Crystalline silicon / perovskite laminated cell and preparation method thereof
By using widebandgap oxides as electron transport and connection layers in crystalline silicon/perovskite stacked batteries, the optical parasitic absorption problem caused by doped silicon film layers is solved, and the effect of improving the short-circuit current density and photoelectric conversion efficiency is achieved.
Patent Information
- Application Number
- CN202510266857.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-07-01
AI Technical Summary
In existing crystalline silicon/perovskite stacked batteries, doped silicon film layers lead to optical parasitic absorption, reducing short-circuit current density and photoelectric conversion efficiency.
Wide bandgap oxide is used as the electron transport layer of the crystalline silicon base battery and as a connecting layer to contact the perovskite battery to reduce optical parasitic absorption and improve the short-circuit current density of the battery.
It effectively avoids optical parasitic absorption loss of the intermediate connection layer, and improves the battery's short-circuit current density and photoelectric conversion efficiency.
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Figure CN120239407A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of solar cells, and in particular to a crystalline silicon / perovskite tandem cell and a preparation method thereof. Background Art
[0002] For single-junction silicon-based solar cells, whether it is a tunnel oxide passivated contact solar cell (TOPCon) or a silicon heterojunction solar cell (HJT), they are getting closer and closer to the theoretical limit. Further improving the photoelectric conversion efficiency requires the design of multi-junction cells, such as perovskite / single-crystalline silicon tandem solar cells.
[0003] Whether using an HJT cell or a TOPCon cell as the bottom cell, a doped silicon film layer is required on the side in contact with the perovskite as the electron collection layer of the silicon bottom cell. For example, for an HJT bottom cell, it is usually an intrinsic amorphous silicon and a phosphorus-doped amorphous silicon layer; for a TOPCon bottom cell, it is usually a phosphorus-doped polycrystalline silicon film layer. Due to the narrow optical bandgap of these film layers, there is a certain parasitic absorption, which limits the light trapping ability of the bottom cell, and thus reduces the short-circuit current density of the overall tandem cell.
[0004] Therefore, there is an urgent need to develop a crystalline silicon / perovskite tandem cell that can effectively reduce the loss of optical parasitic absorption, improve the short-circuit current density of the device, and thus improve the photoelectric conversion efficiency. Summary of the Invention
[0005] In order to solve the above technical problems, the present invention provides a crystalline silicon / perovskite tandem cell and a preparation method thereof. By using a wide-bandgap oxide as the electron transport layer of the crystalline silicon bottom cell and as a connection layer (the first electron transport layer) to contact the perovskite cell, a perovskite / crystalline silicon tandem cell is constructed, which can effectively avoid the optical parasitic absorption loss of the intermediate connection layer, improve the short-circuit current density of the cell, and thus improve the photoelectric conversion efficiency of the tandem cell.
[0006] To achieve the above object, the present invention is implemented according to the following technical solutions:
[0007] The first technical solution of the present invention is a crystalline silicon / perovskite tandem cell, which includes an n-type monocrystalline silicon substrate, a metal top electrode and a metal bottom electrode. The lower end face of the n-type monocrystalline silicon substrate is successively provided with a first passivation layer, a first hole transport layer and a first antireflection layer from top to bottom, and the top end of the metal bottom electrode is connected to the lower end face of the first antireflection layer; the upper end face of the n-type monocrystalline silicon substrate is successively provided with a second passivation layer, a first electron transport layer, a second hole transport layer, a perovskite layer, a second electron transport layer and a second antireflection layer from bottom to top, and the end of the metal top electrode is connected to the upper end face of the second antireflection layer.
[0008] Further, the material of the first passivation layer is silicon oxide and / or intrinsic hydrogenated amorphous silicon; the thickness of the first passivation layer is 1-10 nm.
[0009] Further, the material of the first hole transport layer is boron-doped polysilicon or boron-doped hydrogenated amorphous silicon; when the material of the first hole transport layer is boron-doped polysilicon, its thickness is 20-120 nm; when the material of the second transport layer is boron-doped hydrogenated amorphous silicon, its thickness is 5-15 nm.
[0010] Further, the materials of the first antireflection layer and the second antireflection layer are each one or more of aluminum oxide, silicon nitride, hydrogenated silicon nitride, and magnesium fluoride; the thicknesses of the first antireflection layer and the second antireflection layer are both 20-200 nm; preferably, the thicknesses of the first antireflection layer and the second antireflection layer are both 80-120 nm.
[0011] Further, the material of the second passivation layer is silicon oxide; the thickness of the second passivation layer is 0.5-2.5 nm.
[0012] Further, the material of the first electron transport layer is one or more of aluminum-doped zinc oxide, boron-doped zinc oxide, and gallium-doped zinc oxide; the thickness of the first electron transport layer is 3-80 nm.
[0013] Further, the second hole transport layer is composed of an indium-doped zinc oxide layer and a Me-4PACz layer from bottom to top; the thickness of the second hole transport layer is 2-100 nm.
[0014] Further, the material of the perovskite layer is metal halide perovskite.
[0015] Further, the second electron transport layer is composed of a C60 thin film and a SnO2 layer from bottom to top; the thickness of the second electron transport layer is 10-100 nm.
[0016] The second technical solution of the present invention is a preparation method of a crystalline silicon / perovskite tandem cell, which includes the following steps:
[0017] S1. Perform pre - cleaning and alkaline texturing treatment on the n - type monocrystalline silicon substrate;
[0018] S2. Form a first passivation layer on the lower end face of the n - type monocrystalline silicon substrate; when the first passivation layer is silicon oxide, its preparation method can be one of the conventional ultraviolet / ozone oxidation method, oxygen plasma treatment method, thermal oxidation method, and wet oxidation method; when the second passivation layer is intrinsic hydrogenated amorphous silicon, its preparation method can be one of the conventional plasma - enhanced chemical vapor deposition, microwave electron cyclotron resonance chemical vapor deposition method, magnetron sputtering method, and hot - wire chemical vapor deposition method;
[0019] S3. Form a first hole - transporting layer on the lower end face of the first passivation layer; when the first hole - transporting layer is boron - doped polysilicon, its preparation method can be one of the conventional plasma - enhanced chemical vapor deposition method, high - temperature diffusion method, molecular beam epitaxy, and hot - wire chemical vapor deposition method; when the first hole - transporting layer is boron - doped hydrogenated amorphous silicon, its preparation method can be one of the conventional plasma - enhanced chemical vapor deposition, microwave electron cyclotron resonance chemical vapor deposition method, magnetron sputtering method, and hot - wire chemical vapor deposition method;
[0020] S4. Form a first antireflection layer on the lower end face of the first hole - transporting layer; the first antireflection layer can be prepared by one of the conventional atomic layer deposition, magnetron sputtering, thermal evaporation coating, and chemical vapor deposition;
[0021] S5. Form two metal bottom electrodes in contact with the lower end face of the first antireflection layer on the lower end face of the first antireflection layer; the metal bottom electrode is a silver electrode, and it can be prepared by one of the conventional thermal evaporation method, screen printing method, electroplating method, electroless plating method, and physical vapor deposition method; the thickness of the metal bottom electrode is 100 - 500 nm;
[0022] S6. Form a second passivation layer on the upper end face of the n - type monocrystalline silicon substrate; the second passivation layer can be prepared by one of the conventional thermal oxidation growth, ultraviolet / ozone growth method, oxygen plasma growth method, wet oxidation growth method, and low - pressure chemical vapor deposition;
[0023] S7. Form a first electron - transporting layer on the upper end face of the second passivation layer; the first electron - transporting layer can be prepared by one of the conventional atomic layer deposition, chemical vapor deposition, magnetron sputtering, thermal evaporation coating, and pulsed laser deposition method;
[0024] S8. Form an aluminum oxide sacrificial layer on the upper end face of the first electron transport layer; the aluminum oxide sacrificial layer can be prepared by one of conventional atomic layer deposition, thermal evaporation coating, magnetron sputtering coating, plasma-enhanced chemical vapor deposition, and low-pressure chemical vapor deposition. The thickness of the aluminum oxide sacrificial layer is 10 - 50 nm; further preferably, the thickness of the aluminum oxide sacrificial layer is 25 - 30 nm; preferably, the annealing temperature of the aluminum oxide sacrificial layer is 400 - 600 °C, and the time is 15 - 50 min; the annealing atmosphere of the aluminum oxide sacrificial layer is FGA gas, nitrogen / argon: hydrogen = 95%: 5% (volume ratio);
[0025] S9. After completely removing the aluminum oxide sacrificial layer by wet etching of the aluminum oxide sacrificial layer, preferably, the etching solution for the aluminum oxide sacrificial layer is Na2CO3 solution, and the etching time is 5 s - 30 min; form a second hole transport layer on the upper end face of the first electron transport layer; the Me-4PACz layer can be prepared by a conventional spin coating method, and the indium-doped zinc oxide layer can be prepared by one of conventional atomic layer deposition, plasma chemical vapor deposition, low-pressure chemical vapor deposition, pulsed laser deposition, and magnetron sputtering method;
[0026] S10. Form a perovskite layer on the upper end face of the second hole transport layer; the perovskite layer can be prepared by a conventional solution-spin coating method and annealing;
[0027] S11. Form a second electron transport layer on the upper end face of the perovskite layer; the second electron transport layer is a SnO2 / C60 stack. The preparation method of SnO2 can be one of conventional chemical vapor deposition, sputtering deposition, and atomic layer deposition, and the preparation method of the C60 molecular layer can be a conventional solution-spin coating method and thermal evaporation coating method;
[0028] S12. Form a second antireflection layer on the upper end face of the second electron transport layer; the second antireflection layer can be prepared by one of conventional plasma-enhanced chemical vapor deposition method, low-pressure chemical vapor deposition, magnetron sputtering, thermal oxidation nitridation method, and spray sintering method;
[0029] S13. Form two metal top electrodes in contact with the upper end face of the second antireflection layer on the upper end face of the second antireflection layer; the metal top electrode is a silver electrode, and the metal top electrode can be prepared by one of conventional thermal evaporation coating method, screen printing method, electroplating method, electroless plating method, and physical vapor deposition method; the thickness of the metal top electrode is 100 - 500 nm.
[0030] Compared with the prior art, the present invention has the following beneficial effects:
[0031] In the present invention, the second passivation layer of ultrathin silicon oxide film can passivate the surface defects of single crystal silicon. Due to the different tunneling probabilities of electrons and holes, the carrier selective transmission ability can be achieved by controlling the film thickness; the first hole transport layer of boron-doped polysilicon film forms a p+ structure, and the back field sweeps away electrons; the p-type doping of a-Si:H in the first hole transport layer will cause band bending of the work function, thereby generating carrier selectivity. By selecting functional materials that match the band structure, a high potential barrier for electrons and a small or even zero potential barrier for holes can be directly formed at the interface, ensuring that both J0 and ρc form the best hole selective transport.
[0032] In the present invention, the perovskite film is uniform and has a uniform thickness, stably generating photo-generated carriers. It has a high utilization rate of medium and short wavelength light on the incident light side, and the remaining long wavelength light is absorbed by the single crystal silicon, improving the overall open circuit voltage of the battery.
[0033] In the present invention, the use of the first and second antireflection layers not only improves the light absorption rate of the battery and thus the light utilization rate, but also forms a field effect to improve the passivation ability of the battery.
[0034] In the present invention, the second hole transport layer of SAM layer weakens the surface non-radiative recombination by forming dipoles on the perovskite surface, passivates the perovskite layer, induces the surface energy band to bend upward, and forms a strong hole extraction ability. IZO can promote the stability and uniformity of the surface electric field of SAM, reduce current recombination, SAM generates more dipoles, and improves the hole selectivity ability.
[0035] In the present invention, the second electron transport layer of C60 film induces the surface energy band of perovskite to bend downward to extract electrons. SnO2 enhances the action sites of the C60 film, improves the energy band bending ability, realizes electron selective transmission, and the doping of iodide ions in perovskite helps to form an ohmic contact.
[0036] In the present invention, the connection layer blocks the direct contact between the perovskite absorption layer and n-Si, avoiding the loss of electrons and holes during the transmission process, and isolating the influence of perovskite defects on the recombination of electrons and holes during the carrier transmission at the connection. The low work function property of BZO induces the silicon surface energy band to bend downward to achieve electron selective transmission. Its good conductivity can act as a lateral transport layer for electrons from the silicon wafer. The nanoscale thickness ensures that BZO will not generate resistance. Contact with IZO improves the energy band bending ability of BZO. At the contact surface of the two, the similar lattice structure and groups will result in a good lattice matching degree after annealing, avoiding non-radiative recombination at the connection. BZO has a transmittance of more than 95% for the spectrum and a low thickness, and there will be no parasitic absorption problem.
[0037] In the present invention, an alumina sacrificial layer is covered on the connection layer. During the thermal annealing process, hydrogen diffuses towards the interface to repair the passivation layer and the surface defects of the crystalline silicon, improving passivation. On the other hand, it prevents the weakening of passivation caused by hydrogen overflow.
[0038] The crystalline silicon / perovskite tandem cell of the present invention can effectively solve the problem of non-radiative recombination of electrons and holes in the tandem cell, improve the ability of photo-generated electrons to be transported in the silicon wafer, and will not cause parasitic absorption, realizing an all-round improvement in the open-circuit voltage, fill factor, and short-circuit current of the tandem solar cell. Description of the Drawings
[0039] Figure 1 It is a schematic structural diagram of the crystalline silicon / perovskite tandem cell of Embodiment 1 of the present invention.
[0040] Figure 2 It is a preparation flow chart of the crystalline silicon / perovskite tandem cell of the present invention.
[0041] Reference numerals in the drawings: 10 - n-type single-crystalline silicon substrate; 11 - first passivation layer; 12 - first hole transport layer; 13 - first antireflection layer; 14 - metal bottom electrode; 15 - second passivation layer; 16 - first electron transport layer; 21 - second hole transport layer; 22 - perovskite layer; 23 - second electron transport layer; 24 - second antireflection layer; 25 - metal top electrode. Detailed Embodiments
[0042] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.
[0043] Embodiment 1
[0044] As Figure 1 shown, this embodiment exemplarily shows a crystalline silicon / perovskite tandem cell, including an n-type single-crystalline silicon substrate 10, a metal top electrode 25, and a metal bottom electrode 14. The lower end surface of the n-type single-crystalline silicon substrate 10 is successively provided with a first passivation layer 11, a first hole transport layer 12, and a first antireflection layer 13 from top to bottom, and the top end of the metal bottom electrode 14 is connected to the lower end surface of the first antireflection layer 13; the upper end surface of the n-type single-crystalline silicon substrate 10 is successively provided with a second passivation layer 15, a first electron transport layer 16, a second hole transport layer 21, a perovskite layer 22, a second electron transport layer 23, and a second antireflection layer 24 from bottom to top, and the end of the metal top electrode 25 is connected to the upper end surface of the second antireflection layer 24. As Figure 2 shown, the specific preparation process of this crystalline silicon / perovskite tandem cell is as follows:
[0045] 1) Select an n-type monocrystalline silicon substrate 10 with a thickness of 130 μm and a resistivity of 1.3 Ω·cm, and perform pre-cleaning on the n-type monocrystalline silicon substrate 10 to remove the surface cutting damage layer and alkaline texturing treatment;
[0046] 2) Polish the n-type monocrystalline silicon substrate 10 using a mixed solution of KOH and a polishing additive, and deposit 1.4 nm of SiO X as the first passivation layer 11 and a 100-nm intrinsic silicon thin film;
[0047] 3) Perform boron-doped polysilicon layer crystallization by thermal diffusion annealing in a quartz tube furnace containing BCl3 gas to form the first hole transport layer 12, with a doping concentration of 1.5E20 cm -3 ;
[0048] 4) Deposit 80 nm of SiN X on the first hole transport layer 12 by plasma-enhanced chemical vapor deposition as the first antireflection layer 13;
[0049] 5) Use an H-pattern grid design screen printing silver grid lines on the first antireflection layer 13 as the metal bottom electrode 14;
[0050] 6) Place the silicon wafer in an ultraviolet ozone machine and treat it at 50 °C for 5 min to form 1.5 nm of SiO X on the side of the n-type silicon wafer away from the first passivation layer as the second passivation layer 15;
[0051] 7) Deposit boron-doped zinc oxide (BZO) as the first electron transport layer 16 on the second passivation layer 15 by atomic layer deposition, using diethylzinc as the zinc source, water as the oxygen source, and isopropyl borate as the boron source. The specific process of atomic layer deposition of BZO is as follows: After pumping the chamber to a low pressure, keep the pump open. ① The precursor diethylzinc source enters the chamber and maintains a pulse of 80 ms, physically adsorbing on the substrate surface; ② Nitrogen purging for 10 s to remove residual diethylzinc; ③ The oxygen source ultrapure water enters the chamber with a pulse of 80 ms, reacting with diethylzinc in a chemisorbed form to generate atomic-level zinc oxide and by-products; ④ Nitrogen purging for 10 s to remove residual water sources and reaction by-products; ⑤ After repeating the above four steps ten times, the precursor isopropyl borate enters the chamber with a pulse of 10 s; ⑥ Use nitrogen to purge the remaining boron source. After repeating the above six steps ten times, a BZO thin film with a doping ratio of 10:1 and a thickness of 8 nm is obtained as the first electron transport layer 16;
[0052] 8) On the first electron transport layer 16, an aluminum oxide sacrificial layer is deposited by atomic layer deposition using trimethylaluminum as the aluminum source and ultrapure water as the oxygen source. The specific process is as follows: ① The precursor trimethylaluminum source enters the chamber and maintains a pulse for 60 ms, physically adsorbing on the substrate surface; ② Nitrogen is purged for 10 s to remove residual trimethylaluminum; ③ The oxygen source ultrapure water enters the chamber with a pulse of 80 ms, reacting with trimethylaluminum in a chemisorption form to form atomic-level aluminum oxide and by-products; ④ Nitrogen is purged for 10 s to remove the residual water source and reaction by-products. Taking the above four steps as one cycle, after 250 cycles, an aluminum oxide sacrificial layer with a thickness of 27 nm is obtained. The sample is taken out and placed in an annealing furnace, annealed at 500 °C for 30 min in an FGA atmosphere. The sample is taken out and etched in a 0.1 mol / L Na2CO3 solution at 60 °C for 2 min to remove the aluminum oxide sacrificial layer.
[0053] 9) A 5-nm IZO is deposited on the connection layer 16 by magnetron sputtering, and then [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphoric acid, i.e., Me-4PACz, is spin-coated to prepare the second hole transport layer 21;
[0054] 10) On the second hole transport layer 21, 1.7MCS 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 )3 perovskite precursor solution is completely dissolved in an anhydrous dimethylformamide / dimethyl sulfoxide (volume ratio 4:1) mixed solution system, spin-coated at 600 / 2000 / 8000 rpm for 6 / 54 / 15 s, and 300 μL of chlorobenzene is added as an antioxidant. The solution is dropped onto the center of the substrate with the first electron transport layer 10 s before the end of the rotation process, and then annealed at 105 °C for 15 min to prepare the perovskite layer 22;
[0055] 11) On the perovskite layer 22, a 15-nm C60 thin film is formed by thermal evaporation at a rate, and then a 9-nm-thick SnO2 is deposited using atomic layer deposition; the second electron transport layer 23 is prepared.
[0056] 12) On the electron transport layer 23, 100 nm of MgF X is deposited by thermal evaporation as the second antireflection layer 24;
[0057] 13) On the second antireflection layer 24, 300 nm of Ag grid lines are thermally evaporated in a masked manner as the metal top electrode 25, obtaining the crystalline silicon / perovskite stacked cell sample 1.
[0058] Example 2
[0059] The difference from Example 1 is that after step 1), a 10-nm intrinsic hydrogenated amorphous silicon thin film is deposited at low temperature using a high-frequency PECVD system (13.56 MHz) as the first passivation layer 11, and a 10-nm boron-doped nanocrystalline layer is used as the first hole transport layer 12; finally, a crystalline silicon / perovskite tandem cell sample 2 is obtained.
[0060] Comparative Example 1
[0061] It is a tandem solar cell with a TOPCon bottom cell without depositing an AZO interlayer in the prior art;
[0062] Comparative Example 2
[0063] It is a tandem solar cell with an SHJ bottom cell without depositing an AZO interlayer in the prior art.
[0064] Standard I-V curve tests were carried out on the crystalline silicon / perovskite tandem cell samples of Example 1 and Example 2, and the tandem solar cells prepared in Comparative Example 1 and Comparative Example 2. The test results are shown in Table 1.
[0065] Table 1 Test results of the cell efficiency prepared in the comparative examples and examples
[0066] <![CDATA[J SC (mA / cm 2 )]]> <![CDATA[V OC (V)]]> FF (%) PCE (%) Comparative Example 1 19.4 1.797 80.2 28.0 Comparative Example 2 19.1 1.812 81.8 28.3 Example 1 19.8 1.806 80.3 28.7 Example 2 19.7 1.791 81.7 28.8
[0067] As can be seen from Table 1, compared with Comparative Example 1 in Example 1 and compared with Comparative Example 2 in Example 2, there is a significant improvement in the short-circuit current, which is mainly attributed to the reduction of the optical parasitic absorption of the interlayer in the tandem cell, thus obtaining a significant improvement in the device efficiency.
[0068] From the above data comparison, it can be seen that this design and preparation method based on the interlayer of the crystalline silicon / perovskite tandem cell can effectively reduce the optical parasitic absorption of the intermediate connection functional layer of the tandem cell and improve the device efficiency.
[0069] The technical solution of the present invention is not limited to the limitations of the above specific embodiments. Any technical deformation made according to the technical solution of the present invention falls within the protection scope of the present invention.
Claims
1. A crystalline silicon / perovskite tandem cell, comprising an n-type single crystal silicon substrate (10), a metal top electrode (25) and a metal bottom electrode (14), characterized in that: The lower end surface of the n-type single crystal silicon substrate (10) is provided with a first passivation layer (11), a first hole transport layer (12), and a first anti-reflection layer (13) in sequence from top to bottom, and the top end of the metal bottom electrode (14) is connected to the lower end surface of the first anti-reflection layer (13); the upper end surface of the n-type single crystal silicon substrate (10) is provided with a second passivation layer (15), a first electron transport layer (16), a second hole transport layer (21), a perovskite layer (22), a second electron transport layer (23), and a second anti-reflection layer (24) in sequence from bottom to top, and the end of the metal top electrode (25) is connected to the upper end surface of the second anti-reflection layer (24).
2. The crystalline silicon / perovskite tandem cell according to claim 1, characterized in that: The material of the first passivation layer (11) is silicon oxide and / or intrinsic hydrogenated amorphous silicon; the thickness of the first passivation layer (11) is 1-10 nm.
3. The crystalline silicon / perovskite tandem cell according to claim 1, characterized in that: The material of the first hole transport layer (12) is boron-doped polysilicon or boron-doped hydrogenated amorphous silicon; when the material of the first hole transport layer (12) is boron-doped polysilicon, its thickness is 20-120 nm; when the material of the second hole transport layer (12) is boron-doped hydrogenated amorphous silicon, its thickness is 5-15 nm.
4. The crystalline silicon / perovskite tandem cell according to claim 1, characterized in that: The materials of the first anti-reflection layer (13) and the second anti-reflection layer (24) are one or more of aluminum oxide, silicon nitride, hydrogenated silicon nitride, and magnesium fluoride; the thickness of the first anti-reflection layer (13) and the second anti-reflection layer (24) are both 20-200 nm.
5. The crystalline silicon / perovskite tandem cell according to claim 1, characterized in that: The material of the second passivation layer (15) is silicon oxide; the thickness of the second passivation layer (15) is 0.5-2.5 nm.
6. The crystalline silicon / perovskite tandem cell according to claim 1, characterized in that: The material of the first electron transport layer (16) is one or more of aluminum-doped zinc oxide, boron-doped zinc oxide and gallium-doped zinc oxide; the thickness of the first electron transport layer (16) is 3-80 nm.
7. The crystalline silicon / perovskite tandem cell according to claim 1, characterized in that: The second hole transport layer (21) consists of an indium-doped zinc oxide layer and a Me-4PACz layer from bottom to top; the thickness of the second hole transport layer (21) is 2-100 nm.
8. The crystalline silicon / perovskite tandem cell according to claim 1, characterized in that: The material of the perovskite layer (22) is metal halide perovskite.
9. The crystalline silicon / perovskite tandem cell according to claim 1, characterized in that: The second electron transport layer (22) consists of a C60 thin film and a SnO2 layer from bottom to top; the thickness of the second electron transport layer (22) is 10-100 nm.
10. A method for preparing a crystalline silicon / perovskite tandem cell according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, pre-cleaning and alkali texturing treatment of an n-type single crystal silicon substrate (10); S2, forming a first passivation layer (11) on the lower end surface of the n-type single crystal silicon substrate (10); S3, forming a first hole transport layer (12) on the lower end surface of the first passivation layer (11); S4, forming a first anti-reflection layer (13) on the lower end surface of the first hole transport layer (12); S5, forming two metal bottom electrodes (14) on the lower end surface of the first anti-reflection layer (13) and in contact with the lower end surface of the first anti-reflection layer (13); S6, forming a second passivation layer (15) on the upper end surface of the n-type single crystal silicon substrate (10); S7, forming a first electron transport layer (16) on the upper end surface of the second passivation layer (15); S8, forming an aluminum oxide sacrificial layer on the upper end surface of the first electron transport layer (16); S9, after completely removing the aluminum oxide sacrificial layer by wet etching, forming a second hole transport layer (21) on the upper end surface of the first electron transport layer (16); S10, forming a perovskite layer (22) on the upper end surface of the second hole transport layer (21); S11, forming a second electron transport layer (23) on the upper end surface of the perovskite layer (22); S12, forming a second anti-reflection layer (24) on the upper end surface of the second electron transport layer (23); S13. Form two metal top electrodes (25) on the upper end surface of the second anti-reflection layer (24) and in contact with the upper end surface of the second anti-reflection layer (24).