Fluorenyl tetramine pyrene hole transport material and application thereof in perovskite solar cell
阅读说明：本技术 一种芴基四胺芘空穴传输材料及其在钙钛矿太阳能电池中的应用 (Fluorenyl tetramine pyrene hole transport material and application thereof in perovskite solar cell ) 是由 钟羽武 邵将洋 崔彬彬 于 2019-09-12 设计创作，主要内容包括：本发明公开了一种芴基四胺芘空穴传输材料及其在钙钛矿太阳能电池中的应用。该类材料具有式I所示结构通式,端基含有芴基结构单元。所述制备方法为：将1,3,6,8-四溴芘与胺基衍生物溶于有机溶剂中,分别加入碱和钯催化剂,氮气条件下回流反应,经柱层析分离提纯,得到相应目标产物。该空穴传输材料在有机溶剂中溶解性好及成膜性好,且制备成本低。所述空穴传输材料具有良好的空穴提取和迁移能力,能级与钙钛矿能级相匹配。将其作为空穴传输层应用于钙钛矿太阳能电池中,具有良好的光电转换效率。因此,该类空穴传输材料具有非常好的应用前景。<Image he="588" wi="700" file="DDA0002200463000000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention discloses a fluorenyl tetramine pyrene hole transport material and application thereof in a perovskite solar cell. The material has a structural general formula shown in formula I, and the end group contains a fluorenyl structural unit. The preparation method comprises the following steps: dissolving 1,3,6, 8-tetrabromopyrene and an amino derivative in an organic solvent, respectively adding an alkali and a palladium catalyst, carrying out reflux reaction under the condition of nitrogen, and carrying out column chromatography separation and purification to obtain a corresponding target product. The hole transport material has good solubility and film forming property in an organic solvent, and the preparation cost is low. The hole transport material has good propertiesHole extraction and migration capacity, and energy level matched with that of perovskite. The hole transport layer is applied to the perovskite solar cell as the hole transport layer, and has good photoelectric conversion efficiency. Therefore, the hole transport material has a very good application prospect.)
1. A compound of the formula I, wherein,
in the formula I, R is C1～C12Alkoxy group of (2).
2. The compound of claim 1, wherein: in the formula I, R is C1～C6Alkoxy group of (a); in particular methoxy or ethoxy.
3. A process for the preparation of a compound of formula I as claimed in claim 1 or 2, comprising:
refluxing 1,3,6, 8-tetrabromopyrene and the compound shown in the formula Ia under the condition of alkali and catalyst to perform C-N coupling reaction, and obtaining the compound shown in the formula I after the reaction is finished;
in the formula Ia, R is as defined for R in the formula I as defined in claim 1;
the structural formula of the 1,3,6, 8-tetrabromopyrene is shown in the specification
4. The method of claim 3, wherein: the alkali is selected from at least one of sodium tert-butoxide, potassium carbonate, sodium carbonate, cesium carbonate, potassium phosphate and sodium hydroxide;
the catalyst is a palladium catalyst; specifically at least one selected from palladium acetate, palladium bis (triphenylphosphine) dichloride, tetrakis (triphenylphosphine) palladium and palladium/carbon;
the C-N coupling reaction is carried out in a solvent; the solvent is at least one selected from toluene, xylene, tetrahydrofuran, dioxane, N-dimethylformamide, ethanol and dimethyl sulfoxide;
the feeding molar ratio of the 1,3,6, 8-tetrabromopyrene to the compound shown in the formula 1a to the alkali to the palladium catalyst is 1 (4-8) to (4-20) to (0.01-0.10).
5. The method according to any one of claims 3-4, wherein: in the step of C-N coupling reaction, the temperature is 80-140 ℃; the time is 12h-48 h;
the C-N coupling reaction is carried out in an inert atmosphere;
the inert atmosphere is specifically a nitrogen atmosphere.
6. Use of a compound of formula I according to any of claims 1 or 2 as a hole transport layer for the preparation of a solar cell;
a solar cell comprising a compound of formula I according to any one of claims 1 or 2;
a solar cell having a compound of formula I as defined in any one of claims 1 or 2 as a hole transport layer.
7. The use or solar cell according to claim 6, characterized in that: the solar cell is a perovskite solar cell;
the thickness of the hole transport layer is 50-200 nm.
8. A compound of the formula Ia,
in the formula Ia, R is as defined for R in the formula I as defined in claim 1.
9. A process for preparing a compound of formula Ia according to claim 8, comprising:
carrying out coupling reaction on 9, 9-dimethyl-2-bromofluorene and a compound shown as a formula IIa in the presence of a catalyst and alkali to obtain the compound shown as the formula Ia after the reaction is finished;
in said formula IIa, R is as defined for R in formula I as defined in claim 1.
10. The method of claim 9, wherein: the catalyst is a palladium catalyst; specifically at least one selected from tris (dibenzylideneacetone) dipalladium, palladium acetate and tetrakis (triphenylphosphine) palladium;
the alkali is selected from at least one of sodium tert-butoxide, potassium carbonate, sodium carbonate, cesium carbonate, potassium phosphate and sodium hydroxide;
the feeding molar ratio of the 9, 9-dimethyl-2-bromofluorene, the compound shown in the formula IIa, the catalyst and the base is 1: 1: 0.01-0.1: 1 to 20; specifically, 1: 1: 0.05: 1:
the coupling reaction is carried out in a solvent; the solvent is at least one selected from toluene, xylene, tetrahydrofuran, dioxane, N-dimethylformamide, ethanol and dimethyl sulfoxide;
the coupling reaction is carried out in an inert atmosphere; the inert atmosphere is specifically nitrogen atmosphere;
in the coupling reaction step, the time is 12-48 hours.
Technical Field
The invention belongs to the field of photoelectricity, relates to a novel photoelectric transmission material, and particularly relates to a fluorenyl tetramine pyrene hole transmission material and application thereof in a perovskite solar cell.
Background
The perovskite material has the characteristics of unique photoelectric properties (long carrier diffusion distance and high light absorption coefficient) and simple synthesis, and becomes a research hotspot which is widely concerned by global researchers. The perovskite solar cell is considered as a novel cell system with the most industrialized prospect, and the highest authentication efficiency reaches 25.2 percent at present. The perovskite solar cell mainly comprises a transparent substrate, an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode. Hole transport materials have a significant impact on the photoelectric conversion efficiency of perovskite cells. The high-efficiency perovskite solar cell reported at present mostly uses spiro-OMeTAD and PTAA as hole transport materials. But they have disadvantages of high preparation cost and poor conductivity. Therefore, the synthesis of the economical and efficient hole transport material is of great significance.
Disclosure of Invention
The invention aims to provide a fluorenyl tetramine pyrene hole transport material and application thereof in a perovskite solar cell.
The fluorenyl tetramine pyrene hole transport material claimed by the invention is also a compound shown in formula I,
in the formula I, R is C1～C12Alkoxy group of (2).
In the formula I, R is C1～C6Alkoxy group of (a); in particular methoxy or ethoxy.
The invention provides a method for preparing the compound shown in the formula I, which comprises the following steps:
refluxing 1,3,6, 8-tetrabromopyrene and the compound shown in the formula Ia under the condition of alkali and catalyst to perform C-N coupling reaction, and obtaining the compound shown in the formula I after the reaction is finished;
in the formula Ia, R is the same as R in the formula I;
the structural formula of the 1,3,6, 8-tetrabromopyrene is shown in the specification
In the above process, the base is at least one selected from the group consisting of sodium tert-butoxide, potassium carbonate, sodium carbonate, cesium carbonate, potassium phosphate and sodium hydroxide;
the catalyst is a palladium catalyst; specifically at least one selected from palladium acetate, palladium bis (triphenylphosphine) dichloride, tetrakis (triphenylphosphine) palladium and palladium/carbon;
the C-N coupling reaction is carried out in a solvent; the solvent is at least one selected from toluene, xylene, tetrahydrofuran, dioxane, N-dimethylformamide, ethanol and dimethyl sulfoxide;
the feeding molar ratio of the 1,3,6, 8-tetrabromopyrene to the compound shown in the formula 1a to the alkali to the catalyst is 1 (4-8) to (4-20) to (0.01-0.10); specifically 1:4.2:4.2: 0.2;
in the step of C-N coupling reaction, the temperature is 80-140 ℃; the time is 12h-48 h; specifically 24 h;
the C-N coupling reaction is carried out in an inert atmosphere;
the inert atmosphere is specifically a nitrogen atmosphere.
The above method may further comprise: after the C-N coupling reaction step, cooling the reaction system, then spin-drying the solvent, and performing column chromatography separation and purification; in the step of column chromatography separation and purification, the eluent is a mixed solution composed of petroleum ether and ethyl acetate with the volume ratio of 1: 1.
In addition, the application of the compound shown in the formula I as a hole transport layer in the preparation of a solar cell, the solar cell containing the compound shown in the formula I and the solar cell using the compound shown in the formula I as a hole transport layer also belong to the protection scope of the invention.
Specifically, the solar cell is a perovskite solar cell;
the thickness of the hole transport layer is 50-200 nm; in particular 100 nm.
More specifically, the perovskite solar cell may be composed of a transparent substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode.
The preparation method of the solar cell can be various conventional methods, for example, the solar cell can be prepared according to the following method:
1) preparing dense SnO layer on transparent conductive substrate ITO by adopting spin coating technology2And forming an electron transport layer.
2) And (3) spinning and coating the perovskite precursor solution on the electron transport layer, and growing a high-quality perovskite structure light absorption layer (namely a perovskite layer) thin film after annealing.
3) A hole transport layer (fluorenyltetramine pyrene hole transport material) was prepared on the perovskite layer by spin coating.
4) And preparing a metal electrode Au on the hole transport layer by vacuum thermal evaporation.
In the step 1), the transparent substrate may be a transparent conductive substrate; the transparent conductive substrate can be specifically ITO glass, and the square resistance of the substrate is about less than 10 omega/sq; the raw material of the spin-coated precursor solution is tin oxide aqueous solution;
in the spin coating step, the spin coating speed is 1000-; in the sintering step, the sintering temperature is 100-200 ℃, and the sintering time can be 10-60 minutes; a preferred operation may be 30s at 3000rpm and 30 minutes at 150 ℃.
The perovskite precursor solution in the step 2) is PbI2And CH3NH3I perovskite precursor formed by random combination. The selected solvent can be gamma-butyrolactone (GBL), dimethyl sulfoxide (DMSO), dimethyl formamide (DMF) and the like, or a mixed solution according to a certain proportion; specifically, a perovskite precursor solution having the following composition may be used: CH (CH)3NH3PbI3；
The precursor solution is firstly formed into a film on a substrate by a spin coating method, and meanwhile, a certain high-concentration solvent atmosphere is ensured in a spin coating chamber. Wherein the rotating speed can be 3000 plus 5000rpm, and the time for film throwing is 10s-45 s; preferably 4000rpm, for 25 s.
The annealing temperature can be between 80 and 120 ℃, and the annealing time is between 1 and 60 minutes; preferably, the operation is carried out at 100 ℃ for 2 minutes.
In the spin coating step of step 3), the rotation speed can be 2000-5000rpm, and the spin coating time is 30-45 s. Preferably 3000rpm, for 30 s.
In addition, the invention also claims intermediate compounds used in the preparation of the compound shown in the formula I, which are also the compound shown in the formula Ia,
in the formula Ia, R is as defined for R in the formula I.
The invention also claims a process for preparing the compound of formula Ia, comprising:
carrying out coupling reaction on 9, 9-dimethyl-2-bromofluorene and a compound shown as a formula IIa in the presence of a catalyst and alkali to obtain the compound shown as the formula Ia after the reaction is finished;
in the formula IIa, R is as defined for R in the formula I.
In the above method, the catalyst is a palladium catalyst; specifically at least one selected from tris (dibenzylideneacetone) dipalladium, palladium acetate and tetrakis (triphenylphosphine) palladium;
the alkali is selected from at least one of sodium tert-butoxide, potassium carbonate, sodium carbonate, cesium carbonate, potassium phosphate and sodium hydroxide;
the feeding molar ratio of the 9, 9-dimethyl-2-bromofluorene, the compound shown in the formula IIa, the catalyst and the base is 1: 1: 0.01-0.1: 1 to 20; specifically, 1: 1: 0.05: 1:
the coupling reaction is carried out in a solvent; the solvent is at least one selected from toluene, xylene, tetrahydrofuran, dioxane, N-dimethylformamide, ethanol and dimethyl sulfoxide;
the coupling reaction is carried out in an inert atmosphere; the inert atmosphere is specifically nitrogen atmosphere;
in the coupling reaction step, the time is 12-48 hours; specifically 24 hours.
In the coupling reaction system, the (1,1' -bis (diphenylphosphino) ferrocene can be added for complexing with a catalyst;
the above method may further comprise: after the coupling reaction step, cooling the reaction system, then spin-drying the solvent, and performing column chromatography separation and purification; in the step of column chromatography separation and purification, the eluent is a mixed solution of petroleum ether and ethyl acetate with the volume ratio of 5: 1.
The invention has the following beneficial effects:
1) the fluorenyl tetramine pyrene hole transport material prepared by the invention has better solubility in strong polar solvents such as dimethyl sulfoxide, alcohols and the like and weak polar solvents such as toluene, chlorobenzene, dichloromethane, chloroform and the like.
2) The fluorenyl tetramine pyrene hole transport material prepared by the invention has good hole transport performance and electron blocking performance, and is beneficial to effective selective transport of holes.
3) Compared with the traditional classical spiro-OMeTAD, the fluorenyl tetramine pyrene hole transport material prepared by the invention is convenient to purify and lower in price.
4) Fluorene structural units are introduced into the fluorenyl tetramine pyrene hole transport material, so that the solubility of the polymer is improved, and the energy level can be adjusted. The fluorene unit has a conjugated structure larger than that of phenyl, so that the material has better hole transmission performance, and the photoelectric conversion efficiency and the current density of the battery are improved.
Drawings
FIG. 1 shows an ultraviolet absorption spectrum and a fluorescence spectrum of example 1 of the present invention;
FIG. 2 is a spectrum of cyclic voltammetry test according to example 1 of the present invention;
FIG. 3 is a graph of current versus voltage for a perovskite solar cell prepared in example 1 of the present invention.
Detailed Description
The present invention will be further illustrated with reference to the following specific examples, but the present invention is not limited to the following examples. The method is a conventional method unless otherwise specified. The starting materials are commercially available from the open literature unless otherwise specified.