Perovskite / silicon laminated solar cell and preparation method thereof

Abstract

The invention provides a perovskite / silicon laminated solar cell and a preparation method thereof. The perovskite / silicon laminated solar cell comprises a silicon bottom cell, a hole transport layer, a perovskite light absorption layer, a two-dimensional perovskite interface modification layer, an electron transport layer, an electrode, a buffer layer and a silicon oxide protection layer which are laminated in sequence. By means of the unique structure of the perovskite / silicon laminated solar cell, the problem of stability degradation caused by atomic oxygen erosion and ultraviolet radiation in the space service process can be effectively reduced, and the service life of the perovskite / silicon laminated solar cell is prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solar cells, and relates to a perovskite / silicon laminated solar cell and a preparation method thereof. BACKGROUND

[0002] Solar cells operating in space environments such as low earth orbit (LEO) are subject to various severe external challenges, including atomic oxygen (AtO x ) generated by high-energy ultraviolet radiation. AtO x has extremely high chemical activity, which can cause serious structural and functional degradation of materials when directly in contact with the surface of a perovskite / silicon laminated solar cell, including surface corrosion, roughening of the morphology, and oxidation of metal electrodes, resulting in a significant decrease in the performance of the perovskite / silicon laminated solar cell during on-orbit service and a substantial reduction in the service life.

[0003] In practical applications, the perovskite / silicon laminated cell is usually externally provided with a packaging glass and an adhesive such as a film. However, the glass may break due to impact or substrate instability during use, and cannot effectively protect the solar cell. On the other hand, the adhesive has weak resistance to atomic oxygen, and is prone to problems such as peeling, perforation, cracking, and embrittlement. Therefore, it is necessary to add an additional protective structure to the surface of the perovskite / silicon laminated solar cell to improve its resistance to atomic oxygen.

[0004] Traditional solutions enhance the resistance to atomic oxygen by depositing a dense metal oxide thin layer on the surface of the solar cell, or covering a polyimide (PI) film resistant to atomic oxygen. However, the metal oxide thin layer will produce pinhole defects under long-term high-energy AtOx bombardment, leading to increased local erosion; while the PI film can provide some protection, its relatively large weight increases the payload of the satellite, which cannot meet the requirement of lightweight for space missions. SUMMARY

[0005] The purpose of the present application is to provide a perovskite / silicon laminated solar cell and a preparation method thereof. The perovskite / silicon laminated solar cell of the present application can effectively reduce the stability degradation problem caused by atomic oxygen erosion and ultraviolet radiation during the space service of the solar cell while ensuring the efficiency of the solar cell, can effectively block the penetration of atomic oxygen, and can significantly improve the service life of the laminated cell.

[0006] To achieve the purpose of the present application, the following technical solutions are adopted:

[0007] In a first aspect, the present application provides a perovskite / silicon tandem solar cell, comprising a silicon bottom cell, a hole transport layer, a perovskite light-absorbing layer, a two-dimensional perovskite interface modification layer, an electron transport layer, an electrode, a buffer layer and a silicon oxide protective layer arranged in sequence.

[0008] The two-dimensional perovskite interface modification layer has hydrophobicity and interface modification effect.

[0009] In the perovskite / silicon tandem solar cell, the two-dimensional perovskite interface modification layer can effectively passivate the interface defects of the perovskite light-absorbing layer, reduce the non-radiative recombination loss, and inhibit the ion migration behavior, thereby reducing the risk of forming a penetration channel at the interface by high-reactivity oxygen atoms. The buffer layer has a non-porous dense structure, and the water vapor and atomic oxygen permeability is extremely low. In addition, the buffer layer can also relieve the stress concentration of the silicon oxide protective layer, prevent cracks in the silicon oxide from occurring in the thermal cycle, and avoid the formation of water and oxygen channels through the cracks. The silicon oxide protective layer has high density, which can not only effectively block the atomic oxygen erosion induced by high-energy ultraviolet radiation, but also has certain heat dissipation performance, thereby improving the environmental adaptability of the device.

[0010] In the perovskite / silicon tandem solar cell, the silicon oxide protective layer as the main barrier layer can effectively prevent the macroscopic diffusion of external high-reactivity oxygen atoms. The buffer layer has a high-density non-porous structure, and the water vapor and atomic oxygen permeability is extremely low. At the same time, the buffer layer can relieve the stress concentration of the silicon oxide, prevent cracks in the silicon oxide from occurring in the thermal cycle, and avoid the formation of water and oxygen channels through the cracks. The hydrophobic organic component contained in the two-dimensional perovskite interface modification layer can form a low-polarity protective layer on a microscale, further slowing down the penetration of a small amount of high-reactivity oxygen atoms through the silicon oxide film. The three work together to build a "double protection" mechanism on two levels of physical barrier and chemical passivation, significantly reducing the erosion of water vapor and oxygen atoms on the perovskite light-absorbing layer, thereby effectively prolonging the service life of the device and improving its long-term operation stability.

[0011] Preferably, the silicon bottom cell comprises any one of a heterojunction solar cell (HJT), a tunnel oxide passivated contact solar cell (TOPCon), a back contact solar cell (BC) or an emitter and backside passivated solar cell (PERC), preferably an HJT cell.

[0012] Preferably, the material of the hole transport layer comprises any one or a combination of at least two of nickel oxide (NiO x ), self-assembled monolayer (SAMs) or polytriazole (PTAA).

[0013] The self-assembled monolayer material (SAMs material) comprises any one of a phosphoric acid SAMs material, a thiol SAMs material, a silane SAMs material, or a carbazole SAMs material, or a combination of at least two of them.

[0014] Preferably, the chemical formula of the material in the perovskite light-absorbing layer is FA x Cs 1-x Pb(I y Br 1-y )3, wherein x = 0.9-0.95, and y = 0.6-0.9.

[0015] Preferably, the material of the two-dimensional perovskite interface modification layer comprises any one of (2-AEP)2PbI4, (2-PEA)2PbI4, (2-BA)2PbI4, (2-PMA)2PbI4, or (2-F-PEA)2PbI4, or a combination of at least two of them, wherein the organic cations in the above-mentioned materials are 2-aminoethylpyridine AEP, phenethylamine PEA, butylamine BA, phenylamine PMA, and 4-fluorophenethylamine F-PEA, respectively.

[0016] The above-mentioned materials are selected as the material of the two-dimensional perovskite interface modification layer, which can optimize the energy level alignment of the electron transport layer and the perovskite layer, improve the carrier transport capacity, and the organic cations in the above-mentioned materials can inhibit the halogen reaction between the perovskite layer and the electrode.

[0017] Preferably, the thickness of the two-dimensional perovskite interface modification layer is 5-15 nm, such as 5 nm, 8 nm, 10 nm, 12 nm, 14 nm, or 15 nm, etc., and is not limited to the listed values, and other values not listed in this range are also applicable, and preferably 10-15 nm.

[0018] Preferably, the material of the electron transport layer comprises any one of C 60 70, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), tin oxide (SnO2), or other fullerene derivatives, or a combination of at least two of them.

[0019] Preferably, the material of the electrode comprises indium tin oxide (ITO) and silver.

[0020] Preferably, the material of the buffer layer comprises silicon nitride (SiN x ) and / or aluminum trioxide (Al2O3).

[0021] Preferably, the thickness of the buffer layer is 1-20 nm, for example 3 nm, 5 nm, 8 nm, 10 nm, 13 nm, 15 nm, 17 nm or 20 nm, and the like, not limited to the listed values, and other values not listed in the range are also applicable.

[0022] Preferably, the material of the silicon oxide protective layer is SiO x , x = 1-2.

[0023] Preferably, the thickness of the silicon oxide protective layer is 80-120 nm, for example 80 nm, 90 nm, 100 nm, 110 nm or 120 nm, and the like, not limited to the listed values, and other values not listed in the range are also applicable, preferably 90-110 nm.

[0024] Preferably, the water vapor transmission rate of the silicon oxide protective layer is ≤10-3g / m 2 / d.

[0025] In a second aspect, the present application provides a preparation method of the perovskite / silicon stacked solar cell according to the first aspect, the preparation method comprising the following steps:

[0026] The hole transport layer, the perovskite light absorption layer, the two-dimensional perovskite interface modification layer, the electron transport layer, the electrode, the buffer layer and the silicon oxide protective layer are sequentially prepared on the silicon bottom cell.

[0027] Preferably, the preparation method of the perovskite light absorption layer or the two-dimensional perovskite interface modification layer is independently any one or a combination of at least two of blade coating, slot coating, inkjet printing or spin coating.

[0028] Preferably, the preparation method of the hole transport layer, the electron transport layer or the buffer layer independently comprises any one or a combination of at least two of magnetron sputtering, radio frequency sputtering, atomic layer deposition or thermal evaporation.

[0029] Preferably, the preparation method of the electrode comprises thermal evaporation and / or screen printing.

[0030] Preferably, the preparation method of the silicon oxide protective layer comprises any one or a combination of at least two of electron beam evaporation, plasma enhanced chemical vapor deposition (PECVD) or magnetron sputtering.

[0031] Preferably, the deposition temperature of the silicon oxide protective layer is <80℃.

[0032] Preferably, the vacuum degree of the deposition of the silicon oxide protective layer is <10 -5 Torr.

[0033] Preferably, the deposition rate of the silicon oxide protective layer is For example: or The term "etc." is not limited to the listed values; it also applies to other unlisted values ​​within the range.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The perovskite / silicon tandem solar cell of the present invention can effectively reduce the stability degradation caused by atomic oxygen erosion and ultraviolet radiation during its service in space due to its unique structure, and can effectively block atomic oxygen penetration, thus significantly improving the lifespan of the tandem cell.

[0036] (2) The buffer layer and silicon oxide protective layer described in this invention can be directly applied above the metal electrode, are compatible with low-temperature processes, and synergistically improve the battery's resistance to water vapor and atomic oxygen, making them suitable for the protection of aerospace solar devices.

[0037] (3) The optimal perovskite / silicon tandem solar cell described in this invention operates in an atomic oxygen environment (atomic oxygen dose 10). 20 atoms / cm 2 The initial efficiency can reach over 31%, and the battery efficiency retention rate can reach 85% after 400 hours of continuous testing. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of a perovskite / silicon tandem solar cell provided in an embodiment of the present invention. 1 is the silicon substrate, 2 is the hole transport layer, 3 is the perovskite light-absorbing layer, 4 is the two-dimensional perovskite interface modification layer, 5 is the electron transport layer, 6 is the electrode, 7 is the buffer layer, and 8 is the SiO2 layer. x Protective layer. Detailed Implementation

[0039] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0040] Example 1

[0041] This embodiment provides a perovskite / silicon tandem solar cell, the structural schematic diagram of which is shown below. Figure 1 As shown, the perovskite / silicon tandem solar cell includes a silicon base cell 1 and a hole transport layer 2, a perovskite light-absorbing layer 3, a two-dimensional perovskite interface modification layer 4, an electron transport layer 5, an electrode 6, a buffer layer 7, and a SiO2 protective layer 8, which are sequentially stacked on the surface of the silicon base cell 1.

[0042] The hole transport layer is nickel oxide with a thickness of 20 nm, the perovskite light-absorbing layer is FA 0.9 Cs 0.1 Pb(I 0.65 Br 0.35 )3, the two-dimensional perovskite interface modification layer is (2-AEP)2PbI4 with a thickness of 12 nm, the electron transport layer is C 60 and tin oxide with a thickness of 10 nm, the electrode is 70 nm of ITO and silver grid lines, the buffer layer is Al2O3 with a thickness of 10 nm, and the SiO2 protective layer has a thickness of 100 nm.

[0043] The perovskite / silicon tandem solar cell is prepared by the following method:

[0044] A 210 mm heterojunction silicon bottom cell is used, RCA or ultrasonic cleaning, and finally N2 blowing dry; low temperature (100°C) drying, and no organic liquid residue on the surface. Nickel oxide target material is sputtered on the surface of the silicon bottom cell by radio frequency, and is annealed on a 150°C hot plate for 10 min to form a 20 nm thick nickel oxide hole transport layer. FAI:CsBr:PbI2 is dissolved in a mixed solvent of DMF and DMSO (DMF:DMSO=4:1) according to a molar ratio of 0.9:0.1:1 to obtain a perovskite precursor with a concentration of 1.6 mol / L, and the perovskite composition is FA 0.9 Cs 0.1 Pb(I 0.65 Br 0.35 )3. Then 12 mL of MACl DMSO solution with a concentration of 20 mol% is added to the precursor, and the perovskite is deposited using a slot coating process, with a coating speed of 20 mm / s, a pressure of 50 mbar, and a flow rate controlled at 200 μL / min. Annealing is performed in an oven at 120°C for 90 min to form a 500 nm thick perovskite light-absorbing layer. 2-AEPI is dissolved in an IPA solvent to prepare a solution with a concentration of 20 mg / mL; the 2-AEPI solution is deposited on the surface of the perovskite layer by slot coating, and is annealed at 100°C for 10 min after standing for 30 s to form a 12 nm thick (2-AEP)2PbI4 two-dimensional perovskite interface modification layer. C 60 is evaporated on the surface of the two-dimensional perovskite interface modification layer, and then 10 nm of SnO2 is prepared by atomic layer deposition to form an electron transport layer; 70 nm of ITO is magnetron sputtered on the surface of the electron transport layer, and a silver grid line is screen printed to form an electrode; by atomic layer deposition, precursor TMA and H2O are introduced at a temperature of 100°C, a cavity pressure of 0.1 Torr, and a rate An Al2O3 buffer layer with a thickness of 10 nm is prepared. Finally, a SiO2 protective layer is prepared using an electron beam evaporation method, and the vacuum degree during deposition is <10 - 5 Torr, and the deposition rate is The temperature during deposition is <80℃, and the perovskite / silicon stacked solar cell is obtained.

[0045] Example 2

[0046] This example provides a perovskite / silicon stacked solar cell, a schematic structural diagram of which is shown in Figure 1 The perovskite / silicon stacked solar cell includes a silicon base cell 1, a hole transport layer 2, a perovskite light-absorbing layer 3, a two-dimensional perovskite interface modification layer 4, an electron transport layer 5, an electrode 6, a buffer layer 7, and a SiO2 protective layer 8 which are sequentially stacked on the surface of the silicon base cell 1.

[0047] The hole transport layer is nickel oxide with a thickness of 20 nm, the perovskite light-absorbing layer is FA 0.9 Cs 0.1 Pb(I 0.65 Br 0.35 )3 with a thickness of 500 nm, the two-dimensional perovskite interface modification layer is (2-PEA)2PbI4 with a thickness of 10 nm, the electron transport layer is C 60 and SnO2 with a thickness of 10 nm, the electrode is ITO with a silver grid line disposed thereon with a thickness of 70 nm, and the buffer layer is aluminum oxide with a thickness of 5 nm. The thickness of the SiO2 protective layer is 90 nm.

[0048] The perovskite / silicon stacked solar cell is prepared by the following method:

[0049] A 210 mm heterojunction silicon base cell is used, and RCA or ultrasonic cleaning is performed, and finally N2 blowing is performed. Low-temperature (100℃) drying is performed, and no organic liquid residue is left on the surface. Nickel oxide target material is sputtered onto the surface of the silicon base cell by radio frequency sputtering, and annealing is performed on a 150℃ hot plate for 10 min to form a nickel oxide hole transport layer with a thickness of 20 nm. FAI:CsBr:PbI2 is dissolved in a mixed solvent of DMF and DMSO (DMF:DMSO=4:1) at a molar ratio of 0.9:0.1:1 to obtain a perovskite precursor with a concentration of 1.6 mol / L, and the perovskite components are FA 0.9 Cs 0.1 Pb(I 0.65 Br 0.35)3. Then 12 mL of MACl solution in DMSO with a concentration of 20 mol% was added to the precursor, and a perovskite was deposited using a slot coating process at a coating speed of 20 mm / s, a pressure of 50 mbar, and a flow rate of 200 μL / min, and annealed at 120 °C for 90 min in an oven to form a perovskite light-absorbing layer with a thickness of 500 nm. 2-PEAI was dissolved in an IPA solvent to prepare a solution with a concentration of 20 mg / mL; the 2-PEAI solution was deposited on the surface of the perovskite layer using a slot coating method, and annealed at 100 °C for 10 min after being left to stand for 30 s to form a (2-PEA)2Pbl4 two-dimensional perovskite interface modification layer with a thickness of 10 nm. C 60 Then, a 10-nm-thick Sn02 electron transport layer was prepared using atomic layer deposition, and a 70-nm-thick ITO layer was deposited on the surface of the electron transport layer by magnetron sputtering. A silver grid line was screen-printed to form an electrode, and a precursor TMA and H2O were introduced to the electrode using atomic layer deposition at a temperature of 100 °C, a cavity pressure of 0.1 Torr, and a rate of 0.1 A / s. A 5-nm-thick Al203 buffer layer was prepared. Finally, a Si02 protective layer was deposited using electron beam evaporation at a vacuum degree of <10 - 5 Torr and a deposition rate of at a deposition temperature of <80 °C to obtain the perovskite / silicon stacked solar cell.

[0050] Example 3

[0051] This example provides a perovskite / silicon stacked solar cell, a schematic structural diagram of which is shown in Figure 1 The perovskite / silicon stacked solar cell includes a silicon base cell 1 and, sequentially stacked on the surface of the silicon base cell 1, a hole transport layer 2, a perovskite light-absorbing layer 3, a two-dimensional perovskite interface modification layer 4, an electron transport layer 5, an electrode 6, a buffer layer 7, and a Si02 protective layer 8.

[0052] The hole transport layer is a 20-nm-thick nickel oxide, the perovskite light-absorbing layer is a 500-nm-thick FA 0.9 Cs 0.1 Pb(I 0.65 Br 0.35 )3, the two-dimensional perovskite interface modification layer is a 15-nm-thick (2-F-PEA)2Pbl4, the electron transport layer is a 20-nm-thick C 60 and a 10-nm-thick tin oxide, the electrode is a 70-nm-thick ITO and silver grid line, the buffer layer is a 15-nm-thick Al203, and the Si02 protective layer has a thickness of 110 nm.

[0053] The perovskite / silicon tandem solar cell is prepared by the following method:

[0054] A 210 mm heterojunction silicon cell is used, RCA or ultrasonic cleaning, and finally N2 blowing dry; low temperature (100°C) drying, no organic liquid residue on the surface. The nickel oxide target is sputtered by radio frequency on the surface of the silicon bottom cell, and is annealed on a 150°C hot plate for 10 min to form a 20 nm thick nickel oxide hole transport layer. FAI:CsBr:PbI2 is dissolved in a mixed solvent of DMF and DMSO (DMF:DMSO = 4:1) according to a molar ratio of 0.9:0.1:1 to obtain a perovskite precursor with a concentration of 1.6 mol / L, and the perovskite composition is FA 0.9 Cs 0.1 Pb(I 0.65 Br 0.35 )3. Then 12 mL of MACl DMSO solution with a concentration of 20 mol% is added to the precursor, and the perovskite is deposited using a slot coating process, with a coating speed of 20 mm / s, a pressure of 50 mbar, and a flow rate controlled at 200 μL / min. The oven is annealed at 120°C for 90 min to form a 500 nm thick perovskite light absorbing layer. 2-F-PEAI is dissolved in an IPA solvent to prepare a solution with a concentration of 20 mg / mL; the 2-F-PEAI solution is deposited on the surface of the perovskite layer using a slot coating method, and is annealed at 100°C for 10 min after standing for 30 s to form a 15 nm thick (2-F-PEA)2PbI4 two-dimensional perovskite interface modification layer. C 60 is evaporated on the surface of the two-dimensional perovskite interface modification layer, and then 10 nm of SnO2 is prepared using an atomic layer deposition method to form an electron transport layer. A 70 nm ITO is magnetron sputtered on the surface of the electron transport layer, and a silver grid line is screen printed to form an electrode. A precursor TMA and H2O are introduced using an atomic layer deposition method on the electrode, at a temperature of 100°C, a cavity pressure of 0.1 Torr, and a rate A 15 nm thick Al2O3 buffer layer is prepared. Finally, an SiO2 protective layer is deposited using an electron beam evaporation method, at a vacuum degree <10 -5 Torr, a deposition rate of a deposition temperature <80°C, to obtain the perovskite / silicon tandem solar cell.

[0055] Example 4

[0056] This example is different from Example 1 only in that the thickness of the SiO2 protective layer is 80 nm, and other conditions and parameters are completely the same as those of Example 1.

[0057] Example 5

[0058] The embodiment differs from example 1 only in that the thickness of the SiO2 protective layer is 120 nm, and other conditions and parameters are exactly the same as example 1.

[0059] Example 6

[0060] The embodiment differs from example 1 only in that the thickness of the (2-AEP)2PbI4 two-dimensional perovskite interface modification layer is 5 nm, and other conditions and parameters are exactly the same as example 1.

[0061] Example 7

[0062] The embodiment differs from example 1 only in that the thickness of the (2-AEP)2PbI4 two-dimensional perovskite interface modification layer is 20 nm, and other conditions and parameters are exactly the same as example 1.

[0063] Example 8

[0064] The embodiment differs from example 1 only in that the thickness of the Al2O3 buffer layer is 2 nm, and other conditions and parameters are exactly the same as example 1.

[0065] Example 9

[0066] The embodiment differs from example 1 only in that the thickness of the Al2O3 buffer layer is 20 nm, and other conditions and parameters are exactly the same as example 1.

[0067] Comparative example 1

[0068] The comparative example differs from example 1 only in that no Al2O3 buffer layer is set, and other conditions and parameters are exactly the same as example 1.

[0069] Comparative example 2

[0070] The comparative example differs from example 1 only in that no two-dimensional perovskite interface modification layer is set, and other conditions and parameters are exactly the same as example 1.

[0071] Comparative example 3

[0072] The comparative example differs from example 1 only in that no SiO2 protective layer is set, and other conditions and parameters are exactly the same as example 1.

[0073] Performance test:

[0074] After the initial efficiency of the solar cell obtained by testing the example and the comparative example is tested, the solar cell is exposed to an atomic oxygen environment, the atomic oxygen dose is 10 20 atoms / cm 2 , and the effect is tested after 400 h of continuous testing, and the test results are shown in table 1:

[0075] Table 1

[0076] Battery initial efficiency Battery efficiency retention (%) Example 1 31.2％ 85％ Example 2 30.9％ 84％ Example 3 30.8％ 83％ Example 4 28.2％ 81％ Example 5 27.7％ 82％ Example 6 28.5％ 81％ Example 7 27.8％ 80％ Example 8 28.8％ 81％ Example 9 28.3％ 83％ Comparative Example 1 26.3％ 77％ Comparative Example 2 24％ 70％ Comparative Example 3 26％ 53％

[0077] As can be seen from Table 1, it can be obtained from Examples 1-9 that the initial efficiency of the perovskite / silicon tandem solar cell described in the application in the atomic oxygen environment can reach 27.7% or more, and the battery efficiency retention rate after 400h of continuous testing can reach 80% or more.

[0078] As can be obtained from the comparison of Example 1 and Examples 4-5, in the perovskite / silicon tandem solar cell described in the application, the thickness of the silicon oxide protective layer will affect its sealing effect. The perovskite / silicon tandem solar cell has the best anti-atomic oxygen effect when the thickness of the protective layer is controlled to be 90-110nm. If the thickness of the silicon oxide protective layer is too thick (>110nm), it may cause mechanical stress concentration, which is not conducive to long-term stability. In addition, too thick protective layer will also lead to the decrease of the light transmittance of the device, affecting the conversion efficiency of the battery. If the thickness of the silicon oxide protective layer is too thin (<90nm), the ability to block highly reactive oxygen atoms is reduced, resulting in a decrease in efficiency retention rate.

[0079] As can be obtained from the comparison of Example 1 and Examples 6-7, in the perovskite / silicon tandem solar cell described in the application, the thickness of the two-dimensional perovskite interface modification layer will affect its performance. The solar cell has the best effect when the thickness of the two-dimensional perovskite interface modification layer is controlled to be 10-15nm. If the thickness of the two-dimensional perovskite interface modification layer is too thick, it may introduce additional interface resistance, hinder the carrier transport, and affect the initial efficiency. If the thickness of the two-dimensional perovskite interface modification layer is too thin, the interface passivation effect and protection effect are weakened, resulting in accelerated efficiency decay.

[0080] As can be obtained from the comparison of Example 1 and Examples 8-9, in the perovskite / silicon tandem solar cell described in the application, the thickness of the buffer layer will affect its effect. The solar cell has the best effect when the thickness of the buffer layer is controlled to be 5-15nm. If the thickness of the buffer layer is too thick, the optical absorption of the perovskite light-absorbing layer is inhibited, and the efficiency of the solar cell decreases. If the thickness of the buffer is too thin, the atomic oxygen blocking ability is weak, resulting in accelerated battery efficiency decay.

[0081] As can be obtained from the comparison of Example 1 and Comparative Example 1, the battery efficiency retention rate in Comparative Example 1 is obviously decreased to 77%, which is about 8 percentage points lower than that of Example 1. This shows that introducing a dense Al2O3 buffer layer between the silicon oxide protective layer and the electrode helps to buffer thermal stress and improve the bonding ability of the silicon oxide and the battery, thereby improving the overall stability of the perovskite / silicon tandem solar cell.

[0082] As can be seen from the comparison of Example 1 and Comparative Examples 2-3, in the solar cell of the present application, the two-dimensional perovskite interface modification layer can effectively passivate the interface defects of the three-dimensional perovskite light-absorbing layer, reduce non-radiative recombination, and at the same time inhibit ion migration, thereby reducing the risk of forming a high-reactivity oxygen atom penetration channel at the interface. The silicon oxide thin film has high compactness, can effectively block the oxidation effect of oxygen molecules induced by high-energy ultraviolet light, and has certain heat dissipation capacity.

[0083] The applicant declares that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by any person skilled in the art, and all such changes or replacements fall within the protection scope and disclosure scope of the present application.

Claims

1. A perovskite / silicon tandem solar cell, characterized in that, The perovskite / silicon tandem solar cell comprises a silicon base cell, a hole transport layer, a perovskite light-absorbing layer, a two-dimensional perovskite interface modification layer, an electron transport layer, an electrode, a buffer layer, and a silicon oxide protective layer, which are stacked sequentially.

2. The perovskite / silicon tandem solar cell as described in claim 1, characterized in that, The silicon-based battery includes any one of HJT batteries, TOPCon batteries, BC batteries, or PERC batteries, with HJT batteries being preferred.

3. The perovskite / silicon tandem solar cell as described in claim 1 or 2, characterized in that, The hole transport layer is made of any one or a combination of at least two of nickel oxide, self-assembled monolayer materials, or polytriarylamine.

4. The perovskite / silicon tandem solar cell according to any one of claims 1-3, characterized in that, The chemical formula of the material in the perovskite light-absorbing layer is FA. x Cs 1-x Pb(I y Br 1-y )3, where x = 0.9~0.95, y = 0.6~0.

9.

5. The perovskite / silicon tandem solar cell according to any one of claims 1-4, characterized in that, The material of the two-dimensional perovskite interface modification layer includes any one or a combination of at least two of (2-AEP)2PbI4, (2-PEA)2PbI4, (2-BA)2PbI4, (2-PMA)2PbI4, or (2-F-PEA)2PbI4; Preferably, the thickness of the two-dimensional perovskite interface modification layer is 5–15 nm, and more preferably 10–15 nm.

6. The perovskite / silicon tandem solar cell according to any one of claims 1-5, characterized in that, The material of the electron transport layer includes C 60 Any one or a combination of at least two of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, tin oxide or other fullerene derivatives.

7. The perovskite / silicon tandem solar cell according to any one of claims 1-6, characterized in that, The electrode is made of indium tin oxide and silver; Preferably, the material of the buffer layer includes silicon nitride and / or aluminum oxide; Preferably, the thickness of the buffer layer is 1–20 nm.

8. The perovskite / silicon tandem solar cell structure according to any one of claims 1-7, characterized in that, The silicon oxide protective layer is made of SiO₂. x Where x = 1 to 2; Preferably, the thickness of the silicon oxide protective layer is 80–120 nm, and more preferably 90–110 nm.

9. A method for fabricating a perovskite / silicon tandem solar cell as described in any one of claims 1-8, characterized in that, The preparation method includes the following steps: A hole transport layer, a perovskite light-absorbing layer, a two-dimensional perovskite interface modification layer, an electron transport layer, an electrode, a buffer layer, and a silicon oxide protective layer are sequentially fabricated on a silicon-based solar cell.

10. The preparation method according to claim 9, characterized in that, The preparation methods of the perovskite light-absorbing layer or the two-dimensional perovskite interface modification layer independently include any one or a combination of at least two of the following: blade coating, slot coating, inkjet printing, or spin coating; Preferably, the hole transport layer, electron transport layer, or buffer layer is prepared independently by any one or a combination of at least two of magnetron sputtering, radio frequency sputtering, atomic layer deposition, or thermal evaporation; Preferably, the electrode is prepared by thermal evaporation and / or screen printing; Preferably, the method for preparing the silicon oxide protective layer includes any one or a combination of at least two of electron beam evaporation, PECVD, or magnetron sputtering; Preferably, the deposition temperature of the silicon oxide protective layer is <80°C; Preferably, the deposition vacuum degree of the silicon oxide protective layer is <10. -5 Torr; Preferably, the deposition rate of the silicon oxide protective layer is

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