low fill factor and poor energy level matching of the solar cell device, which will lead to the conversion efficiency of the perovskite solar cell. The first aspect of the present invention provides a perovskite solar cell, the perovskite solar cell includes a substrate, a hole transport layer, a perovskite layer, and an electron transport layer sequentially provided on the substrate, and the electron transport layer includes a C 60 layer; the perovskite layer includes a perovskite material and dimethylbiguanide hydrochloride; and / or, the perovskite solar cell further includes a passivation layer, the passivation layer is provided between the perovskite layer and the electron transport layer, and the passivation layer includes dimethylbiguanide hydrochloride.

[0023] That is to say, the present invention may be to incorporate dimethylbiguanide hydrochloride into the perovskite layer, that is, the perovskite layer includes a perovskite material and a dimethylbiguanide hydrochloride material. It may also be to add a passivation layer between the perovskite layer and the electron transport layer, and the passivation layer uses dimethylbiguanide hydrochloride. It may also be to incorporate dimethylbiguanide hydrochloride into the perovskite layer and add a passivation layer containing dimethylbiguanide hydrochloride between the perovskite layer and the electron transport layer.

[0024] It can be understood that in the present invention, by doping the perovskite layer with dimethylbiguanide hydrochloride material and / or by adding a passivation layer containing dimethylbiguanide hydrochloride material between the perovskite layer and the electron transport layer, the problem of poor compatibility between the perovskite layer and the electron transport layer can be effectively improved. Dimethylbiguanide hydrochloride effectively guides the crystallization growth of the perovskite thin film, further combines with the defects in the perovskite bulk phase, inhibits non-radiative recombination, promotes the electron transport layer to cover the perovskite layer more uniformly, and has a good passivation effect, increasing the device fill factor of the solar cell, reducing the open-circuit voltage loss, and improving the photoelectric conversion efficiency.

[0025] It can be understood that in the present invention, the chemical formula of dimethylbiguanide hydrochloride is C 4 H 12 ClN 5 , which is a white substance obtained by the self-polymerization reaction of dimethylbiguanide under hydrochloric acid conditions. There are a large number of functional groups on the surface of dimethylbiguanide hydrochloride, such as biguanide groups containing free hydrochloric acid groups, etc., which can be well attached to the surface of the relevant film layer through the combined action of N-C bonds, strong covalent bonds, non-covalent bonds, and hydrogen bonds. Thus, the perovskite layer and / or passivation layer containing this material can serve as anchor points for fixing metal ions and active sites for in-situ growth. Especially the perovskite layer with this material can well improve the crystallization quality and will float on the upper interface with annealing to form 2D perovskite anchored at the upper interface of the perovskite layer (i.e., the interface of the perovskite layer far from the hole transport layer), reducing the metal cations that have not reacted completely in the perovskite. In addition, dimethylbiguanide hydrochloride has excellent light-harvesting ability and conductivity, can achieve good light trapping and electron migration ability, and thus effectively improves the optical and electrical properties of the matrix material.

[0026] In some embodiments of the present invention, when dimethylbiguanide hydrochloride is used in the perovskite layer or the passivation layer located between the perovskite layer and the electron transport layer, on the one hand, the crystallization growth of the perovskite thin film can be guided by dimethylbiguanide hydrochloride, enabling the perovskite to grow conformally on the silicon substrate with a textured structure, thereby greatly improving the charge transfer efficiency and stability of the battery. On the other hand, the amino group in dimethylbiguanide hydrochloride will form a covalent bond with the perovskite, and the cl - in dimethylbiguanide hydrochloride will replace I - and combine with the I vacancies on the surface of the perovskite layer, which can improve the defect concentration inside the perovskite layer and reduce non-radiative recombination. And Cl -It will promote the crystallization of perovskite, increase the grain size, and improve the crystallization quality of perovskite. Through the above improvements, not only can the perovskite layer grow better in morphology on the silicon substrate, promoting the uniform coverage of the perovskite layer on the silicon substrate, but also it can play a good role in increasing the grain size, improving the crystallization quality, increasing the device fill factor of the solar cell, reducing the open-circuit voltage loss, and improving the photoelectric conversion efficiency.

[0027] In some embodiments, the perovskite cell can be a perovskite single-junction cell or a perovskite / silicon heterojunction cell. When the perovskite cell is different types of solar cells, the corresponding substrates of the perovskite cells are also of different structures. In addition, the number of hole transport layers can be one layer, two layers or more layers, and the number of electron transport layers can be one layer, two layers or more layers.

[0028] In some embodiments, the substrate has a textured structure, and the perovskite layer has the same shape as the textured structure of the substrate. Exemplarily, the perovskite cell is a perovskite / silicon heterojunction cell, and the substrate is the bottom cell with a textured structure. When the hole transport layer, the perovskite layer, and the electron transport layer are sequentially formed on the bottom cell with a textured structure, these film layer structures have a textured structure that is consistent with the textured structure of the bottom cell to achieve the full-coverage structure characteristics of the solar cell. Through this structure, the utilization rate of sunlight can be improved.

[0029] It can be understood that in order to enable the perovskite layer to better maintain a textured structure consistent with the substrate, a two-step method of co-evaporation and spin-coating can be used to prepare the above-mentioned full-coverage perovskite / silicon heterojunction cell. Exemplarily, a lead skeleton layer is first co-evaporated on the hole transport layer, and then a perovskite cation solution is spin-coated on the lead skeleton layer so that the perovskite cation solution can react with the lead skeleton layer to form a perovskite layer, and then an electron transport layer is formed on the perovskite layer. However, due to the defects of the co-evaporation and spin-coating two-step method itself, it is difficult to achieve uniform coverage of the perovskite layer or the electron transport layer on the textured structure. Therefore, in the present invention, dimethylbiguanide hydrochloride is added to the perovskite layer, and / or a passivation layer containing dimethylbiguanide hydrochloride is added, which can well improve the perovskite quality. For perovskite cells with full-coverage requirements, this improvement can make the perovskite more uniformly cover the textured bottom cell and improve the performance of the battery.

[0030] In some embodiments, when a passivation layer is provided between the perovskite layer and the electron transport layer, the thickness of the passivation layer is the thickness of a single molecular layer of dimethylbiguanide hydrochloride. Among them, the thickness of a single molecular layer means that the thickness of this film layer is only one molecule thick. When the thickness of the passivation layer is controlled at the thickness of a single molecular layer, the influence on the electron transport performance can be reduced, and the problem of reduced conductivity caused by the thickness of the passivation layer being greater than a single molecular layer can be avoided.

[0031] In some embodiments, the perovskite cell is a perovskite / silicon heterojunction tandem cell. The structure of this type of perovskite cell will be described in detail below.

[0032] In some embodiments, the substrate of the perovskite / silicon heterojunction tandem cell includes a bottom cell and an electron-hole recombination layer disposed on the bottom cell, and the hole transport layer is located on the electron-hole recombination layer.

[0033] In some embodiments, the perovskite / silicon heterojunction tandem cell further includes a transparent conductive layer disposed on a side of the electron transport layer away from the perovskite layer. The perovskite cell further includes a positive electrode and a negative electrode. The positive electrode is in ohmic contact with the transparent conductive layer, and the negative electrode is in ohmic contact with the bottom cell.

[0034] It can be understood that in order to obtain a higher photoelectric conversion efficiency, the perovskite solar cell is used as the top cell, and the silicon-based solar cell with a textured structure is used as the bottom cell. By combining the top cell and the bottom cell, a fully protected perovskite / silicon heterojunction tandem cell can be obtained. To solve the problems of low filling and / or mismatched energy levels between the perovskite layer and the electron transport layer in the fully protected perovskite / silicon tandem cell, the present invention adopts the method of incorporating dimethylbiguanide hydrochloride into the perovskite layer and / or adding a passivation layer containing dimethylbiguanide hydrochloride to passivate the perovskite layer. On the one hand, dimethylbiguanide hydrochloride can form a bond with the electron transport layer C 60 and anchor C 60 , so that C 60 covers more uniformly on the surface of the perovskite layer, C 60 the band bending and the energy level of the perovskite layer are more matched, and the charge transfer efficiency and stability of the perovskite cell are greatly improved; on the other hand, the amino group in the dimethylbiguanide hydrochloride solution will also form a covalent bond with the perovskite to passivate the I vacancies on the upper interface of the perovskite layer, change the surface potential of the upper surface of the perovskite layer, reduce non-radiative recombination, and thus reduce the open-circuit voltage loss and improve the photoelectric conversion efficiency.

[0035] In some embodiments, the bottom cell includes at least one of a HJT silicon cell and a TopCon silicon cell. The electron-hole recombination layer includes at least one of an indium tin oxide composite layer, an indium zinc oxide composite layer, and an aluminum zinc oxide composite layer. The thickness of the electron-hole recombination layer is 100 nm to 180 nm. The transparent conductive layer is an IZO (indium zinc oxide) layer. The positive electrode and / or the negative electrode includes silver, copper, or aluminum, and the thickness of the positive electrode and / or the negative electrode is 250 nm to 300 nm. The thickness of the perovskite layer is 450 nm to 550 nm.

[0036] It is understandable that in the above-mentioned perovskite / silicon heterojunction cell, using dimethylbiguanide hydrochloride in the perovskite layer and / or the additional passivation layer can well solve the compatibility problem between perovskite and C 60 , making their energy levels more matched, playing a good passivation role, and enabling C 60 to uniformly cover the corresponding film layer, and perfectly improving the crystallization quality of perovskite on the textured surface. Especially for the fully encapsulated perovskite / silicon heterojunction cell, by using dimethylbiguanide hydrochloride to improve the crystallization quality of perovskite on the textured surface, perovskite can more uniformly cover the textured surface structure, which is a technical effect that is difficult to achieve only through conventional operations such as spin coating or evaporation.

[0037] In some embodiments, in the above-mentioned perovskite / silicon heterojunction cell, one or more hole transport layers can be provided. A self-assembled monolayer can also be provided between the hole transport layer and the perovskite layer. Among them, the first hole transport layer is a nickel oxide layer, and the thickness of this layer is 100 nm to 150 nm. The self-assembled monolayer is a MeO-2PACz layer, and MeO-2PACz is [2-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid.

[0038] It is understandable that the MeO-2PACz used in the present invention is beneficial to improving the nucleation and growth of the perovskite material provided thereon, forming a dense and uniform interface and promoting its interaction with the perovskite layer to passivate interface defects. By providing the above two different hole transport layers, the hole transport effect can be better achieved.

[0039] In some embodiments, the perovskite cell is a perovskite single-junction cell. The structure of this type of perovskite cell will be described below.

[0040] In some embodiments, the substrate of the perovskite single-junction cell is a transparent conductive substrate, and the hole transport layer is located on the transparent conductive substrate. The perovskite single-junction cell further includes a positive electrode and a negative electrode. The positive electrode is in ohmic contact with the transparent conductive layer, and the negative electrode is in ohmic contact with the bottom cell. Among them, the transparent conductive substrate is, for example, an ITO substrate. The positive electrode and / or the negative electrode includes silver, copper or aluminum.

[0041] It is understandable that in the present invention, when using a perovskite single-junction cell, using dimethylbiguanide hydrochloride in the perovskite layer or the additional passivation layer can also achieve the purpose of improving the compatibility between perovskite and C 60 , making their energy levels more matched. The I - in dimethylbiguanide hydrochloride can combine with the I - vacancies on the surface of the perovskite layer, increasing the fill factor of the device and improving the device performance of the solar cell.

[0042] The second aspect of the present invention provides a method for preparing the perovskite battery described in the first aspect above. The preparation method includes the following steps: Provide the substrate; Form the hole transport layer on the substrate; Form the perovskite layer doped with dimethylbiguanide hydrochloride and the electron transport layer in sequence on the hole transport layer; and / or, form the perovskite layer, the passivation layer and the electron transport layer in sequence on the hole transport layer, wherein the passivation layer includes dimethylbiguanide hydrochloride.

[0043] That is to say, according to the setting position of the dimethylbiguanide hydrochloride material, the preparation method of the perovskite battery in the embodiments of the present application can be divided into three cases. The first is that the dimethylbiguanide hydrochloride material is provided in the added passivation layer. At this time, the preparation method is to form the perovskite layer, the passivation layer and the electron transport layer in sequence on the hole transport layer. The passivation layer includes dimethylbiguanide hydrochloride, so as to utilize dimethylbiguanide hydrochloride to improve the energy level adaptability between the perovskite material and the C 60 material, fill the defect positions of the perovskite, and anchor the C 60 function. The second is to incorporate the dimethylbiguanide hydrochloride material into the perovskite layer. In this case, the preparation method forms the perovskite layer and the electron transport layer in sequence on the hole transport layer, and incorporates dimethylbiguanide hydrochloride into the perovskite layer during the formation process, so that the perovskite layer includes the perovskite material and the dimethylbiguanide hydrochloride material, and can also play the above roles. The third case is: incorporating dimethylbiguanide hydrochloride into the perovskite layer and at the same time adding a passivation layer with dimethylbiguanide hydrochloride.

[0044] The third aspect of the present invention provides a photovoltaic module, which includes the perovskite battery described in the first aspect above, or the perovskite battery prepared by the preparation method described in the second aspect above.

[0045] The present invention will be further described below in conjunction with embodiments and the like.

[0046] Example 1 A perovskite battery, which is a perovskite / silicon heterojunction battery. As Figure 1 shown, the perovskite battery includes: a bottom cell 11, and an electron-hole recombination layer 12, a hole transport layer 21, a self-assembled monolayer 22, a perovskite layer 3, a passivation layer 4, a first electron transport layer 51, a second electron transport layer 52 and a transparent conductive layer 6 sequentially provided on the bottom cell 11. The perovskite battery further includes a positive electrode 7 and a negative electrode 8, with ohmic contact between the positive electrode 7 and the transparent conductive layer 6, and ohmic contact between the negative electrode 8 and the bottom cell 11.

[0047] Among them, the bottom cell 11 is an HJT cell, the electron-hole recombination layer 12 is an ITO layer, the hole transport layer 21 is a nickel oxide layer, the self-assembled monolayer 22 is MeO-2PACz, the passivation layer 4 is a dimethylbiguanide hydrochloride layer, and the first electron transport layer 51 is a C 60 layer, and the second electron transport layer 52 is a SnO 2 layer, the transparent conductive layer 6 is an IZO layer, and the positive electrode 7 and the negative electrode 8 are both silver.

[0048] The preparation method of the above perovskite solar cell includes the following steps: (1) Provide a substrate: Use a 300 μm HJT cell as the bottom cell 11, and the bottom cell 11 is subjected to a texturing treatment, with a textured structure on the surface. Anneal the bottom cell 11 on a hot stage, with an annealing temperature of 150°C and an annealing time of 15 min; form an electron-hole recombination layer 12 with a thickness of 150 nm to 180 nm on the annealed bottom cell 11; (2) Prepare the hole transport layer 21: Magnetron sputter a NiO x layer as the hole transport layer 21. During magnetron sputtering, use a NiO x rotating target with a content of 99.99%. The process pressure is 0.5 Pa to 0.6 Pa, the process atmosphere is Ar:O 2 =500:5 to 700:5, and the reciprocating movement times of the carrier plate in the magnetron sputtering equipment are 10 to 15 times, obtaining a hole transport layer 21 with a thickness of 100 nm; (3) Prepare the self-assembled monolayer 22: Weigh 5 mg of MeO-2PACz and dissolve it in absolute ethanol to obtain a 1 mg / mL solution. Spin-coat this solution onto the hole transport layer 21 under the process conditions of a rotation speed of 4000 rpm, an acceleration of 2000 rpm, and a spin-coating time of 30 s, and anneal it under the conditions of an annealing temperature of 100°C and an annealing time of 10 min to form the self-assembled monolayer 22; (4) Prepare the lead skeleton layer: Place the substrate with the self-assembled monolayer 22 formed thereon into a multi-source co-evaporation equipment for co-evaporation to form a 320 nm lead skeleton layer on the self-assembled monolayer 22; (5) Prepare the perovskite layer 3: Weigh 0.35 g of FAI, 0.08 g of MABr, and 0.05 g of MACl respectively, dissolve them in 1 mL of absolute ethanol, stir for 1 h to obtain a perovskite cation solution; aspirate 150 μL of the perovskite cation solution and spin-coat it onto the lead skeleton layer under the conditions of a rotation speed of 4000 rpm and a spin-coating time of 30 s, and then anneal it at 150°C for 30 min with a relative humidity of 5% to form a perovskite layer 3 with a thickness of 450 nm to 500 nm; (6) Preparation of the passivation layer 4: At room temperature, 1 mg of solid powder of dimethylbiguanide hydrochloride is dissolved in 10 mL of ethanol solution, and is fully dispersed in a mixer for 24 h to obtain a solution containing dimethylbiguanide hydrochloride with a concentration of 0.1 mg / mL; 60 μL of the solution containing dimethylbiguanide hydrochloride is spin-coated onto the perovskite layer 3 under the conditions of a rotation speed of 4000 rpm, an acceleration of 4000 rpm / s, a spin-coating time of 30 s, and an air relative humidity of 5%, and then annealed at 100 °C for 20 min to form a single-molecule-layer passivation layer 4; (7) Preparation of the first electron transport layer 51: The first electron transport layer 51 is deposited on the passivation layer 4 through a metal electrode evaporation device, and the evaporation conditions are to weigh 0.2 g to 0.3 g of C 60 in a metal evaporation boat, and evaporate and coat at a rate of <0.5 Å / s to obtain C 60 The thickness of the first electron transport layer 51 is 20 nm to 30 nm; (8) Preparation of the second electron transport layer 52: The SnO 2 layer is deposited on the first electron transport layer 51 by ALD method as the second electron transport layer 52, and the thickness of the second electron transport layer 52 is 20 nm to 30 nm; wherein, the first electron transport layer 51 and the second electron transport layer 52 together form the electron transport layer 5; (9) Preparation of the transparent conductive layer 6: The IZO transparent conductive layer 6 is deposited on the second electron transport layer 52 by PVD method; (10) Preparation of the electrodes: The positive electrode 7 is deposited on the transparent conductive layer 6 through a metal electrode evaporation device to make an ohmic contact between the positive electrode 7 and the transparent conductive layer 6, and the negative electrode 8 is deposited on the bottom cell 11 to make an ohmic contact between the negative electrode 8 and the bottom cell 11. The thicknesses of the positive electrode 7 and the negative electrode 8 are 250 nm to 300 nm.

[0049] Example 2 A perovskite solar cell, which is a perovskite / silicon heterojunction tandem solar cell. As Figure 2 shown, the perovskite solar cell includes: a bottom cell 11, and an electron-hole recombination layer 12, a hole transport layer 21, a self-assembled monolayer 22, a perovskite layer 3, a first electron transport layer 51, a second electron transport layer 52, and a transparent conductive layer 6 sequentially disposed on the bottom cell 11. The perovskite solar cell further includes a positive electrode 7 and a negative electrode 8, and there is an ohmic contact between the positive electrode 7 and the transparent conductive layer 6, and an ohmic contact between the negative electrode 8 and the bottom cell 11.

[0050] Among them, the bottom cell 11 is an HJT cell, the electron-hole recombination layer 12 is an ITO layer, and the hole transport layer 21 is NiO xlayer, the self-assembled monolayer 22 is MeO-4PACz, the perovskite layer 3 includes a perovskite material and dimethylbiguanide hydrochloride, and the first electron transport layer 51 is C 60 layer, and the second electron transport layer 52 is SnO 2 layer, the transparent conductive layer 6 is an IZO layer, and the positive electrode 7 and the negative electrode 8 are both silver.

[0051] The preparation method of the above perovskite battery includes the following steps: (1) Provide a substrate: Use a 140 μm HJT battery as the bottom cell 11, and the bottom cell 11 is subjected to a textured treatment and has a textured structure on its surface. Anneal the bottom cell 11 on a hot stage at an annealing temperature of 150 °C and an annealing time of 15 min; form an electron-hole recombination layer 12 with a thickness of 130 nm to 150 nm on the annealed bottom cell 11; (2) Prepare the hole transport layer 21: Magnetron sputter to form the hole transport layer 21 NiO x layer on the electron-hole recombination layer 12. During magnetron sputtering, use a NiO x rotating target with a content of 99.99%. The process pressure is 0.5 Pa to 0.6 Pa, and the process atmosphere is Ar:O 2 = 500:5 to 700:5. The number of reciprocating movements of the carrier plate in the magnetron sputtering equipment is 10 to 15 times, and the average thickness of the hole transport layer 21 obtained is 100 nm; (3) Prepare the self-assembled monolayer 22: Weigh 5 mg of MeO-2PACz and dissolve it in absolute ethanol to obtain a 1 mg / mL solution. Spin-coat this solution onto the hole transport layer 21 under the process conditions of a rotation speed of 4000 rpm, an acceleration of 2000 rpm, and a spin-coating time of 30 s, and anneal it at an annealing temperature of 100 °C and an annealing time of 10 min to form a self-assembled monolayer 22 of a monolayer; (4) Prepare the lead skeleton layer: Place the substrate with the self-assembled monolayer 22 formed thereon into a multi-source co-evaporation equipment for co-evaporation to form a 320 nm lead skeleton layer on the self-assembled monolayer 22; (5) Preparation of perovskite layer 3: Weigh 0.5 mg of solid powder of dimethylbiguanide hydrochloride, 0.35 g of FAI, 0.08 g of MABr, and 0.05 g of MACl respectively, dissolve them in 1 mL of absolute ethanol, and disperse them thoroughly in a mixer for 24 h to obtain a perovskite cation solution doped with dimethylbiguanide hydrochloride (the concentration of dimethylbiguanide hydrochloride in this solution is denoted as 0.5 mg / mL); aspirate 150 μL of the perovskite cation solution and spin-coat it onto the lead skeleton layer at a rotation speed of 4000 rpm and a spin-coating time of 30 s, then anneal it at 150 °C for 30 min, and the relative humidity during annealing is 5%, to form a perovskite layer 3 with a thickness of 460 nm - 500 nm. The dimethylbiguanide hydrochloride is incorporated into this layer while forming the perovskite material; (6) Preparation of the first electron transport layer 51: Evaporate and deposit the first electron transport layer 51 on the perovskite layer 3 through a metal electrode evaporation device. The evaporation conditions are to weigh 0.2 g - 0.3 g of C 60 in a metal evaporation boat and evaporate and coat it at a rate of <0.5 Å / s to obtain C 60 The thickness of the first electron transport layer 51 is 20 nm - 30 nm; (7) Preparation of the second electron transport layer 52: Deposit an SnO 2 layer as the second electron transport layer 52 on the first electron transport layer 51 by ALD method. The thickness of this second electron transport layer 52 is 20 nm - 30 nm; wherein, the first electron transport layer 51 and the second electron transport layer 52 together form the electron transport layer 5; (8) Preparation of the transparent conductive layer 6: Deposit an IZO layer as the transparent conductive layer 6 on the second electron transport layer 52 by PVD method, with a thickness of 90 nm; (9) Preparation of the electrodes: Deposit a positive electrode 7 on the transparent conductive layer 6 through a metal electrode evaporation device to make an ohmic contact between the positive electrode 7 and the transparent conductive layer 6, and deposit a negative electrode 8 on the bottom cell 11 to make an ohmic contact between the negative electrode 8 and the bottom cell 11. The thicknesses of the positive electrode 7 and the negative electrode 8 are 250 nm - 300 nm.

[0052] Example 3 A perovskite solar cell, which is a perovskite / silicon heterojunction tandem solar cell. As Figure 3As shown in the figure, the perovskite solar cell includes: a bottom cell 11, and an electron-hole recombination layer 12, a hole transport layer 21, a self-assembled monolayer 22, a perovskite layer 3, a passivation layer 4, a first electron transport layer 51, a second electron transport layer 52, and a transparent conductive layer 6 that are sequentially disposed on the bottom cell 11. The perovskite solar cell further includes a positive electrode 7 and a negative electrode 8. There is an ohmic contact between the positive electrode 7 and the transparent conductive layer 6, and an ohmic contact between the negative electrode 8 and the bottom cell 11.

[0053] Among them, the bottom cell 11 is an HJT cell, the electron-hole recombination layer 12 is an ITO layer, and the hole transport layer 21 is a NiO x layer. The self-assembled monolayer 22 is MeO-2PACz. The perovskite layer 3 includes a perovskite material and dimethylbiguanide hydrochloride. The passivation layer 4 is a dimethylbiguanide hydrochloride layer. The first electron transport layer 51 is a C 60 layer. The second electron transport layer 52 is a SnO 2 layer. The transparent conductive layer 6 is an IZO layer. Both the positive electrode 7 and the negative electrode 8 are silver.

[0054] The preparation method of the above perovskite solar cell includes the following steps: (1) Provide a substrate: Use a 100-μm HJT cell as the bottom cell 11. The bottom cell 11 is subjected to a texturing treatment and has a textured surface. Anneal the bottom cell 11 on a hot stage at an annealing temperature of 150 °C and an annealing time of 15 min. Form an electron-hole recombination layer 12 with a thickness of 100 nm to 130 nm on the annealed bottom cell 11. (2) Prepare the hole transport layer 21: Magnetron sputter a NiO hole transport layer 21 on the electron-hole recombination layer 12 x layer. During the magnetron sputtering process, use a NiO x rotating target with a content of 99.99%. The process pressure is 0.5 Pa to 0.6 Pa, and the process atmosphere is Ar:O 2 =500:5 to 700:5. The number of reciprocating movements of the carrier plate in the magnetron sputtering equipment is 10 to 15 times, and the thickness of the obtained hole transport layer 21 is 100 nm to 120 nm. (3) Prepare the self-assembled monolayer 22: Weigh 5 mg of MeO-2PACz and dissolve it in absolute ethanol to obtain a 1 mg / mL solution. Spin-coat the solution onto the hole transport layer 21 under the process conditions of a rotation speed of 4000 rpm, an acceleration of 2000 rpm, and a spin-coating time of 30 s, and anneal it at an annealing temperature of 100 °C and an annealing time of 10 min to form a self-assembled monolayer 22 with a monolayer thickness; among them, the hole transport layer 21 and the self-assembled monolayer 22 together form the hole transport layer 2. (4)Preparation of the lead skeleton layer: Place the substrate with the self-assembled monolayer 22 formed thereon into a multi-component co-evaporation device for co-evaporation to form a lead skeleton layer with a thickness of 320 nm on the self-assembled monolayer 22; (5)Preparation of the perovskite layer 3: Weigh 0.5 mg of solid powder of dimethylguanidine hydrochloride, 0.35 g of FAI, 0.08 g of MABr, and 0.05 g of MACl respectively, dissolve them in 1 mL of anhydrous ethanol, and disperse them thoroughly in a mixer for 24 h to obtain a perovskite cation solution doped with dimethylguanidine hydrochloride (the concentration of dimethylguanidine hydrochloride in this solution is denoted as 0.5 mg / mL); Aspirate 150 μL of the perovskite cation solution and spin-coat it onto the lead skeleton layer under the conditions of a rotation speed of 4000 rpm and a spin-coating time of 30 s, and then anneal it at 150 °C for 30 min with a relative humidity of 5% to form a perovskite layer 3 with a thickness of 480 nm - 520 nm. The dimethylguanidine hydrochloride is incorporated into this layer while the perovskite material is formed; (6)Preparation of the passivation layer 4: At room temperature, dissolve 1 mg of solid powder of dimethylguanidine hydrochloride in 10 mL of isopropanol solution, disperse it thoroughly in a mixer for 24 h to obtain a solution containing dimethylguanidine hydrochloride with a concentration of 0.1 mg / mL; Aspirate 60 μL of the solution containing dimethylguanidine hydrochloride and spin-coat it onto the perovskite layer 3 under the conditions of a rotation speed of 4000 rpm, an acceleration of 4000 rpm / s, a spin-coating time of 30 s, and an air relative humidity of 5%, and then anneal it at 100 °C for 20 min to form a monolayer passivation layer 4; (7)Preparation of the first electron transport layer 51: Evaporate and deposit the first electron transport layer 51 on the passivation layer 4 through a metal electrode evaporation device. The evaporation conditions are to weigh 0.2 g - 0.3 g of C 60 in a metal evaporation boat and evaporate and coat it at a rate of <0.5 Å / s to obtain the C 60 The thickness of the first electron transport layer 51 is 20 nm - 30 nm; Formation of the second electron transport layer 52: Deposit an SnO 2 layer as the second electron transport layer 52 on the first electron transport layer 51 by ALD method. The thickness of this second electron transport layer 52 is 20 nm - 30 nm; Among them, the first electron transport layer 51 and the second electron transport layer 52 together constitute the electron transport layer 5; (8)Preparation of the transparent conductive layer 6: Deposit IZO as the transparent conductive layer 6 on the second electron transport layer 52 by PVD method with a thickness of 110 nm; (9) Fabricating the electrodes: Deposit the positive electrode 7 on the transparent conductive layer 6 through a metal electrode evaporation device to achieve ohmic contact between the positive electrode 7 and the transparent conductive layer 6, deposit the negative electrode 8 on the bottom cell 11 to achieve ohmic contact between the negative electrode 8 and the bottom cell 11. The thicknesses of the positive electrode 7 and the negative electrode 8 are 250 nm to 300 nm.

[0055] Example 4 A perovskite solar cell, which is a perovskite single-junction solar cell. The perovskite solar cell includes: a transparent conductive substrate, and a hole transport layer, a perovskite layer, a passivation layer, an electron transport layer, and a buffer layer sequentially disposed on the transparent conductive substrate. The perovskite solar cell further includes a positive electrode and a negative electrode, with ohmic contact between the positive electrode and the buffer layer, and ohmic contact between the negative electrode and the transparent conductive substrate.

[0056] Among them, the transparent conductive substrate is an ITO layer, and the hole transport layer is a NiO x layer, the passivation layer is a dimethyl biguanide hydrochloride layer with a single-molecule layer thickness, and the electron transport layer is a C 60 layer. Both the positive electrode and the negative electrode are silver.

[0057] The preparation method of the above perovskite solar cell includes the following steps: (1) Provide an ITO layer as the transparent conductive substrate; (2) Magnetron sputter to form a hole transport layer of NiO x layer on the transparent conductive substrate. During the magnetron sputtering process, use a NiO target with a content of 99.99% x rotating target, the process pressure is 0.5 Pa to 0.6 Pa, the process atmosphere is Ar:O 2 =500:5 to 700:5, and the number of reciprocating movements of the carrier plate in the magnetron sputtering device is 10 to 15 times to obtain a hole transport layer with a thickness of 23 nm; (3) Place the substrate with the formed hole transport layer into a multi-source co-evaporation device for co-evaporation to form a 320-nm lead skeleton layer on the hole transport layer; (4) Weigh 0.35 g of FAI, 0.08 g of MABr, and 0.05 g of MACl respectively, dissolve them in 1 mL of absolute ethanol, stir for 1 h to obtain a perovskite cation solution; suck 150 μL of the perovskite cation solution and spin-coat it on the lead skeleton layer at a rotation speed of 4000 rpm and a spin-coating time of 30 s, and then anneal at 150 °C for 30 min with a relative humidity of 5% during annealing to form a perovskite layer with a thickness of 380 nm; (5) At room temperature, 2 mg of solid powder of metformin hydrochloride was dissolved in 2 mL of ethanol solution, and was fully dispersed in a shaker for 24 h to obtain a solution containing metformin hydrochloride with a concentration of 1 mg / mL; 60 μL of the solution containing metformin hydrochloride was spin-coated onto the perovskite layer under the conditions of a rotation speed of 4000 rpm, an acceleration of 4000 rpm / s, a spin-coating time of 30 s, and an air relative humidity of 5%, and then annealed at 100 °C for 20 min to form a single-molecule passivation layer; (6) An electron transport layer was evaporated onto the passivation layer by a metal electrode evaporation device, and the evaporation conditions were to weigh 0.2 g to 0.3 g of C 60 in a metal evaporation boat and evaporate the coating at a rate of <0.5 Å / s to obtain C 60 The thickness of the electron transport layer was 18 nm; (7) A buffer layer was deposited on the electron transport layer by PVD method, and the thickness was 20 nm to 30 nm; (8) A positive electrode was deposited on the buffer layer by a metal electrode evaporation device to make an ohmic contact between the positive electrode and the buffer layer, and a negative electrode was deposited on the transparent substrate to make an ohmic contact between the negative electrode and the transparent conductive substrate. The thicknesses of the positive electrode and the negative electrode were 250 nm to 300 nm.

[0058] Example 5 This example is basically the same as Example 2, except that when forming the perovskite layer, the concentration of the cation solution containing metformin hydrochloride was spin-coated. In this example, the solid powder of 0.1 mg of metformin hydrochloride was contained in the perovskite cation solution doped with metformin hydrochloride, that is, the concentration of metformin hydrochloride in the perovskite cation solution was 0.1 mg / mL.

[0059] Example 6 This example is basically the same as Example 2, except that when forming the perovskite layer, the concentration of the cation solution containing metformin hydrochloride was spin-coated. In this example, the solid powder of 1 mg of metformin hydrochloride was contained in the perovskite cation solution doped with metformin hydrochloride, that is, the concentration of metformin hydrochloride in the perovskite cation solution was 1 mg / mL.

[0060] Example 7 This example is basically the same as Example 1, except for steps (5)-(6), that is, after spin-coating the perovskite cation solution, annealing was not performed, and the preparation of the passivation layer was directly carried out. In this example, steps (5) and (6) are specifically as follows: (5) Preparation of perovskite layer 3: Weigh 0.35 g of FAI, 0.08 g of MABr, and 0.05 g of MACl respectively, dissolve them in 1 mL of anhydrous ethanol, and stir for 1 h to obtain a perovskite cation solution; draw 150 μL of the perovskite cation solution and spin coat it on the lead skeleton layer at a speed of 4000 rpm and a spin coating time of 30 s to form a perovskite layer 3 with a thickness of 450 nm~500 nm; (6) Preparation of passivation layer 4: At room temperature, 1 mg of solid powder of dimethyl biguanide hydrochloride was dissolved in 10 mL of ethanol solution and fully dispersed in a mixer for 24 h to obtain a solution containing dimethyl biguanide hydrochloride with a concentration of 0.1 mg / mL; 60 µL of the solution containing dimethyl biguanide hydrochloride was spin-coated onto the perovskite layer 3 at a rotation speed of 4000 rpm, an acceleration of 4000 rpm / s, a spin coating time of 30 s, and an air relative humidity of 5%, and then annealed at 100 °C for 20 min to form a monolayer passivation layer 4.

[0061] Comparative Example 1 Compared with Example 1, the only difference of this comparative example is that the first electron transport layer is formed directly on the perovskite layer after the perovskite layer is formed, that is, no passivation layer is provided in the perovskite cell of this comparative example, and dimethyl biguanide hydrochloride is not doped into the perovskite layer.

[0062] Test Example: The perovskite cells of the embodiment and the comparative example were tested as follows: The halm test sorting equipment is used to perform performance tests on open circuit voltage, short circuit current density, fill factor and energy conversion efficiency. The halm machine is a device that simulates sunlight, and is equipped with electronic loads, data acquisition and computing equipment to test the electrical properties of photovoltaic devices (including perovskite cells, such as Eta, Voc, A, FF, Irev2, Jsc, PCE, etc. These parameters are used to reflect the performance of solar cells. The silicon wafer of the solar cell under control test is 1.07cm 2 , the calibration light intensity is 1000±50W / m², and the experimental test results are as follows, where Voc represents the open circuit voltage, Jsc represents the short circuit current density, FF represents the fill factor, and PCE represents the power conversion efficiency. The experimental test results are shown in Table 1.

[0063] Table 1. Electrical performance test data of perovskite cells of Examples and Comparative Examples

[0064] As can be seen from Table 1, by comparing Example 1 and Comparative Example 1, in the perovskite solar cell, after passivation with the dimethylbiguanide hydrochloride solution, the open-circuit voltage Voc, fill factor FF, and power conversion efficiency PCE are all significantly better than those of Comparative Example 1 without passivation, indicating that the upper interface energy level adaptability of the perovskite layer is improved by dimethylbiguanide hydrochloride, and C 60 is anchored to make it more evenly dispersed in the textured structure. After improving the perovskite crystallization quality, the improvement effect on the performance of the perovskite solar cell is obvious. Among them, combined with Figure 4 it can be known that because the Cl in dimethylbiguanide hydrochloride - can increase the grain size, it can effectively improve the filling performance and increase the fill factor.

[0065] By comparing Example 1 with Examples 2-3, it can be seen that in Example 1, there is a passivation layer made of dimethylbiguanide hydrochloride material. In Example 2, the dimethylbiguanide hydrochloride material is incorporated into the perovskite layer. In Example 3, there is both a passivation layer made of dimethylbiguanide hydrochloride material and a perovskite layer containing the incorporated dimethylbiguanide hydrochloride material. The experimental results show that the open-circuit voltage, short-circuit current density, and power conversion efficiency of Example 2 are all better than those of Example 1 and Example 3, indicating that the effect of dimethylbiguanide hydrochloride on the bulk phase of the perovskite layer is stronger than that on the interfacial defects, that is, the effect of dimethylbiguanide hydrochloride on the interior of the perovskite is stronger, and the effect of incorporating and adding a passivation layer to the perovskite layer is slightly worse than that of simply incorporating it into the perovskite layer. This is because there are more defects with poor internal crystallization quality, which can further promote the increase of Voc. In addition, MET can form 2D perovskite and the electron transport layer C 60 anchor each other to enhance the interfacial bonding ability and promote the increase of the fill factor FF.

[0066] By comparing Example 2 with Examples 5-6, it can be seen that 0.5 mg / mL is the optimal concentration of dimethylbiguanide hydrochloride as a perovskite doping material. Under this concentration condition, the open-circuit voltage, short-circuit current density, and power conversion efficiency of the solar cell are all at a higher level. Especially the power conversion efficiency has reached a relatively high level of 27.92%. When the concentration is reduced to 0.1 mg / mL or increased to 1 mg / mL, the open-circuit voltage, short-circuit current density, fill factor, and power conversion efficiency will all be affected to varying degrees. When the concentration is less than 1 mg / mL, the concentration is too low and the passivation effect is not obvious. When the concentration is greater than 2 mg / mL, it will lead to a decrease in the device conductivity.

[0067] In addition, it should be noted that Example 4 of the present application is a perovskite single-junction cell, not a perovskite-crystalline silicon stacked cell, so its energy conversion efficiency is not comparable with other embodiments and Comparative Example 1. However, the perovskite single-junction cell of Example 4 has a certain performance improvement compared to the current conventional perovskite single-junction cell. Example 7 did not undergo annealing treatment, and its overall performance was relatively lower than that of Example 1.

[0068] The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A perovskite battery, characterized in that: The perovskite cell comprises a substrate, a hole transport layer, a perovskite layer and an electron transport layer sequentially arranged on the substrate, wherein the electron transport layer comprises C 60 layer; The perovskite layer includes a perovskite material and dimethyl biguanidine hydrochloride salt; and / or, The perovskite cell further includes a passivation layer, which is disposed between the perovskite layer and the electron transport layer, and the passivation layer includes dimethyl biguanide hydrochloride.

2. The perovskite battery according to claim 1, characterized in that: The substrate is a transparent conductive substrate, and the hole transport layer is disposed on the transparent conductive substrate; The perovskite battery further comprises a positive electrode and a negative electrode, wherein the positive electrode is in ohmic contact with the electron transport layer, and the negative electrode is in ohmic contact with the transparent conductive substrate; The thickness of the electron transport layer is 20 nm to 30 nm; The passivation layer has a thickness of a monomolecular layer; The thickness of the perovskite layer is 450 nm to 550 nm; The hole transport layer is a nickel oxide layer with a thickness of 100 nm to 150 nm; The positive electrode and / or the negative electrode are made of silver, copper or aluminum, and the thickness of the positive electrode and / or the negative electrode is 250 nm to 300 nm.

3. The perovskite battery according to claim 1, characterized in that: The substrate comprises a bottom battery and an electron-hole combination layer, wherein the electron-hole combination layer is arranged between the bottom battery and the hole transport layer; The perovskite cell further comprises a transparent conductive layer; the transparent conductive layer is arranged on a side of the electron transport layer away from the perovskite layer; The perovskite battery also includes a positive electrode and a negative electrode; The positive electrode is in ohmic contact with the transparent conductive layer, and the negative electrode is in ohmic contact with the bottom cell.

4. The perovskite battery according to claim 3, characterized in that: A self-assembled monolayer is further provided between the hole transport layer and the perovskite layer; and / or, The electron transport layer comprises a first electron transport layer disposed close to the perovskite layer and a second electron transport layer disposed far away from the perovskite layer, wherein the first electron transport layer is a C60 layer; The transparent conductive layer is disposed on a side of the second electron transport layer away from the first electron transport layer; The bottom cell includes at least one of a HJT silicon cell and a TopCon silicon cell; and / or, The electron-hole composite layer includes at least one of an indium tin oxide composite layer, an indium zinc oxide composite layer, and an aluminum zinc oxide composite layer; and / or, The thickness of the electron-hole composite layer is 100 nm to 180 nm; and / or, The hole transport layer is a nickel oxide layer; and / or, The thickness of the hole transport layer is 100 nm to 150 nm; and / or, The self-assembled monolayer is a MeO-2PACz layer; and / or, The thickness of the perovskite layer is 450 nm to 550 nm; and / or, The passivation layer has a thickness of a monomolecular layer; and / or, The thickness of the first electron transport layer is 20 nm to 30 nm; and / or, The second electron transport layer is a SnO2 layer; and / or, The thickness of the second electron transport layer is 20 nm to 30 nm; and / or, The transparent conductive layer is an IZO layer; and / or, The thickness of the transparent conductive layer is 80 nm to 120 nm; and / or, The positive electrode and / or the negative electrode are made of silver, copper or aluminum, and the thickness of the positive electrode and / or the negative electrode is 250 nm to 300 nm.

5. A method for preparing a perovskite battery according to any one of claims 1 to 4, characterized in that: The preparation method comprises: forming the hole transport layer on the substrate; The perovskite layer and the electron transport layer are sequentially formed on the hole transport layer, wherein the perovskite layer comprises dimethyl biguanidine hydrochloride; and / or, The perovskite layer, the passivation layer and the electron transport layer are sequentially formed on the hole transport layer, and the passivation layer includes dimethyl biguanidine hydrochloride.

6. The preparation method according to claim 5, characterized in that: The preparation method comprises: forming the hole transport layer on the substrate; forming the perovskite layer on the hole transport layer; Spin coating a solution containing dimethyl biguanidine hydrochloride on the perovskite layer, and annealing to obtain the passivation layer; forming the electron transport layer on the passivation layer; Preferably, the preparation of the perovskite layer comprises: (1) preparing a perovskite cation solution for later use; (2) preparing a lead skeleton layer on the hole transport layer by co-evaporation; (3) then spin coating the perovskite cation solution on the lead skeleton layer and annealing to obtain a perovskite layer; In step (1), the perovskite cation solution is obtained by dissolving FAI, MABr and MACl in a solvent; the mass ratio of FAI, MABr and MACl is 35:8:5; In step (2), the thickness of the lead skeleton layer is 300 nm to 340 nm; In step (3), the spin coating speed is 3000 rpm to 4000 rpm; the time is 25 s to 35 s; and / or, The annealing temperature is 100°C to 150°C; the annealing time is 25 min to 35 min; and / or, The relative humidity of the annealing is 4% to 10%; In the preparation of the passivation layer, the concentration of the solution containing dimethyl biguanide hydrochloride is 0.1 mg / mL to 1.0 mg / mL, and the solution containing dimethyl biguanide hydrochloride is obtained by dissolving dimethyl biguanide hydrochloride in an ethanol solution; and / or, The rotation speed of the spin coating is 3000 rpm to 4000 rpm, the acceleration is 3000 rpm / s to 4000 rpm / s, and the spin coating time is 20 s to 40 s; the air humidity of the spin coating is 4% to 6%; and / or, The annealing temperature is 130°C to 150°C, and the annealing time is 15 min to 25 min; The preparation method further comprises performing a suede treatment on the substrate; Preferably, the hole transport layer, the perovskite layer, and the electron transport layer are sequentially formed on the substrate and are consistent with the shape of the suede.

7. The preparation method according to claim 5, characterized in that: The preparation method comprises: forming the hole transport layer on the substrate; Dissolve FAI, MABr, MACl, and dimethyl biguanide hydrochloride in a solvent to obtain a perovskite cation solution for later use; a lead skeleton layer prepared by co-evaporation on the hole transport layer; Spin coating the perovskite cation solution on the lead skeleton layer, and annealing to obtain the perovskite layer; forming the electron transport layer on the perovskite layer; The mass ratio of FAI, MABr, MACl and dimethyl biguanide hydrochloride is 35:8:5:0.01-1.0; The mass volume ratio of the dimethyl biguanide hydrochloride salt to the solvent is 0.01-1.0:1 in mg / mL.

8. The preparation method according to claim 7, characterized in that: The preparation method further comprises forming a passivation layer on the perovskite layer before forming the electron transport layer on the perovskite layer, that is, spin coating a solution containing dimethyl biguanide hydrochloride on the perovskite layer by a spin coating method, and obtaining a monomolecular layer of dimethyl biguanide hydrochloride as the passivation layer after annealing; Then forming the electron transport layer on the passivation layer; It also includes performing suede treatment on the substrate; Preferably, the hole transport layer, the perovskite layer, and the electron transport layer are sequentially formed on the substrate and are consistent with the shape of the suede.

9. The preparation method according to any one of claims 5 to 8, characterized in that: The preparation method comprises: Providing a bottom battery with a velvet surface, and forming an electron-hole recombination layer on the bottom battery after annealing; forming a hole transport layer on the electron-hole composite layer by magnetron sputtering; Spin coating a self-assembled monolayer on the hole transport layer and annealing; Co-evaporating a lead skeleton layer on the self-assembled monolayer, spin-coating the perovskite cation solution on the lead skeleton layer, and annealing to form the perovskite layer; and / or, Spin coating a solution containing dimethyl biguanide hydrochloride on the perovskite layer, and annealing to form the passivation layer; Vapor depositing a first electron transport layer on the passivation layer; Depositing a second electron transport layer on the first electron transport layer by an ALD method; Depositing a transparent conductive layer on the second electron transport layer by a PVD method; Depositing a positive electrode on the transparent conductive layer to make ohmic contact between the positive electrode and the transparent conductive layer, and depositing a negative electrode on the bottom battery to make ohmic contact between the negative electrode and the bottom battery; Preferably, in the step of providing a bottom battery with a velvet surface, the annealing temperature is 140° C. to 160° C., and the annealing time is 10 min to 20 min; and / or, In the preparation step of the hole transport layer, NiO with a content of 99.99% is used. x Rotating target, process pressure is 0.5 Pa~0.6 Pa, process atmosphere is Ar:O2=500:5~700:5, the number of reciprocating motions of the carrier in the magnetron sputtering equipment is 10~15 times; and / or, When the first electron transport layer is evaporated, the evaporation rate is less than 0.5 Å / s.

10. A photovoltaic module, characterized in that: The photovoltaic module comprises the perovskite cell according to any one of claims 1 to 5, or the perovskite cell prepared by the preparation method according to any one of claims 6 to 9.

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