New-structure two-terminal perovskite-silicon laminated solar cell based on micron-sized textured silicon and preparation method thereof

Abstract

The invention discloses a new-structure two-terminal perovskite-silicon laminated solar cell based on micron-sized texturing silicon and a preparation method thereof, an applied silicon substrate is a texturing surface of a pyramid structure formed by alkali texturing, the depth of a pyramid is more than 1 micron, and the solar cell has excellent light trapping performance; according to the invention, the surface of the textured silicon cell is optimized by preparing a special dielectric layer from nano silicon oxide, a novel laminated structure with local contact is constructed, the light trapping advantage of the original textured silicon is further improved or maintained, and meanwhile, the smooth transportation of photon-generated carriers on one side of the perovskite sub-cell is ensured; therefore, the photoelectric conversion efficiency of the two-terminal perovskite-silicon laminated solar cell is remarkably improved. The method for preparing the perovskite-silicon laminated solar cell by using the dielectric layer as a modification layer to optimize the texturing surface and construct a new local contact structure is ingenious, simple and effective in process, and has important practical value for preparing the efficient and low-cost perovskite-silicon laminated solar cell.

Description

Technical Field

[0001] The present invention belongs to the field of laminated photovoltaics, and specifically relates to a two-terminal perovskite-silicon laminated solar cell with a new structure based on micron-scale textured silicon and a preparation method thereof. Background Art

[0002] In the preparation of perovskite-silicon tandem solar cells, the application of micron-scale textured silicon cells is crucial. Compared with planar silicon cells or nano-scale small textured silicon cells, micron-scale textured silicon cells are more compatible with the industry, their own light trapping performance is better, and the prepared tandem has lower potential cost. However, the micron-sized pyramid texture on its surface poses great challenges to the conformal deposition of the hole transport layer and the perovskite absorption layer. The performance of the functional layer prepared by vapor deposition is greatly limited, and the film quality is poorer than that of the solution method. This makes the current perovskite-silicon tandem solar cell based on the textured silicon structure have a low photoelectric conversion efficiency, which lags far behind the efficiency of small textured silicon-perovskite tandem solar cells.

[0003] However, the carrier diffusion length of the perovskite layer prepared directly by the solution method is usually less than 1μm, and the 1μm thick perovskite cannot achieve full coverage on the micron-sized textured silicon surface; the process challenges faced at this stage are huge in order to achieve thicker perovskite layer deposition and matching carrier diffusion length by increasing the concentration of the perovskite precursor solution, and the film often has many defects. Both physical vapor deposition of perovskite and solution deposition of thick film perovskite are not conducive to the large-scale production of perovskite-silicon stacked cells; and in theory, the perovskite absorption layer prepared by the above method has many defects, which will greatly affect the performance and stability of the stacked cells. Therefore, using a dielectric layer to reconstruct the textured silicon surface to form a local contact structure and achieve the coverage deposition of a 1μm full solution method perovskite absorption layer is crucial to improving the photoelectric performance of perovskite-silicon stacked solar cells based on micron-sized textured silicon and its commercialization. Summary of the invention

[0004] In view of the problem of low photoelectric conversion efficiency of two-terminal perovskite-silicon tandem solar cells based on micron-scale textured silicon, the present invention aims to propose a two-terminal perovskite-silicon tandem solar cell with a new structure based on micron-scale textured silicon and a preparation method thereof.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A new structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon, the new structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon is composed of a micron-scale textured silicon cell with a dielectric layer on the surface as a bottom cell and a perovskite solar cell as a top cell stacked; the micron-scale textured silicon cell adopts a commercial micron-scale textured heterojunction silicon cell, and the depth of the pyramids formed by alkali texturing on the surface of the micron-scale textured silicon cell is more than 1 micron, the material of the dielectric layer is nano silicon oxide, and after the dielectric layer is formed, the depth of the pyramids formed by alkali texturing on the surface of the micron-scale textured silicon cell is less than 1 micron, and the surface of the micron-scale textured silicon cell is reconstructed by the dielectric layer on the surface to form a local contact structure.

[0007] In a specific embodiment, nano-silicon oxide dispersion is dropped onto micron-sized textured silicon, and spin-coated so that nano-silicon oxide is deposited on the bottom of the pyramid formed by alkali texturing on the surface of the micron-sized textured silicon and forms a dielectric layer of a certain thickness, and then the sample is heat-treated on a heating table at 80-150° C. for 5-10 minutes. The spin-coating conditions are: spin-coating at a rotation speed of 2000-5000 rpm for 25-40 seconds.

[0008] In a specific embodiment, the mass concentration of the nano-silicon oxide dispersion is 3-7 mg / L.

[0009] In a specific embodiment, the micron-scale texturing silicon cell is a heterojunction silicon cell, which includes from bottom to top: a metal electrode layer, a transparent conductive layer, an amorphous passivation layer, a P-type amorphous silicon layer, an N-type silicon wafer, an N-type amorphous silicon layer, an amorphous passivation layer, and a tunneling layer (intermediate composite layer); the perovskite solar cell includes from bottom to top: a hole transport layer, a perovskite active layer, an electron transport layer, a buffer layer, a transparent conductive layer, and an anti-reflection layer. That is: the new structure two-terminal perovskite-silicon stacked solar cell based on micron-scale texturing silicon is an inversion device, which includes from bottom to top: a metal electrode layer (preferably silver), a transparent conductive layer, an amorphous passivation layer, a P-type amorphous silicon layer, an N-type silicon wafer, an N-type amorphous silicon layer, an amorphous passivation layer, a tunneling layer (intermediate composite layer), a hole transport layer, a perovskite active layer, an electron transport layer, a buffer layer, a transparent conductive layer, and an anti-reflection layer.

[0010] In a specific embodiment, the perovskite active layer used in the perovskite solar cell is Cs x MA y FA 1-x-y PbI z Br 3-z , the band gap is 1.45-1.80eV, and the thickness of the prepared perovskite film is 800-2000nm.

[0011] In a specific embodiment, the intermediate composite layer is a thin layer of metal such as ITO, IZO, AZO or Ag / Au, with a sheet resistance of 100-1000Ω / □, a transmittance of 80-95%, and a thickness of 1-60nm.

[0012] In a specific embodiment, the hole transport layer is nickel oxide, PTAA or self-assembled monolayer materials (SAMs) such as 2PACz, MeO-4PACz, etc., and has a thickness of 5 to 50 nm.

[0013] In a specific embodiment, the electron transport layer is C60 and has a thickness of 5 to 20 nm.

[0014] In a specific embodiment, the buffer layer is BCP or tin oxide, and has a thickness of 5 to 20 nm.

[0015] In a specific embodiment, the transparent conductive layer is ITO or IZO, and has a thickness of 80 to 140 nm.

[0016] In a specific embodiment, the anti-reflection layer is LiF or MgF X , thickness is 50~200nm.

[0017] Based on the same principle, the present invention also provides a method for preparing a novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale texturing silicon, comprising:

[0018] Prepare a dielectric layer on the surface of a micron-scale textured silicon cell containing an intermediate composite layer;

[0019] A hole transport layer is then prepared on the surface of the dielectric layer, and then a perovskite active layer is prepared by a solution method. The present invention reconstructs the micron-scale textured silicon surface by using a specific dielectric layer, which not only maintains / improves the light trapping advantage of the textured silicon, but also constructs a new type of locally contacted stacked structure to achieve high-quality perovskite absorption layer deposition by a full solution method, thereby reducing the density of non-radiative recombination centers in the perovskite film. At the same time, a large area coverage of the hole transport layer is achieved, thereby suppressing leakage of the buried interface.

[0020] Finally, an electron transport layer, a buffer layer, a transparent conductive layer and an anti-reflection layer are sequentially prepared on the surface of the perovskite active layer to obtain the new structure two-terminal perovskite-silicon stacked solar cell based on micron-scale textured silicon.

[0021] In a specific embodiment, the specific preparation method of preparing a dielectric layer on the surface of a micron-scale texturing silicon cell containing an intermediate composite layer is as follows:

[0022] (1) Mixing the nano-silicon oxide solution with deionized water to prepare a uniform nano-silicon oxide dispersion, wherein the mass concentration of the nano-silicon oxide dispersion is 3-7 mg / mL.

[0023] (2) Spin coating the nano-silicon oxide dispersion on the textured silicon cell containing the intermediate composite layer at a rotation speed of 2000-5000 rpm for 25-40 seconds, and then preheating at 80-150° C. for 5-10 minutes to obtain a silicon bottom cell with a surface reconstruction.

[0024] In a specific embodiment, a hole transport layer and a perovskite active layer are sequentially prepared on the surface of the dielectric layer by a solution method, as follows:

[0025] (1) A hole transport layer is prepared by a solution method. The hole transport layer is made of nickel oxide, PTAA or a self-assembled monolayer material with a thickness of 5 to 50 nm.

[0026] (2) The perovskite active layer is prepared by a solution method, wherein the perovskite active layer is Cs x MA y FA 1-x-y PbI z Br 3-z , the band gap is 1.45-1.80eV, and the thickness of the prepared perovskite film is 800-2000nm.

[0027] In a specific embodiment, PTAA and SAMs are prepared by the following method:

[0028] Spin-coat a 0.2-1.2 mg / mL PTAA (chlorobenzene or toluene as solvent) or SAMs (alcohol solution or tetrahydrofuran as solvent) solution on a silicon cell substrate at a rotation speed of 2000-5000 rpm for 30-60 seconds. Then, use a heating stage to heat the sample at 50-150°C for 10-30 minutes.

[0029] In a more specific embodiment, SAM is prepared by:

[0030] A 0.2-1.2 mg / mL SAM solution dissolved in ethanol was spin-coated at a rotation speed of 2000-5000 rpm for 25-40 seconds, and then preheated at 60-120° C. for 5-15 minutes to complete the preparation of the hole transport layer.

[0031] In a specific embodiment, the hole transport layer is nickel oxide, which is prepared by the following method:

[0032] A 1-5% mass fraction of nickel oxide nanocrystal aqueous solution is spin-coated on a silicon battery substrate at a rotation speed of 2000-5000 rpm for 30-60 seconds. Subsequently, a heating table is used to heat the sample at 100-250°C for 30-90 minutes; or a magnetron sputtering device is directly used at a power of 20-100W to sputter a nickel oxide layer of a certain thickness, and the sample is heated at 100-250°C for 10-30 minutes.

[0033] In a specific embodiment, the method for preparing the perovskite active layer is as follows:

[0034] The perovskite precursor solution is spin-coated or scraped onto a substrate, and the substrate film is formed into a perovskite intermediate phase by using an anti-solvent, blowing or vacuuming method, and then the sample is heat-treated at 100-170°C on a heating table for 10-60 minutes to obtain a precursor film. The precursor solution is composed of CsI, MAI, MABr, FAI, MACl, PbI 2 and PbBr 2 The powder is dissolved in a mixed solvent in a molar ratio, wherein the mixed solvent is composed of DMF and DMSO in a volume ratio of 4:1, and the total molar concentration is 1.2-2 mol / L.

[0035] In one embodiment, the electron transport layer is C 60 The preparation method is as follows: using thermal evaporation equipment to The evaporation speed is about 5-20nm thick.

[0036] In a specific embodiment, the buffer layer can be BCP or tin oxide with a thickness of 5 to 20 nm, wherein the BCP layer is prepared by physical vapor deposition and the tin oxide layer is prepared by atomic layer vapor deposition equipment; the buffer layer material can also be a thin layer of Ag or Au with a thickness of 0.5-1 nm, prepared by physical vapor deposition.

[0037] In a specific embodiment, the transparent conductive layer is ITO or IZO, has a thickness of 80 to 140 nm, and is prepared by magnetron sputtering.

[0038] In a specific embodiment, the anti-reflection layer is LiF or MgF X , with a thickness of 50 to 200 nm, and is prepared by physical vapor deposition.

[0039] In a specific embodiment, the humidity of the environment in which the device is prepared is ≤50%.

[0040] Compared with the prior art, the present invention has the following beneficial technical effects:

[0041] By using a specific dielectric layer to reconstruct the micron-scale textured silicon surface, not only the light trapping advantage of the textured silicon is maintained / improved, but also a new type of locally contacted stacked structure is constructed, achieving high-quality perovskite absorption layer deposition by the full solution method, reducing the density of non-radiative recombination centers in the perovskite film; at the same time, a large area coverage of the hole transport layer is achieved, suppressing leakage of the buried interface. This method can effectively improve the photoelectric conversion efficiency, short-circuit current density and open-circuit voltage of the device at the same time. The preparation process of using a dielectric layer to reconstruct the surface of the textured silicon to improve the photoelectric performance of the perovskite-silicon stacked solar cell is simple in the present invention, and has important practical value for preparing high-efficiency and low-cost two-terminal perovskite-silicon stacked solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a cross-sectional SEM schematic diagram of a silicon dioxide dielectric layer in an embodiment of the present invention;

[0043] Figure 2 Schematic diagram of the device structure of a two-terminal perovskite-silicon tandem solar cell in an embodiment of the present invention;

[0044] Figure 3 The reflectivity spectrum of the stacked device with / without a dielectric layer in Example 1 of the present invention;

[0045] Figure 4 The SAM layer distribution diagram on the textured silicon substrate with / without a dielectric layer in Example 2 of the present invention;

[0046] Figure 5 A comparison diagram of non-radiative recombination of a perovskite film on a textured silicon substrate with and without a dielectric layer in Example 3 of the present invention;

[0047] Figure 6 The current-voltage curves of the tandem solar cells with and without the dielectric layer in Example 4 of the present invention;

[0048] Figure 7 Statistical diagram of photovoltaic performance parameters of tandem solar cells with different dielectric layer thicknesses in Example 5 of the present invention;

[0049] Figure 8 Schematic diagram of SEM morphology of different dielectric layers on a textured silicon substrate in Example 6 of the present invention. DETAILED DESCRIPTION

[0050] The present invention provides a two-terminal perovskite-silicon stacked solar cell with a new structure based on micron-scale textured silicon and a preparation method thereof. A layer of dielectric is spin-coated on the surface of the micron-scale textured silicon to deposit it at the bottom of a pyramid valley and form a dielectric layer of a certain thickness. The method realizes a novel locally contacted stacked structure and realizes high-quality deposition of a perovskite absorption layer by a full solution method. At the same time, a large-area coverage of a hole transport layer is achieved, and leakage of a buried bottom interface is suppressed. The method can simultaneously and effectively improve the photoelectric conversion efficiency, short-circuit current density and open-circuit voltage of the device.

[0051] The present invention is further described in detail below in conjunction with specific embodiments.

[0052] In the following embodiments, Figure 1 As shown, the nano silicon oxide particles used are wide bandgap insulating materials with specific morphology and good dispersibility. The diameter of the nano silicon oxide particles is about 200nm, which can be directly synthesized by hydrothermal method. At the same time, the dielectric layer deposited by them cannot affect the light trapping performance of the original textured silicon substrate. The depth of the pyramids formed by alkali texturing on the surface of the micron-scale textured silicon cell is more than 1 micron, and the figure shows that it is about 2-3 microns. After the dielectric layer is formed, the depth of the pyramids formed by alkali texturing on the surface of the micron-scale textured silicon cell is less than 1 micron, and the figure shows that it is about 0.5 microns, so as to obtain a new type of local contact stacked structure.

[0053] For the convenience of comparison and explanation of the effect of the method of the present invention, the following Figure 2 The structure of the two-terminal perovskite-silicon stacked solar cell device shown in the figure includes, from top to bottom: an anti-reflection layer, a silver metal electrode (gate line), a transparent conductive layer (transparent conductive electrode), a tin dioxide buffer layer, a C 60 Electron transport layer, passivation layer, Cs x MA y FA 1-x-y PbI z Br 3-z Perovskite active layer, SAM hole transport layer, dielectric layer, micron-scale texturing silicon cell; wherein, in this embodiment, a metal electrode is added for the electrode lead-out of the silicon bottom cell, and a passivation layer is used to passivate the surface defects of the perovskite. The depth of the pyramid formed by alkali texturing on the surface of the micron-scale texturing silicon cell is 2-3 microns. As a silicon bottom cell, the micron-scale texturing silicon cell includes, from bottom to top: a metal electrode layer (metal electrode, silver is used in this embodiment), a transparent conductive layer (transparent conductive electrode), an amorphous passivation layer, a P-type amorphous silicon layer, an N-type silicon wafer, an N-type amorphous silicon layer, an amorphous passivation layer, and a tunneling layer (intermediate composite layer).

[0054] Example 1

[0055] Compare the reflectivity of two-terminal perovskite-silicon tandem solar cell devices with and without a dielectric layer: prepare a nano-silicon oxide aqueous solution with a concentration of 5 mg / ml, treat the prepared silicon bottom cell with a UV ozone cleaner for 20 minutes, and ultrasonicate the nano-silicon oxide aqueous solution for 10 minutes before use. Then, let the dielectric dispersion droplets stand on the textured silicon substrate for 15 seconds, and then spin-coat at a speed of 1500 rpm for 20 seconds. After the spin coating is completed, transfer to a hot stage at 100°C and heat for 10 minutes.

[0056] Figure 1 This is a cross-sectional SEM schematic diagram of a silicon dioxide dielectric layer in an embodiment of the present invention;

[0057] like Figure 3 This is the reflectivity spectrum of the two-terminal perovskite-silicon stacked solar cell device with and without a dielectric layer. After adding the dielectric layer, the overall reflectivity of the device decreases, which is conducive to the full utilization of sunlight and increasing the device current.

[0058] Example 2

[0059] The processing of the silicon bottom cell and the preparation of the dielectric are the same as those in Example 1. Then, a hole transport layer is prepared on the silicon bottom cell with a dielectric layer prepared in Example 1. The specific steps are as follows:

[0060] A SAM solution (2PACz) with a concentration of 1 mg / ml was prepared, and the solvent was ethanol, and the solution was shaken in an oscillator for 30 minutes. Then, the solution was spin-coated on the silicon-based cell with a dielectric layer prepared in Example 1, with a spin-coating speed of 5000 rpm and a spin-coating time of 30 seconds. After the spin-coating was completed, the solution was transferred to a hot plate at 100° C. and heated for 10 minutes.

[0061] The same method was used to prepare the hole transport layer directly on the silicon bottom cell as a control.

[0062] Figure 4 Figure 3 shows the distribution of the SAM layer on the textured silicon substrate with and without a dielectric layer. The SAM distribution on the textured silicon substrate without a dielectric layer is uneven, but after adding the dielectric layer, the SAM distribution is obviously more uniform, indicating that the dielectric layer reconstructs the micron-scale textured silicon surface and achieves better coverage of the hole transport layer.

[0063] Example 3

[0064] The preparation of the dielectric layer and the hole transport layer is the same as in Example 2, and then the perovskite active layer is prepared on the hole transport layer prepared in Example 2, and the specific steps are as follows:

[0065] Perovskite layer preparation: FAI, CsI, PbBr, PbI 2 Prepared according to the stoichiometric ratio 0.25 FA0.75 Pb(I 0.75 Br 0.25 ) 3 Perovskite precursor solution: The precursor solution is dissolved in DMF and DMSO in a volume ratio of 4:1, and the concentration of the precursor solution is 1.75 mol / L.

[0066] The perovskite precursor solution was dropped onto the hole transport layer substrate, and the substrate was rotated at 2000 rpm for 45 seconds, and then spun at 7000 rpm for 10 seconds. 250 μl of chlorobenzene antisolvent was added 10 seconds after the spin coating, and then annealed at 100° C. for 15 minutes on a heating table. The band gap of the perovskite film was about 1.68 eV.

[0067] The same method was used to prepare the hole transport layer and perovskite active layer on the silicon bottom cell as a control.

[0068] Figure 5 This is the time-resolved fluorescence spectrum of the perovskite film on the textured silicon substrate with / without a dielectric layer. After adding the dielectric layer, the fluorescence lifetime of the perovskite film increases, which indicates that the density of non-radiative recombination centers in the perovskite film is reduced after adding the dielectric layer.

[0069] Example 4

[0070] The preparation of the dielectric layer, the hole transport layer and the perovskite layer is the same as in Example 3. Then, a passivation layer, an electron transport layer, a buffer layer, a transparent conductive electrode, a metal electrode and an anti-reflection layer are sequentially prepared on the perovskite active layer prepared in Example 3, and the specific steps are as follows:

[0071] Preparation of the passivation layer: Prepare a 1 mg / ml passivation layer (piperazine) solution, the solvent is isopropanol, and oscillate in an oscillator for 30 minutes. Then take the passivation layer solution and drop it on the device prepared in Example 3 for spin coating. The spin coating speed is 5000 rpm and the spin coating time is 30 seconds. After the spin coating is completed, transfer it to a hot plate at 100° C. and heat it for 5 minutes.

[0072] Preparation of electron transport layer: The samples with passivation layer were transferred to electron beam evaporation coating machine and -4 Pa vacuum condition, 15 nm C was deposited at a rate of 60 .

[0073] Preparation of buffer layer: The sample with prepared electron transport layer was transferred to the atomic layer deposition equipment. The buffer layer was deposited at 100°C using tin source and water source. The tin source was heated to 80°C, the water source was at room temperature, and the nitrogen flow rate was 90 sccm. One cycle included: tin source pulse 1s and purge 6s, water source pulse 1s and purge 6s. A total of 120 cycles were run.

[0074] Preparation of transparent conductive electrode: The sample with prepared buffer layer was transferred to a magnetron sputtering instrument, and IZO or ITO target was used for sputtering at a power of 80 W under a gas pressure of 0.35 Pa for 10 min.

[0075] Preparation of metal electrode layer: thermal evaporation coating machine was used at 5.0×10 -4 Pa, a 300 nm thick silver electrode layer was thermally evaporated.

[0076] Preparation of anti-reflection layer: thermal evaporation coating machine was used at 5.0×10 -4 Under vacuum conditions of 1.5 Pa, a 120 nm magnesium fluoride anti-reflection layer was thermally evaporated.

[0077] The same method was used to prepare a hole transport layer, a perovskite active layer, a passivation layer, an electron transport layer, a buffer layer, a transparent conductive electrode, a metal electrode, and an anti-reflection layer on a silicon-bottom cell as a control.

[0078] Table 1 shows the performance parameters of the battery of this embodiment and the control battery without dielectric layer under the same experimental conditions. The IV curve is as follows: Figure 6 As shown, it can be seen that when the dielectric layer is not added, the open circuit voltage and fill factor of the device are very low, mainly due to leakage, and after the dielectric layer is added, the open circuit voltage and photoelectric conversion efficiency of the battery are improved. The preparation process of introducing a dielectric layer to improve the photoelectric performance of a two-terminal perovskite-silicon stacked solar cell in the present invention can be completed under ambient conditions, and the cost is low, and there is great potential for commercialization.

[0079] Table 1 Performance parameters of the battery of Example 1 and the control battery

[0080]

[0081] Example 5

[0082] Preparation of dielectric layer: prepare dielectric solutions of different concentrations, which are 3mg / ml, 5mg / ml and 7mg / ml respectively. Treat the prepared silicon bottom battery with UV ozone cleaning machine for 20min, ultrasonicate the dielectric solution for 10min before use, then drop dielectric dispersions of different concentrations on the textured silicon substrate and let stand for 15s, then spin coat at 1500rpm for 20s, and transfer to a hot plate at 100°C for heating for 10min after spin coating. Then prepare hole transport layer, perovskite active layer, passivation layer, electron transport layer, buffer layer, transparent conductive electrode, metal electrode and anti-reflection layer in sequence on the silicon bottom battery with dielectric layer. The preparation method is the same as that in Example 4.

[0083] Figure 7The photovoltaic performance parameter statistics of the tandem solar cells with different dielectric layer concentrations show that although 3mg / ml can reconstruct a new type of local contact tandem structure, the leakage is still serious due to the low dielectric concentration, resulting in a low opening voltage and fill factor. Similarly, 7mg / ml can reconstruct a new type of local contact tandem structure, but the increase in series resistance caused by the excessive thickness of the dielectric layer leads to a decrease in short-circuit current and fill factor. 5mg / ml is the best concentration, achieving a tandem solar cell with high opening voltage and high photoelectric conversion efficiency.

[0084] Comparative Example 1

[0085] An aluminum oxide layer was prepared on the surface of the silicon-based cell: an aluminum oxide aqueous solution with a concentration of 5 mg / ml was prepared, and the other steps were the same as in Example 1. The results are shown in FIG. Figure 8 As shown in a, alumina particles easily agglomerate to form larger particles that cannot settle at the bottom of the pyramid valley.

[0086] Comparative Example 2

[0087] A PMMA layer was prepared on the surface of the silicon-based cell: a PMMA aqueous solution with a concentration of 5 mg / ml was prepared, and the other steps were the same as in Example 1. The results are shown in FIG. Figure 8 As shown in b, PMMA forms a continuous thick film due to its polymer properties and is less likely to deposit at the bottom of the valley.

[0088] Neither alumina nor PMMA can reconstruct a new type of locally contacted stacked structure.

[0089] The above is only a non-limiting implementation mode of the present invention. For ordinary technicians in this field, several modifications and improvements can be made without departing from the creative concept of the present invention and without making creative work. These all fall within the protection scope of the present invention.

Claims

1. A new structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon, characterized in that: The new structure two-terminal perovskite-silicon stacked solar cell based on micron-scale texturing silicon is composed of a micron-scale texturing silicon cell with a dielectric layer on the surface as the bottom cell and a perovskite solar cell as the top cell stack; the depth of the pyramid formed by alkali texturing on the surface of the micron-scale texturing silicon cell is more than 1 micron, and the material of the dielectric layer is nano-silicon oxide. After the dielectric layer is formed, the depth of the pyramid formed by alkali texturing on the surface of the micron-scale texturing silicon cell is less than 1 micron.

2. The novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to claim 1 is characterized in that: The dielectric layer is prepared by the following method: The nano-silicon oxide dispersion is dropped onto the micron-scale texturing silicon cell, and then spin-coated to deposit the nano-silicon oxide on the surface of the micron-scale texturing silicon cell at the bottom of the pyramid formed by alkali texturing and form a dielectric layer of a certain thickness, followed by heat treatment at 80-150°C for 5-10 minutes.

3. The novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to claim 2 is characterized in that: The mass concentration of the nano-silicon oxide dispersion is 3-7 mg / mL.

4. The novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to claim 1 is characterized in that: The micron-scale texturing silicon cell includes, from bottom to top, a metal electrode layer, a transparent conductive layer, an amorphous passivation layer, a P-type amorphous silicon layer, an N-type silicon wafer, an N-type amorphous silicon layer, an amorphous passivation layer and an intermediate composite layer; the perovskite solar cell includes, from bottom to top, a hole transport layer, a perovskite active layer, an electron transport layer, a buffer layer, a transparent conductive layer and an anti-reflection layer.

5. The novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to claim 4 is characterized in that: The perovskite active layer used in the perovskite solar cell is Cs x MA y FA 1-x-y PbI z Br 3-z , the band gap is 1.45-1.80eV, and the thickness of the prepared perovskite film is 800-2000nm.

6. The novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to claim 4 is characterized in that: The intermediate composite layer is ITO, IZO, AZO or Ag / Au, with a sheet resistance of 100-1000Ω / □, a light transmittance of 80-95%, and a thickness of 1-60nm.

7. The novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to claim 4 is characterized in that: The hole transport layer is made of nickel oxide, PTAA or a self-assembled monomolecular layer material, and has a thickness of 5 to 50 nm.

8. The novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to claim 4 is characterized in that: The electron transport layer is C60 and has a thickness of 5 to 20 nm.

9. The novel structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to claim 4, characterized in that: The buffer layer is BCP or tin oxide, with a thickness of 5 to 20 nm; the transparent conductive layer is ITO or IZO, with a thickness of 80 to 140 nm; the anti-reflection layer is LiF or MgF X , thickness is 50~200nm.

10. A method for preparing a new structure two-terminal perovskite-silicon tandem solar cell based on micron-scale textured silicon according to any one of claims 1 to 9, characterized in that: include: Prepare a dielectric layer on the surface of a micron-scale textured silicon cell containing an intermediate composite layer; Then, a hole transport layer is prepared on the surface of the dielectric layer, and then a perovskite active layer is prepared by a solution method; Finally, an electron transport layer, a buffer layer, a transparent conductive layer and an anti-reflection layer are sequentially prepared on the surface of the perovskite active layer to obtain the new structure two-terminal perovskite-silicon stacked solar cell based on micron-scale textured silicon.

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