Electron transport layer, perovskite solar cell, perovskite / silicon laminated cell and preparation method thereof

Abstract

The invention relates to the technical field of solar cell materials, and particularly discloses an electron transport layer, a perovskite solar cell, a perovskite / silicon laminated cell and a preparation method thereof. According to the preparation method of the electron transport layer, the electron transport layer is used for a perovskite solar cell and a perovskite / silicon laminated cell, and the electron transport layer is prepared by thermally evaporating fullerene C60. Due to the adoption of the thermal evaporation C60 process, the stability of the solar cell is improved, the problem of uniform coverage of the electron transport layer in the laminated cell is solved, and large-area production is facilitated.

Description

Technical Field

[0001] The present invention belongs to the field of solar cell materials and technologies, and specifically relates to an electron transport layer, a perovskite solar cell, a perovskite / silicon stacked cell and a preparation method thereof. Background Art

[0002] Perovskite solar cells are representatives of the third generation of high-efficiency thin-film cells. They have good light absorption, fast charge transfer rate, and huge development potential, showing the characteristics of high efficiency, high flexibility and low cost. The highest efficiency of perovskite single-junction cells in the laboratory reached 26.1%, gradually approaching the highest efficiency level of silicon cells at 27.09%. Perovskite cells and silicon cells have a good matching degree of stacked cells. A new type of stacked cell can be formed by stacking wide-bandgap perovskite cells on narrow-bandgap crystalline silicon cells. This structure broadens the utilization range of the solar energy spectrum and produces stacked cells with higher efficiency than single-junction cells. At present, the laboratory efficiency of perovskite / silicon stacked cells has reached 34.6%, which is still far from its theoretical limit of 45%. Perovskite solar cells and perovskite / silicon stacked cells have the advantages of high conversion efficiency and low manufacturing cost, and are expected to become an important direction for the development of photovoltaic industry technology in the future.

[0003] The electron transport layer of the inverse perovskite solar cell is generally prepared by a solution method, where the fullerene derivative PCBM is dissolved in an organic solvent and deposited on the substrate by spin coating or scraping. Since the PCBM film prepared by the solution method has a large energy disorder and insufficient ability to passivate defects on the perovskite interface, the device efficiency is limited. PCBM molecules tend to self-aggregate under photothermal conditions, reducing the long-term stability of the device. In addition, the electron transport layer prepared by the solution method cannot be evenly covered on the velvet silicon bottom cell. Therefore, it is necessary to develop an electron transport layer with better electron extraction and transport capabilities, lower energy disorder, and better stability. Summary of the invention

[0004] In view of the above problems, the present invention provides an electron transport layer, a perovskite solar cell, a perovskite / silicon stacked cell and a preparation method thereof. The commonly used electron transport layer PCBM is a molecule containing a benzene ring and an ester group. The ester group is easily hydrolyzed under conditions such as high temperature, light, and moisture, resulting in the destruction of the molecular structure. Fullerene C60 is a spherical molecule composed of 60 carbon atoms, and its structure is very stable. The preparation of an electron transport layer by thermal evaporation of C60 can solve the problems of its stability and uniform coverage in the stacked cell.

[0005] The technical solution provided by the present invention is as follows: A method for preparing an electron transport layer, wherein the electron transport layer is used for a perovskite solar cell and a perovskite / silicon stacked cell, and the electron transport layer is prepared by thermal evaporation of fullerene C60.

[0006] Furthermore, the electron transport layer material is C60.

[0007] Furthermore, the thermal evaporation rate is 0.1 Å / s-10 Å / s.

[0008] Furthermore, the thickness of the electron transport layer is in the range of 5-50 nm.

[0009] The present invention also provides a perovskite solar cell, comprising a conductive glass substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and a metal electrode.

[0010] Furthermore, there is a passivation layer between the hole transport layer and the perovskite absorption layer, and the passivation layer contains one or both of MeO-2PACz and MeO-4PACz.

[0011] Furthermore, there is a hole blocking layer between the electron transport layer and the metal electrode, and the hole blocking layer is BCP with a thickness ranging from 5 to 20 nm.

[0012] The present invention also provides a perovskite / silicon stacked battery, wherein the electron transport layer is an electron transport layer prepared by adopting the above technical solution.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides an electron transport layer, a perovskite solar cell, a perovskite / silicon tandem cell and a preparation method thereof. The method for the electron transport layer of the perovskite solar cell and the perovskite / silicon tandem cell adopts a thermal evaporation C60 process to improve its stability and solve the problem of uniform coverage of the electron transport layer in the tandem cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Short-circuit current density of the perovskite solar cells obtained in the comparative example and examples 1-3.

[0015] Figure 2 Open circuit voltage of the perovskite solar cells obtained in the comparative example and examples 1-3.

[0016] Figure 3 Filling factors of perovskite solar cells obtained in Comparative Example and Examples 1-3.

[0017] Figure 4 Conversion efficiency of perovskite solar cells obtained in Comparative Example and Examples 1-3. DETAILED DESCRIPTION

[0018] The purpose of the present invention is to provide an electron transport layer, a perovskite solar cell, a perovskite / silicon tandem cell and a preparation method thereof. The thermal evaporation C60 process is adopted to improve its stability and solve the problem of uniform coverage of the electron transport layer in the tandem cell.

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. Example 1

[0020] A method for preparing an electron transport layer, wherein the electron transport layer is used for a perovskite solar cell and a perovskite / silicon stacked cell, and the electron transport layer is prepared by thermal evaporation of fullerene C60.

[0021] Furthermore, the electron transport layer material is C60.

[0022] Furthermore, the thermal evaporation rate is 0.1 Å / s.

[0023] Furthermore, the thickness of the electron transport layer is 10 nm.

[0024] A perovskite solar cell comprises a conductive glass substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and a metal electrode.

[0025] Furthermore, there is a passivation layer between the hole transport layer and the perovskite absorption layer, and the passivation layer is a mixture of MeO-2PACz and MeO-4PACz.

[0026] Furthermore, there is a hole blocking layer between the electron transport layer and the metal electrode, and the hole blocking layer is BCP with a thickness of 8 nm. Example 2

[0027] A method for preparing an electron transport layer, wherein the electron transport layer is used for a perovskite solar cell and a perovskite / silicon stacked cell, and the electron transport layer is prepared by thermal evaporation of fullerene C60.

[0028] Furthermore, the electron transport layer material is C60.

[0029] Furthermore, the thermal evaporation rate is 0.1 Å / s.

[0030] Furthermore, the thickness of the electron transport layer is 20 nm.

[0031] A perovskite solar cell comprises a conductive glass substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and a metal electrode.

[0032] Furthermore, there is a passivation layer between the hole transport layer and the perovskite absorption layer, and the passivation layer is a mixture of MeO-2PACz and MeO-4PACz.

[0033] Furthermore, there is a hole blocking layer between the electron transport layer and the metal electrode, and the hole blocking layer is BCP with a thickness of 8 nm. Example 3

[0034] A method for preparing an electron transport layer, wherein the electron transport layer is used for a perovskite solar cell and a perovskite / silicon stacked cell, and the electron transport layer is prepared by thermal evaporation of fullerene C60.

[0035] Furthermore, the electron transport layer material is C60.

[0036] Furthermore, the thermal evaporation rate is 0.1 Å / s.

[0037] Furthermore, the thickness of the electron transport layer is 40 nm.

[0038] A perovskite solar cell comprises a conductive glass substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and a metal electrode.

[0039] Furthermore, there is a passivation layer between the hole transport layer and the perovskite absorption layer, and the passivation layer is a mixture of MeO-2PACz and MeO-4PACz.

[0040] Furthermore, there is a hole blocking layer between the electron transport layer and the metal electrode, and the hole blocking layer is BCP with a thickness of 8 nm.

[0041] Comparative Example The electron transport layer of the inverse perovskite solar cell is generally prepared by a solution method. The fullerene derivative PCBM is dissolved in an organic solvent and deposited on the substrate by spin coating or scraping. The specific preparation steps of the electron transport layer in the perovskite solar cell are as follows: First, prepare the PCBM solution, add 20 mg of PCBM powder to 1 mL of chlorobenzene solvent, stir well for 2 hours and filter. Static spin coating is performed at a speed of 2000 rpm for 30 s to obtain the PCBM electron transport layer, and annealing treatment is performed at 100 ° C for 4 min in a glove box. The preparation method of other layers of the battery is the same as that in Example 1. The perovskite solar cells obtained in Examples 1-3 and the comparative example were subjected to JV tests, and their performance parameters are shown in Tables 1 and Figure 1-4As shown. We found that the efficiency of perovskite solar cells prepared by thermal evaporation of C60 and spin coating of PCBM solution is similar, and the thickness of C60 has a great influence on the performance of the cell. However, C60 has better stability, and thermal evaporation is more suitable for large-scale production.

[0042] Table 1 Performance parameters of the best perovskite solar cells obtained in comparative examples and examples 1-3 serial number <![CDATA[Short-circuit current density J sc (mA / cm 2 )]]> <![CDATA[Open circuit voltage V oc (v)]]> Fill factor (%) Conversion efficiency (%) Comparative Example 25.65 1.065 63.01 17.21 Example 1 21.06 0.952 57.21 11.47 Example 2 24.36 1.056 69.30 17.83 Example 3 18.51 1.005 52.61 9.79

[0043] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. 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 electron transport layer, wherein the electron transport layer is used for a perovskite solar cell and a perovskite / silicon tandem cell, characterized in that: The preparation method of the electron transport layer is: obtaining a thin film by thermal evaporation of fullerene.

2. The method for preparing an electron transport layer according to claim 1, characterized in that: The electron transport layer material is C60.

3. The method for preparing an electron transport layer according to claim 1, characterized in that: The thermal evaporation rate is 0.1 Å / s-10 Å / s.

4. The method for preparing an electron transport layer according to claim 1, characterized in that: The thickness of the electron transport layer is in the range of 5-50 nm.

5. A perovskite solar cell, characterized in that: The solar cell structure comprises, in sequence, a conductive glass substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer as described in any one of claims 1 to 4, and a metal electrode.

6. The perovskite solar cell according to claim 5, characterized in that: A passivation layer is provided between the hole transport layer and the perovskite absorption layer, and the passivation layer contains one or both of MeO-2PACz and MeO-4PACz.

7. The perovskite solar cell according to claim 5, characterized in that There is a hole blocking layer between the electron transport layer and the metal electrode. The hole blocking layer is BCP and has a thickness ranging from 5 to 20 nm.

8. A perovskite / silicon tandem battery, characterized in that: An electron transport layer prepared by the electron transport layer preparation method according to any one of claims 1 to 4.

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