A perovskite solar cell

Abstract

The present invention relates to the field of solar cell technology, and in particular to a perovskite solar cell. The present invention provides a perovskite solar cell, comprising a bottom substrate, a bottom electrode layer, a hole transport layer, a passivation layer, a perovskite photoactive layer, an interface modification layer, an electron transport layer, a buffer layer and a top electrode layer stacked in sequence from bottom to top; the material of the interface modification layer is bis(2-hydroxyethyl)dimethylammonium chloride. The material of the interface modification layer in the perovskite solar cell can passivate the surface defects of the perovskite well, thereby improving the stability of the solar cell.

Description

Technical Field

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

[0002] In recent years, metal halide perovskite materials have attracted widespread attention in the field of solar cells. Their power conversion efficiency has reached 25.7% in just a few years, which is close to the best efficiency of crystalline silicon solar cells. However, as its efficiency gradually approaches the Shockley-Queisser limit, further improvement becomes more difficult. Stacking wide-bandgap materials on narrow-bandgap cell layers to form a tandem cell can expand the spectral response of the cell, maximize the use of solar energy, and thus break through the theoretical limit of single-junction cells. The quality of the top cell of wide-bandgap perovskite (1.65-1.75eV) is a key factor in the preparation of efficient tandem solar cells. Wide-bandgap perovskites are obtained by partially replacing iodine with bromine in the lattice. They are easily separated into different halide phases under light, which locally changes the bandgap, not only adversely affecting the current matching of the tandem cell, but also impairing the long-term stability of the cell. Studies have shown that there is a strong correlation between halide segregation and perovskite surface and grain boundary defects and ion migration. As a mixture of ions containing positive and negative charges, the perovskite surface is a strongly sensitive interface affected by processing details and environmental conditions. The complex solution precursor composition and rapid heating annealing will cause a large number of defects to form on the surface of the perovskite light absorbing layer. These defects include intrinsic point defects, uncoordinated Pb 2+ and organic cations (MA) during heating annealing + / FA +) vacancy defects formed by volatilization, etc. These defects can lead to interface charge capture, non-radiative recombination and hysteresis. Under the influence of external stress, the defect state can lead to charge accumulation and ion migration, thus leading to the destruction of the material lattice. Considering the ionic bonding nature of halide perovskite materials, molecular modification has become an important means to passivate their surface defects. At present, materials that can passivate perovskite defects have been reported one after another. Chen et al. used 4-fluoro-phenylethylammonium iodide as a bifunctional reagent for directional crystallization and defect passivation of wide-bandgap perovskites, which improved the crystallinity and spontaneously formed RP-type 2D perovskites at the perovskite grain boundaries and surfaces, reducing defects and protecting the perovskite film from moisture erosion. Zhou et al. (Zhou Y, Wang F, Cao Y, et al. Benzylamine-treated wide-bandgap perovskite with high thermal-photostability and photovoltaic performance [J]. Advanced Energy Materials, 2017, 7 (22): 1701048.) used benzylamine molecules to post-treat wide-bandgap perovskite films, which can effectively passivate the high-density defects on the film surface and grain boundaries, thereby inhibiting the decomposition of the film and the photoinduced phase segregation problem. Li et al. (Li H, Shi J, Deng J, et al. Intermolecular π–π conjugation self-assembly to stabilize surface passivation of highly efficient perovskite solar cells [J]. Advanced materials, 2020, 32 (23): 1907396.) introduced tribenzylphosphine oxide on the perovskite surface to achieve perovskite surface passivation through strong -P=O-Pb coordination on the perovskite surface and intermolecular π-π conjugation. Xiong et al. (Xiong J, Liu N, Hu X, et al. Bulk Restructure of Perovskite Films via Surface Passivation for High-Performance Solar Cells[J]. Advanced Energy Materials, 2022, 12(33): 2201787.) proposed to post-treat the perovskite surface with N-benzyloxycarbonyl-D-valine, which significantly eliminated the perovskite trap states and caused secondary grain growth, resulting in increased crystallinity.However, in most cases, the reported passivators can only passivate one type of defect, and the passivation effect is limited. Therefore, it is very important to develop a multifunctional molecule to passivate multiple defects of perovskite. In addition, from a structural point of view, perovskite solar cells are composed of multiple functional layer materials. Whether the carriers generated by the perovskite active layer after absorbing sunlight can pass through each interface smoothly during the transmission process depends largely on whether the energy level structure matches. Therefore, the energy level optimization at the interface is another key factor in obtaining high-efficiency batteries in addition to improving the crystal quality. Summary of the invention

[0003] The object of the present invention is to provide a perovskite solar cell, wherein the material of the interface modification layer in the perovskite solar cell can passivate the surface defects of the perovskite and improve the stability of the solar cell.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a perovskite solar cell, comprising a bottom substrate, a bottom electrode layer, a hole transport layer, a passivation layer, a perovskite photoactive layer, an interface modification layer, an electron transport layer, a buffer layer and a top electrode layer stacked in sequence from bottom to top;

[0006] The material of the interface modification layer is bis(2-hydroxyethyl)dimethylammonium chloride.

[0007] Preferably, the perovskite solar cell is a PIN-type perovskite solar cell;

[0008] The perovskite solar cell is a wide bandgap perovskite solar cell or a wide bandgap perovskite-based tandem solar cell;

[0009] The band gap of the perovskite solar cell is 1.6-1.72 eV.

[0010] Preferably, the bottom electrode layer is one or more of an ITO transparent electrode layer, a FTO transparent electrode layer, an AZO transparent electrode layer, an IGZO transparent electrode layer, a graphene-oxide electrode, and an oxide-metal-oxide multilayer composite transparent electrode;

[0011] The oxide in the graphene-oxide electrode or the oxide in the oxide-metal-oxide multilayer composite transparent electrode independently includes one or more of bismuth oxide, molybdenum oxide, tungsten oxide, tin oxide, titanium oxide, nickel oxide and zinc oxide;

[0012] The metal in the oxide-metal-oxide multilayer composite transparent electrode includes one or more of gold, silver, copper and aluminum.

[0013] Preferably, the top electrode layer is a metal electrode and / or a carbon material electrode;

[0014] The material of the buffer layer includes one or more of BCP, Cu2O, molybdenum oxide, PEI, SnO2, Zr(AC)4, TPBi and nano ZnO.

[0015] Preferably, the material of the metal electrode includes one or more of gold, silver, copper and aluminum;

[0016] The carbon material of the carbon material electrode includes one or more of carbon black, graphite and multi-walled carbon nanotubes.

[0017] Preferably, the bottom substrate is one or more of transparent glass, a flexible PET substrate, a flexible PEN substrate, a Si bottom cell, a CIGS bottom cell, a CZTS bottom cell, a PSC bottom cell and a CdTe bottom cell.

[0018] Preferably, the material of the hole transport layer is one or more of PTAA, Spiro-TTB, nitrogen oxide, fullerene derivatives and self-limiting monolayer;

[0019] The material of the self-limiting monolayer includes one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid and [2-(9H-carbazole-9-yl)ethyl]phosphonic acid;

[0020] The material of the electron transport layer is SnO2, TiO2, ZnO, PCBM, C 60 , zinc tin oxide, and graphene.

[0021] Preferably, the material of the perovskite photoactive layer is an ABX3 type perovskite semiconductor material;

[0022] Wherein, A is one or more of alkylamine, alkylamidine and alkali element, and the alkali element is rubidium and / or cesium; B is lead; and X is one or more of iodine, bromine and chlorine.

[0023] Preferably, the method for preparing the interface modification layer comprises the following steps:

[0024] Mixing bis(2-hydroxyethyl)dimethylammonium chloride and an organic solvent to obtain a slurry;

[0025] After the slurry is coated on the surface of the perovskite photoactive layer, annealing is performed to obtain the interface modification layer.

[0026] Preferably, the coating method is spin coating, and the rotation speed of the spin coating is 3000-7000 rpm;

[0027] The annealing temperature is 100-130° C. and the annealing time is 5-15 minutes.

[0028] The present invention provides a perovskite solar cell, comprising a bottom substrate, a bottom electrode layer, a hole transport layer, a passivation layer, a perovskite photoactive layer, an interface modification layer, an electron transport layer, a buffer layer and a top electrode layer stacked in sequence from bottom to top; the material of the interface modification layer is bis(2-hydroxyethyl)dimethylammonium chloride. The present invention uses bis(2-hydroxyethyl)dimethylammonium chloride as a modification material for the perovskite photoactive layer to passivate the surface defects of the perovskite surface, and the bis(2-hydroxyethyl)dimethylammonium chloride is used as a modification material for the perovskite photoactive layer. - With Pb 2+ Binding can inhibit Pb 0 The choline group in the bis(2-hydroxyethyl)dimethylammonium chloride can fill the cation vacancies formed by the volatilization of organic matter, and Cl - It can passivate halogen vacancies, reduce the defect state density of the perovskite photoactive layer, and at the same time form a more suitable energy level structure, which is beneficial to the extraction and transmission of holes, improves the open circuit voltage of the battery, and has significantly improved battery efficiency and repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of the perovskite solar cell described in Comparative Example 1;

[0030] Figure 2 is the JV curve of the perovskite solar cell described in Comparative Example 1;

[0031] Figure 3 is the JV curve of the perovskite solar cell described in Example 1;

[0032] Figure 4 A comparison chart of the photoelectric conversion efficiency, open circuit voltage, fill factor and short circuit current density of the perovskite solar cells described in Examples 1 to 4;

[0033] Figure 5 The XRD pattern of the interface modification layer prepared in Example 1;

[0034] Figure 6 This is a schematic diagram of the structure of the wide bandgap perovskite-based tandem solar cell described in Comparative Example 2;

[0035] Figure 7 The JV curve of the wide bandgap perovskite-based tandem solar cell described in Comparative Example 2;

[0036] Figure 8 This is the JV curve of the wide bandgap perovskite-based tandem solar cell described in Example 5. DETAILED DESCRIPTION

[0037] The present invention provides a perovskite solar cell, comprising a bottom substrate, a bottom electrode layer, a hole transport layer, a passivation layer, a perovskite photoactive layer, an interface modification layer, an electron transport layer, a buffer layer and a top electrode layer stacked in sequence from bottom to top;

[0038] The material of the interface modification layer is bis(2-hydroxyethyl)dimethylammonium chloride.

[0039] In the present invention, the chemical formula of the bis(2-hydroxyethyl)dimethylammonium chloride is as shown in Formula 1:

[0040]

[0041] In the present invention, the perovskite solar cell is preferably a wide bandgap perovskite solar cell or a wide bandgap perovskite-based tandem solar cell; the bandgap of the perovskite solar cell is preferably 1.6 to 1.72 eV. The present invention does not have any special restrictions on the area of ​​the wide bandgap perovskite-based tandem solar cell, and any area known to those skilled in the art can be used. In the present invention, the perovskite solar cell is preferably a PIN-type perovskite solar cell.

[0042] In the present invention, the bottom substrate is one or more of transparent glass, flexible PET substrate, flexible PEN substrate, Si bottom cell, CIGS bottom cell, CZTS bottom cell, PSC bottom cell and CdTe bottom cell; the Si bottom cell is preferably a silicon heterojunction cell; when the bottom substrate is transparent glass, flexible PET substrate and flexible PEN substrate, the perovskite solar cell is a wide bandgap perovskite solar cell; when the bottom substrate is one or more of Si bottom cell, CIGS bottom cell, CZTS bottom cell, PSC bottom cell and CdTe bottom cell, the perovskite solar cell is a wide bandgap perovskite-based tandem solar cell; the present invention does not have any special limitation on the specific structure of the Si bottom cell, CIGS bottom cell, CZTS bottom cell, PSC bottom cell and CdTe bottom cell, and the structure familiar to those skilled in the art can be adopted. In an embodiment of the present invention, the bottom substrate is transparent glass or a Si bottom cell; the Si bottom cell is specifically a silicon heterojunction bottom cell; the silicon heterojunction bottom cell comprises, from bottom to top, a silver electrode, a back transparent electrode ITO, a hole selection layer a-Si:H(p), a passivation layer a-Si:H(i), a silicon substrate N-Silicon, a passivation layer a-Si:H(i) and an electron selection layer a-Si:H(n) stacked in sequence; the electron selection layer a-Si:H(n) is in contact with the bottom electrode layer.

[0043] In the present invention, the bottom electrode layer is a transparent electrode layer. In the present invention, the bottom electrode layer is preferably one or more of an ITO transparent electrode layer, a FTO transparent electrode layer, an AZO transparent electrode layer, an IZO transparent electrode layer, an IGZO transparent electrode layer, a graphene-oxide electrode, and an oxide-metal-oxide multilayer composite transparent electrode; the oxide in the graphene-oxide electrode or the oxide in the oxide-metal-oxide multilayer composite transparent electrode independently preferably includes one or more of bismuth oxide, molybdenum oxide, tungsten oxide, tin oxide, titanium oxide, nickel oxide and zinc oxide; the metal in the oxide-metal-oxide multilayer composite transparent electrode includes one or more of gold, silver, copper and aluminum. When the bottom electrode layer is two or more of the above-mentioned specific selections, each electrode layer is preferably stacked. The present invention does not have any special restrictions on the thickness of the bottom electrode layer, and the thickness well known to those skilled in the art can be used.

[0044] In the present invention, the preparation method of the bottom electrode layer is preferably deposition; the present invention does not have any special limitation on the deposition process, and the process well known to those skilled in the art can be used. After the deposition is completed, the present invention also preferably includes cleaning, drying and ozone treatment in sequence; the cleaning is preferably carried out in sequence using a detergent, deionized water, acetone and isopropanol; the present invention does not have any special limitation on the type of the detergent, and the type well known to those skilled in the art can be used. In the present invention, the cleaning is preferably carried out under ultrasonic conditions, and the present invention does not have any special limitation on the ultrasonic process, and the process well known to those skilled in the art can be used. In the present invention, the drying is preferably carried out using N2. In the present invention, the ozone treatment is preferably carried out by ultraviolet ozone treatment.

[0045] In the present invention, the top electrode layer is preferably a metal electrode and / or a carbon material electrode; the material of the metal electrode preferably includes one or more of gold, silver, copper and aluminum; the carbon material of the carbon material electrode preferably includes one or more of carbon black, graphite and multi-walled carbon nanotubes; when the material of the top electrode layer is two or more of the above-mentioned specific selections, the present invention does not have any special restrictions on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. The present invention does not have any special restrictions on the position structure of the top electrode in the electron transport layer, and a metal grid electrode structure familiar to those skilled in the art can be used. The present invention does not have any special restrictions on the thickness of the top electrode layer, and a thickness familiar to those skilled in the art can be used.

[0046] In the present invention, the preparation method of the top electrode layer is preferably thermal evaporation. The present invention has no special limitation on the thermal evaporation process, and the process well known to those skilled in the art can be used.

[0047] In the present invention, the material of the hole transport layer is preferably one or more of PTAA, Spiro-TTB, nitrogen oxide, fullerene derivatives and self-limiting monolayer; the self-limiting monolayer preferably includes one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz) and [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz); when the material of the hole transport layer is two or more of the above-mentioned specific selections, the present invention does not have any special restrictions on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. The present invention does not have any special restrictions on the thickness of the hole transport layer, and the thickness well known to those skilled in the art can be used.

[0048] The present invention has no special limitation on the preparation process of the hole transport layer, and the process can be performed by a process well known to those skilled in the art. In an embodiment of the present invention, the preparation method of the hole transport layer is specifically spin coating.

[0049] In the present invention, the material of the passivation layer is preferably PMMA. The present invention does not have any special limitation on the thickness of the passivation layer, and any thickness known to those skilled in the art can be used.

[0050] The present invention has no special limitation on the preparation process of the passivation layer, and the process can be performed by a process well known to those skilled in the art. In an embodiment of the present invention, the preparation method of the passivation layer is specifically spin coating.

[0051] In the present invention, the material of the perovskite photoactive layer is preferably an ABX3 type perovskite semiconductor material; wherein A is preferably one or more of alkylamine, alkylamidine and alkali element, and the alkali element is rubidium and / or cesium; B is preferably lead; X is preferably one or more of iodine, bromine and chlorine; the alkylamine is preferably methylamine; the alkylamidine is preferably formamidine. The present invention does not have any special limitation on the thickness of the perovskite photoactive layer, and the thickness well known to those skilled in the art can be used.

[0052] In the present invention, the preparation method of the perovskite photoactive layer is preferably a two-step solution method, a one-step anti-solvent method, an evaporation method or a chemical vapor deposition method; the present invention does not have any special limitations on the processes of the two-step solution method, the one-step anti-solvent method, the evaporation method and the chemical vapor deposition method, and conventional methods familiar to those skilled in the art can be used.

[0053] In the present invention, the material of the interface modification layer is bis(2-hydroxyethyl)dimethylammonium chloride. The present invention does not have any special limitation on the thickness of the interface modification layer, and a thickness well known to those skilled in the art can be used; in the present invention, the preparation method of the interface modification layer preferably includes the following steps: mixing bis(2-hydroxyethyl)dimethylammonium chloride and an organic solvent to obtain a slurry; coating the slurry on the surface of the perovskite photoactive layer, and then annealing to obtain the interface modification layer.

[0054] The invention mixes bis(2-hydroxyethyl)dimethylammonium chloride and an organic solvent to obtain slurry.

[0055] In the present invention, the organic solvent is preferably isopropanol.

[0056] The present invention has no special limitation on the mixing process, and the mixing process may be carried out by a process well known to those skilled in the art and ensuring that the bis(2-hydroxyethyl)dimethylammonium chloride is completely dissolved in the organic solvent.

[0057] In the present invention, the concentration of the slurry is preferably 0.2 to 2 mg / mL, more preferably 0.4 to 1.6 mg / mL, and most preferably 0.8 to 1.2 mg / mL.

[0058] After obtaining the slurry, the present invention applies the slurry on the surface of the perovskite photoactive layer and then performs annealing to obtain the interface modification layer.

[0059] In the present invention, the coating method is preferably spray coating, fumigation or spin coating; the spin coating speed is preferably 3000-7000 rpm, more preferably 4000-6000 rpm, and most preferably 5000 rpm; the present invention has no special limitation on the spin coating time, and the time well known to those skilled in the art can be used to obtain the target thickness of the interface modification layer. The present invention has no special limitation on the spray coating and fumigation process, and the process well known to those skilled in the art can be used.

[0060] In the present invention, the annealing temperature is preferably 100-130°C, more preferably 110-120°C, and most preferably 113-116°C; the time is preferably 5-15 min, more preferably 8-12 min. In the present invention, the purpose of annealing is to remove excess organic solvent.

[0061] In the present invention, the preparation process of the interface modification layer is simple to operate. After annealing, the bis(2-hydroxyethyl)dimethylammonium chloride interacts with the surface of the perovskite photoactive layer to achieve interface passivation, reduce surface defects, and inhibit the recombination of carriers. At the same time, the passivated perovskite surface is more n-type, which is more conducive to the transmission of carriers, reduces interface non-radiative recombination, significantly improves the open circuit voltage and fill factor of the solar cell, and increases the photoelectric conversion efficiency of the cell.

[0062] In the present invention, the material of the electron transport layer is preferably SnO2, TiO2, ZnO, PCBM, C 60 , zinc tin oxide, graphene; when the material of the electron transport layer is two or more of the above specific selections, the present invention has no special restrictions on the ratio of the above specific substances, and they can be mixed in any ratio. The present invention has no special restrictions on the thickness of the electron transport layer, and a thickness familiar to those skilled in the art can be used.

[0063] In the present invention, the method for preparing the electron transport layer is preferably spin coating; the present invention does not have any special limitation on the spin coating process, and the process well known to those skilled in the art can be used.

[0064] In the present invention, the material of the buffer layer preferably includes one or more of BCP, Cu2O, molybdenum oxide, PEI, SnO2, Zr(AC)4, TPBi and nano ZnO; when the material of the buffer layer is two or more of the above specific selections, the present invention has no special restrictions on the ratio of the above specific substances, and they can be mixed in any ratio. The present invention has no special restrictions on the thickness of the buffer layer, and a thickness well known to those skilled in the art can be used.

[0065] When the bottom substrate is one or more of Si bottom cell, CIGS bottom cell, CZTS bottom cell, PSC bottom cell and CdTe bottom cell, the perovskite solar cell is preferably provided with a transparent conductive electrode layer between the buffer layer and the top electrode layer; the material of the transparent conductive electrode layer is preferably one or more of ITO, FTO, AZO, IZO, IGZO, graphene-oxide, oxide-metal-oxide; the oxide in the graphene-oxide or the oxide in the oxide-metal-oxide independently preferably includes one or more of bismuth oxide, molybdenum oxide, tungsten oxide, tin oxide, titanium oxide, nickel oxide and zinc oxide; the metal in the oxide-metal-oxide includes one or more of gold, silver, copper and aluminum. When the transparent conductive electrode layer is two or more of the above-mentioned specific selections, each electrode layer is preferably stacked. The present invention does not have any special limitation on the thickness of the transparent conductive electrode layer, and the thickness well known to those skilled in the art can be used.

[0066] The perovskite solar cell provided by the present invention is described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0067] Example 1

[0068] Using glass as the bottom substrate, after depositing a transparent conductive ITO electrode layer on the upper surface of the glass, ultrasonic cleaning is performed with a detergent, deionized water, acetone and isopropanol in sequence, and then dried with N2, and finally treated with ultraviolet ozone for 20 minutes, and placed in a glove box with N2 atmosphere to obtain a bottom electrode layer;

[0069] Spin coating PTAA on the surface of the bottom electrode layer to obtain a hole transport layer;

[0070] Spin coating a PMMA layer on the surface of the hole transport layer;

[0071] 1.13mmol PbI2 and 0.24mmol PbBr2 were dissolved in 1mL of a mixed solvent of DMF and DMSO (the volume ratio of DMF and DMSO in the mixed solvent was 9:1) to obtain a lead-based inorganic solution; 0.34mmol FAI, 0.11mmol MACl and 0.08mmol MABr were dissolved in 1mL of an isopropanol solvent to obtain an organic salt solution; 50μL of the lead-based inorganic solution was spin-coated at a speed of 2200rpm, and annealed on a heating table at 70°C to prepare an inorganic layer, and then 50μL of the organic salt solution was spin-coated at a speed of 2500rpm, annealed at 150°C for 15min in an air atmosphere with a certain humidity (humidity value was 20%-40%), and cooled to room temperature to obtain a perovskite photoactive layer (material was FA 0.88 MA 0.12 Pb(I 0.83 Br 0.17 )3);

[0072] 0.5 mg of bis(2-hydroxyethyl)dimethylammonium chloride was dissolved in 1 mL of isopropanol and dissolved by stirring at room temperature to obtain a slurry; the slurry was spin-coated on the surface of the perovskite photoactive layer, and then annealed on a heating table at 100° C. for 10 min to obtain an interface modification layer ( Figure 5 To prepare the XRD pattern of the interface modification layer, Figure 5 It can be seen that the interface modification layer has an effect on the crystallinity of the perovskite photoactive layer. In the perovskite film with the interface modification layer, the position of the diffraction peak has no obvious change, and no new diffraction peak is observed, indicating that the interface modification layer has not changed the crystal structure of the perovskite photoactive layer).

[0073] Spin coating PCBM on the surface of the interface modification layer to obtain an electron transport layer;

[0074] Spin coating BCP on the surface of the electron transport layer to obtain a buffer layer;

[0075] The silver electrode of the metal grid electrode structure is thermally evaporated on the surface of the buffer layer to obtain a perovskite solar cell.

[0076] The perovskite solar cell was placed under a standard solar intensity (AM1.5, 100 mW / cm 2 ) irradiation, the photoelectric performance of the perovskite solar cell was tested, wherein the JV curve is as follows Figure 3 As shown by Figure 3 It can be seen that the open circuit voltage of the perovskite solar cell is 1.16V, the fill factor is 77.70%, and the short circuit current density is 21.28mA / cm 2 , the photoelectric conversion efficiency is 19.17%.

[0077] Example 2

[0078] Reference Example 1, except that the amount of bis(2-hydroxyethyl)dimethylammonium chloride used is 0.2 mg.

[0079] Example 3

[0080] Reference Example 1, except that the amount of bis(2-hydroxyethyl)dimethylammonium chloride used is 0.7 mg.

[0081] Example 4

[0082] Reference Example 1, except that the amount of bis(2-hydroxyethyl)dimethylammonium chloride used was 1.0 mg.

[0083] Figure 4 is a comparison chart of the photoelectric conversion efficiency, open circuit voltage, fill factor and short circuit current density of the perovskite solar cells described in Examples 1 to 4; Figure 4 It can be seen that the average photoelectric conversion efficiency of the perovskite solar cells in Examples 1 to 4 is 19.6%, 17.4%, 18.6% and 16.4%, respectively; the average open circuit voltage is 1.182V, 1.162V, 1.163V and 1.075V, respectively; the average fill factor is 77.2%, 71.8%, 73.6% and 70.1%, respectively; the average short circuit current density is 21.6 mA / cm 2 , 20.7mA / cm 2 , 21.8mA / cm 2 and 21.9mA / cm 2Among them, the perovskite solar cell of Example 1 has good repeatability and the best efficiency, which is mainly due to the significant improvement of open circuit voltage and fill factor. As the concentration increases, the short-circuit current density of the battery increases, but the open circuit voltage and fill factor decrease.

[0084] Comparative Example 1

[0085] Referring to Example 1, the difference is that after the hole transport layer is obtained, PMMA is spin-coated on the hole transport layer, and then a perovskite photoactive layer is prepared, and then PCBM is spin-coated on the perovskite layer as an electron transport layer to obtain a perovskite solar cell (structure as shown in FIG. Figure 1 shown).

[0086] The perovskite solar cell was placed under a standard solar intensity (AM1.5, 100 mW / cm 2 ) irradiation, the photoelectric performance of the perovskite solar cell was tested, wherein the JV curve is as follows Figure 2 As shown by Figure 2 It can be seen that the open circuit voltage of the perovskite solar cell is 1.12V, the fill factor is 70.82%, and the short circuit current density is 21.06mA / cm 2 , the photoelectric conversion efficiency is 16.76%.

[0087] Example 5

[0088] Wide bandgap perovskite-based tandem solar cells: from bottom to top, they include a silicon heterojunction bottom cell, an ITO transparent electrode, a PTAA hole transport layer, a PMMA layer, a perovskite photoactive layer, an interface modification layer, and an electron transport layer C. 60 , buffer layer SnO2, IZO transparent conductive film and silver electrode;

[0089] The silicon heterojunction bottom cell comprises, from bottom to top, a back electrode silver, a back transparent electrode ITO, a hole selection layer a-Si:H(p), a passivation layer a-Si:H(i), a silicon substrate N-Silicon, a passivation layer a-Si:H(i) and an electron selection layer a-Si:H(n) which are stacked in sequence; the electron selection layer a-Si:H(n) is in contact with the ITO transparent electrode;

[0090] Preparation method:

[0091] Place the silicon substrate N-Silicon (including the polished surface and the textured surface) in a vacuum chamber with a vacuum degree of 10 -6 Pa in a PECVD chamber, and depositing a layer of intrinsic passivation layer a-Si:H(i) on the upper and lower surfaces of the silicon substrate N-Silicon;

[0092] An electron selection layer a-Si:H(n) is deposited on the polished surface, a hole selection layer a-Si:H(p) is deposited on the textured surface, and a back transparent electrode ITO is thermally evaporated on the surface of the hole selection layer a-Si:H(p);

[0093] Thermally evaporating an ITO transparent electrode layer (i.e., a bottom electrode layer) on the surface of the electron selective layer a-Si:H(n) by electron beam thermal evaporation;

[0094] Spin coating PTAA on the surface of the ITO transparent electrode layer to obtain a hole transport layer;

[0095] Spin coating a PMMA layer on the surface of the hole transport layer;

[0096] 1.28mmol PbI2 and 0.27mmol PbBr2 were dissolved in 1mL of a mixed solvent of DMF and DMSO (the volume ratio of DMF and DMSO in the mixed solvent was 9:1) to obtain a lead-based inorganic solution; 0.58mmol FAI, 0.16mmol MACl and 0.12mmol MABr were dissolved in 1mL of isopropanol solvent to obtain an organic salt solution; 50μL of the lead-based inorganic solution was spin-coated at a speed of 2500rpm for 30s, and annealed on a heating table at 70°C for 1min to prepare an inorganic layer, and then 50μL of the organic salt solution was spin-coated at a speed of 2500rpm for 30s, annealed at 150°C for 15min in an air atmosphere with a certain humidity (humidity value is 35%), and cooled to room temperature to obtain a perovskite photoactive layer (material is FA 0.88 MA 0.12 Pb(I 0.83 Br 0.17 )3);

[0097] Dissolve 0.5 mg of bis(2-hydroxyethyl)dimethylammonium chloride in 1 mL of isopropanol, and stir to dissolve at room temperature to obtain a slurry; spin-coat the slurry on the surface of the perovskite photoactive layer, and then anneal on a heating table at 100° C. for 10 minutes to obtain an interface modification layer;

[0098] 20 nm of C was thermally evaporated on the surface of the perovskite photoactive layer. 60 As an electron transport layer;

[0099] Depositing 30 nm of SnO2 as a buffer layer on the surface of the electron transport layer by thermal atomic layer deposition technology;

[0100] sputtering an 85 nm IZO layer on the surface of the buffer layer to obtain a transparent conductive film;

[0101] The wide bandgap perovskite-based tandem solar cell is obtained by thermally evaporating metal electrode silver on the surface of the transparent conductive film and the back transparent electrode ITO.

[0102] The wide bandgap perovskite-based tandem solar cell was exposed to a standard solar intensity (AM1.5, 100 mW / cm 2 ) irradiation, the photoelectric performance of the wide bandgap perovskite-based tandem solar cell was tested, wherein the JV curve is as follows Figure 8 As shown by Figure 8 It can be seen that the open circuit voltage of the wide bandgap perovskite-based tandem solar cell is 1.84V, the fill factor is 79.01%, and the short circuit current density is 17.87mA / cm 2 , the photoelectric conversion efficiency is 25.94%.

[0103] Comparative Example 2

[0104] like Figure 6 As shown, the wide bandgap perovskite-based tandem solar cell includes, from bottom to top, a silicon heterojunction bottom cell, an ITO transparent electrode, a PTAA hole transport layer, a PMMA layer, a perovskite photoactive layer, and an electron transport layer C. 60 , buffer layer SnO2, transparent conductive film and silver electrode;

[0105] The silicon heterojunction bottom cell comprises, from bottom to top, a back electrode silver, a back transparent electrode ITO, a hole selection layer a-Si:H(p), a passivation layer a-Si:H(i), a silicon substrate N-Silicon, a passivation layer a-Si:H(i) and an electron selection layer a-Si:H(n) which are stacked in sequence; the electron selection layer a-Si:H(n) is in contact with the ITO transparent electrode;

[0106] Preparation method:

[0107] Place the silicon substrate N-Silicon (including the polished surface and the textured surface) in a vacuum chamber with a vacuum degree of 10 -6 Pa in a PECVD chamber, and depositing a layer of intrinsic passivation layer a-Si:H(i) on the upper and lower surfaces of the silicon substrate N-Silicon;

[0108] An electron selection layer a-Si:H(n) is deposited on the polished surface, a hole selection layer a-Si:H(p) is deposited on the textured surface, and a back transparent electrode ITO is thermally evaporated on the surface of the hole selection layer a-Si:H(p);

[0109] Thermally evaporating an ITO transparent electrode layer on the surface of the electron selective layer a-Si:H(n) by electron beam thermal evaporation;

[0110] Spin coating PTAA on the surface of the ITO transparent electrode layer to obtain a hole transport layer;

[0111] 1.28mmol PbI2 and 0.27mmol PbBr2 were dissolved in 1mL of a mixed solvent of DMF and DMSO (the volume ratio of DMF and DMSO in the mixed solvent was 9:1) to obtain a lead-based inorganic solution; 0.58mmol FAI, 0.16mmol MACl and 0.12mmol MABr were dissolved in 1mL of an isopropanol solvent to obtain an organic salt solution; 50μL of the lead-based inorganic solution was spin-coated at a speed of 2500rpm for 30s, and annealed on a heating table at 70°C for 1min to prepare an inorganic layer, and then 50μL of the organic salt solution was spin-coated at a speed of 2500rpm for 30s, annealed at 150°C for 15min in an air atmosphere with a certain humidity (humidity value is 35%), and cooled to room temperature to obtain a perovskite photoactive layer;

[0112] 20 nm of C was thermally evaporated on the surface of the perovskite photoactive layer. 60 As an electron transport layer;

[0113] Depositing 30 nm SnO2 as a buffer layer on the surface of the electron transport layer by thermal atomic layer deposition technology;

[0114] sputtering 85nm IZO on the surface of the buffer layer to obtain a transparent conductive film;

[0115] The wide bandgap perovskite-based tandem solar cell is obtained by thermally evaporating metal electrode silver on the surface of the transparent conductive film and the back transparent electrode ITO.

[0116] The wide bandgap perovskite-based tandem solar cell was exposed to a standard solar intensity (AM1.5, 100 mW / cm 2 ) irradiation, the photoelectric performance of the wide bandgap perovskite-based tandem solar cell was tested, wherein the JV curve is as follows Figure 7 As shown by Figure 7 It can be seen that the wide bandgap perovskite-based tandem solar cell has an open circuit voltage of 1.75 V, a fill factor of 73.54%, and a short circuit current density of 17.71 mA / cm 2 , the photoelectric conversion efficiency is 22.75%.

[0117] In summary, the present invention introduces bis(2-hydroxyethyl)dimethylammonium chloride on the surface of the perovskite photoactive layer, which eliminates the defects on the perovskite surface to the greatest extent, promotes the extraction and transmission of charges, reduces the difference between forward and reverse scans, significantly improves the open circuit voltage and fill factor of the battery, and significantly improves the efficiency of the PIN-type wide-bandgap perovskite-based stacked battery. The method is simple, easy to implement, and has a high repetition rate.

[0118] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A perovskite solar cell, characterized in that: It includes a bottom substrate, a bottom electrode layer, a hole transport layer, a passivation layer, a perovskite photoactive layer, an interface modification layer, an electron transport layer, a buffer layer and a top electrode layer stacked in sequence from bottom to top; The material of the interface modification layer is bis(2-hydroxyethyl)dimethylammonium chloride.

2. The perovskite solar cell according to claim 1, characterized in that: The perovskite solar cell is a PIN type perovskite solar cell; The perovskite solar cell is a wide bandgap perovskite solar cell or a wide bandgap perovskite-based tandem solar cell; The band gap of the perovskite solar cell is 1.6-1.72 eV.

3. The perovskite solar cell according to claim 1 or 2, characterized in that: The bottom electrode layer is one or more of an ITO transparent electrode layer, a FTO transparent electrode layer, an AZO transparent electrode layer, an IGZO transparent electrode layer, a graphene-oxide electrode, and an oxide-metal-oxide multilayer composite transparent electrode; The oxide in the graphene-oxide electrode or the oxide in the oxide-metal-oxide multilayer composite transparent electrode independently includes one or more of bismuth oxide, molybdenum oxide, tungsten oxide, tin oxide, titanium oxide, nickel oxide and zinc oxide; The metal in the oxide-metal-oxide multilayer composite transparent electrode includes one or more of gold, silver, copper and aluminum.

4. The perovskite solar cell according to claim 1 or 2, characterized in that: The top electrode layer is a metal electrode and / or a carbon material electrode; The material of the buffer layer includes one or more of BCP, Cu2O, molybdenum oxide, PEI, SnO2, Zr(AC)4, TPBi and nano ZnO.

5. The perovskite solar cell according to claim 4, characterized in that: The material of the metal electrode includes one or more of gold, silver, copper and aluminum; The carbon material of the carbon material electrode includes one or more of carbon black, graphite and multi-walled carbon nanotubes.

6. The perovskite solar cell according to claim 1, characterized in that: The bottom substrate is one or more of transparent glass, a flexible PET substrate, a flexible PEN substrate, a Si bottom battery, a CIGS bottom battery, a CZTS bottom battery, a PSC bottom battery and a CdTe bottom battery.

7. The perovskite solar cell according to claim 1, characterized in that: The material of the hole transport layer is one or more of PTAA, Spiro-TTB, nitrogen oxide, fullerene derivatives and self-limiting monolayer; The material of the self-limiting monolayer includes one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid and [2-(9H-carbazole-9-yl)ethyl]phosphonic acid; The material of the electron transport layer is SnO2, TiO2, ZnO, PCBM, C 60 , zinc tin oxide, and graphene.

8. The perovskite solar cell according to claim 1, characterized in that: The material of the perovskite photoactive layer is an ABX3 type perovskite semiconductor material; Wherein, A is one or more of alkylamine, alkylamidine and alkali element, and the alkali element is rubidium and / or cesium; B is lead; and X is one or more of iodine, bromine and chlorine.

9. The perovskite solar cell according to claim 1, characterized in that: The preparation method of the interface modification layer comprises the following steps: Mixing bis(2-hydroxyethyl)dimethylammonium chloride and an organic solvent to obtain a slurry; After the slurry is coated on the surface of the perovskite photoactive layer, annealing is performed to obtain the interface modification layer.

10. The perovskite solar cell according to claim 9, characterized in that: The coating method is spin coating, and the rotation speed of the spin coating is 3000-7000 rpm; The annealing temperature is 100-130° C. and the annealing time is 5-15 minutes.

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