Perovskite solar cell passivation method based on glycine solid-solid reaction

Abstract

The invention discloses a perovskite solar cell passivation method based on a glycine solid-solid reaction, and the method comprises the steps: enabling one surface, with a glycine thin film, of a glass plate to cover the surface of a perovskite thin film of a perovskite solar cell during the preparation of the perovskite solar cell, carrying out the solid-solid reaction through heating and pressurization, and carrying out the passivation of the perovskite solar cell. And preparing the all-inorganic CsPbI3 perovskite thin film with the perovskite thin film compounded with the glycine thin film. According to the method disclosed by the invention, secondary growth of perovskite crystal grains can be realized, the crystal grains are enlarged, and the perovskite crystal structure is stabilized, so that the moisture resistance of perovskite is effectively enhanced, the conversion of the perovskite crystal to an amorphous phase is reduced, and the humidity stability of a perovskite light absorption layer is greatly improved. And the influence of current density reduction caused by poor conductivity of the device due to glycine residue caused by spin coating of the glycine solution can be effectively avoided, so that the open voltage and the short-circuit current of the device are remarkably improved, and finally, the stability and the efficiency of the device are improved.

Description

Technical Field

[0001] The invention relates to the technical field of solar cells, and in particular to a perovskite solar cell passivation method based on glycine solid-solid reaction. Background Art

[0002] Perovskite (PVSK) materials have the advantages of high light absorption coefficient, long carrier lifetime, adjustable bandgap, easy processing and low cost. In just 10 years, the efficiency of perovskite solar cells has increased from 3% to more than 26%, which is close to the efficiency of crystalline silicon solar cells developed over decades. However, perovskite solar cells also have some problems that need to be solved, especially perovskite cells are prone to serious decomposition in complex environments such as high temperature and high humidity, which leads to device failure, which is also the main factor limiting its commercialization.

[0003] The stability of organic-inorganic hybrid perovskite cells is improved compared to pure organic components, but there are still problems of volatility and poor thermal stability. All-inorganic CsPbI3 perovskite solar cells have attracted widespread attention due to their excellent thermal stability, but they are more sensitive to moisture in the air, so the requirements for phase deformation nuclei and preparation processes are also significantly higher. Under the erosion of water molecules, the crystal structure is prone to collapse, and the grains are difficult to grow. At the same time, defects will appear on the surface of the film, resulting in decreased battery performance and stability. Therefore, how to improve the ability of all-inorganic CsPbI3 perovskite to resist erosion by water molecules, promote grain growth and smooth the surface of the film is the core of improving the stability of perovskite cells.

[0004] Studies have shown that the surface and grain boundaries of perovskite are the most vulnerable parts to decomposition. To solve this problem, researchers have tried many strategies. The common method is to add the passivator to the perovskite precursor solution for spin coating, or directly spin coat it on the surface of the perovskite film, use organic molecules or polymers to chemically passivate the perovskite, or use hydrophobic organic materials to physically cover the structural defects to achieve the effect of passivating surface defects. Although these passivation effects have a certain effect on the stability of the perovskite, the excess passivator covering the surface of the perovskite will affect the electrical properties of the device. In addition, by covering the passivator on the surface of the perovskite by spin coating, it is impossible to accurately control the secondary growth of the perovskite grains. Therefore, it is particularly important to find a method that can not only improve the stability of the perovskite crystal itself, but also control the grain size, deal with surface defects and improve the electrical performance of the device. Summary of the invention

[0005] The purpose of the present invention is to provide a perovskite solar cell passivation method based on glycine solid-solid reaction to solve the above defects.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A glycine solid-solid reaction-based perovskite solar cell passivation method comprises the following steps: when preparing an all-inorganic CsPbI3 perovskite solar cell, the side of a glass plate with a glycine film is covered on the surface of a perovskite film of the perovskite solar cell, and then a solid-solid reaction is performed by heating and pressurizing to prepare an all-inorganic CsPbI3 perovskite film of a perovskite film composited with a glycine film.

[0008] Preferably, the perovskite solar cell consists of a metal electrode, a hole transport layer, a perovskite film light absorbing layer, an electron transport layer and FTO conductive glass from top to bottom, and the perovskite film light absorbing layer is made of a perovskite film with a thickness of 150-800nm.

[0009] Preferably, the pressurizing is to apply a force of 0.1-1N.

[0010] Preferably, the heating is specifically as follows: covering a glass plate with a glycine film on the surface of the perovskite film, and then continuously heating the perovskite film using a heating table under the perovskite film, controlling the heating table to make the temperature of the FTO conductive glass substrate 70-180° C., and heating time 3-5 hours.

[0011] Preferably, the perovskite film is obtained by spin coating a perovskite solution and performing secondary annealing followed by cooling; the first annealing environment is: a sealed bag filled with nitrogen, the temperature is 60-100°C, and the annealing time is 1-10 minutes; the second annealing environment is: in air, the temperature is 150-210°C, the annealing time is 15-30 minutes, and the cooling is room temperature.

[0012] Preferably, the hole transport layer is made of 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene.

[0013] Preferably, the electron transport layer is made of SnO2.

[0014] Preferably, the FTO conductive glass has a sheet resistance of 5-25Ω and a transmittance of 70-95%.

[0015] Preferably, the FTO conductive glass is firstly treated with glass cleaning agent, water, acetone and ethanol ultrasonic cleaning for 10-20 minutes in sequence before use, and then treated with ultraviolet ozone for 5-60 minutes after drying, and then used for standby;

[0016] The electron transport layer is prepared by spin coating, specifically: first, dilute the SnO2 colloidal aqueous solution with a concentration of 12% to a concentration of 1%-10%, and then spin coat it on the FTO conductive glass. 210-80 μL of SnO2 aqueous solution was dropped onto the glass slide, the spin coating speed was 3000 rpm, and the spin coating time was 30 s; after spin coating, it was placed on a heating table at 150°C for annealing for 30 min;

[0017] The perovskite film is prepared by: dissolving 100-200g of dimethylammonium iodide DMAI, 300-400g of lead iodide PbI3 and 200-300g of cesium iodide CsI mixed powder in 1ml of DMF, stirring overnight at 30-70°C, filtering to obtain a precursor solution, and spin coating to obtain a film; annealing the film twice, the first annealing environment is: a sealed bag filled with nitrogen, the temperature is 60-100°C, the annealing time is 1-10 minutes, the second annealing environment is: in the air, the temperature is 150-210°C, the annealing time is 15-30 minutes, and cooling to room temperature to obtain the perovskite film;

[0018] The hole transport layer is prepared by spin coating the Spiro-OMeTAD hole transport layer precursor solution on the perovskite light absorption layer, at a spin coating speed of 2000-6000 rpm and a spin coating time of 20-60 s, and dropping 10-40 μL of the hole transport layer precursor solution per square centimeter of the glass sheet;

[0019] The metal electrode includes gold and silver, and has a thickness of 50-300 nm. The metal electrode is prepared by evaporation, and the vacuum degree reaches 1×10 -5 -8×10 -4 Pa, evaporation began, with an evaporation rate of 0.001-0.5nm / s.

[0020] The beneficial effects of the present invention are:

[0021] (1) The present invention provides a perovskite solar cell passivation method based on a glycine solid-solid reaction, wherein a glass plate covered with a glycine film is superimposed on the surface of the perovskite film to achieve solid-solid contact between the perovskite film and the glycine film, and the two films are heated and pressurized, thereby passivating the surface, controlling grain growth, and improving device stability, and improving device electrical performance, thereby ultimately achieving improved device stability and efficiency.

[0022] (2) The present invention provides a perovskite solar cell passivation method based on a glycine solid-solid reaction, which can not only improve the crystallinity during the secondary growth of perovskite crystals, but also control the combination of the passivator and the surface of the perovskite film through a solid-solid reaction, thereby effectively enhancing the ability of the perovskite to resist moisture, reducing the transformation of the perovskite crystals to an amorphous phase, and greatly improving the humidity stability of the perovskite light absorption layer, and can stabilize the perovskite phase and passivate the surface defects of the perovskite.

[0023] (3) The present invention provides a perovskite solar cell passivation method based on a glycine solid-solid reaction, which will not leave an excessive amount of passivator on the surface of the perovskite film, and can solve the problem of a large amount of passivator residue causing a decrease in the conductivity of the battery, thereby reducing the current density, thereby greatly improving the stability of the perovskite light absorption layer, and at the same time, significantly improving the device's on-voltage and short-circuit current. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of a perovskite solar cell device;

[0025] Figure 2 Schematic diagram of the molecular structure of glycine;

[0026] Figure 3 Schematic diagram of passivation based on glycine solid-solid reaction in Example 2;

[0027] Figure 4 Humidity test photos of the perovskite solar cells prepared in Example 3, Example 1 and Example 2 of the present invention;

[0028] Figure 5 This is a current-voltage (JV) curve of the perovskite solar cells prepared in Example 3, Example 1 and Example 2 of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the embodiments. It should be noted that these are merely examples and illustrations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should be deemed to fall within the protection scope of the present invention.

[0030] Embodiment 1:

[0031] This embodiment is an embodiment of a passivation method and a preparation method for a perovskite solar cell based on spin coating of glycine in air.

[0032] Figure 1 The schematic diagram of the structure of a perovskite solar cell device is shown in the figure. The perovskite solar cell consists of a metal electrode, a hole transport layer, a perovskite film light absorption layer, an electron transport layer and FTO conductive glass from top to bottom. The specific preparation method of the perovskite solar cell based on glycine spin coating in air includes the following steps:

[0033] S1. Substrate pretreatment:

[0034] FTO conductive glass is used as the substrate, with a square resistance of 5-25Ω, a transmittance of 70-95%, and a size of 1.5cm×1.5cm. Before use, the FTO conductive glass is first treated with glass cleaning agent (2% detergent aqueous solution), deionized water, acetone, and anhydrous ethanol for 20 minutes, then blown dry with nitrogen, and then placed in a UV ozone cleaning machine for UV ozone pretreatment. The wavelength of the UV lamp is 185nm, and the treatment time is 20 minutes, and it is ready for use.

[0035] S2. Preparation of electron transport layer:

[0036] The electron transport layer is made of SnO2 and is prepared by a spin coating method, specifically: first, a 12% SnO2 colloidal aqueous solution is diluted with deionized water to a concentration of 1%-10%, and then spin-coated onto the FTO conductive glass;

[0037] During spin coating, the diluted SnO2 solution was dropped onto the ozone-treated FTO conductive glass, 3 cm 2 10-80 μL of SnO2 aqueous solution was dropped onto the glass slide, and the solution was spread completely with a pipette. After spin coating at 4000 rpm for 30 seconds, a 100 nm dense SnO2 layer was obtained. Finally, it was annealed at 150 °C for 30 minutes, cooled naturally to room temperature, and treated with a UV ozone cleaner for 30 minutes for use.

[0038] S3. Preparation of all-inorganic CsPbI3 perovskite films based on glycine spin coating passivation:

[0039] (1) Preparation of glycine solution:

[0040] Figure 2 The schematic diagram of the molecular structure of glycine. Dissolve 0.01 g of glycine in 1 mL of isopropanol (IPA) to obtain a glycine solution for later use;

[0041] (2) Preparation of perovskite film:

[0042] 138.05g of dimethylammonium iodide DMAI, 367.88g of lead iodide PbI3 and 208.68g of cesium iodide CsI mixed powder were dissolved in 1ml of DMF, stirred at 50°C overnight, filtered to prepare a precursor solution, and spin-coated to prepare a film; the film was annealed twice, the first annealing environment was: a sealed bag filled with nitrogen, the temperature was 70°C, and the annealing time was 5 minutes, and the second annealing environment was: in the air, the temperature was 190°C, and the annealing time was 25 minutes, and cooled to room temperature to obtain a perovskite film;

[0043] (3) Preparation of all-inorganic CsPbI3 perovskite films:

[0044] The prepared glycine solution is spin-coated on the surface of the perovskite film, that is, 20uL of glycine solution is added to the surface of the perovskite film at the 10th second of the spin coating, the spin coating speed is 4000rpm / min, the spin coating time is 30s, and after the spin coating is completed, it is stored in dry air or nitrogen to obtain an all-inorganic CsPbI3 perovskite film based on glycine spin coating passivation. The all-inorganic CsPbI3 perovskite film is used as the perovskite film light-absorbing layer, and its thickness is 150-800nm.

[0045] S4. Preparation of hole transport layer:

[0046] 72.3 mg of Spiro-OMeTAD, 17.5 μL of 520 mg / mL acetonitrile solution of lithium bis(trifluoromethanesulfonyl)imide, and 28.8 μL of 4-tert-butylpyridine were dissolved in 1 mL of chlorobenzene to obtain the Spiro-OMeTAD hole transport layer precursor solution. Then 60 μL of the precursor solution was dropped on the perovskite film light absorption layer. The spin coating speed was 3000 rpm and the acceleration was 1500 rpm / s. 2 , time is 30s, prepare a 100nm hole transport layer, and prepare it for scraping and evaporation (i.e., use a cotton swab dipped in DMF to scrape off the thin film at the common electrode, then install the device into a 6×8 evaporation template, put the evaporation template into the evaporation chamber, and evaporation after vacuuming);

[0047] S5. Preparation of metal electrodes:

[0048] Metal electrodes, including gold and silver, have a thickness of 50-300nm. The metal electrodes are prepared by evaporation, as follows:

[0049] When the vacuum degree of the evaporation chamber reaches 5×10 -4 After Pa, the heating power supply was turned on, and silver was deposited at a rate of 0.05nm / s, with a deposition thickness of 80nm. Among them, the effective area of ​​the battery evaporated by the evaporation template was 0.12cm 2 , and finally the perovskite solar cell was prepared.

[0050] Embodiment 2:

[0051] This embodiment is an embodiment of a passivation method and a preparation method for a perovskite solar cell based on a glycine solid-solid reaction.

[0052] Figure 3 is a schematic diagram of the passivation based on glycine solid-solid reaction, such as Figure 1As shown, a glycine solid-solid reaction-based perovskite solar cell passivation method of the present invention, when preparing an all-inorganic CsPbI3 perovskite solar cell, the side of a glass plate with a glycine film is covered on the surface of the perovskite film of the perovskite solar cell, and then a solid-solid reaction is carried out by heating and pressurizing to prepare an all-inorganic CsPbI3 perovskite film of a perovskite film composite with a glycine film.

[0053] The specific preparation method of the perovskite solar cell based on the glycine solid-solid reaction is basically the same as that of Example 1, except that: in the preparation of the all-inorganic CsPbI3 perovskite film in step S3 (3):

[0054] The prepared glycine solution is coated on a glass plate to form a glycine film; after the glycine film side of the glass plate is covered on the surface of the perovskite film of the perovskite solar cell, a force of 0.5N is applied on the top, and a heating table is used to continuously heat the bottom, and the heating table is controlled to make the substrate temperature 100°C, and this state is maintained for continuous heating for 5 hours; the glass plate covered with glycine on the top is removed, and after cooling the bottom, an all-inorganic CsPbI3 perovskite film passivated by glycine solid-solid reaction is obtained; the all-inorganic CsPbI3 perovskite film is used as the perovskite film light absorption layer, and its thickness is 150-800nm.

[0055] Embodiment 3:

[0056] This embodiment is an embodiment of a method for preparing a perovskite solar cell that has not been treated with glycine.

[0057] The specific preparation method of the perovskite solar cell not treated with glycine is basically the same as that of Example 1, except that:

[0058] S3. Preparation of all-inorganic CsPbI3 perovskite film without glycine treatment:

[0059] A mixed powder of 138.05g of dimethylammonium iodide (DMAI), 367.88g of lead iodide (PbI3) and 208.68g of cesium iodide (CsI) was dissolved in 1ml of DMF, stirred at 50°C overnight, filtered to make a precursor solution, and spin-coated to make a film; the film was annealed twice, the first annealing environment was: a sealed bag filled with nitrogen, the temperature was 70°C, and the annealing time was 5 minutes, and the second annealing environment was: in the air, the temperature was 190°C, and the annealing time was 25 minutes. After cooling to room temperature, an all-inorganic CsPbI3 perovskite film that was not treated with glycine was obtained; the all-inorganic CsPbI3 perovskite film that was not treated with glycine was used as the perovskite film light absorption layer.

[0060] (1) Humidity stability test:

[0061] The humidity stability test was performed on the all-inorganic CsPbI3 perovskite films prepared in Example 1, Example 2, and Example 3, that is, the three unencapsulated films were placed in air with a relative humidity of 40% at the same time, and the different decomposition conditions of the films were observed within 0-144h (24h, 48h, 96h, 144h). The results are as follows: Figure 4 shown.

[0062] Depend on Figure 4 It can be seen that at 0 hours, the perovskite film has a good morphology. At 24 hours, the unpassivated perovskite film has begun to decompose, while the passivated film is still intact. At 48 hours, the unpassivated film is obviously decomposed, the spin-coated passivated film begins to decompose, and the solid-solid reaction passivated film is still intact. At 96 hours, both the unpassivated and spin-coated passivated films are seriously decomposed, and the solid-solid reaction passivated film also begins to decompose. At 144 hours, all films are decomposed. It can be seen that the structural stability of the glycine passivated perovskite film has been improved, and the stability of the perovskite film obtained by solid-solid reaction passivation has been significantly improved.

[0063] (2) Photoelectric performance test

[0064] Under the simulated AM1.5G standard sunlight irradiation condition (light intensity of 100mW / cm2), the current-voltage curve (JV) and photoelectric conversion efficiency data of the perovskite solar cells prepared in Example 1, Example 2, and Example 3 were tested respectively. The scanning voltage during the test was 1.3V→-0.1V, and the scanning interval was 20mV. The results are shown in Tables 1 and Figure 5 .

[0065] Table 1. Photoelectric performance parameters of perovskite solar cells in Examples 1-3

[0066] Test sample Glycine treatment <![CDATA[J sc (mA / cm 2 )]]> <![CDATA[V oc (mV)]]> FF PCE Example 1 Spin coating 20.05 1.06 68.79％ 14.02％ Example 2 Solid-solid reaction 20.11 1.11 72.37％ 16.01％ Example 3 Control 19.72 1.05 67.32％ 13.94％

[0067] from Figure 5 From the JV curve, it can be seen that after glycine passivation, the open circuit voltage (Voc) and fill factor (FF) of the perovskite solar cell have been significantly improved. Among them, the efficiency of the cell passivated by solid-solid reaction has been improved the most, and the performance is also better.

[0068] As shown in Table 1, the photoelectric performance parameters of the devices in Examples 1 and 2 are better than those in Example 3. Among them, the photoelectric conversion efficiency of the battery in Example 1 after glycine spin coating passivation treatment is 14.02%; the photoelectric conversion efficiency of the battery in Example 2 after glycine solid-solid reaction passivation treatment is 16.01%, and the photoelectric efficiency of the untreated battery in Example 3 is 13.94%.

[0069] The present invention discloses a perovskite solar cell passivation method based on glycine solid-solid reaction, wherein a glass plate covered with a glycine film is superimposed on the surface of a perovskite film, so that the perovskite film and the glycine film are in solid-solid contact, and are heated and pressurized, thereby passivating the surface, controlling grain growth, improving device stability, and improving device electrical performance, thereby ultimately achieving improved device stability and efficiency.

[0070] The invention discloses a perovskite solar cell passivation method based on glycine solid-solid reaction, which can not only improve the crystallinity during the secondary growth of perovskite crystals, but also control the combination of a passivator and the surface of a perovskite film through a solid-solid reaction, thereby effectively enhancing the ability of the perovskite to resist moisture, reducing the transformation of the perovskite crystals to an amorphous phase, greatly improving the humidity stability of the perovskite light absorption layer, and being able to stabilize the perovskite phase and passivate the surface defects of the perovskite.

[0071] The invention discloses a glycine solid-solid reaction-based perovskite solar cell passivation method, which does not leave excessive passivator on the surface of the perovskite film, and can solve the problem that a large amount of passivator residue reduces the conductivity of the battery, thereby reducing the current density, thereby greatly improving the stability of the perovskite light absorption layer, and at the same time, significantly improving the on-voltage and short-circuit current of the device.

[0072] The above is an exemplary description of the invention. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as such non-substantial improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A perovskite solar cell passivation method based on glycine solid-solid reaction, characterized in that: When preparing an all-inorganic CsPbI3 perovskite solar cell, the side of a glass plate with a glycine film is covered on the surface of the perovskite film of the perovskite solar cell, and then a solid-solid reaction is carried out by heating and pressurizing to prepare an all-inorganic CsPbI3 perovskite film of a perovskite film composited with a glycine film.

2. The method for passivating a perovskite solar cell based on a glycine solid-solid reaction according to claim 1, characterized in that: The perovskite solar cell consists of a metal electrode, a hole transport layer, a perovskite film light-absorbing layer, an electron transport layer and FTO conductive glass from top to bottom. The perovskite film light-absorbing layer is made of a perovskite film with a thickness of 150-800nm.

3. The method for passivating a perovskite solar cell based on a glycine solid-solid reaction according to claim 1, characterized in that: The pressurizing specifically refers to applying a force of 0.1 to 1N.

4. The method for passivating a perovskite solar cell based on a glycine solid-solid reaction according to claim 1, characterized in that: The heating is specifically as follows: a glass plate with a glycine film is covered on the surface of the perovskite film, and then a heating platform is used under the perovskite film to continuously heat it, and the heating platform is controlled so that the temperature of the FTO conductive glass substrate is 70-180° C., and the heating time is 3-5 hours.

5. The method for passivating a perovskite solar cell based on a glycine solid-solid reaction according to claim 1, characterized in that: The perovskite film is obtained by spin coating a perovskite solution and performing secondary annealing followed by cooling; the first annealing environment is: a sealed bag filled with nitrogen, the temperature is 60-100°C, and the annealing time is 1-10 minutes; the second annealing environment is: in air, the temperature is 150-210°C, the annealing time is 15-30 minutes, and the cooling is room temperature.

6. The method for passivating a perovskite solar cell based on a glycine solid-solid reaction according to claim 1, characterized in that: The hole transport layer is made of 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene.

7. The method for passivating a perovskite solar cell based on a glycine solid-solid reaction according to claim 1, characterized in that: The electron transport layer is made of SnO2.

8. The method for passivating a perovskite solar cell based on a glycine solid-solid reaction according to claim 1, characterized in that: The FTO conductive glass has a square resistance of 5-25Ω and a transmittance of 70-95%.

9. The method for passivating a perovskite solar cell based on a glycine solid-solid reaction according to claim 2, characterized in that: The FTO conductive glass is firstly treated with glass cleaning agent, water, acetone and ethanol ultrasonic cleaning for 10-20 minutes in sequence before use, and then treated with ultraviolet ozone for 5-60 minutes after drying, and then used for standby; The electron transport layer is prepared by spin coating, specifically: first, dilute the SnO2 colloidal aqueous solution with a concentration of 12% to a concentration of 1%-10%, and then spin coat it on the FTO conductive glass. 2 10-80 μL of SnO2 aqueous solution was dropped onto the glass slide, the spin coating speed was 3000 rpm, and the spin coating time was 30 s; after spin coating, it was placed on a heating table at 150°C for annealing for 30 min; The perovskite film is prepared by: dissolving 100-200g of dimethylammonium iodide DMAI, 300-400g of lead iodide PbI3 and 200-300g of cesium iodide CsI mixed powder in 1ml of DMF, stirring overnight at 30-70°C, filtering to obtain a precursor solution, and spin coating to obtain a film; annealing the film twice, the first annealing environment is: a sealed bag filled with nitrogen, the temperature is 60-100°C, the annealing time is 1-10 minutes, the second annealing environment is: in the air, the temperature is 150-210°C, the annealing time is 15-30 minutes, and cooling to room temperature to obtain the perovskite film; The hole transport layer is prepared by spin coating the Spiro-OMeTAD hole transport layer precursor solution on the perovskite light absorption layer, at a spin coating speed of 2000-6000 rpm and a spin coating time of 20-60 s, and dropping 10-40 μL of the hole transport layer precursor solution per square centimeter of the glass sheet; The metal electrode includes gold and silver, and has a thickness of 50-300 nm. The metal electrode is prepared by evaporation, and the vacuum degree reaches 1×10 -5 -8×10 -4 Pa, evaporation began, with an evaporation rate of 0.001-0.5nm / s.

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