Perovskite light absorption layer thin film, perovskite solar cell and preparation method and application thereof

Abstract

The invention belongs to the technical field of photoelectric materials and devices, and particularly relates to a perovskite light absorption layer thin film, a perovskite solar cell and a preparation method and application of the perovskite solar cell. The perovskite solar cell comprises a transparent conductive oxide substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a metal back electrode which are arranged in sequence, wherein the perovskite light absorption layer thin film comprises a boron and nitrogen heterocyclic fused ring compound and an organic-inorganic hybrid perovskite material. The boron-nitrogen fused ring compound material disclosed by the invention is simple in structure, and has diversity, easy expansibility and universality; and the perovskite photoelectric device doped with the boron-nitrogen fused ring compound not only reduces the defect number of the perovskite thin film, enables the surface of the thin film to be uniform, but also improves the photoelectric conversion efficiency and stability of the perovskite solar cell.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic materials and devices, and specifically relates to a perovskite light absorption layer film, a perovskite solar cell, and a preparation method and application thereof. Background Art

[0002] Organic-inorganic metal halide perovskite semiconductor materials have attracted extensive attention from academia and industry in recent years due to their excellent optoelectronic properties, such as adjustable band gap, easy availability of raw materials, direct band gap, and high absorption coefficient. They are used in various fields including photovoltaic power generation, luminescence, and detectors. Among them, perovskite solar cells, as a representative of the new generation of thin-film photovoltaic cells, have the advantages of high theoretical photoelectric conversion efficiency, low cost, and easy processing. At present, their photoelectric conversion efficiency is comparable to that of crystalline silicon cells.

[0003] The basic structure of a perovskite solar cell includes a glass substrate coated with a transparent conductive oxide film (as the top electrode), an electron transport layer, a perovskite light absorption layer, a hole transport layer, and a back electrode. Its basic working principle is that when a beam of light with an energy greater than the perovskite band gap is irradiated on the perovskite surface and absorbed, it excites the generation of electron-hole pairs, and the free electrons and holes are transferred from the corresponding charge transport layers, and then arrive at the back electrode through an external circuit to recombine, thus completing a circuit. Therefore, the smooth transmission of carriers is one of the keys to determining the photoelectric conversion efficiency of the device.

[0004] However, due to the easy crystallization property of perovskite materials, there are a large number of defects at the surface interface of the crystal. These defects will become the recombination center of carriers, thus affecting the photoelectric performance of the device. At the same time, these defects are also the sites where the perovskite material decomposes. By introducing substances with defect passivation ability into the perovskite precursor solution, such as functional groups containing oxygen atoms, sulfur atoms, and halogen atoms, and interacting with the corresponding defect atoms by coordination, the defects are passivated, thereby improving the photoelectric performance of the perovskite material. Although the commonly used defect passivation materials can improve the photoelectric conversion efficiency of the device, the high photoelectric conversion efficiency of the current perovskite solar cell is at the expense of the effective illumination area of ​​the device. As the device area increases, the photoelectric conversion efficiency of the battery is greatly reduced, which is difficult to meet the needs of large-scale commercial applications. One of the reasons for this problem is the poor uniformity of the perovskite film.

[0005] Therefore, developing multifunctional additives to passivate perovskite film defects while regulating the crystallization properties of perovskite and improving the quality of the film is of great practical significance for accelerating the commercial application of perovskite solar cells. Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In order to solve the existing problems, the present invention provides a perovskite light absorption layer film, a perovskite solar cell and a preparation method and application thereof. The perovskite light absorption layer film is prepared by introducing a boron nitrogen condensed ring compound into a perovskite precursor solution, and applied to a formally structured perovskite solar cell, which can effectively passivate the defects of the perovskite material and overcome the problem of poor uniformity of the perovskite film.

[0008] Solutions for solving problems

[0009] [1] A perovskite light absorption layer film comprising a boron nitrogen condensed ring compound and an organic-inorganic hybrid perovskite material;

[0010] Wherein, the structure of the boron nitrogen fused ring compound is:

[0011]

[0012] R is selected from a hydrogen atom, a fluorine atom, a chlorine atom and a bromine atom.

[0013] [2] The perovskite light absorbing layer thin film according to [1], characterized in that

[0014] The chemical formula of the organic-inorganic hybrid perovskite material is MA x FA 1-x PbI3, wherein MA represents a methylamine cation, FA represents a formamidinium cation, and 0≤x≤1.

[0015] [3] A method for preparing a perovskite light absorbing layer film according to [2], comprising the following steps:

[0016] 1) dissolving the boron nitrogen fused ring compound and lead iodide in a mixed solution to obtain a perovskite precursor solution; dissolving methylamine hydroiodide, formamidine hydroiodide and methylamine hydrochloride in isopropanol to obtain an amine salt isopropanol solution;

[0017] 2) spin coating the perovskite precursor solution in step 1) on the substrate, and then performing annealing treatment;

[0018] 3) Spin coating the amine salt isopropanol solution in step 1) on the annealed material in step 2), and then heat treating to obtain a perovskite light absorption layer film.

[0019] [4] The preparation method according to [3], characterized in that

[0020] In step 1),

[0021] The mixed solution is a mixed solution of DMF and DMSO, preferably a mixed solution in which the volume ratio of DMF to DMSO is 9:1.

[0022] [5] The preparation method according to [3] or [4], characterized in that

[0023] In step 1),

[0024] The concentration of the boron nitrogen fused ring compound in the perovskite precursor solution is 0.05-6.0 mg / mL; and / or,

[0025] The concentration of lead iodide in the perovskite precursor solution is 691 mg / mL.

[0026] [6] The preparation method according to any one of [3] to [5], characterized in that

[0027] In step 1),

[0028] At a concentration of mg / mL, the concentration ratio of methylamine hydroiodide, formamidine hydroiodide and methylamine hydrochloride is (7-10):(70-100):(7-10), preferably 9:85:10.

[0029] [7] The preparation method according to any one of [3] to [6], characterized in that

[0030] In step 2),

[0031] The spin coating speed is 1200-1800 rpm, preferably 1500 rpm; and / or,

[0032] The spin coating time is 20-40 seconds, preferably 30 seconds; and / or,

[0033] The annealing temperature is 60-80°C, preferably 70°C; and / or,

[0034] The annealing time is 40-80 seconds, preferably 60 seconds.

[0035] [8] The preparation method according to any one of [3] to [7], characterized in that

[0036] In step 3),

[0037] The spin coating speed is 1500-2500 rpm, preferably 2000 rpm; and / or,

[0038] The spin coating time is 20-40 seconds, preferably 30 seconds; and / or,

[0039] The heating temperature is 120-180°C, preferably 150°C; and / or,

[0040] Heating time is 15-20 minutes.

[0041] [9] A perovskite solar cell comprising a transparent conductive oxide substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a metal back electrode arranged in sequence;

[0042] The perovskite light absorbing layer comprises the perovskite light absorbing layer thin film according to [1] or [2] or the perovskite light absorbing layer thin film obtained by the preparation method according to any one of [3] to [8].

[0043]

[10] Use of the perovskite light absorption layer film according to [1] or [2] or the perovskite solar cell according to [9] in the field of perovskite optoelectronics, preferably in the preparation of optoelectronic devices, more preferably in the preparation of solar cells.

[0044] Effects of the Invention

[0045] 1) The boron nitrogen fused ring compound material of the present invention has a simple structure, diversity, easy scalability and universality;

[0046] 2) The boron nitrogen condensed ring compound material described in the present invention can be applied to perovskite photoelectric devices, which not only reduces the number of defects in the perovskite film and makes the film surface uniform, but also improves the photoelectric conversion efficiency and stability of the perovskite solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Perovskite solar cell device structure.

[0048] Figure 2 The volt-ampere characteristic (JV) curves of the perovskite solar cells prepared in Examples 1-4 of the present invention and Comparative Example 1.

[0049] Figure 3 (a) Electron scanning microscopy image of the perovskite light absorbing layer film prepared in Comparative Example 1; (b) Electron scanning microscopy image of the perovskite light absorbing layer film prepared in Example 1.

[0050] Figure 4 Schematic diagram of the photoelectric conversion efficiency of the perovskite solar cells prepared in Example 1 of the present invention and Comparative Example 1 under continuous illumination. DETAILED DESCRIPTION

[0051] Various exemplary embodiments, features and aspects of the present invention will be described in detail below. The word "exemplary" used here means "used as an example, embodiment or illustrative". Any embodiment described here as "exemplary" is not necessarily interpreted as being superior or better than other embodiments.

[0052] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In other examples, methods, means, equipment and steps well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0053] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0054] In this specification, the word "may" includes both performing a certain process and not performing a certain process.

[0055] In this specification, the references to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0056] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints A and B.

[0057] The present invention provides a perovskite light absorption layer film, which comprises a boron nitrogen hetero-condensed ring compound and an organic-inorganic hybrid perovskite material;

[0058] Wherein, the structure of the boron nitrogen fused ring compound is:

[0059]

[0060] Here, R is selected from the group consisting of a hydrogen atom, a fluorine atom, a chlorine atom and a bromine atom.

[0061] When R is a hydrogen atom, the boron nitrogen condensed ring compound is named BNH; when R is a fluorine atom, the boron nitrogen condensed ring compound is named BNF; when R is a chlorine atom, the boron nitrogen condensed ring compound is named BNCl; when R is a bromine atom, the boron nitrogen condensed ring compound is named BNBr.

[0062] The perovskite light absorbing layer film according to the present invention is characterized in that:

[0063] The chemical formula of organic-inorganic hybrid perovskite material is MA x FA 1-xPbI3, wherein MA represents a methylamine cation, FA represents a formamidinium cation, and 0≤x≤1.

[0064] For the perovskite light absorption layer film of the present invention, the thickness thereof is not particularly limited and can be adjusted according to specific needs.

[0065] In the perovskite light absorption layer film of the present invention, the dosage ratio of the boron nitrogen condensed ring compound and the organic-inorganic hybrid perovskite material (or the doping ratio of the boron nitrogen condensed ring compound) can also be adjusted according to specific needs.

[0066] The present invention also provides a method for preparing a perovskite light absorbing layer film, which comprises the following steps:

[0067] 1) dissolving the boron nitrogen fused ring compound and lead iodide in a mixed solution to obtain a perovskite precursor solution; dissolving methylamine hydroiodide, formamidine hydroiodide and methylamine hydrochloride in isopropanol to obtain an amine salt isopropanol solution;

[0068] 2) spin coating the perovskite precursor solution in step 1) on the substrate, and then performing annealing treatment;

[0069] 3) Spin coating the amine salt isopropanol solution in step 1) on the annealed material in step 2), and then heat treating to obtain a perovskite light absorption layer film.

[0070] The method for preparing the perovskite light absorbing layer film according to the present invention is characterized in that:

[0071] In step 1), the mixed solution is a mixed solution of DMF and DMSO, preferably a mixed solution in which the volume ratio of DMF to DMSO is 9:1.

[0072] The method for preparing the perovskite light absorbing layer film according to the present invention is characterized in that:

[0073] In step 1), the concentration of the boron nitrogen fused ring compound in the perovskite precursor solution is 0.05-6.0 mg / mL; and / or the concentration of lead iodide in the perovskite precursor solution is 691 mg / mL.

[0074] The method for preparing the perovskite light absorbing layer film according to the present invention is characterized in that:

[0075] The concentrations of methylamine hydroiodide, formamidine hydroiodide and methylamine hydrochloride are not particularly limited and can be adjusted according to specific needs.

[0076] Preferably, at a concentration of mg / mL, the concentration ratio of methylamine hydroiodide, formamidine hydroiodide and methylamine hydrochloride is (7-10):(70-100):(7-10).

[0077] More preferably, at a concentration of mg / mL, the concentration ratio of methylamine hydroiodide, formamidine hydroiodide and methylamine hydrochloride is 9:85:10.

[0078] The method for preparing the perovskite light absorbing layer film according to the present invention is characterized in that:

[0079] In step 2), the spin coating speed is 1200-1800 rpm; and / or,

[0080] The spin coating time is 20-40 seconds; and / or,

[0081] The annealing temperature is 60-80° C.; and / or,

[0082] The annealing time is 40-80 seconds.

[0083] Preferably, in step 2), the spin coating speed is 1500 rpm; and / or the spin coating time is 30 seconds; and / or the annealing temperature is 70° C.; and / or the annealing time is 60 seconds.

[0084] The method for preparing the perovskite light absorbing layer film according to the present invention is characterized in that:

[0085] In step 3), the spin coating speed is 1500-2500 rpm; and / or the spin coating time is 20-40 seconds; and / or the heating temperature is 120-180° C.; and / or the heating time is 15-20 minutes.

[0086] Preferably, in step 3), the spin coating speed is 2000 rpm; and / or the spin coating time is 30 seconds; and / or the heating temperature is 150° C.; and / or the heating time is 15-20 minutes.

[0087] The method for preparing the perovskite light absorbing layer film according to the present invention is characterized in that:

[0088] The present invention also provides a perovskite solar cell, which comprises a transparent conductive oxide substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a metal back electrode arranged in sequence;

[0089] Wherein, the perovskite light absorbing layer comprises the perovskite light absorbing layer film according to the present invention or the perovskite light absorbing layer film obtained by the preparation method of the present invention.

[0090] The method for preparing the above-mentioned perovskite solar cell comprises the following steps:

[0091] 1) Ultrapure water, anhydrous ethanol and isopropanol are used to ultrasonically clean the transparent conductive oxide substrate, and nitrogen is blown dry and the surface of the transparent conductive oxide substrate is treated with ultraviolet ozone;

[0092] 2) spin coating a tin dioxide colloidal solution on a transparent conductive oxide substrate, and then performing a heat treatment to form an electron transport layer;

[0093] 3) forming a perovskite light absorption layer on the electron transport layer by the preparation method according to the present invention;

[0094] 4) Spin-coating Spiro-OMeTAD chlorobenzene solution on the perovskite light absorption layer to form a hole transport layer;

[0095] 5) Evaporate 60-100 nM gold electrode on the hole transport layer.

[0096] The present invention also provides a use of the perovskite light absorption layer film according to the present invention or the perovskite solar cell according to the present invention in the perovskite photoelectric field, preferably in the preparation of photoelectric devices, and more preferably in the preparation of solar cells.

[0097] Example

[0098] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. 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. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0099] Example 1

[0100] The boron nitrogen fused ring compound BNH of the present invention is used to prepare a perovskite solar cell, and the photovoltaic parameters of the device are tested. The structure of the device adopts a formal nip-type structure, such as Figure 1 As shown, it includes a transparent conductive oxide substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a metal back electrode.

[0101] The device preparation process is as follows:

[0102] 1) Cleaning of the transparent conductive oxide substrate: After ultrasonic cleaning with a cleaning agent, ultrapure water, anhydrous ethanol and isopropanol for 20 minutes, nitrogen is blown to dry the residual solvent on the surface. Then, the transparent conductive oxide substrate is treated with ultraviolet ozone to remove the residual organic matter on the surface.

[0103] 2) Spin coating a tin dioxide colloidal solution on the transparent conductive oxide substrate at a spin coating speed of 3000 rpm for 30 seconds, and heating at 100° C. for 10 minutes to form an electron transport layer.

[0104] 3) The perovskite light absorption layer was prepared by a two-step solvent method. First, the boron nitrogen fused ring compound BNH and lead iodide were dissolved in a mixed solution of DMF:DMSO with a volume ratio of 9:1 to obtain a perovskite precursor solution, in which the concentration of lead iodide was 691 mg mL -1 , the concentration of boron nitrogen fused ring compound is 1.0 mg mL -1 ; Weigh 9 mg of methylamine hydroiodide (MAI), 85 mg of formamidine hydroiodide (FAI) and 10 mg of methylamine hydrochloride (MACl) and dissolve them in 1 mL of isopropanol to obtain an amine salt isopropanol solution. Spin-coat the perovskite precursor solution on the electron transport layer at a speed of 1500 rpm for 30 seconds. Then perform annealing at a temperature of 70°C for 60 seconds. Spin-coat a certain amount of amine salt isopropanol solution on the annealed material at a speed of 2000 rpm for 30 seconds. Then, heat at 150°C in air for 15-20 minutes to obtain a perovskite light absorption layer.

[0105] (4) Spin-coat the Spiro-OMeTAD chlorobenzene solution on the perovskite light absorption layer to form a hole transport layer.

[0106] (5) Evaporate 60-100 nM gold electrode on the hole transport layer.

[0107] Example 2

[0108] The perovskite solar cell was prepared according to the method of Example 1, except that the boron nitrogen condensed ring compound was BNF with a concentration of 0.05 mg mL -1 .

[0109] Example 3

[0110] The perovskite solar cell was prepared according to the method of Example 1, except that the boron nitrogen condensed ring compound was BNCl with a concentration of 2.0 mg mL -1 .

[0111] Example 4

[0112] The perovskite solar cell was prepared according to the method of Example 1, except that the boron nitrogen condensed ring compound was BNBr with a concentration of 6.0 mg mL -1 .

[0113] Comparative Example 1

[0114] A perovskite solar cell was prepared according to the method of Example 1, except that no boron nitrogen condensed ring compound was added.

[0115] Photovoltaic parameters

[0116] Perovskite solar cell photoelectric performance test:

[0117] (1) The JV curves of the perovskite solar cells prepared in Examples 1-4 and Comparative Example 1 are shown in FIG. Figure 2 The photovoltaic parameters of perovskite solar cells prepared by doping perovskite precursor solutions with different boron nitrogen condensed ring compounds are shown in Table 1.

[0118] From Table 1 and Figure 2 It can be found that the short-circuit current density, open-circuit voltage, fill factor and photoelectric conversion efficiency of Examples 1-4 are all improved, and the performance of the devices made of the four boron nitrogen condensed ring compounds is close, indicating that the boron nitrogen condensed ring compounds have good universality. Among them, the increase in short-circuit current density is related to the certain hole transport properties of boron nitrogen condensed ring compounds; the increase in open-circuit voltage indicates that the non-radiative recombination inside the device is well suppressed; the increase in fill factor indicates that the series resistance inside the battery is reduced and the parallel resistance is increased, and the introduction of organic boron nitrogen condensed ring compounds does not block the transmission of carriers. The improvement in photoelectric conversion efficiency shows that the introduction of boron nitrogen condensed ring compounds can effectively passivate the defects of perovskite materials, making the surface of the perovskite film uniform.

[0119] (2) The perovskite light absorbing layer film prepared in Comparative Example 1 and the perovskite light absorbing layer film prepared in Example 1 were subjected to SEM testing. The results are as follows: Figure 3 as shown in (a) and (b).

[0120] Figure 3 Compared with (a) and (b), the perovskite light absorption layer film in comparative example 1 has a large number of holes. These defects provide channels for the infiltration of external substances such as water and oxygen, thereby reducing the performance of the device; while the grains of the perovskite light absorption layer film in embodiment 1 of the present invention are significantly enlarged, and the surface of the film is uniform.

[0121] Table 1

[0122]

[0123] (3) The perovskite solar cells prepared in Example 1 and Comparative Example 1 were subjected to stability tests. The results are as follows: Figure 4 shown.

[0124] from Figure 4It can be found that under 500h of continuous illumination, the photoelectric conversion efficiency of the perovskite solar cell prepared in Example 1 decreases more slowly, and its stability is significantly improved compared with Comparative Example 1. This result shows that the introduction of boron nitrogen condensed ring compounds can effectively passivate the defects of the perovskite material, making the surface of the perovskite film uniform, thereby improving the performance and stability of the perovskite solar cell.

[0125] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention.

Claims

1. A perovskite light absorption layer film, comprising a boron nitrogen condensed ring compound and an organic-inorganic hybrid perovskite material; in, The structure of the boron nitrogen fused ring compound is: R is selected from a hydrogen atom, a fluorine atom, a chlorine atom and a bromine atom.

2. The perovskite light absorbing layer film according to claim 1, characterized in that: The chemical formula of the organic-inorganic hybrid perovskite material is MA x FA 1-x PbI3, wherein MA represents a methylamine cation, FA represents a formamidinium cation, and 0≤x≤1.

3. A method for preparing a perovskite light absorbing layer film according to claim 2, comprising the following steps: 1) dissolving the boron nitrogen fused ring compound and lead iodide in a mixed solution to obtain a perovskite precursor solution; dissolving methylamine hydroiodide, formamidine hydroiodide and methylamine hydrochloride in isopropanol to obtain an amine salt isopropanol solution; 2) spin coating the perovskite precursor solution in step 1) on the substrate, and then performing annealing treatment; 3) Spin coating the amine salt isopropanol solution in step 1) on the annealed material in step 2), and then heat treating to obtain a perovskite light absorption layer film.

4. The preparation method according to claim 3, characterized in that: In step 1), The mixed solution is a mixed solution of DMF and DMSO, preferably a mixed solution in which the volume ratio of DMF to DMSO is 9:

1.

5. The preparation method according to claim 3 or 4, characterized in that: In step 1), The concentration of the boron nitrogen fused ring compound in the perovskite precursor solution is 0.05-6.0 mg / mL; and / or, The concentration of lead iodide in the perovskite precursor solution is 691 mg / mL.

6. The preparation method according to any one of claims 3 to 5, characterized in that: In step 1), At a concentration of mg / mL, the concentration ratio of methylamine hydroiodide, formamidine hydroiodide and methylamine hydrochloride is (7-10):(70-100):(7-10), preferably 9:85:

10.

7. The preparation method according to any one of claims 3 to 6, characterized in that: In step 2), The spin coating speed is 1200-1800 rpm, preferably 1500 rpm; and / or, The spin coating time is 20-40 seconds, preferably 30 seconds; and / or, The annealing temperature is 60-80°C, preferably 70°C; and / or, The annealing time is 40-80 seconds, preferably 60 seconds.

8. The preparation method according to any one of claims 3 to 7, characterized in that: In step 3), The spin coating speed is 1500-2500 rpm, preferably 2000 rpm; and / or, The spin coating time is 20-40 seconds, preferably 30 seconds; and / or, The heating temperature is 120-180°C, preferably 150°C; and / or, Heating time is 15-20 minutes.

9. A perovskite solar cell comprising a transparent conductive oxide substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a metal back electrode arranged in sequence; in, The perovskite light absorbing layer comprises the perovskite light absorbing layer thin film according to claim 1 or 2 or the perovskite light absorbing layer thin film obtained by the preparation method according to any one of claims 3 to 8.

10. Use of the perovskite light absorption layer film according to claim 1 or 2 or the perovskite solar cell according to claim 9 in the field of perovskite optoelectronics, preferably in the preparation of optoelectronic devices, more preferably in the preparation of solar cells.

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