Hole transport layer, preparation method thereof and perovskite solar cell

Abstract

The invention discloses a hole transport layer, a preparation method thereof and a perovskite solar cell, nickel oxide nanoparticles and SAM are simply mixed and then dissolved in an organic solution such as ethanol and n-hexanol, the surface of conductive glass is coated with the mixture after ultrasonic treatment, and the hole transport layer is formed after heat treatment. The wettability of the perovskite on the SAM surface can be effectively improved by preparing the perovskite layer on the surface, so that the defects of a perovskite buried interface are fewer, the interface contact is better, and the efficiency of the perovskite cell is remarkably improved. Meanwhile, the preparation process of the perovskite cell is simplified, and time cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy solar cells, and in particular to a hole transport layer and a preparation method thereof, and a perovskite solar cell. Background Art

[0002] Perovskite solar cells are considered one of the most promising photovoltaic technologies of the future. Inverse perovskite solar cells, due to their competitive photoelectric conversion efficiency, good stability, and compatibility with tandem solar cells, are considered a mainstream technology path for the commercialization of this emerging photovoltaic technology. Hole transport layers based on SAM materials, in particular, have been widely used in high-efficiency inverse perovskite solar cells in recent years due to their advantages such as suitable energy levels for efficient carrier extraction and low non-radiative recombination losses. However, the poor wettability of perovskite solutions on SAM surfaces can lead to interfacial losses, hindering the development of high-efficiency, large-scale perovskite solar cells.

[0003] In view of this, many studies have been conducted to improve the wettability of perovskite solution on the SAM surface. The most common method is to insert a layer of nickel oxide between the conductive glass and the SAM layer. For example: "Improved Anchoring of "Self-Assembled Monolayer on Hydroxylated NiOx Film Surface for Efficient and Stable Inverted Perovskite Solar Cells" reports a double-layer NiOx hole transport layer (HTL). By preparing an ultra-thin NiOx buffer film (ALD-NiOx) and a spin-coated NiOx film (Spin-NiOx) on the surface of conductive glass by atomic layer deposition, more anchoring sites are provided for SAM molecules. A SAM film with better coverage and molecular arrangement can be obtained. For small-area perovskite solar cells (0.06cm2) prepared using the composite HTL, a championship power conversion efficiency of 25.25% was achieved, and the device stability was also significantly improved. The above-mentioned traditional preparation method can effectively improve the wettability of the perovskite solution on the SAM surface, but it requires the preparation of a composite transport layer, which is a complex process and time-consuming.

[0004] Therefore, how to prepare a hole transport layer that can solve the above problems has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the prior art and provide a hole transport layer and a preparation method thereof, as well as a perovskite solar cell.

[0006] The objective of the present invention is achieved through the following technical solution: a method for preparing a hole transport layer, wherein nickel oxide nanoparticles and SAM material are mixed and dissolved in an organic alcohol solution, coated on the surface of a conductive glass after ultrasonic treatment, and formed into a hole transport layer after heat treatment.

[0007] Furthermore, the nickel oxide nanoparticles and the SAM material are mixed and dissolved in an organic alcohol solution to a final concentration of any value between 0.01 and 30 mg / ml and any value between 0.1 and 5 mg / ml.

[0008] Furthermore, the SAM material is one of Me-4PACZ, MeO-2PACZ, and 4PADCB;

[0009] The organic alcohol is one or more of ethanol and n-hexanol.

[0010] Furthermore, the ultrasonic treatment time is 15-60 minutes.

[0011] Furthermore, the heat treatment temperature is 100-150° C. and the time is 10-60 min.

[0012] Application of the hole transport layer prepared according to the above preparation method in perovskite solar cells.

[0013] The present invention also provides a perovskite solar cell, which comprises, from bottom to top, a transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, and a metal electrode; wherein the hole transport layer is prepared by the above-mentioned preparation method.

[0014] Furthermore, the transparent conductive layer is one or more of FTO, ITO, ZnO, and In2O3;

[0015] The material of the perovskite layer is an ABX3 type metal halide material; wherein A is an organic amine ion or an alkali metal ion; B is a divalent metal ion; and X is a halogen ion.

[0016] The material of the electron transport layer is carbon 60;

[0017] The material of the metal electrode is one of silver, aluminum, magnesium, copper, gold, indium tin oxide, and fluorine-doped tin oxide.

[0018] Furthermore, the thickness of the transparent conductive layer is 1-500 nm;

[0019] The thickness of the hole transport layer is 1-300 nm;

[0020] The thickness of the perovskite layer is 300-1000 nm;

[0021] The thickness of the electron transport layer is 50-100 nm;

[0022] The thickness of the metal electrode is 1-300 nm.

[0023] The present invention also provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0024] (1) coating a conductive layer on the conductive glass;

[0025] (2) mixing nickel oxide nanoparticles and SAM material and dissolving them in an organic alcohol solution, coating them on the conductive layer after ultrasonic treatment, and then heat treating them to obtain a hole transport layer;

[0026] (3) preparing a perovskite precursor solution, coating it on the hole transport layer, and then heat treating it to obtain a perovskite optical layer;

[0027] (4) Then, an electron transport layer and a metal electrode are sequentially prepared on the perovskite light absorption layer to obtain a perovskite solar cell.

[0028] The present invention has the following beneficial effects: by simply mixing nickel oxide nanoparticles and SAM materials, dissolving them in an organic solution such as ethanol or n-hexanol, and then applying them to the surface of conductive glass after ultrasonic treatment to prepare a hole transport layer, and then coating the surface with a perovskite solution, the hole transport layer can be effectively improved in the wettability of the perovskite on the SAM surface, resulting in fewer defects at the buried perovskite interface and better interface contact, significantly improving the efficiency of the perovskite cell. This also simplifies the perovskite cell preparation process, saving time and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of a perovskite solar cell. DETAILED DESCRIPTION

[0030] The invention discloses a method for preparing a hole transport layer, comprising the steps of mixing nickel oxide nanoparticles and a SAM material, dissolving the mixture in an organic alcohol solution, coating the mixture on a conductive glass surface after ultrasonic treatment, and forming the hole transport layer after heat treatment.

[0031] The nickel oxide nanoparticles can be commercially available nickel oxide nanoparticles (dispersed in an alcohol solution) or prepared by referring to “Preparation and Characteristics of Nanocrystalline NiO by Organic Solvent Method”.

[0032] In one embodiment, nickel oxide nanoparticles and SAM materials are mixed and dissolved in an organic alcohol solution to a final concentration of any value between 0.01-30 mg / ml and any value between 0.1-5 mg / ml.

[0033] In one embodiment, the organic alcohol is one or more of ethanol and n-hexanol.

[0034] In one embodiment, the ultrasonication time is 15-60 min.

[0035] In one embodiment, the heat treatment temperature is 100-150° C., and the time is 10-60 minutes.

[0036] The present invention also provides a hole transport layer prepared according to the above preparation method.

[0037] The present invention also provides a perovskite solar cell, see Figure 1 , which from bottom to top are respectively a transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, and a metal electrode; wherein the hole transport layer is prepared by the above-mentioned preparation method.

[0038] In one embodiment, the transparent conductive layer is one or more of FTO, ITO, ZnO, and In2O3; the material of the perovskite layer is an ABX3 type metal halide material; wherein A is an organic amine ion or an alkali metal ion; B is a divalent metal ion; X is a halogen ion; the material of the electron transport layer is carbon 60; and the material of the metal electrode is one of silver, aluminum, magnesium, copper, gold, indium tin oxide, and fluorine-doped tin oxide.

[0039] In one embodiment, the thickness of the transparent conductive layer is 1-500 nm;

[0040] The thickness of the hole transport layer is 1-300 nm;

[0041] The thickness of the perovskite layer is 300-1000 nm;

[0042] The thickness of the electron transport layer is 50-100 nm;

[0043] The thickness of the metal electrode is 1-300 nm.

[0044] The present invention also provides a method for preparing a perovskite solar cell, comprising the following steps:

[0045] Step 1, coating a conductive layer on the conductive glass;

[0046] Step 2: nickel oxide nanoparticles and SAM material are mixed and dissolved in an organic alcohol solution, coated on the conductive layer after ultrasonic treatment, and then heat-treated to obtain a hole transport layer;

[0047] Step 3, preparing a perovskite precursor solution, coating it on the hole transport layer, and then heat treating it to obtain a perovskite optical layer;

[0048] Step 4: After preparing an electron transport layer and a metal electrode on the perovskite light absorption layer, a perovskite solar cell is obtained.

[0049] Example 1

[0050] Obtaining the hole transport layer solution 1 comprises the following steps:

[0051] According to “Preparation and Characteristics of Nickel oxide nanoparticles were prepared using the "Nanocrystalline NiO by Organic Solvent Method". 10 mg of nickel oxide nanoparticles and 0.5 mg of Me-4PACZ were weighed into a glass bottle. 1 ml of ethanol solution was added to the bottle and ultrasonicated for 1 hour. The mixture was filtered through a PTFE filter before use.

[0052] Comparative Example 1

[0053] Weigh 0.5 mg of Me-4PACZ into a glass bottle, add 1 ml of ethanol solution into the bottle, sonicate for 1 h, and filter with a PTFE filter before use.

[0054] Example 2

[0055] Obtaining the hole transport layer solution 2 comprises the following steps:

[0056] 1 ml of nickel oxide n-hexanol dispersion (commercially available) was weighed into a glass bottle, 0.5 mg of Me-4PACZ was added thereto, and ultrasonicated for 1 h. The mixture was filtered through a PTFE filter before use.

[0057] Comparative Example 2

[0058] Weigh 0.5 mg of 4PADCB into a glass bottle, add 1 ml of ethanol solution into the bottle, sonicate for 1 h, and filter with a PTFE filter before use.

[0059] In order to verify that the hole transport solutions of Example 1 and Example 2 help to improve the efficiency of perovskite cells when prepared with the hole transport solution compared to the hole transport solution of the comparative example, the following provides methods for preparing perovskite cells using these two solutions and test data.

[0060] The method for preparing a perovskite cell comprises the following steps:

[0061] 1. The glass substrate coated with indium tin oxide (ITO) was ultrasonically cleaned with detergent and deionized water for 30 minutes respectively. The ITO glass was then blown dry with dry nitrogen and then treated with ultraviolet ozone for 30 minutes to remove organic residues and impurities on the surface of the ITO glass.

[0062] 2. In a glove box, the hole transport solutions of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were spin-coated on an ITO substrate at a rotation speed of 3500 rpm, and then annealed at 100° C. for 30 minutes.

[0063] 3. The prepared perovskite solution (1.5 mol / L, solvent volume ratio of DMF:DMSO = 4:1) was spin-coated at 4000 rpm in a glove box, annealed at 100°C for 10 minutes, and then cooled.

[0064] 4. The substrate was transferred to a vacuum deposition chamber (pressure of 5×10-4Pa) to deposit approximately 30nm of C60 and 100nm of Ag. At this point, the four perovskite solar cell devices were completed.

[0065] The efficiency of the four perovskite solar cell devices obtained above was tested, and the test results are as follows:

[0066]

[0067]

[0068] The SAM materials in the above-mentioned Example 1, Example 2, Comparative Example 1 and Comparative Example 2 can also be replaced with MeO-2PACZ or 4PADCB. The efficiency of the embodiments of the present invention is better than that of the perovskite solar cells prepared in the corresponding comparative examples, and they are not listed one by one here.

[0069] It should be noted that in other embodiments of the present invention, within the scope of the steps, components, ratios, and process parameters recorded in the present invention, other different schemes obtained by making specific selections can all achieve the technical effects recorded in the present invention, so the present invention will no longer list them one by one.

[0070] The above embodiments are intended only to illustrate the design concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The scope of protection of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the principles and design concepts disclosed in the present invention are within the scope of protection of the present invention.

Claims

1. A method for preparing a hole transport layer, characterized in that: Nickel oxide nanoparticles and SAM materials are mixed and dissolved in an organic alcohol solution, coated on the surface of a conductive glass after ultrasonic treatment, and formed into a hole transport layer after heat treatment.

2. The preparation method according to claim 1, characterized in that The nickel oxide nanoparticles and the SAM material are mixed and dissolved in an organic alcohol solution to a final concentration of any value between 0.01 and 30 mg / ml and any value between 0.1 and 5 mg / ml.

3. The preparation method according to claim 1, characterized in that The SAM material is one of Me-4PACZ, MeO-2PACZ, and 4PADCB; The organic alcohol is one or more of ethanol and n-hexanol.

4. The preparation method according to claim 1, characterized in that The ultrasonic time is 15-60 minutes.

5. The preparation method according to claim 1, characterized in that The heat treatment temperature is 100-150° C. and the time is 10-60 minutes.

6. Use of the hole transport layer prepared according to the preparation method according to any one of claims 1 to 5 in perovskite solar cells.

7. A perovskite solar cell, characterized in that: From bottom to top, they are a transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, and a metal electrode; wherein the hole transport layer is prepared by the preparation method according to any one of claims 1 to 5.

8. The perovskite solar cell according to claim 7, characterized in that: The transparent conductive layer is one or more of FTO, ITO, ZnO, and In2O3; The material of the perovskite layer is an ABX3 type metal halide material; wherein A is an organic amine ion or an alkali metal ion; B is a divalent metal ion; and X is a halogen ion. The material of the electron transport layer is carbon 60; The material of the metal electrode is one of silver, aluminum, magnesium, copper, gold, indium tin oxide, and fluorine-doped tin oxide.

9. The perovskite solar cell according to claim 7, characterized in that: The thickness of the transparent conductive layer is 1-500 nm; The thickness of the hole transport layer is 1-300 nm; The thickness of the perovskite layer is 300-1000 nm; The thickness of the electron transport layer is 50-100 nm; The thickness of the metal electrode is 1-300 nm.

10. A method for preparing a perovskite solar cell according to any one of claims 7 to 9, characterized in that: The following steps are involved: (1) coating a conductive layer on the conductive glass; (2) mixing nickel oxide nanoparticles and SAM material and dissolving them in an organic alcohol solution, coating them on the conductive layer after ultrasonic treatment, and then heat treating them to obtain a hole transport layer; (3) preparing a perovskite precursor solution, coating it on the hole transport layer, and then heat treating it to obtain a perovskite optical layer; (4) Then, an electron transport layer and a metal electrode are sequentially prepared on the perovskite light absorption layer to obtain a perovskite solar cell.

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