A Cu x Low-temperature preparation method of O hole transport layer and perovskite solar cell

Abstract

This application belongs to the technical field of solar cells and provides a Cu x A low-temperature preparation method for a hole transport layer and a perovskite solar cell comprises the following steps: firstly dissolving sodium dodecylbenzenesulfonate in a first solvent to obtain a first solution; uniformly mixing the first solution with a copper salt solution to form a second solution; then adding a hydroxide solution to the second solution to obtain a third solution; and adding a reducing agent to the third solution and uniformly mixing the mixture to obtain a fourth solution; wherein the molar ratio of the sodium dodecylbenzenesulfonate, the copper salt, the hydroxide, and the reducing agent is 1000:1:x:34, where 4≤x≤9; and finally subjecting the fourth solution to a constant temperature aging treatment to obtain a fifth solution. The fifth solution is spin-coated on a substrate and annealed to form a hole transport layer, thereby avoiding the problem of impurity defects being easily introduced during the preparation of the hole transport layer.

Description

Technical Field

[0001] This application relates to the technical field of solar cells, in particular to a Cu x Low-temperature preparation method of O hole transport layer and perovskite solar cell. Background Art

[0002] Since achieving a 3.8% photoelectric conversion efficiency in 2009, perovskite solar cells have, after more than a decade of development, achieved a photoelectric conversion efficiency of 25.5% for single-cell perovskite solar cells. Inverted solar cells, due to their simplified fabrication process, lack of significant hysteresis, excellent photoelectric conversion efficiency, and ability to be printed on a large scale, have become a key research area in the photovoltaic field.

[0003] The hole transport layer (HTL), a key component of inverted perovskite solar cells, is crucial to device performance. Early HTL materials primarily consisted of organic materials such as PEDOT:PSS and PTAA. The introduction of PSS into the PEDOT:PSS spin-coating precursor (a water-based suspension, also known as 4083 suspension spin-coating fluid) improves PEDOT film formation quality, but its high water absorption can damage the interface between the conductive substrate and the perovskite, hindering device stability. Furthermore, the poor energy band match between PEDOT:PSS and the perovskite leads to low open-circuit voltage, impacting overall device performance. PTAA exhibits excellent hole transport and transport capabilities, resulting in a good energy level match, but also suffers from poor film coverage and high cost. Consequently, inorganic semiconductor materials such as NiO, CuI, CuO, and Cu2O have also gained interest as HTL materials and are being used in perovskite solar cell component selection. Cu2O is a P-type semiconductor with a direct band gap of 1.9-2.2 eV, which has a good energy level match with perovskite materials and a high co-absorption capacity in the visible light range (10 -4 cm -1 ), low resistivity (0.42–36.2Ω·cm) and excellent carrier mobility (0.013–0.083cm 2 / V·s) has also received attention. Currently, there are many methods for preparing Cu2O thin films, which can be divided into two categories: (1) non-solvent methods such as magnetron sputtering, atomic deposition, and chemical vapor deposition, which have high equipment requirements. The films prepared by this method have good film forming properties. In order to obtain high-crystallinity films, they all need to be annealed and sintered at high temperatures in a protective gas atmosphere, which makes the preparation process costly, unfavorable for future commercial development, and unable to be prepared on flexible substrates; (2) solution spin coating method. The general process is to prepare a layer of CuI thin film on a conductive substrate and then use the successive ionic layer adsorption and reaction method (SILAR) or to indirectly prepare a Cu2O thin film layer by first generating CuOH in an alkaline environment and then controlling the annealing temperature and time. The solution method preparation process is simple, but it still has the disadvantages of poor film coverage and easy introduction of impurity defects, which makes the film have poor optical properties. Summary of the Invention

[0004] The purpose of this application is to provide a Cu x The low-temperature preparation method of the hole transport layer and the perovskite solar cell can solve the problem that the existing hole transport layer is prone to introducing impurity defects and resulting in poor performance.

[0005] In a first aspect, the embodiment of the present application provides a Cu x A low-temperature preparation method for a hole transport layer, the low-temperature preparation method comprising:

[0006] dissolving sodium dodecylbenzenesulfonate in a first solvent to obtain a first solution;

[0007] uniformly mixing the first solution and the copper salt solution to form a second solution;

[0008] adding a hydroxide solution to the second solution to obtain a third solution;

[0009] A reducing agent is added to the third solution and uniformly mixed to obtain a fourth solution; wherein the molar ratio of sodium dodecylbenzenesulfonate, copper salt, hydroxide, and reducing agent is 1000:1:x:34, wherein 4≤x≤9;

[0010] Placing the fourth solution in an environment of 0-5° C. for constant temperature aging to obtain a fifth solution;

[0011] The fifth solution is spin-coated on a substrate and annealed to form a hole transport layer.

[0012] In one embodiment, the step of uniformly mixing the first solution with the copper salt solution to form the second solution comprises:

[0013] The copper salt solution is added to the first solution which is continuously stirred, and the mixture is stirred for a first preset time until the second solution having a light blue color is obtained.

[0014] In one embodiment, the step of adding a hydroxide solution to the second solution to obtain a third solution comprises:

[0015] The second solution is magnetically stirred at a rotation speed of 500 rpm to 1000 rpm;

[0016] A hydroxide solution is added dropwise to the second solution under magnetic stirring, and the solution is stirred at a rotation speed of 500 rpm to 1000 rpm for a second preset time to obtain the third solution.

[0017] In one embodiment, the solute in the copper salt solution is at least one of CuSO4, CuCl2, and Cu(NO3)2.

[0018] In one embodiment, the solvent in the copper salt solution is a first solvent, which is a mitigating agent formed by uniformly mixing deionized water and ethanol in a volume ratio of 1:y, wherein 5≤y≤9.

[0019] In one embodiment, the solute in the hydroxide solution is sodium hydroxide or potassium hydroxide.

[0020] In one embodiment, the reducing agent is added to the third solution and uniformly mixed to obtain the fourth solution, comprising:

[0021] After adding a reducing agent dropwise to the third solution in a stirring state, stirring is performed at a rotation speed of 500 rpm to 1000 rpm for a third preset time to obtain the light yellow fourth solution.

[0022] In one embodiment, the reducing agent is ascorbic acid or sodium ascorbate.

[0023] In one embodiment, the step of spin-coating the fifth solution on a substrate and annealing the solution to form a hole transport layer comprises:

[0024] Placing the substrate on a spin coater, wherein the substrate rotates along with the spin coater at a rotation speed of 500 rpm to 1000 rpm;

[0025] The fifth solution is filtered through a polytetrafluoroethylene water filter head and then dropped onto the surface of the substrate, and the hole transport layer is formed on the surface of the substrate through annealing treatment.

[0026] The second aspect of the present application also provides a perovskite solar cell, comprising a substrate, a hole transport layer, a perovskite active layer, an electron transport layer, a cathode interface layer and a metal electrode layer stacked in sequence, wherein the hole transport layer is prepared by the low-temperature preparation method as described in any one of the above items.

[0027] The present application embodiment provides a Cu x A low-temperature preparation method for a hole transport layer and a perovskite solar cell comprises the following steps: firstly dissolving sodium dodecylbenzenesulfonate in a first solvent to obtain a first solution; uniformly mixing the first solution with a copper salt solution to form a second solution; then adding a hydroxide solution to the second solution to obtain a third solution; and adding a reducing agent to the third solution and uniformly mixing the mixture to obtain a fourth solution; wherein the molar ratio of the sodium dodecylbenzenesulfonate, the copper salt, the hydroxide, and the reducing agent is 1000:1:x:34, where 4≤x≤9; and finally subjecting the fourth solution to a constant temperature aging treatment to obtain a fifth solution. The fifth solution is spin-coated on a substrate and annealed to form a hole transport layer, thereby avoiding the problem of impurity defects being easily introduced during the preparation of the hole transport layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic flow chart of a low-temperature preparation method for a hole transport layer according to an embodiment of the present invention;

[0029] Figure 2 The conductive substrate FTO of the present invention and the Cu prepared on the substrate x Comparative SEM images of O films;

[0030] Figure 3 The conductive substrate FTO of the present invention and the Cu prepared on the substrate x O film contrast light transmittance chart

[0031] Figure 4 The Cu provided in the embodiment of the present invention x SEM images of O nanoparticles;

[0032] Figure 5 The Cu provided in the embodiment of the present invention x O nanoparticles XRD pattern;

[0033] Figure 6 The perovskite solar cell structure diagram and the corresponding material energy level structure diagram provided by the embodiment of the present invention;

[0034] Figure 7 This is a performance curve diagram of the hole transport layer provided in an embodiment of the present invention applied to an inverse perovskite solar cell. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0036] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features.

[0037] The present invention provides a hole transport layer Cu x Low-temperature preparation method of O spin coating solution for perovskite solar cells, Figure 1 A schematic flow chart of a low-temperature preparation method for a hole transport layer according to an embodiment of the present invention is shown in FIG. Figure 1 As shown, the low-temperature preparation method in this embodiment includes steps S100 to S500.

[0038] In step S100, sodium dodecylbenzenesulfonate is dissolved in a first solvent to obtain a first solution.

[0039] In this embodiment, a proper amount of sodium dodecylbenzenesulfonate is dissolved in a first solvent to obtain a first solution. The first solvent may be deionized water, ethanol, or a mixed solvent of deionized water and ethanol.

[0040] In step S200 , the first solution and the copper salt solution are uniformly mixed to form a second solution.

[0041] In this embodiment, the copper salt solution can be obtained by configuring copper salt and solvent in a certain proportion. The solvent used to dissolve the copper salt can be deionized water, ethanol or a mixed solvent of deionized water and ethanol. The copper salt can be copper sulfate, copper chloride, etc.

[0042] In a specific application, in step S200, the first solution and the copper salt solution are uniformly mixed to form a second solution, including: adding the copper salt solution to the first solution that is continuously stirred, and stirring for a first preset time until the light blue second solution is obtained.

[0043] Specifically, the first solution obtained in step S100 is continuously stirred at a set stirring speed, and then the copper salt solution is added to the continuously stirred first solution to obtain a light blue second solution after stirring for a first preset time.

[0044] In some embodiments, the first preset time may be 1 to 3 hours.

[0045] In some embodiments, after obtaining the light blue second solution in step S200, the second solution is continuously magnetically stirred at room temperature (25°C-30°C).

[0046] In some embodiments, the second solution is magnetically stirred at a rotation speed of 500 r / s-1000 r / s.

[0047] In step S300, a hydroxide solution is added to the second solution to obtain a third solution.

[0048] In this embodiment, the second solution is in a state of continuous strong stirring, and an appropriate amount of hydroxide solution is added dropwise to the second solution in the continuous stirring state to obtain the third solution.

[0049] In some embodiments, the hydroxide is an inorganic compound that is soluble in the first solvent.

[0050] In a specific application embodiment, in step S300, the adding of a hydroxide solution to the second solution to obtain a third solution includes: magnetically stirring the second solution at a rotation speed of 500 r / s-1000 r / s; dropwise adding a hydroxide solution to the second solution under magnetic stirring, and stirring at a rotation speed of 500 r / s-1000 r / s for a second preset time to obtain the third solution.

[0051] Specifically, the second solution is magnetically stirred at a rotation speed of 500r / s-1000r / s to ensure the uniformity of the second solution, and then the hydroxide solution is added dropwise to the second solution under magnetic stirring, and stirred at a rotation speed of 500r / s-1000r / s for a second preset time to obtain the third solution.

[0052] In some embodiments, the solute in the copper salt solution is at least one of CuSO4 (copper sulfate), CuCl2 (copper chloride), and Cu(NO3)2 (copper nitrate).

[0053] Specifically, the copper salt can be CuSO4, CuSO4·5H2O, CuCl2, CuCl2·2H2O, Cu(NO3)2, Cu(NO3)2·6H2O.

[0054] In some embodiments, the solvent in the copper salt solution is a first solvent, which is a mitigating agent formed by uniformly mixing deionized water and ethanol in a volume ratio of 1:y, wherein 5≤y≤9.

[0055] In some embodiments, the solute in the hydroxide solution is sodium hydroxide or potassium hydroxide.

[0056] In step S400, a reducing agent is added to the third solution and uniformly mixed to obtain a fourth solution; wherein the molar ratio of sodium dodecylbenzenesulfonate, copper salt, hydroxide, and reducing agent is 1000:1:x:34, wherein 4≤x≤9.

[0057] In this embodiment, the third solution can be formed by sequentially adding sodium dodecylbenzenesulfonate, copper salt, and hydroxide to the first solvent, and the fourth solution can be formed by adding a reducing agent to the formed third solution and then mixing and stirring. The molar ratio of sodium dodecylbenzenesulfonate, copper salt, hydroxide, and reducing agent is 1000:1:x:34, and 4≤x≤9. For example, 1000 mol of sodium dodecylbenzenesulfonate, 1 mol of copper salt, x mol of hydroxide, and 34 mol of reducing agent are dissolved in the first solvent in sequence to form the fourth solution.

[0058] In a specific embodiment, the fourth solution can also be formed by dissolving sodium dodecylbenzenesulfonate, copper salt, hydroxide, and reducing agent in the first solvent according to a preset concentration ratio. The preset concentration ratio can be formed according to a molar ratio of sodium dodecylbenzenesulfonate, copper salt, hydroxide, and reducing agent of 1000:1:x:34.

[0059] Specifically, copper salt is sequentially added dropwise to the continuously stirred first solution and stirred for a first preset time, and hydroxide solution is added dropwise and stirred for a second preset time to obtain a nano alkaline colloid with good dispersion uniformity, wherein the copper salt and hydroxide are inorganic compounds soluble in the first solvent.

[0060] In a specific embodiment, in step S400, a reducing agent is added to the third solution and mixed uniformly to obtain a fourth solution, comprising: adding the reducing agent dropwise to the third solution in a stirring state, and stirring at a rotation speed of 500r / s-1000r / s for a third preset time to obtain the light yellow fourth solution.

[0061] In this embodiment, the third solution is in a stirring state. After the reducing agent is added to the stirring third solution, it is stirred at a rotation speed of 500r / s-1000r / s for a third preset time. At this time, the third solution is reduced to obtain a light yellow fourth solution.

[0062] In a specific application embodiment, the reducing agent may be ascorbic acid or sodium ascorbate.

[0063] In step S500, the fourth solution is placed in an environment of 0-5°C for constant temperature aging to obtain a fifth solution.

[0064] In this embodiment, the fourth solution formed in the above steps is placed in a constant temperature box at 0-5° C. and aged at the constant temperature to obtain a fifth solution. The aged fifth solution can be used as a spin coating solution for preparing a hole transport layer.

[0065] In a specific application embodiment, the aging temperature of the fourth solution can be 0-5°C.

[0066] In this embodiment, a translucent light yellow solution is obtained by dropwise adding a reducing agent into the third solution and stirring for a third predetermined time, wherein the reducing agent is an organic compound soluble in the first solvent.

[0067] In a specific application embodiment, the ambient temperature of the solution preparation process in step S100 and step S400 is 0-10°C.

[0068] A hydroxide is dissolved in a first solvent to form an alkaline solution, and a copper salt is dissolved in the first solvent as a copper source and then added dropwise to the first solution to form a precursor solution. Sodium dodecylbenzenesulfonate (SDS) is an organic compound and a type of anionic surfactant. It has a hydrophobic tail and a hydrophilic head, and can reduce the surface tension of water, making the liquid an emulsion with a balanced distribution of aqueous and oily phases.

[0069] By adding a precipitant to the precursor solution, the copper source dissolved in the SDS precursor solution reacts to initially obtain alkaline colloid Cu(OH)2 with good particle uniformity in the nanometer size range, and continuously stirs to evenly diffuse and disperse it in the SDS precursor solution.

[0070] In a specific embodiment, the precipitant in this embodiment is an alkaline solution. After the SDS precursor solution containing copper salt is mixed and stirred with the alkaline solution for a second preset time to obtain an alkaline colloid, the reducing agent solution is continuously added dropwise to obtain a light yellow translucent solution and stirred for a third preset time, wherein the reducing agent is an organic compound reducing agent. The light yellow solution is placed in a constant temperature chamber of a refrigerator for aging treatment, and finally a dispersed solution of copper oxide nanoparticles with good stability is obtained.

[0071] In specific applications, the chemical reaction equation occurring in the above preparation process is as follows:

[0072] 2Cu(OH)2+C6H7O6 - →Cu2O+C6H6O6+2H2O+OH - ;

[0073] 2Cu(OH)4 2- +C6H7O6 - →Cu2O+C6H6O6+2H2O+5OH - .

[0074] In step S600 , the fifth solution is spin-coated on a substrate and annealed to form a hole transport layer.

[0075] In this embodiment, the hole transport layer is obtained by spin-coating the fifth solution obtained after the aging treatment on the substrate and then performing an annealing treatment.

[0076] In one embodiment, the rotation speed of the spin coater may be 1500-3000 rpm.

[0077] In one embodiment, the spin coater may have a spinning time of 30-60 seconds.

[0078] In one embodiment, the annealing temperature of the prepared hole transport layer may be 100-150°C.

[0079] In one embodiment, the annealing time of the prepared hole transport layer may be 5-15 minutes.

[0080] In one embodiment, the substrate in this embodiment may be one of FTO (fluorine-doped tin oxide) conductive glass, conductive glass ITO (indium tin oxide) conductive glass.

[0081] In one embodiment, the first solvent may be deionized water, ethanol, or a mixture of deionized water and alcohol in a certain proportion.

[0082] In one embodiment, the hydroxide in this embodiment can be sodium hydroxide or potassium hydroxide, wherein sodium hydroxide and potassium hydroxide can be dissolved in the first solvent.

[0083] In one embodiment, the copper salt in this embodiment includes any one or more of copper sulfate, copper sulfate pentahydrate, copper nitrate, copper nitrate hexahydrate, copper chloride, and copper chloride dihydrate.

[0084] In one embodiment, the first preset time can be set according to user needs. Preferably, the first preset time can be 5-30 minutes.

[0085] In one embodiment, the second preset time can be set according to user needs. Preferably, the second preset time can be 0.5-5 minutes.

[0086] By adding the alkaline solution formed by the hydroxide to the SDS precursor solution formed by the copper salt, the hydroxide and the copper salt can react to generate an intermediate product, copper hydroxide. After stirring for a second preset time, an alkaline colloid is obtained, which includes the intermediate product copper hydroxide and the first solvent.

[0087] In one embodiment, the third preset time can be set according to user needs. Preferably, the third preset time can be 5-15 minutes.

[0088] In a specific application, in step S600, the fifth solution is spin-coated on the substrate and annealed to form a hole transport layer, including: placing the substrate on a spin coater, wherein the substrate rotates following the spin coater at a rotation speed of 500r / s-1000r / s; filtering the fifth solution through a polytetrafluoroethylene water filter head and then dripping it onto the surface of the substrate, and forming the hole transport layer on the surface of the substrate through annealing.

[0089] In one embodiment, the specification of the polytetrafluoroethylene water filter head may be 0.48 μm.

[0090] In the process of preparing the hole transport layer, the above dispersion is formed into a Cu2O3 layer on the conductive substrate by low temperature spinning. x O hole transport layer.

[0091] In one embodiment, the substrate cleaning process in this embodiment includes: placing the front side (i.e., the conductive side) of the FTO conductive glass facing up in a culture dish, adding detergent powder and tap water for ultrasonic cleaning for 10-20 minutes; taking out the FTO conductive glass and placing it on a cleaning rack; then using detergent, deionized water, acetone, and isopropyl alcohol for ultrasonic cleaning for 10-20 minutes respectively; drying, and ultraviolet ozone treatment for 20-40 minutes.

[0092] Figure 2 Cu on the prepared FTO conductive substrate x Comparison of the SEM morphology of the CuO hole transport layer and the conductive substrate FTO shows that x The O hole transport layer has good film forming properties and improved roughness, eliminating the defects of holes and cracks that are prone to occur in the poor film forming of the hole transport layer, effectively improving the interface contact between the perovskite layer and the nickel oxide hole transport layer, and improving the photoelectric performance of the perovskite battery.

[0093] Further, Figure 3 The FTO conductive substrate was compared with the prepared Cu x The light transmittance of the FTO conductive substrate of the O hole transport layer can be known. In the visible light range, Cu x The FTO conductive substrate of the O hole transport layer improves the light transmittance of the conductive substrate, which can increase the light absorption rate of the perovskite light absorption layer and improve the photoelectric performance of the battery.

[0094] Cu x The O spin coating liquid is centrifuged using a high-speed centrifuge, washed several times with a second solvent, and then vacuum dried in a vacuum drying oven at an appropriate temperature for several hours to obtain nanocrystalline powder (wherein the second solvent is one or more of deionized water, methanol, ethanol, and isopropanol) and characterized by SEM morphology and XRD phase.

[0095] Figure 4 This is the SEM morphology of the washed and dried nanocrystalline powder. The nanocrystals have a square structure, a particle size distribution between 100-150nm, and good particle uniformity. Figure 5 The corresponding XRD pattern is shown in Figure 2. The horizontal axis (2θ) is the scanning angle of the X-ray, and the vertical axis (Intensity) is the intensity of the diffraction peak produced by the copper oxide nanocrystals under X-ray irradiation. Figure 5 As can be seen in the figure, the three strongest diffraction peaks of the copper oxide nanocrystals correspond to the (111), (200), and (220) crystal planes, respectively. This indicates that the oxygen nanocrystals prepared in this example have a cubic phase structure, good crystallinity, and are essentially free of other impurities or other phases. The copper oxide nanocrystal hole transport layer prepared in this example has the characteristics of low preparation temperature, low preparation cost, high transmittance, and high hole mobility.

[0096] Figure 6 This is a diagram of the perovskite solar cell implemented by the present invention and the corresponding material energy level structure diagram. The valence band top (-5.32eV) of the copper oxide nanocrystal has a high energy band match with the perovskite light-absorbing layer, and the conduction band bottom is at a low position, which can effectively prevent electron transmission. At the same time, inorganic oxides have better chemical stability than organic small molecule hole conduction materials, which can greatly improve the stability of perovskite solar cells.

[0097] In one embodiment, this embodiment provides an inverse perovskite solar cell, Figure 6 The schematic diagram of the structure of the inverted perovskite solar cell provided in this embodiment is as follows: Figure 6 As shown, the inverted perovskite solar cell in this embodiment includes an FTO substrate 101, a hole transport layer 102, a perovskite active layer 103, an electron transport layer 104, an interface modification layer 105 and a metal electrode layer 106 stacked in sequence, wherein the hole transport layer 102 is prepared by the low-temperature preparation method as described in any one of the above.

[0098] Combine Figure 6 As shown, the conduction band energy level of the hole transport layer 102 is -3.12 eV, the valence band energy level of the hole transport layer 102 is -5.32 eV, the conduction band energy level of the perovskite active layer 103 is -3.90 eV, the valence band energy level of the perovskite active layer 103 is -5.40 eV, the conduction band energy level of the electron transport layer 104 is -3.95 eV, the valence band energy level of the electron transport layer 104 is -5.85 eV, and the work function of the metal electrode layer 106 is -4.74 eV.

[0099] Figure 7The photoelectric performance spectrum of the perovskite solar cell assembled with the hole transport layer prepared by the low-temperature preparation method of the hole transport layer provided by the embodiment of the present invention, wherein Reverse represents the IV curve of the perovskite solar cell using the reverse voltage sweep method, and Forward represents the IV curve of the perovskite solar cell using the forward voltage sweep method, wherein V oc represents the open circuit voltage of the perovskite solar cell, J sc It represents the short-circuit current density of the perovskite solar cell, Fill Factor represents the filling factor of the perovskite solar cell, and PCE represents the photoelectric conversion efficiency of the perovskite solar cell.

[0100] In one embodiment, the substrate with the hole transport layer formed thereon is transferred into a glove box, and a perovskite active layer is spin-coated on the hole transport layer, and chlorobenzene is used as an anti-solvent for extraction.

[0101] In one embodiment, the annealing temperature of the perovskite active layer may be 90-120° C., and the annealing time may be 10-30 minutes.

[0102] In one embodiment, the PC 61 The BM chlorobenzene solution is spin-coated on the perovskite light-absorbing layer to form an electron transport layer. The spin-coating parameters are 1800-2000 rpm and the spin-coating time is 30-60 seconds.

[0103] In one embodiment, the interface modification layer is formed by dynamically spin-coating a methanol solution of zirconium acetylacetonate on the electron transport layer, and no annealing treatment is performed.

[0104] In one embodiment, a working electrode layer is formed by evaporating a metal electrode on the cathode interface layer under vacuum conditions. Optionally, the metal electrode can be one of copper, silver, and gold.

[0105] In one embodiment, the effective area of ​​the metal electrode layer can be set according to user needs.

[0106] In a low-temperature preparation method of a hole transport layer and a perovskite solar cell provided by an embodiment of the present invention, by 2+ In the SDS solution environment of ions, the previous product of copper salt and hydroxide is moderately reduced by reducing agent SA and then aged for a fourth preset time to obtain a stable and well-dispersed nano-scale Cu xO spin coating liquid, and prepare a uniform, dense, hole-free hole transport layer by low-temperature solution spin coating, which greatly reduces the surface roughness of the hole transport layer, effectively improves the interface contact between the perovskite light absorbing layer and the hole transport layer, and has better stability than the traditional organic hole transport layer, solving the problem of low device stability caused by the use of organic materials in the hole transport layer of the existing inverted perovskite solar cell. In addition, the present invention also provides a Cu x The low temperature solution method of O spin coating liquid can well solve the problem of Cu x O film coverage, crystallinity and other process issues as well as effectively reducing the cost of the experiment provide a way of thinking and strategy for the low-temperature preparation of the hole transport layer in inverse perovskite solar cells.

[0107] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A Cu x The low-temperature preparation method of the hole transport layer is characterized in that: The low-temperature preparation method comprises: dissolving sodium dodecylbenzenesulfonate in a first solvent to obtain a first solution; uniformly mixing the first solution and a copper salt solution to form a second solution, and adding a hydroxide solution to the second solution to obtain a third solution; The step of uniformly mixing the first solution with a copper salt solution to form a second solution, and adding a hydroxide solution to the second solution to obtain a third solution comprises: Adding copper salt dropwise to the continuously stirred first solution and stirring for a first preset time, and then adding hydroxide solution dropwise and stirring for a second preset time, to obtain a nano alkaline colloid with good dispersion uniformity; A reducing agent is added to the third solution and uniformly mixed to obtain a fourth solution; wherein the molar ratio of sodium dodecylbenzenesulfonate, copper salt, hydroxide, and reducing agent is 1000:1:x:34, wherein 4≤x≤9; Placing the fourth solution in an environment of 0-5° C. for constant temperature aging to obtain a fifth solution; The fifth solution is spin-coated on a substrate and annealed to form a hole transport layer.

2. Cu as claimed in claim 1 x The low-temperature preparation method of the hole transport layer is characterized in that: The step of adding a hydroxide solution to the second solution to obtain a third solution comprises: The second solution is magnetically stirred at a rotation speed of 500 rpm to 1000 rpm; A hydroxide solution is added dropwise to the second solution under magnetic stirring, and the solution is stirred at a rotation speed of 500 rpm to 1000 rpm for a second preset time to obtain the third solution.

3. Cu as claimed in claim 1 x The low-temperature preparation method of the hole transport layer is characterized in that: The solute in the copper salt solution is at least one of CuSO4, CuCl2, and Cu(NO3)2.

4. Cu as claimed in claim 3 x The low-temperature preparation method of the hole transport layer is characterized in that: The solvent in the copper salt solution is a first solvent, which is a mitigating agent formed by uniformly mixing deionized water and ethanol in a volume ratio of 1:y, wherein 5≤y≤9.

5. Cu as claimed in claim 1 x The low-temperature preparation method of the hole transport layer is characterized in that: The solute in the hydroxide solution is sodium hydroxide or potassium hydroxide.

6. Cu as claimed in claim 1 x The low-temperature preparation method of the hole transport layer is characterized in that: The reducing agent is added to the third solution and uniformly mixed to obtain a fourth solution, comprising: After adding a reducing agent dropwise to the third solution in a stirring state, stirring is performed at a rotation speed of 500 rpm to 1000 rpm for a third preset time to obtain the light yellow fourth solution.

7. Cu as claimed in claim 1 x The low-temperature preparation method of the hole transport layer is characterized in that: The reducing agent is ascorbic acid or sodium ascorbate.

8. Cu as claimed in claim 1 x The low-temperature preparation method of the hole transport layer is characterized in that: The step of spin-coating the fifth solution on a substrate and annealing the solution to form a hole transport layer comprises: Placing the substrate on a spin coater, wherein the substrate rotates along with the spin coater at a rotation speed of 500 rpm to 1000 rpm; The fifth solution is filtered through a polytetrafluoroethylene water filter head and then dropped onto the surface of the substrate, and the hole transport layer is formed on the surface of the substrate through annealing treatment.

9. A perovskite solar cell, characterized in that: It comprises a substrate, a hole transport layer, a perovskite active layer, an electron transport layer, a cathode interface layer and a metal electrode layer stacked in sequence, wherein the hole transport layer is prepared by the low-temperature preparation method according to any one of claims 1 to 8.

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