Method for improving efficiency of perovskite solar cell

Abstract

The invention provides a method for improving the efficiency of a perovskite solar cell, and relates to the technical field of solar cells, the cell structure sequentially comprises a bottom substrate, a transparent electrode, a hole transport layer, a perovskite light absorption layer, an interface modification layer, an electron transport layer, a buffer layer and a metal electrode from bottom to top; a new additive 4-(2-aminoethyl) benzenesulfonic acid hydrochloride is introduced into the perovskite light absorption layer, the additive is introduced into the perovskite light absorption layer by being dissolved in a perovskite precursor solution, and the dosage of the additive is 0.1-1.5 mg / mL. Based on the method, the defect density of shallow energy level and deep energy level of perovskite is reduced, a more intrinsic perovskite absorption layer is formed through induction, balance extraction of electrons and holes is promoted, and then the open-circuit voltage and efficiency of the solar cell are remarkably improved.

Description

Technical Field

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

[0002] In recent years, metal halide perovskites have become the light-absorbing materials for perovskite solar cells (PSCs) due to their high absorption coefficient, low exciton dissociation energy, and low manufacturing cost. Currently, the power conversion efficiency of single-junction perovskite cells has reached 26.7%. In addition, due to their adjustable bandgap and simple preparation method, metal halide perovskites are also particularly suitable for the application of tandem solar cells (TSCs) to further improve their power conversion efficiency.

[0003] Although perovskite solar cells have developed rapidly, their low extraction efficiency of photo-generated carriers and serious non-radiative recombination losses limit the improvement of open-circuit voltage and efficiency. Especially for wide-bandgap perovskite solar cells with a high bromine content, photo- and thermally induced halide segregation leads to a significant increase in the defect density on the surface and inside the perovskite, resulting in serious non-radiative recombination. In addition, the mismatch in the energy level alignment between the perovskite layer and the charge transport layer, and the imbalance in electron-hole extraction also exacerbate the carrier recombination. Therefore, optimizing the energy level alignment, improving carrier dynamics, and effectively suppressing V OC losses are necessary conditions for improving the efficiency of perovskite solar cells.

[0004] To reduce the defect density of the perovskite absorption layer, Yan et al. (Yan, N.; Gao, Y.; Yang, J.; Fang, Z.; Feng, J.; Wu, X.; Chen, T.; Liu, S. J. A. C. I. E. Wide-bandgap perovskite solar cell using a fluoride-assisted surface gradient passivation strategy. Angew. Chem. Int. Ed. 2023, 62(11), e202216668.) introduced F-substituted phenethylamine salts into the anti-solvent. The authors found that as the distance between the F atom and the -NH3 + functional group increased, -NH3 + showed stronger electropositivity, thus significantly reducing I PbInverse defects, ultimately achieving significantly improved device efficiency. To reduce the energy level mismatch between the perovskite absorption layer and the electron transport layer and reduce interfacial charge recombination, Chen et al. (Chen, H.; Maxwell, A.; Li, C.; Teale, S.; Chen, B.; Zhu, T.; Ugur, E.; Harrison, G.; Grater, L.; Wang, J. J. N. Regulating surface potential maximizes voltage in all-perovskite tandems. Nature 2023, 613, 676-681.) utilized field-effect passivation to improve the perovskite surface state by introducing 1,3-propanediamine at the perovskite / electron transport layer interface, achieving a more uniform surface potential distribution, inducing surface n-type doping, and significantly reducing the open-circuit voltage loss. However, NH3 + The enhanced electropositivity is beneficial for adsorption on acceptor defects, while for electropositive donor defects, its adsorption ability is significantly reduced. In addition, for P-I-N type devices, a more intrinsic perovskite absorption layer and a more n-type perovskite surface are more conducive to carrier extraction. However, most current studies mainly focus on achieving a more n-type perovskite surface, and there is less research on the intrinsic properties of the perovskite absorption layer, leaving a large research space. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide a method for improving the efficiency of perovskite solar cells. By introducing a 4-(2-aminoethyl)benzenesulfonic acid hydrochloride material into the perovskite, the defect density is reduced, a more intrinsic perovskite absorption layer is achieved, which is beneficial for the balanced extraction of electron holes, and thus significantly improves the open-circuit voltage and power conversion efficiency of the solar cell.

[0006] To achieve the above object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for improving the efficiency of perovskite solar cells. The cell structure sequentially includes a bottom substrate, a transparent electrode, a hole transport layer, a perovskite light absorption layer, an interface modification layer, an electron transport layer, a buffer layer, and a metal electrode from bottom to top;

[0008] A new additive is introduced into the perovskite absorption layer. The additive material is 4-(2-aminoethyl)benzenesulfonic acid hydrochloride, and its chemical formula is shown in Formula 1:

[0009]

[0010] The additive is introduced into the perovskite light absorption layer by dissolving it in the perovskite precursor solution.

[0011] Preferably, the perovskite solar cell is a P-I-N type wide-bandgap perovskite solar cell;

[0012] The perovskite solar cell includes a single-junction perovskite solar cell or a perovskite-based tandem solar cell;

[0013] The bandgap of the perovskite solar cell is 1.6 - 1.8 eV;

[0014] The perovskite material is an organic-inorganic hybrid multi-halogen mixed perovskite material.

[0015] Preferably, the transparent electrode can be one or more of an FTO transparent electrode, an ITO transparent electrode, an IZO transparent electrode, an IZrO transparent electrode, and an AZO transparent electrode.

[0016] Preferably, the hole transport layer is one or more of PTAA, Poly-TPD, Spiro-TTB, PEDOT:PSS, P3HT, self-assembled monolayers, CuSCN, and NiO x in a hole transport material;

[0017] The self-assembled monolayers include one or more of (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz), (2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl)phosphonic acid (MeO-2PACz), and (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid (Me-4PACz) self-assembled monolayers.

[0018] Preferably, the electron transport layer is one or more of SnO2, TiO2, ZnO, PCBM, C 60 or other electron transport materials such as fullerene derivatives.

[0019] Preferably, the interface modification layer includes one or more of PEAI, MAI, 2-thiopheneethylamine iodide, ethylenediamine dihydroiodide, 1,3-diaminopropane dihydroiodate, bis(2-hydroxyethyl)dimethylammonium chloride, and choline chloride;

[0020] The buffer layer is one or more of BCP, PEI, SnO2, Al2O3, SiO2, LiF, and MgF2.

[0021] Preferably, the metal electrode material is one or more of Ag, Au, Cu, and Al, and the thickness is 80 - 120 nm.

[0022] Preferably, the bottom substrate includes one or more of transparent glass, flexible PET substrate, flexible PEN substrate, silicon bottom cell, copper indium gallium selenide bottom cell, perovskite bottom cell, and CdTe bottom cell.

[0023] Preferably, the preparation method of the perovskite absorption layer in the present invention is one or more of spin coating, blade coating, and slot die coating;

[0024] More preferably, the preparation method of the perovskite absorption layer in the present invention is spin coating, the spin coating speed is 3000-7000 r / min, the spin coating time is 40-60 s, the annealing temperature is 100-130 °C, and the annealing time is 15-30 min. The present invention does not have any special limitations on the perovskite thin film preparation process, and the process well-known to those skilled in the art can be adopted.

[0025] The additive is 4-(2-aminoethyl)benzenesulfonic acid hydrochloride;

[0026] The additive 4-(2-aminoethyl)benzenesulfonic acid hydrochloride is introduced into the perovskite light absorption layer by dissolving it in the perovskite precursor solution;

[0027] The dosage of the additive is 0.1-1.5 mg / mL.

[0028] Advantages and positive effects of the present invention:

[0029] The present invention provides a method for improving the efficiency of perovskite solar cells. By dissolving the additive 4-(2-aminoethyl)benzenesulfonic acid hydrochloride in the perovskite precursor solution and introducing it into the perovskite light absorption layer, the efficiency of perovskite solar cells is improved. On the one hand, the additive can passivate the shallow energy level and deep energy level defects inside the perovskite, effectively reducing the perovskite defect density; on the other hand, a more intrinsic perovskite absorption layer is realized, which is conducive to the balanced extraction of electrons and holes, thereby significantly improving the open circuit voltage and power conversion efficiency of the solar cell. Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of the perovskite solar cell described in Example 1;

[0031] Figure 2 It is the J-V curve of the perovskite solar cell described in Example 1;

[0032] Figure 3 It is the J-V curve of the perovskite solar cell described in Example 2;

[0033] Figure 4 It is the J-V curve of the perovskite solar cell described in Example 3;

[0034] Figure 5 It is the J-V curve of the perovskite solar cell described in Example 4;

[0035] Figure 6 It is the J-V curve of the perovskite solar cell described in Comparative Example 1;

[0036] Figure 7 Schematic diagram of the structure of the wide-bandgap perovskite-based tandem solar cell described in Example 5;

[0037] Figure 8 J-V curve of the wide-bandgap perovskite-based tandem solar cell described in Example 5;

[0038] Figure 9 J-V curve of the wide-bandgap perovskite-based tandem solar cell described in Comparative Example 2. Detailed implementation manners

[0039] The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are provided to better understand the present invention further, and are not limited to the best implementation manners, and do not constitute a limitation to the content and protection scope of the present invention. For those without specific experimental steps or conditions noted in the embodiments, the operations or conditions of the conventional experimental steps described in the literature in the art can be followed. For those reagents or instruments without the manufacturer noted, they are all conventional reagent products that can be obtained through commercial purchase.

[0040] Example 1

[0041] The bandgap of a P-I-N type perovskite solar cell provided in this example is about 1.68 eV, and the structure is as Figure 1 shown, including, from bottom to top in sequence: ITO conductive glass, NiO x (HTL), Me-4PACz (HTL), perovskite light absorption layer, MP (interface modification layer), PCBM (ETL), BCP (buffer layer), silver electrode.

[0042] The P-I-N type perovskite solar cell in this example is prepared by a one-step solution method, including the following steps:

[0043] Step 1, pretreatment of the transparent electrode: The ITO conductive glass is successively cleaned with a detergent, deionized water, acetone and isopropanol, then dried with nitrogen, and treated with ultraviolet ozone.

[0044] Step 2, preparation of the hole transport layer: (1) Spin-coat a NiO x solution on the surface of the pretreated ITO conductive glass as the hole transport layer; (2) Transfer the substrate to an N2 glove box, and spin-coat a Me-4PACz solution on the surface of NiO x as the hole transport layer; (3) Clean the Me-4PACz thin film with an ethanol solvent to remove uncoordinated Me-4PACz molecules.

[0045] Step 3, preparing the perovskite light absorption layer: (1) Dissolve 0.4 mg of 4-(2-aminoethyl)benzenesulfonic acid hydrochloride in 1 mL of 1.3 M Cs x FA 1-x Pb(I y Br 1-y )3 perovskite precursor solution, with the solvent being DMF / DMSO (3 / 1: v / v); (2) Uniformly cover the surface of the hole transport layer with 50 μL of the perovskite precursor solution obtained in step (1), and quickly add 200 μL of the antisolvent during the spin-coating process; (3) Anneal the obtained wet film at 130 °C for 20 min and cool it to room temperature to obtain the perovskite light absorption layer.

[0046] Step 4, preparing the interface modification layer: Spin-coat the MP solution (MAI: PEAI = 1 mg: 2 mg) on the perovskite surface as the interface modification layer.

[0047] Step 5, preparing the electron transport layer: Prepare a PCBM layer on the surface of the interface modification layer as the electron transport layer.

[0048] Step 6, preparing the buffer layer: Prepare a BCP layer on the surface of the electron transport layer as the buffer layer.

[0049] Step 7, preparing the metal electrode: Prepare a metal silver electrode on the surface of the buffer layer.

[0050] Step 8, photovoltaic performance test: The effective area of the perovskite solar cell device prepared by the above method is 0.08875 cm 2 , and it is measured under the illumination intensity of 100 mW / cm 2 (AM 1.5G), with the scanning range from 1.3 V to 0 V and the scanning step of 0.02 V.

[0051] The J-V characteristic curve of the obtained perovskite solar cell is as Figure 2 shown, and it can be seen from Figure 2 that the open-circuit voltage of the perovskite solar cell is 1.211 V, the fill factor is 82.21%, the short-circuit current density is 20.80 mA / cm 2 , and the power conversion efficiency is 20.71%.

[0052] Example 2

[0053] The bandgap of a P-I-N type perovskite solar cell provided in this example is about 1.68 eV, and the structure is as Figure 1 shown, including in sequence from bottom to top: ITO conductive glass, NiO x (HTL), Me-4PACz (HTL), perovskite light absorption layer, MP (interface modification layer), PCBM (ETL), BCP (buffer layer), silver electrode.

[0054] The P-I-N type perovskite solar cell of this embodiment is prepared by a one-step solution method, including the following steps:

[0055] Step 1, pretreatment of the transparent electrode: Clean the ITO conductive glass successively with a detergent, deionized water, acetone and isopropanol, then dry it with nitrogen and perform ultraviolet ozone treatment.

[0056] Step 2, preparation of the hole transport layer: (1) Spin-coat a NiO x solution on the surface of the pretreated ITO conductive glass as the hole transport layer; (2) Transfer the substrate to an N2 glove box and spin-coat a Me-4PACz solution on the surface of the NiO x as the hole transport layer; (3) Wash the Me-4PACz film with an ethanol solvent to remove uncoordinated Me-4PACz molecules.

[0057] Step 3, preparation of the perovskite light absorption layer: (1) Dissolve 0.6 mg of 4-(2-aminoethyl)benzenesulfonic acid hydrochloride in 1 mL of 1.3 M Cs x FA 1-x Pb(I y Br 1-y )3 perovskite precursor solution, and the solvent is DMF / DMSO (3 / 1: v / v); (2) Uniformly cover the surface of the hole transport layer with 50 μL of the perovskite precursor solution obtained in step (1), and quickly add 200 μL of an antisolvent during the spin-coating process; (3) Anneal the obtained wet film at 130 °C for 20 min and cool it to room temperature to obtain the perovskite light absorption layer.

[0058] Step 4, preparation of the interface modification layer: Spin-coat an MP solution (MAI: PEAI = 1 mg: 2 mg) on the perovskite surface as the interface modification layer.

[0059] Step 5, preparation of the electron transport layer: Prepare a PCBM layer on the surface of the interface modification layer as the electron transport layer.

[0060] Step 6, preparation of the buffer layer: Prepare a BCP layer on the surface of the electron transport layer as the buffer layer.

[0061] Step 7, preparation of the metal electrode: Prepare a metal silver electrode on the surface of the buffer layer.

[0062] Step 8, photovoltaic performance test: The effective area of the perovskite solar cell device prepared by the above method is 0.08875 cm 2 , and it is measured under a light intensity of 100 mW / cm 2 (AM 1.5G), and the scanning range is from 1.3 V to 0 V with a scanning step of 0.02 V.

[0063] The J-V characteristic curve of the obtained perovskite solar cell is as follows Figure 3 shown. It can be seen from Figure 3 that the open-circuit voltage of the perovskite solar cell is 1.231 V, the fill factor is 84.27%, the short-circuit current density is 21.01 mA / cm 2 , and the power conversion efficiency is 21.80%.

[0064] Example 3

[0065] The bandgap of a P-I-N type perovskite solar cell provided in this example is about 1.68 eV, and the structure is as follows Figure 1 shown, which includes, from bottom to top in sequence: ITO conductive glass, NiO x (HTL), Me-4PACz (HTL), perovskite light absorption layer, MP (interface modification layer), PCBM (ETL), BCP (buffer layer), and silver electrode.

[0066] The P-I-N type perovskite solar cell in this example is prepared by a one-step solution method, including the following steps:

[0067] Step 1, pretreatment of the transparent electrode: Clean the ITO conductive glass successively with a detergent, deionized water, acetone, and isopropyl alcohol, then dry it with nitrogen, and perform ultraviolet ozone treatment.

[0068] Step 2, preparation of the hole transport layer: (1) Spin-coat a NiO x solution on the surface of the pretreated ITO conductive glass as the hole transport layer; (2) Transfer the substrate to a N2 glove box and spin-coat a Me-4PACz solution on the surface of NiO x as the hole transport layer; (3) Clean the Me-4PACz thin film with an ethanol solvent to remove uncoordinated Me-4PACz molecules.

[0069] Step 3, preparation of the perovskite light absorption layer: (1) Dissolve 0.8 mg of 4-(2-aminoethyl)benzenesulfonic acid hydrochloride in 1 mL of 1.3 M Cs x FA 1-x Pb(I y Br 1-y )3 perovskite precursor solution, and the solvent is DMF / DMSO (3 / 1: v / v); (2) Uniformly cover the surface of the hole transport layer with 50 μL of the perovskite precursor solution obtained in step (1), and quickly drop 200 μL of an antisolvent during the spin-coating process; (3) Anneal the obtained wet film at 130 °C for 20 min and cool it to room temperature to obtain the perovskite light absorption layer.

[0070] Step 4, preparation of the interface modification layer: Spin-coat an MP solution (MAI: PEAI = 1 mg: 2 mg) on the perovskite surface as the interface modification layer.

[0071] Step 5, preparing the electron transport layer: preparing a PCBM layer on the surface of the interface modification layer as the electron transport layer.

[0072] Step 6, preparing the buffer layer: preparing a BCP layer on the surface of the electron transport layer as the buffer layer.

[0073] Step 7, preparing the metal electrode: preparing a silver metal electrode on the surface of the buffer layer.

[0074] Step 8, photovoltaic performance testing: the effective area of the perovskite solar cell device prepared by the above method is 0.08875 cm 2 , and it is measured under the illumination intensity of 100 mW / cm 2 (AM 1.5G), the scanning range is from 1.3 V to 0 V, and the scanning step is 0.02 V.

[0075] The J-V characteristic curve of the obtained perovskite solar cell is as Figure 4 shown, and it can be known from Figure 4 that the open-circuit voltage of the perovskite solar cell is 1.244 V, the fill factor is 84.64%, and the short-circuit current density is 21.37 mA / cm 2 , and the power conversion efficiency is 22.49%.

[0076] Example 4

[0077] The band gap of a P-I-N type perovskite solar cell provided in this example is about 1.68 eV, and the structure is as Figure 1 shown, which successively includes from bottom to top: ITO conductive glass, NiO x (HTL), Me-4PACz (HTL), perovskite light absorption layer, MP (interface modification layer), PCBM (ETL), BCP (buffer layer), silver electrode.

[0078] The P-I-N type perovskite solar cell in this example is prepared by a one-step solution method, including the following steps:

[0079] Step 1, pretreatment of the transparent electrode: cleaning the ITO conductive glass successively with a detergent, deionized water, acetone and isopropyl alcohol, then drying it with nitrogen, and treating it with ultraviolet ozone.

[0080] Step 2, preparing the hole transport layer: (1) spin-coating a NiO x solution on the surface of the pretreated ITO conductive glass as the hole transport layer; (2) transferring the substrate to a N2 glove box and spin-coating a Me-4PACz solution on the surface of NiO x as the hole transport layer; (3) cleaning the Me-4PACz film with an ethanol solvent to remove uncoordinated Me-4PACz molecules.

[0081] Step 3, preparing the perovskite light absorption layer: (1) Dissolve 1.0 mg of 4-(2-aminoethyl)benzenesulfonic acid hydrochloride in 1 mL of 1.3 M Cs x FA 1-x Pb(I y Br 1-y )3 perovskite precursor solution, and the solvent is DMF / DMSO (3 / 1: v / v); (2) Uniformly cover the surface of the hole transport layer with 50 μL of the perovskite precursor solution obtained in step (1), and quickly drop 200 μL of the antisolvent during the spin-coating process; (3) Anneal the obtained wet film at 130 °C for 20 min and cool it to room temperature to obtain the perovskite light absorption layer.

[0082] Step 4, preparing the interface modification layer: Spin-coat the MP solution (MAI: PEAI = 1 mg: 2 mg) on the perovskite surface as the interface modification layer.

[0083] Step 5, preparing the electron transport layer: Prepare a PCBM layer on the surface of the interface modification layer as the electron transport layer.

[0084] Step 6, preparing the buffer layer: Prepare a BCP layer on the surface of the electron transport layer as the buffer layer.

[0085] Step 7, preparing the metal electrode: Prepare a metal silver electrode on the surface of the buffer layer.

[0086] Step 8, photovoltaic performance test: The effective area of the perovskite solar cell device prepared by the above method is 0.08875 cm 2 , and it is measured under the illumination intensity of 100 mW / cm 2 (AM 1.5G). The scanning range is from 1.3 V to 0 V, and the scanning step is 0.02 V.

[0087] The J-V characteristic curve of the obtained perovskite solar cell is as Figure 5 shown. It can be seen from Figure 5 that the open-circuit voltage of the perovskite solar cell is 1.235 V, the fill factor is 84.24%, the short-circuit current density is 21.09 mA / cm 2 , and the power conversion efficiency is 21.95%.

[0088] Comparative Example 1

[0089] The band gap of a P-I-N type perovskite solar cell provided in this example is about 1.68 eV, and the structure is as Figure 1 shown, which sequentially includes from bottom to top: ITO conductive glass, NiO x(HTL), Me-4PACz (HTL), perovskite light absorption layer, MP (interface modification layer), PCBM (ETL), BCP (buffer layer), silver electrode.

[0090] The P-I-N type perovskite solar cell in this embodiment is prepared by a one-step solution method, including the following steps:

[0091] Step 1, pretreatment of the transparent electrode: Clean the ITO conductive glass successively with a detergent, deionized water, acetone and isopropanol, then dry it with nitrogen, and perform ultraviolet ozone treatment.

[0092] Step 2, preparation of the hole transport layer: (1) Spin-coat a NiO x solution on the surface of the pretreated ITO conductive glass as the hole transport layer; (2) Transfer the substrate to a N2 glove box and spin-coat a Me-4PACz solution on the surface of NiO x as the hole transport layer; (3) Wash the Me-4PACz film with an ethanol solvent to remove uncoordinated Me-4PACz molecules.

[0093] Step 3, preparation of the perovskite light absorption layer: (1) Prepare a 1.3M Cs x FA 1-x Pb(I y Br 1-y )3 perovskite precursor solution in a DMF / DMSO (3 / 1: v / v) co-solvent; (2) Uniformly cover the surface of the hole transport layer with 50 μL of the perovskite precursor solution obtained in step (1), and quickly add 200 μL of an anti-solvent during the spin-coating process; (3) Anneal the obtained wet film at 130 °C for 20 min and cool it to room temperature to obtain the perovskite light absorption layer.

[0094] Step 4, preparation of the interface modification layer: Spin-coat an MP solution (MAI: PEAI = 1 mg: 2 mg) on the perovskite surface as the interface modification layer.

[0095] Step 5, preparation of the electron transport layer: Prepare a PCBM layer on the surface of the interface modification layer as the electron transport layer.

[0096] Step 6, preparation of the buffer layer: Prepare a BCP layer on the surface of the electron transport layer as the buffer layer.

[0097] Step 7, preparation of the metal electrode: Prepare a metal silver electrode on the surface of the buffer layer.

[0098] Step 8, photovoltaic performance test: The effective area of the perovskite solar cell device prepared by the above method is 0.08875 cm 2 , under 100 mW / cm 2Measured under the light intensity (AM 1.5G), the scanning range is from 1.3V to 0V, and the scanning step is 0.02V.

[0099] The J-V characteristic curve of the obtained perovskite solar cell is as Figure 6 shown. It can be seen from Figure 6 that the open-circuit voltage of the perovskite solar cell is 1.184V, the fill factor is 81.21%, and the short-circuit current density is 20.68mA / cm 2 , and the power conversion efficiency is 19.88%.

[0100] Example 5

[0101] The perovskite-based tandem solar cell provided in this example is a perovskite / silicon tandem solar cell, and its structure is as Figure 7 shown, which successively includes from bottom to top: back electrode Ag, ITO (back transparent electrode), a-Si-p + (hole-selective layer), a-Si-i (passivation layer), silicon substrate N-type-Si, a-Si-i (passivation layer), a-Si-n + (electron-selective layer), ITO (connection layer), NiO x (perovskite cell HTL), Me-4PACz (perovskite cell HTL), perovskite light absorption layer, MP (interface modification layer), C 60 (perovskite cell ETL), ALD-SnO x (buffer layer), IZO (transparent conductive thin film), metal grid silver electrode.

[0102] In the perovskite / silicon tandem solar cell of this example, the silicon heterojunction bottom cell uses a single-side polished and single-textured silicon heterojunction bottom cell, and the perovskite absorption layer is a P-I-N type wide-bandgap organic-inorganic hybrid perovskite prepared by a one-step solution method. The perovskite / silicon tandem solar cell of this example is prepared by the following method:

[0103] Step 1, prepare the passivation layer of the silicon heterojunction bottom cell: deposit an a-Si-i passivation layer on both the front and back sides of the N-type silicon wafer.

[0104] Step 2, prepare the hole transport layer and electron transport layer of the silicon heterojunction bottom cell: deposit an a-Si-n + layer and an a-Si-p + layer on the upper and lower surfaces of the prepared sample respectively, as the electron-selective layer and hole-selective layer of the Si bottom cell.

[0105] Step 3, prepare the back transparent electrode of the silicon heterojunction bottom cell: prepare an ITO transparent electrode on the surface of the a-Si-p + layer.

[0106] Step 4, preparing the connection layer of the perovskite / silicon tandem solar cell: preparing a layer of ITO connection layer on the surface of the a-Si-n + layer.

[0107] Step 5, preparing the hole transport layer of the perovskite cell: (1) preparing a layer of NiO x thin film on the surface of the ITO connection layer; (2) transferring the sample to a glove box protected by nitrogen, and spin-coating the Me-4PACz solution on the surface of the NiO x as the hole transport layer; (3) cleaning the Me-4PACz thin film with an ethanol solvent to remove the uncoordinated Me-4PACz molecules.

[0108] Step 6, preparing the perovskite light absorption layer: (1) dissolving 0.8 mg of 4-(2-aminoethyl)benzenesulfonic acid hydrochloride in 1 mL of 1.3 M Cs x FA 1-x Pb(I y Br 1-y )3 perovskite precursor solution, and the solvent is DMF / DMSO (3 / 1: v / v); (2) uniformly covering 50 μL of the perovskite precursor solution obtained in step (1) on the surface of the hole transport layer, and quickly dropping 200 μL of the anti-solvent during the spin-coating process; (3) quickly annealing the obtained wet film at 130 °C for 20 min and cooling it to room temperature to obtain the perovskite light absorption layer.

[0109] Step 7, preparing the interface modification layer: spin-coating the MP solution (MAI: PEAI = 1 mg: 2 mg) on the perovskite surface as the interface modification layer.

[0110] Step 8, preparing the electron transport layer of the perovskite solar cell: preparing a C 60 layer on the perovskite layer as the electron transport layer.

[0111] Step 9, preparing the buffer layer: preparing a SnO2 buffer layer on the surface of the C 60 surface.

[0112] Step 10, preparing the transparent conductive thin film: preparing IZO on the SnO2 surface as the transparent electrode.

[0113] Step 11, preparing the metal electrode: preparing a silver back electrode and a metal grid silver electrode on the bottom ITO surface and the top IZO surface.

[0114] Step 12, photovoltaic performance test: the effective area of the perovskite / silicon tandem solar cell device prepared by the above method is 1.05 cm 2 , measured under the illumination intensity of 100 mW / cm 2 (AM 1.5G), the scanning range is from 2.0 V to 0 V, and the scanning step is 0.02 V.

[0115] The J-V characteristic curve of the obtained perovskite / silicon tandem solar cell is as Figure 8 shown. It can be seen from Figure 8 that the open-circuit voltage of the perovskite / silicon tandem solar cell is 1.919 V, the fill factor is 79.58%, and the short-circuit current density is 16.51 mA / cm 2 , and the power conversion efficiency is 25.22%.

[0116] Comparative Example 2

[0117] The perovskite-based tandem solar cell provided in this comparative example is a perovskite / silicon tandem solar cell, and the structure is as Figure 7 shown, which successively includes from bottom to top: back electrode Ag, ITO (back transparent electrode), a-Si-p + (hole-selective layer), a-Si-i (passivation layer), silicon substrate N-type-Si, a-Si-i (passivation layer), a-Si-n + (electron-selective layer), ITO (connection layer), NiO x (perovskite cell HTL), Me-4PACz (perovskite cell HTL), perovskite light absorption layer, MP (interface modification layer), C 60 (perovskite cell ETL), ALD-SnO x (buffer layer), IZO (transparent conductive thin film), metal grid silver electrode.

[0118] In the perovskite / silicon tandem solar cell of this example, the silicon heterojunction bottom cell uses a single-side polished and single-textured silicon heterojunction bottom cell, and the perovskite absorption layer is a P-I-N type wide-bandgap organic-inorganic hybrid perovskite prepared by a one-step solution method. The perovskite / silicon tandem solar cell of this example is prepared by the following method:

[0119] Step 1, prepare the passivation layer of the silicon heterojunction bottom cell: deposit an a-Si-i passivation layer on both the front and back sides of the N-type silicon wafer.

[0120] Step 2, prepare the hole transport layer and electron transport layer of the silicon heterojunction bottom cell: deposit an a-Si-n + layer and an a-Si-p + layer on the upper and lower surfaces of the prepared sample respectively, as the electron-selective layer and hole-selective layer of the Si bottom cell.

[0121] Step 3, prepare the back transparent electrode of the silicon heterojunction bottom cell: prepare an ITO transparent electrode on the surface of the a-Si-p + layer.

[0122] Step 4, prepare the connection layer of the perovskite / silicon tandem solar cell: on the a-Si-n +Prepare an ITO connection layer on the layer surface.

[0123] Step 5, prepare the hole transport layer of the perovskite solar cell: (1) Prepare a layer of NiO x thin film on the surface of the ITO connection layer; (2) Transfer the sample to a glove box protected by nitrogen, and spin-coat the Me-4PACz solution on the surface of NiO x as the hole transport layer; (3) Wash the Me-4PACz thin film with an ethanol solvent to remove uncoordinated Me-4PACz molecules.

[0124] Step 6, prepare the perovskite light absorption layer: (1) Prepare a 1.3M Cs x FA 1-x Pb(I y Br 1-y )3 perovskite precursor solution in a DMF / DMSO (3 / 1:v / v) co-solvent; (2) Uniformly cover the surface of the passivation layer with 50 μL of the perovskite precursor solution obtained in step (1), and quickly add 200 μL of an anti-solvent during the spin-coating process; (3) Anneal the obtained wet film at 130 °C for 20 min and cool it to room temperature to obtain the perovskite light absorption layer.

[0125] Step 7, prepare the interface modification layer: Spin-coat the MP solution (MAI:PEAI = 1 mg:2 mg) on the perovskite surface as the interface modification layer.

[0126] Step 8, prepare the electron transport layer of the perovskite solar cell: Prepare a C 60 layer on the perovskite layer surface as the electron transport layer.

[0127] Step 9, prepare the buffer layer: Prepare a SnO2 buffer layer on the surface of C 60 surface.

[0128] Step 10, prepare the transparent conductive thin film: Prepare IZO on the SnO2 surface as the transparent electrode.

[0129] Step 11, prepare the metal electrode: Prepare a silver back electrode and a metal grid silver electrode on the bottom ITO surface and the top IZO surface.

[0130] Step 12, photovoltaic performance test: The effective area of the perovskite / silicon tandem solar cell device prepared by the above method is 1.05 cm 2 , and it is measured under a light intensity of 100 mW / cm 2 (AM 1.5G). The scanning range is from 2.0 V to 0 V, and the scanning step is 0.02 V.

[0131] The J-V characteristic curve of the obtained perovskite / silicon tandem solar cell in Comparative Example 2 is as Figure 9 shown, and it is composed of Figure 9It can be seen that the open-circuit voltage of the perovskite solar cell is 1.851 V, the fill factor is 75.94%, and the short-circuit current density is 16.52 mA / cm 2 , and the power conversion efficiency is 23.23%.

[0132] In summary, in the present invention, 4-(2-aminoethyl)benzenesulfonic acid hydrochloride is introduced into the perovskite precursor solution, which maximally eliminates the shallow and deep energy level defect densities of the perovskite absorption layer and reduces non-radiative recombination. At the same time, the additive induces the formation of a more intrinsic perovskite absorption layer, which is beneficial to the balanced extraction of electrons and holes, thereby significantly improving the open-circuit voltage and power conversion efficiency of the solar cell. This method is simple to operate, easy to implement, has a high repetition rate, and has good application prospects.

[0133] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for improving the efficiency of perovskite solar cells, characterized in that: The battery structure includes, from bottom to top, a bottom substrate, a transparent electrode, a hole transport layer, a perovskite light absorption layer, an interface modification layer, an electron transport layer, a buffer layer, and a metal electrode; A new additive 4-(2-aminoethyl)benzenesulfonic acid hydrochloride is introduced into the perovskite absorption layer. The additive is introduced into the perovskite light absorption layer by being dissolved in a perovskite precursor solution.

2. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The perovskite solar cell is a PIN-type wide bandgap perovskite solar cell; The perovskite solar cell includes a single-junction perovskite solar cell or a perovskite-based tandem solar cell; The band gap of the perovskite solar cell is 1.6 to 1.8 eV; The perovskite material is an organic-inorganic hybrid multi-halogen mixed perovskite material.

3. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The transparent electrode is one or more of a FTO transparent electrode, an ITO transparent electrode, an IZO transparent electrode, an IZrO transparent electrode, and an AZO transparent electrode.

4. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The hole transport layer is PTAA, Poly-TPD, Spiro-TTB, PEDOT:PSS, P3HT, self-assembled monolayer, CuSCN, NiO x One or more hole transport materials; The self-assembled monolayer comprises one or more of (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid, and (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid self-assembled monolayers.

5. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The electron transport layer is SnO2, TiO2, ZnO, PCBM, C 60 Or one or more of fullerene derivative electron transport materials.

6. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The interface modification layer includes one or more of PEAI, MAI, 2-thiopheneethylamine iodide, ethylenediamine dihydroiodide, 1,3-diaminopropane dihydroiodide, bis(2-hydroxyethyl)dimethylammonium chloride, and choline chloride; The buffer layer is one or more of BCP, PEI, SnO2, Al2O3, SiO2, LiF or MgF2.

7. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The metal electrode material is one or more of Ag, Au, Cu and Al.

8. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The bottom substrate includes one or more of transparent glass, a flexible PET substrate, a flexible PEN substrate, a silicon bottom cell, a copper indium gallium selenide bottom cell, a perovskite bottom cell, and a CdTe bottom cell.

9. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The perovskite absorption layer preparation method is one or more of spin coating, blade coating, and slit coating; In the spin coating method, the spin coating speed is 3000-7000 r / min, the spin coating time is 40-60 s, the annealing temperature is 100-130° C., and the annealing time is 15-30 min.

10. The method for improving the efficiency of perovskite solar cells according to claim 1, characterized in that: The dosage of the additive is 0.1-1.5 mg / mL.

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