Preparation method of acidic modification layer and trans-perovskite cell

Abstract

The invention relates to the technical field of photovoltaic cells, and provides a preparation method of an acidic modification layer and a trans-perovskite cell, and the preparation method of the acidic modification layer comprises the steps: preparing a fullerene layer on a substrate through employing a vacuum thermal evaporation coating mode, and enabling the fullerene layer to serve as an electron transmission layer; the surface of the electron transport layer is coated with an acidic solution to form an acidic modification layer, the acidic solution can be dispersed in the electron transport layer, and the acidic solution is used for adjusting the pH value of the electron transport layer. By using the method, the problem that the conductivity of the C60 electron transport layer which is low in price and can be evaporated is low can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, in particular to a method for preparing an acidic modification layer and an inverse perovskite cell. Background Art

[0002] With the growing demand for renewable energy, solar cells have attracted widespread attention as a clean energy technology. Among the various solar cell technologies, perovskite solar cells have become a research hotspot due to their high efficiency, low cost, and ease of preparation. Among them, inverse perovskite solar cells (PIN structure) have shown great potential in commercial applications due to their low-temperature preparation process, good stability, and compatibility with flexible substrates. However, the performance of inverse perovskite solar cells is still limited by the quality of the electron transport layer (ETL), including its energy level matching, carrier mobility, and interface defects.

[0003] The electron transport layer plays a key role in extracting and transporting photogenerated electrons in perovskite cells. Currently, commonly used electron transport materials include fullerene derivatives (such as PCBM), metal oxides (such as TiO2, SnO2) and organic polymers. However, these materials still face some challenges in practical applications. For example, although fullerene derivatives have excellent electron mobility, their energy level matching and interface defect problems limit the open circuit voltage and fill factor of the battery; although metal oxides have good stability, they usually require high-temperature annealing processes, which increases the preparation cost; organic polymer materials have problems with insufficient conductivity and stability.

[0004] In recent years, researchers have found that optimizing the performance of the electron transport layer through chemical modification or interface engineering can effectively improve the photoelectric conversion efficiency of perovskite cells. Among them, the adjustment of pH value is considered to be a simple and effective method. The pH value of the electron transport layer directly affects its energy level structure, surface state density, and interface charge transfer characteristics. For example, an acidic environment can change the hydroxylation state of the metal oxide surface, thereby adjusting its work function and energy level arrangement; for organic electron transport materials, acidic solutions can protonate their surface groups, reduce the interface defect state density, and improve electron extraction efficiency.

[0005] However, in the existing technology, the regulation of the pH value of the electron transport layer is mostly concentrated in the material synthesis stage or achieved through complex post-processing processes. These methods often have problems such as complex processes, high costs, or difficulty in precise control. In addition, traditional pH adjustment methods may damage the perovskite active layer or other functional layers, affecting the overall performance of the device. Therefore, developing a simple, efficient and harmless pH control method for other parts of the device is of great significance for further improving the performance of inverse perovskite solar cells. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem of C 60 To solve the problem of low conductivity of the electron transport layer, a method for preparing an acidic modification layer and an inverse perovskite battery are provided.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for preparing an acidic modification layer comprises preparing a fullerene layer as an electron transport layer on a substrate by vacuum thermal evaporation coating; applying an acidic solution on the surface of the electron transport layer to form an acidic modification layer, wherein the acidic solution can be dispersed in the electron transport layer, and the acidic solution is used to adjust the pH of the electron transport layer.

[0009] The present invention adopts a method for preparing an acidic modified layer, which adjusts the pH of the fullerene electron transport layer by adding an acidic solution, thereby effectively improving its conductivity and solving the problem of traditional C 60 The problem of low conductivity of the electron transport layer is solved; at the same time, the method is simple in process, low in cost, and avoids high-temperature annealing process, and is suitable for flexible substrates and low-temperature preparation scenarios.

[0010] As a preferred embodiment of the present invention, the solute of the acidic solution comprises acetic acid, benzoic acid, phenylacetic acid, phenylpropionic acid, phenylbutyric acid or phenylvaleric acid.

[0011] As a preferred embodiment of the present invention, the thickness of the acidic modification layer is 100-150 nm; and the curing temperature of the acidic solution is 50-120°C.

[0012] As a preferred embodiment of the present invention, the coating method includes blade coating and spin coating.

[0013] As a preferred embodiment of the present invention, the concentration of the acidic solution is 0.1 to 1.0 mol / L.

[0014] An inverse perovskite battery comprises a substrate, a hole transport layer, a perovskite layer, an electron transport layer, an acidic modification layer prepared by the above-mentioned method for preparing an acidic modification layer, and a metal electrode stacked in sequence.

[0015] The invention adopts an inverted perovskite battery, in which the introduction of an acidic modification layer significantly optimizes the interface characteristics between the electron transport layer and the perovskite layer, improves the open circuit voltage and fill factor of the battery, and improves the overall photoelectric conversion efficiency.

[0016] As a preferred embodiment of the present invention, the hole transport layer comprises poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA), NiO x, CuO, Cu2O or a self-assembled molecular layer, wherein the self-assembled molecular layer comprises one or a combination of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACZ) and derivatives thereof.

[0017] As a preferred embodiment of the present invention, the invention further comprises a hole blocking layer, wherein the material of the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer is 2 to 20 nm.

[0018] As a preferred embodiment of the present invention, the perovskite layer comprises two-dimensional perovskite or three-dimensional perovskite.

[0019] As a preferred embodiment of the present invention, the material of the metal electrode is selected from one of gold, silver, copper and aluminum, and the thickness of the metal electrode is 300 to 5000 nm.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0021] 1. A method for preparing an acidic modified layer, which effectively improves the conductivity of the fullerene electron transport layer by adding an acidic solution. 60 The problem of low conductivity of the electron transport layer is solved; at the same time, the method is simple in process, low in cost, and avoids high-temperature annealing process, and is suitable for flexible substrates and low-temperature preparation scenarios.

[0022] 2. An inverse perovskite battery. The introduction of an acidic modification layer significantly optimizes the interface properties between the electron transport layer and the perovskite layer, improves the open circuit voltage and fill factor of the battery, and improves the overall photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a battery performance diagram of an inverse perovskite battery;

[0024] Table 1 is a statistical table of battery performance of the control battery and battery A under a standard solar radiation intensity. DETAILED DESCRIPTION

[0025] The present invention is described in detail below.

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail in the following examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] Example 1

[0028] The present invention discloses a method for preparing an acidic modification layer, which comprises preparing a fullerene layer as an electron transport layer on a substrate by vacuum thermal evaporation coating; applying an acidic solution on the surface of the electron transport layer to form an acidic modification layer, wherein the acidic solution can be dispersed in the electron transport layer, and the acidic solution is used to adjust the pH of the electron transport layer.

[0029] Furthermore, the solute of the acidic solution comprises acetic acid, benzoic acid, phenylacetic acid, phenylpropionic acid, phenylbutyric acid or phenylvaleric acid.

[0030] Furthermore, the thickness of the acidic modification layer is 100-150 nm; and the curing temperature of the acidic solution is 50-120°C.

[0031] Furthermore, the coating method includes blade coating and spin coating.

[0032] Furthermore, the concentration of the acidic solution is 0.1 to 1.0 mol / L.

[0033] By adding acidic solution to adjust the pH of the fullerene electron transport layer, its conductivity is effectively improved, solving the problem of traditional C 60 The problem of low conductivity of the electron transport layer is solved; at the same time, the method is simple in process, low in cost, and avoids high-temperature annealing process, and is suitable for flexible substrates and low-temperature preparation scenarios.

[0034] In this embodiment, the specific preparation process is as follows:

[0035] Substrate pretreatment: The glass substrate (or flexible PET substrate) was cleaned and dried, and then subjected to UV-ozone treatment for 10 minutes to enhance the surface hydrophilicity.

[0036] Fullerene layer deposition: Vacuum thermal evaporation coating equipment is used to evaporate C60 thin film on the substrate as the electron transport layer, and the evaporation rate is The final thickness was 80 nm.

[0037] Preparation of acidic solution: dissolve benzoic acid in anhydrous ethanol to prepare an acidic solution with a concentration of 0.5 mol / L.

[0038] Applying the acidic solution: The acidic solution was evenly coated on the surface of the C60 layer using a spin coating method (rotation speed 3000 rpm, time 30 s), and then cured at 80° C. for 10 minutes to form an acidic modification layer with a thickness of 120 nm.

[0039] Example 2

[0040] An inverted perovskite cell used in the present invention comprises a substrate, a hole transport layer, a perovskite layer, an electron transport layer, an acidic modification layer prepared by the preparation method of an acidic modification layer as described in Example 1, and a metal electrode stacked in sequence.

[0041] Furthermore, the hole transport layer comprises poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA), NiO x , CuO, Cu2O or a self-assembled molecular layer, wherein the self-assembled molecular layer comprises one or a combination of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACZ), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACZ), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACZ) and derivatives thereof.

[0042] Furthermore, the invention further comprises a hole blocking layer, wherein the material of the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer is 2 to 20 nm.

[0043] Furthermore, the perovskite layer comprises two-dimensional perovskite or three-dimensional perovskite.

[0044] Furthermore, the material of the metal electrode is selected from one of gold, silver, copper and aluminum, and the thickness of the metal electrode is 300 to 5000 nm.

[0045] The introduction of the acidic modification layer significantly optimizes the interface properties between the electron transport layer and the perovskite layer, improves the open circuit voltage and fill factor of the battery, and improves the overall photoelectric conversion efficiency.

[0046] In this embodiment, the specific preparation method is as follows:

[0047] Substrate and hole transport layer: PTAA solution (concentration 2 mg / mL, rotation speed 4000 rpm) was spin-coated on an ITO glass substrate to form a hole transport layer, and then annealed at 100° C. for 10 minutes.

[0048] Perovskite layer preparation: A CH3NH3PbI3 precursor solution (molar ratio 1:1) was spin-coated on the PTAA layer (rotation speed 6000 rpm, time 20 s), followed by annealing at 100°C for 30 minutes to form a three-dimensional perovskite active layer.

[0049] Electron transport layer and acidic modification layer: a C60 layer and a benzoic acid acidic modification layer were deposited in sequence according to the method of Example 1.

[0050] Hole-blocking layer and metal electrode: A 10nm thick BCP layer was vacuum-deposited as a hole-blocking layer, followed by a 100nm thick silver electrode. The resulting perovskite cell is referred to as the target cell.

[0051] Comparative Example

[0052] A trans perovskite cell, the preparation method of which is basically the same as that of Example 2, except that the acidic modification layer prepared by the preparation method of an acidic modification layer as described in Example 1 is not added, and the obtained trans perovskite cell is recorded as a control cell.

[0053] The control cell and target cell were tested under a standard solar radiation intensity. The best device performance of the control cell and target cell was statistically analyzed. The results are as follows:

[0054] Table 1

[0055]

[0056]

[0057] like Figure 1 As shown in Table 1, the inverse perovskite cell with the acidic modifier layer achieved a photoelectric conversion efficiency (PCE) of 23.44% under reverse scanning, compared to 20.87% for the control group without the modifier layer. This suggests that the use of an acidic modifier layer in inverse perovskite cells can significantly improve the device's photoelectric conversion efficiency and stability, while reducing process costs by approximately 30%.

[0058] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing an acidic modified layer, characterized in that: The method comprises preparing a fullerene layer as an electron transport layer on a substrate by vacuum thermal evaporation coating; coating an acidic solution on the surface of the electron transport layer to form an acidic modification layer, wherein the acidic solution can be dispersed in the electron transport layer, and the acidic solution is used to reduce the pH value of the material used for the electron transport layer.

2. The method for preparing an acidic modification layer according to claim 1, wherein: The solute of the acidic solution comprises acetic acid, benzoic acid, phenylacetic acid, phenylpropionic acid, phenylbutyric acid or phenylvaleric acid.

3. The method for preparing an acidic modification layer according to claim 2, wherein: The thickness of the acidic modification layer is 100-150 nm; the curing temperature of the acidic solution is 50-120° C.

4. The method for preparing an acidic modification layer according to claim 1, wherein: The coating method includes blade coating and spin coating. 5 . The method for preparing an acidic modification layer according to claim 1 , wherein the concentration of the acidic solution is 0.1 to 1.0 mol / L.

6. An inverse perovskite battery, characterized in that: The invention comprises a substrate, a hole transport layer, a perovskite layer, an electron transport layer, an acidic modified layer prepared by the method for preparing an acidic modified layer according to any one of claims 1 to 5, and a metal electrode, which are stacked in sequence.

7. The inverse perovskite battery according to claim 6, characterized in that: The hole transport layer comprises poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), NiO x , CuO, Cu2O or a self-assembled molecular layer, wherein the self-assembled molecular layer comprises one or a combination of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) and derivatives thereof.

8. An inverse perovskite battery according to any one of claims 6 to 7, characterized in that: The invention also comprises a hole blocking layer, wherein the material of the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the thickness of the hole blocking layer is 2-20 nm.

9. An inverse perovskite battery according to any one of claims 6 to 7, characterized in that: The perovskite layer includes two-dimensional perovskite or three-dimensional perovskite.

10. An inverse perovskite battery according to any one of claims 6 to 7, characterized in that: The material of the metal electrode is selected from one of gold, silver, copper and aluminum, and the thickness of the metal electrode is 300 to 5000 nm.

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