CN113637355B - Perovskite solution with controllable and adjustable operation time window, battery, preparation method and application - Google Patents

Perovskite solution with controllable and adjustable operation time window, battery, preparation method and application Download PDF

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CN113637355B
CN113637355B CN202110871024.4A CN202110871024A CN113637355B CN 113637355 B CN113637355 B CN 113637355B CN 202110871024 A CN202110871024 A CN 202110871024A CN 113637355 B CN113637355 B CN 113637355B
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吴聪聪
明逸东
梁子辉
李矜
李静
王世敏
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Hubei University
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Abstract

The invention discloses a perovskite solution with a controllable and adjustable operation time window, a battery, a preparation method and application, belonging to the field of perovskite solar cells 3 Acetonitrile solvent and coordination type solvent, wherein A site is methylamine ion, B site is lead ion, X site is halogen ion, and the coordination type solvent is selected from dimethyl sulfoxide, N-methyl pyrrolidone and 4-tertiary butyl pyridine. The perovskite single crystal or iodomethylamine and lead iodide powder prepared by a stoichiometric ratio are placed in methylamine atmosphere to obtain yellow perovskite precursor liquid, or the perovskite single crystal or iodomethylamine and lead iodide powder prepared by a stoichiometric ratio are dissolved in methylamine ethanol solution to obtain viscous yellow perovskite precursor liquid, and then, a coordination solvent and acetonitrile are used for uniformly mixing to obtain the perovskite ink. The invention also provides a perovskite battery, a preparation method and application. The ink can realize the adjustment of a processing time window, and has strong industrial applicability.

Description

Perovskite solution with controllable and adjustable operation time window, battery, preparation method and application
Technical Field
The invention belongs to the field of perovskite solar cells, and particularly relates to a perovskite solution with a controllable operation time window, a cell and a preparation method.
Background
With the increasing shortage of world energy, solar energy is gradually valued by human beings and developed and utilized as a clean energy. Among a variety of solar cell products, perovskite solar cells are distinguished by the advantages of tunable band gaps, high absorption coefficients, long carrier diffusion lengths and the like.
The photoelectric conversion efficiency of organic-inorganic hybrid solar cells is developed from the first 3.8% to the current 25.2%, however, in the process of developing from laboratory scale to industrialized large-area cells and modules, a plurality of problems still exist, which are not effectively solved. In the process of preparing the perovskite light absorption layer by using the spraying method as an example, the nucleation and crystallization process of ink drops before reaching the substrate is often started, so that the formation of a uniform and flat wet film cannot be realized, and a smooth and uniform solid film cannot be obtained. For such deposition methods, it is desirable to retard the nucleation and crystallization process of the perovskite precursor ink as much as possible. The methods of blade coating and slot die coating, compared with the spin coating method commonly used in the laboratory scale, need to delay the nucleation and crystallization process to different degrees, and need to consider the efficiency actually required by the production. If the ink used in the spin-coating method is transferred to a large-scale deposition method for use, the components of the precursor ink need to be modified correspondingly.
At present, DMF is mostly selected as a main solvent of perovskite precursor ink used by a laboratory scale spin coating method, and due to poor volatility, a film with good morphology can be obtained only by performing solvent-solvent extraction treatment on the perovskite precursor ink by using an anti-solvent after wet film deposition. Acetonitrile as one of green solvents has high saturated vapor pressure, can solve the problem that the solvent volatilization speed is too slow in the deposition process, but cannot be used as a single main perovskite solvent due to poor solubility on solid perovskite. And gaseous methylamine can react MAPbI 3 Single crystal, and iodomethylamine (MAI)/lead iodide (PbI) 2 ) Or iodomethylamine (MAI)/lead iodide (PbI) 2 ) Lead chloride (PbCl) 2 ) Iodomethylamine (MAI)/lead iodide (PbI) 2 ) Lead bromide (PbBr) 2 ) The mixed powder is changed from a solid state to a viscous liquid state, and the acetonitrile can well dilute the viscous liquid into clear yellow perovskite ink. The ink is suitable forThe step spin coating method can obtain a perovskite thin film with good morphology, and achieves the photoelectric conversion efficiency of 19.14% on a small-area device. However, the nucleation and crystallization rate of the ink is high, the processing time window is narrow, and the ink cannot be applied to the deposition of large-area perovskite thin films.
In view of the above situation, it is necessary to develop a method for adjusting the solvent composition of the perovskite precursor ink to achieve different degrees of adjustment of the time window, and further achieve different degrees of extension of the processing time window on the premise that the photoelectric conversion efficiency is not sacrificed greatly. The perovskite solution meeting the requirements can be more suitable for the deposition of large-scale perovskite thin films, and has a repairing effect on cracks generated by the perovskite thin films due to the excessively high nucleation and crystallization speed.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide a perovskite ink with a controllable and adjustable processing time window, and the invention aims to provide a perovskite solar cell device with a perovskite absorption layer without anti-solvent treatment, wherein the structure of the device comprises a functional layer obtained by depositing the perovskite ink. The adjustment of a processing time window is realized by designing the perovskite solution (ink) with unique component proportion, thereby realizing the universality of various deposition methods.
To achieve the above object, the present invention provides a perovskite solution with a controllable operation time window, which comprises the following components:
perovskite ABX 3 A site is methylamine ion, B site is lead ion, X site is one or more of iodide ion, bromide ion and chloride ion,
an acetonitrile solvent, a water-soluble acetonitrile solvent,
and the coordination solvent is one or more selected from dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP) and 4-tert-butylpyridine (4-TBP).
Further, perovskite ABX 3 Is fumigated by methylamine gas and then changed from solid state to liquid state, or perovskite ABX 3 Is in a state of being dissolved by a methylamine ethanol solution, that is, perovskite ABX 3 It is used in a liquid or dissolved state.
Further, the mass concentration of the methylamine ethanol is 25wt.% to 41wt.%, and the volume ratio of the methylamine ethanol solution with the mass concentration of 25wt.% to 41wt.% to the acetonitrile is 1.8-1.2.
Further, the volume ratio of the coordination-type solvent to the acetonitrile solvent is 1.
In the above inventive concept, acetonitrile has limited solubility to perovskite because it has high volatility and has high solubility to Pb in perovskite 2+ The binding capacity of the core is weak. Thus, perovskite crystals or MAI (the name: iodomethylamine in the text) are mixed with PbI 2 The powder is placed in methylamine atmosphere to be changed into viscous liquid. And a protic solvent represented by DMSO (dimethyl sulfoxide) has a high boiling point and reacts with Pb 2+ The stronger binding capacity of the core will result in a mesophase containing molecules of the second solvent in the system. The obtained viscous liquid is diluted by using a mixed solution of ACN (Chinese is abbreviated as acetonitrile) and a second solvent meeting the requirement, so that the nucleation crystallization time can be prolonged during the film deposition, and the time window can be widened to different degrees. The addition of a second solvent with higher viscosity, such as DMSO, with different concentrations can adjust the viscosity of the solvent system which is pure acetonitrile, and change the crystallization nucleation route of the whole system, thereby achieving the effect of prolonging the time window. The addition of a proportion of the second solvent may enlarge the perovskite grains after final annealing. The photoelectric conversion efficiency of a device prepared by using the ink only has a small sacrifice.
Operating time window controllably adjusted perovskite solution in nucleation crystallization process, with typical MA
PbI 3 By way of example, the presence of CH in the wet film stage system 3 NH 2 -CH 3 NH 3 PbI 3 A hydrogen-bonded mesophase of the type (2), and MAI-PbI 2 -DMSO/MAI-PbI 2 NMP, etc., with a competitive and synergistic effect. The addition of a second solvent allows the nucleation path of the perovskite to be changed from simple CH 3 NH 2 -CH 3 NH 3 PbI 3 The hydrogen bonds of (a) form alpha-phase perovskites after being broken, and the change is more complicated, thereby prolonging the time window.
According to a second aspect of the present invention there is also provided a method of preparing a perovskite solution as described above, the method of preparation comprising the steps of: firstly, perovskite single crystal obtained through inverse temperature crystallization in advance or iodomethylamine and lead iodide powder prepared according to a stoichiometric ratio are placed in methylamine atmosphere to obtain viscous yellow perovskite precursor liquid, or perovskite single crystal obtained through inverse temperature crystallization in advance or iodomethylamine and lead iodide powder prepared according to a stoichiometric ratio are dissolved in methylamine ethanol solution to obtain viscous yellow perovskite precursor liquid, then, after a coordination solvent and acetonitrile are uniformly mixed, the perovskite precursor liquid is diluted to obtain perovskite ink, wherein the coordination type solvent is selected from one or more of dimethyl sulfoxide (DMSO), N-methyl pyrrolidone (NMP) and 4-tert-butyl pyridine (4-TBP).
According to a third aspect of the present invention there is also provided a perovskite solar cell employing as a functional layer a perovskite solution with a controllable adjustment of the operating time window as described above.
Furthermore, the battery structure comprises a conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer and a gold electrode which are sequentially stacked, wherein the total thickness of the electron transport layer is 100 nm-140 nm, the thickness of the perovskite film is 400 nm-600 nm, the thickness of the hole transport layer is 150 nm-250 nm, and the thickness of the gold electrode is 60 nm-100 nm.
Further, the conductive substrate is fluorine-doped tin oxide (FTO) conductive glass, indium-doped tin oxide (ITO) conductive glass or a flexible conductive substrate, and the electron transport layer is made of TiO 2 、ZnO 2 、 SnO 2 、Nb 2 O 5 And PCBM, the perovskite has the chemical general formula of MAPbI 3 、MAPb(I 1-x Cl x ) 3 Or MApB (I) 1-x Br x ) 3 The value range of X is less than 0 < X < 1, and the hole transport layer material is selected from 2,2', 7' -tetra [ N, N-di (4-methoxyphenyl) amino]-9,9'-Spirobifluorene (Spiro-OMeTAD), poly-3, 4-ethylenedioxythiophene/polystyrene sulfonate (PEDOT: PSS), poly-3-hexylthiophene (P3 HT), poly [ bis (4-phenyl) (2, 4, 6-trimethylphenyl) amine](PTAA).
According to a fourth aspect of the present invention, there is also provided a method of fabricating a perovskite solar cell as described above, comprising the steps of:
s1: coating the precursor solution of the electron transport layer on a clean conductive substrate, annealing to form a compact electron transport layer film,
s2: diluting the mesoporous slurry by using a solvent, uniformly stirring, coating the solution on the electronic transmission layer film prepared in the step S1, sintering to obtain the mesoporous layer electronic transmission film,
s3: depositing a perovskite precursor solution on the mesoporous layer electron transport film prepared in the step S2, annealing to obtain a perovskite film, wherein the annealing temperature is 100-120 ℃, the annealing time is 10-20 min,
s4: preparing a hole transport layer on the perovskite thin film,
s5: and preparing a gold electrode on the hole transport layer.
According to a fifth aspect of the present invention, there is also provided a use of the perovskite solar cell as described above, which can generate a sustained and stable photovoltage and photocurrent under a standard sunlight irradiation, for a solar electric vehicle, a solar water heater, a wearable flexible solar watch.
Generally, compared with the prior art, the technical scheme conceived by the invention has the following beneficial effects:
(1) The invention provides a perovskite solution with a controllable and adjustable operation time window, a preparation method of the perovskite solution is novel, and through experimental tests, a device prepared by the ink has higher photovoltage and stable output photocurrent while the processing time window is improved, so that higher photoelectric conversion efficiency and stable output efficiency can be obtained.
(2) The invention provides a gold electrode perovskite solar cell taking perovskite solution (ink) as a functional layer and being controllably adjusted based on an operation time window, which can adjust a processing time window by adjusting the formula proportion of the ink according to the requirements of a deposition method, thereby realizing the universality of various deposition methods. In addition, the final surface morphology of the perovskite thin film can be effectively improved, the method can be used for depositing the large-area perovskite thin film and preparing the perovskite solar module, and the preparation method is simple, low in cost, high in repeatability and good in stability.
Drawings
FIG. 1 is a time window definition diagram of a perovskite precursor ink with adjustable process time window prepared in example 1 of the invention during deposition;
FIG. 2 is a graph of the correlation of perovskite inks containing different proportions of low volatility coordinating solvents (in DMSO as an example) prepared in example 1 of the present invention with time windows for different deposition methods;
FIG. 3 is a J-V curve of gold electrode perovskite solar cells prepared from perovskite inks prepared in example 1 of the present invention containing different proportions of low volatility coordinating solvents (in DMSO as an example).
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention provides a perovskite solution with a controllable and adjustable operation time window, which adopts an acetonitrile solvent and a coordination type solvent to dissolve liquid perovskite ABX 3 Or perovskite ABX dissolved by methylamine ethanol solution 3 . Wherein, perovskite ABX 3 In the formula, A site is methylamine ion, B site is lead ion, and X site is one or more of iodide ion, bromide ion and chloride ion. The coordination type solvent is selected from one or more of DMSO, NMP and 4-TBP. The mass concentration of the methylamine ethanol is 25-41 wt.%, and the volume ratio of the methylamine ethanol solution with the mass concentration of 25-41 wt.% to acetonitrile is 1.8-1.2. Coordination type solventThe volume ratio of the acetonitrile solvent to the acetonitrile solvent is 1.
A method of preparing a perovskite solution as described above, the method comprising the steps of:
firstly, perovskite single crystal obtained through inverse temperature crystallization in advance or iodomethylamine and lead iodide powder prepared according to a stoichiometric ratio are placed in methylamine atmosphere to obtain viscous yellow perovskite precursor liquid, or perovskite single crystal obtained through inverse temperature crystallization in advance or iodomethylamine and lead iodide powder prepared according to a stoichiometric ratio are dissolved in methylamine ethanol solution to obtain viscous yellow perovskite precursor liquid, then, after a coordination solvent and acetonitrile are uniformly mixed, the perovskite precursor liquid is diluted to obtain perovskite ink, wherein the coordination type solvent is selected from one or more of DMSO, NMP and 4-TBP.
A preparation method of a gold electrode perovskite solar cell with a functional layer of a perovskite solution deposited thin film with controllable and adjustable operation time window comprises the following steps:
1) Preparation of an electron transport layer: preparation method of electron transport layer (dense layer): coating the precursor solution of the electron transport layer on a clean conductive substrate subjected to ultraviolet treatment, and annealing to form a compact electron transport layer film, wherein the annealing temperature is preferably 100-150 ℃ and the annealing time is 10min.
Such as: mixing titanium tetraisopropoxide with ethanol solution and hydrochloric acid solution in a certain proportion, depositing on the treated conductive substrate, and pre-annealing in an open environment for 10-15 min, preferably at 100-150 ℃.
2) The preparation method of the electron transport layer (mesoporous layer) comprises the following steps: adding TiO into the mixture 2 Diluting the mesoporous slurry with absolute ethyl alcohol according to the mass ratio of TiO 2 Mesoporous slurry: and (2) the absolute ethyl alcohol is 1.
The spin-coating acceleration is, for example, 6000rpm/s, and the spin-coating time is, for example, 20s to 40s.
3) Preparation of perovskite single crystal: the preparation method of the perovskite single crystal comprises the following steps: mixing MAI/PbI according to the molar ratio of 1 2 The powder is dissolved in gamma-GBL (gamma-butyrolactone) solution, slowly heated and stirred until the solution becomes clear, then the solution is put into an oil bath pot to be stirred and heated, and the temperature is kept, preferably, the heating temperature is 100-120 ℃, and preferably, the temperature keeping time is 2-3 h. Obtain black MAPbI 3 And (3) single crystal. Washing the residual solvent on the crystal surface with diethyl ether, and sealing and storing in a vacuum drying oven.
4) Preparing perovskite precursor ink: the preparation method of the perovskite precursor ink comprises the following steps: placing the single crystal obtained in the step 3) or the powder directly prepared according to the stoichiometric ratio or the mixture of the single crystal and lead halide in dry methylamine gas for 3-5 h until viscous yellow liquid is obtained. In addition, the methylamine ethanol solution can be directly added, and then ultrasonic treatment is carried out, wherein the ultrasonic treatment time is preferably 60-90 min. Subsequently, a mixed solution of anhydrous acetonitrile and a low-volatility coordinating solvent is added into the system, the proportion of the mixed solution is determined by the requirement of a processing time window of actual production, and then the mixture is subjected to ultrasonic treatment until the mixture is uniformly mixed.
5) Preparation of perovskite light absorption layer: the preparation method of the perovskite light absorption layer comprises the following steps: depositing the perovskite precursor ink obtained in the step 4) on the film obtained in the step 2) by using a spin coating method or other deposition methods, and annealing to obtain a high-quality perovskite film; the annealing temperature is preferably 100-120 ℃, and the heating time is 10-20 min. The deposition method can be a spin coating method, a blade coating method, a spraying method and other deposition methods which are required by different time windows correspondingly according to the prepared ink with different time windows. Specifically, for example, the spin coating time is 4000rpm and the spin coating time is 20 seconds.
In the step, the deposition of the good absorption layer film can be realized without adding redundant anti-solvent in the deposition process.
6) Preparation of hole transport layer: the preparation method of the hole transport layer comprises the steps of coating the prepared hole transport layer solution or gel on the film in the step 5), and selecting whether to anneal or oxidize according to the type of the hole transport layer. When the hole transport layer is P3HT, PEDOT: PSS, annealing is required. When the hole transport layer is Spiro-OMeTAD, oxidation is required. This can provide a high-quality hole transport layer film.
For example, 72mg of Spiro-OMeTAD powder is dissolved in 1ml of chlorobenzene ， Adding 17.5ul of a Li-TFSI solution with the concentration of 520mg/ml dissolved in an anhydrous acetonitrile solution and 28.8ul of a 4-TBP solution, mixing uniformly, and depositing on the film prepared in the step 5). The spin coating time in this step is, for example, 4000rpm, and the spin coating time is, for example, 20 seconds.
7) Preparing a gold electrode: the gold electrode is prepared by placing gold wire or gold ball with a purity of 99.999% with a mass of about 0.2g on an evaporation boat of a vacuum metal evaporation instrument, and slowly evaporating a layer of high-quality gold electrode on the film obtained in step 6) in a vacuum environment.
To further illustrate the perovskite manufacturing method and the perovskite solar cell manufacturing method of the present invention, further details are provided below with reference to specific examples.
Example 1
1) Preparation of the Electron transport layer (dense layer)
369ul titanium tetraisopropoxide and 35ul hydrochloric acid solution with the concentration of 2M are added into 5.06ml absolute ethyl alcohol solution, the absolute ethyl alcohol solution is stirred and coated on clean FTO conductive glass in a spin coating mode, and relatively compact TiO is formed after 10min annealing at the temperature of 150 DEG C 2 And the thickness of the film is about 30nm.
2) Preparation of the Electron transport layer (mesoporous layer)
Diluting the 18-NRT titanium oxide mesoporous slurry to 15wt.% by using absolute ethyl alcohol, fully stirring the diluted solution for 5h, taking 60ul of the solution to spin-coat the film in the step 1), annealing the film for 10min at 80 ℃, putting the film into a muffle furnace, calcining the film for 1h at 500 ℃, and cooling the film to room temperature to form a layer of TiO 2 The thickness of the mesoporous layer is about 100nm.
3) Preparation of perovskite Single Crystal
Will PbI 2 MAI and MAI powder are dissolved in gamma-GBL solution according to the mol ratio of 1 3 And (3) precursor solution. Slowly heating and stirring to 65 DEGFiltering the solution until the solution becomes clear, placing the filtered solution into an oil bath pan which is preheated to 65 ℃, heating the solution to 110 ℃ at the heating rate of 1 ℃/min, and preserving the heat for 3h to obtain black massive MAPbI 3 And (3) single crystal.
4) Preparation of perovskite inks
And (3) putting the single crystal obtained in the step 3) or the single crystal and other lead halide powder (generally not more than 1%) with a certain molar ratio in a dry methylamine atmosphere for 3-5 h to obtain yellow clear and viscous liquid. Or directly adding 33wt.% of methylamine ethanol solution, and putting into an ultrasonic machine for ultrasonic treatment for 1h until the solution becomes clear. Then, a mixed solution of ACN and DMSO (4-TBP and NMP) in a certain volume ratio prepared according to the actual deposition processing requirement is added. After being fully and uniformly mixed, the perovskite ink with a corresponding processing time window is prepared.
5) Preparation of perovskite layer
Taking a spin coating method as an example: taking 25ul of the perovskite ink prepared in the step 4) in a glove box, adopting a one-step spin coating method, annealing the obtained perovskite thin film on a heating plate at the temperature of 100 ℃ for 10min at the rotating speed of 4000rpm for 30s, and cooling to room temperature to obtain the high-quality perovskite thin film with the thickness of about 500nm.
6) Preparation of hole transport layer
For example, spiro-OMeTAD: 72mg of Spiro-OMeTAD (> 99.9%) was dissolved in 1ml of chlorobenzene solvent, followed by dropwise addition of 28.8ul of 4-TBP solution and 17.5ul of acetonitrile solution of Li-TFSI at a concentration of 520mg/ml, followed by stirring and mixing uniformly, and then 20ul of Spiro-OMeTAD solution was applied to the perovskite thin film in step 5) at a spin coating rate of 4000 rpm. A high quality Spiro-OMeTAD film was obtained with a thickness of about 200nm.
7) Preparation of gold electrodes
And (3) evaporating 0.18g of pure gold (more than 99.999%) onto the high-quality Spiro-OMeTAD film obtained in the step 6) covered with the mask by using a metal evaporation coating instrument to obtain a compact high-quality gold electrode with the thickness of about 80nm.
The manufactured perovskite solar cell generates continuous and stable photovoltage and photocurrent under the standard solar illumination, the photoelectric conversion efficiency is only reduced by 1% under the condition that the processing time window is improved by 3s, the photoelectric conversion efficiency is reduced from 17.41% to 16.01%, the reduction amplitude is very small and can be ignored, and in addition, the problem of surface cracks of the perovskite thin film can be effectively solved.
Example 2
Example 2 differs from example 1 in that:
1) In the preparation of the electron transmission layer (compact layer), ITO conductive glass is adopted to form relatively compact ZnO 2 And the thickness of the film is about 50nm.
2) In the preparation of the electron transport layer (mesoporous layer), the thickness finally obtained is about 140nm.
3) In the preparation of perovskite single crystal, MAPbCl is obtained by preparation 3 And (3) precursor solution.
4) In the preparation of the perovskite ink, the mass concentration of the methylamine ethanol is 41wt., and the solution is placed into an ultrasonic machine for ultrasonic treatment for 1 hour until the solution becomes clear. Then adding a mixed solution of 4-TBP and NMP in a certain volume ratio, which is prepared according to the actual deposition processing requirement. And after being fully and uniformly mixed, the perovskite ink with a corresponding processing time window is prepared. The volume ratio of the methylamine ethanol solution to the acetonitrile is 1. The volume ratio of the coordination-type solvent to the acetonitrile solvent is 1.
5) In the preparation of the perovskite layer, the thickness of the perovskite thin film is about 600nm, the annealing temperature is 120 ℃, and the annealing time is 10min.
6) In the preparation of the hole transport layer, PEDOT and PSS are used as raw materials, and the thickness of the hole transport layer is about 250nm.
7) In the preparation of the gold electrode, the thickness of the gold electrode is about 100nm.
Example 3
Example 3 differs from example 1 in that:
1) In the preparation of the electron transport layer (compact layer), a flexible conductive substrate is adopted to form relatively compact SnO 2 And the thickness of the film is about 30nm.
2) In the preparation of the electron transport layer (mesoporous layer), the thickness finally obtained is about 100nm.
3) In the preparation of perovskite single crystal, MAPbBr is obtained 3 Precursor ofA bulk solution.
4) In the preparation of the perovskite ink, the mass concentration of the methylamine ethanol is 25wt.%, and the solution is placed into an ultrasonic machine for 2 hours until the solution becomes clear. Then adding a certain volume ratio of DMSO solution prepared according to the actual deposition processing requirement. After being fully and uniformly mixed, the perovskite ink with a corresponding processing time window is prepared. The volume ratio of the methylamine ethanol solution to the acetonitrile is 1.2. The volume ratio of the coordination-type solvent to the acetonitrile solvent is 1.
5) In the preparation of the perovskite layer, the thickness of the perovskite thin film is about 400nm, the annealing temperature is 100 ℃, and the annealing time is 20min.
6) In the preparation of the hole transport layer, P3HT was used as a starting material, and the thickness of the hole transport layer was about 150nm.
7) In the preparation of the gold electrode, the thickness of the gold electrode is about 60nm.
Example 4
Example 4 differs from example 1 in that:
1) In the preparation of the electron transport layer (compact layer), ITO conductive glass is adopted to form relatively compact Nb 2 O 5 And the thickness of the film is about 40nm.
2) In the preparation of the electron transport layer (mesoporous layer), the thickness finally obtained is about 120nm.
3) In the preparation of perovskite single crystal, MAPb (I) is obtained 1-x Cl x ) 3 Precursor solution, and x =0.4.
4) In the preparation of the perovskite ink, the mass concentration of the methylamine ethanol is 34 wt.%, and the solution is placed into an ultrasonic machine for ultrasonic treatment for 1 hour until the solution becomes clear. Then adding a certain volume ratio of DMSO solution prepared according to the actual deposition processing requirement. After being fully and uniformly mixed, the perovskite ink with a corresponding processing time window is prepared. The volume ratio of the methylamine ethanol solution to the acetonitrile is 1. The volume ratio of the coordination-type solvent to the acetonitrile solvent is 1.
5) In the preparation of perovskite layer, the thickness of perovskite film is about 490nm, its annealing temperature is 110 deg.C, and annealing time is 15min.
6) In the preparation of the hole transport layer, PTAA was used as a raw material, and the thickness of the hole transport layer was about 190nm.
7) In the preparation of the gold electrode, the thickness of the gold electrode is about 86nm.
Example 5
Example 2 differs from example 1 in that:
1) In the preparation of the electron transport layer (dense layer), FTO conductive glass is adopted to form a relatively dense PCBM film with the thickness of about 41nm.
2) In the preparation of the electron transport layer (mesoporous layer), the thickness finally obtained is about 120nm.
3) In the preparation of perovskite single crystal, MAPbI is obtained 3 And (3) precursor solution.
4) In the preparation of the perovskite ink, the mass concentration of the methylamine ethanol is 29wt., and the solution is placed into an ultrasonic machine for ultrasonic treatment for 3 hours until the solution becomes clear. Then adding a mixed solution of 4-TBP and NMP with a certain volume ratio prepared according to the actual deposition processing requirement. And after being fully and uniformly mixed, the perovskite ink with a corresponding processing time window is prepared. The volume ratio of the methylamine ethanol solution to the acetonitrile is 1. The volume ratio of the coordination-type solvent to the acetonitrile solvent is 1.
5) In the preparation of the perovskite layer, the thickness of the perovskite thin film is about 520nm, the annealing temperature is 115 ℃, and the annealing time is 12min.
6) In the preparation of the hole transport layer, PEDOT (PolyEthyleneEther phosphate: PSS) is used as a raw material, and the thickness of the hole transport layer is about 190nm.
7) In the preparation of the gold electrode, the thickness of the gold electrode is about 90nm.
FIG. 1 is a time window definition diagram of perovskite precursor ink with adjustable processing time window prepared in example 1 during deposition, and it can be known from FIG. 1 that for the room temperature crystallization method, the doped methylamine molecules at the A position are bonded with the amino groups in the one-dimensional structure through weak hydrogen bonds, and the bonding is weak, and the methylamine molecules are easily bonded from MA-CH 3 NH 3 PbI 3 The release in the intermediate phase promotes the transformation of the low-dimensional perovskite phase to the 3D perovskite phase (alpha phase), and the addition of DMSO is more than that of Pb 2+ The center bonds, delaying the time for this transition. As can be seen from FIG. 1, the machiningThe window is directly related to the nucleation and crystallization time of the whole system, and the adoption of the low-volatility coordination solvent for prolonging the nucleation and crystallization time is feasible in principle.
FIG. 2 is a graph showing the correlation between perovskite inks containing different proportions of low volatility coordinating solvents (DMSO as an example) prepared in example 1 and time windows of different deposition methods, and it can be seen from FIG. 2 that as the proportion of DMSO added to the perovskite ink increases, the time windows of the two deposition methods obtained by the test are widened, and the relation between the processing time window requirements actually produced by the two deposition methods is also T Spin coating <T Dispensing And the corresponding requirements can be found and met through the regulation and control of the formula of the ink.
Fig. 3 is a J-V curve of gold electrode perovskite solar cells prepared from perovskite inks containing low-volatility coordinating solvents (DMSO is taken as an example) in different ratios prepared in example 1, and as can be seen from fig. 3, the photoelectric conversion efficiency of gold-based perovskite solar cells prepared from perovskite inks with different DMSO addition ratios can be analyzed to obtain that the photoelectric conversion efficiency loss is the lowest under the condition that the volume ratio of DMSO to ACN is 1.
Table 1 shows the optoelectronic performance parameters of devices prepared with perovskite inks of different formulations.
TABLE 1 photoelectric Property parameter Table for different volume solvent ratios
V(DMSO/ACN) J sc (mA·cm -2 ) V oc (V) FF(％) PCE(％)
0/1 21.61 1.17 0.76 19.14
1/49 21.10 1.17 0.76 18.86
1/39 20.93 1.15 0.77 18.64
1/29 20.36 1.13 0.74 17.12
1/19 20.20 1.13 0.65 14.89
1/9 20.06 0.84 0.54 9.18
The invention belongs to the field of perovskite solar cells, and particularly relates to a method for optimizing and adjusting perovskite precursor ink components correspondingly by taking a gold electrode perovskite solar cell device as a main body and aiming at time window process conditions required by perovskite absorption layers deposited by different deposition methods.
The perovskite ink in the invention can not only not need to use an anti-solvent, but also can meet the requirement of different time windows for different deposition methods by adjusting the solvent ratio. Devices made using such perovskite inks can achieve only a marginal sacrifice in photoelectric conversion efficiency over an extended time window.
The preparation method of the ink comprises two steps: firstly, perovskite single crystal obtained through inverse temperature crystallization in advance or iodomethylamine and lead iodide powder prepared through a stoichiometric ratio are placed in a methylamine atmosphere, yellow perovskite precursor liquid with high viscosity is obtained after a period of time, then low-volatility coordination solvent (such as DMSO, 4-TBP, NMP and the like) and main solvent ACN in a certain proportion are used for being uniformly mixed, and the perovskite precursor liquid obtained in the previous step is diluted to obtain the perovskite ink meeting the requirements. The ink solves the problem that the processing is not facilitated due to the narrow time window of a system with acetonitrile as a single solvent. And meanwhile, a device with photoelectric conversion efficiency less than loss of an acetonitrile system is prepared.
The perovskite solution with the controllable and adjustable operation time window can be suitable for depositing small-area films by a laboratory-scale spin-coating method and can also be suitable for depositing large-area films by a blade coating method, a spraying method, an ink-jet printing method, a slit coating method and the like due to the adjustable and adjustable time window and the adjustable and adjustable viscosity.
The device formed by the perovskite thin film is characterized in that the structure of the device based on the spin coating method is FTO (ITO) or other flexible substrates, wherein the electron transport layer can use SnO 2 、ZnO 2 、TiO 2 、Nb 2 O 5 And PCBM. Any of P3HT, PTAA, spiro-OMeTAD, PEDOT: PSS, etc. can be used for the corresponding hole transport layer. The corresponding electrodes can also be selected from carbon electrodes, gold electrodes, silver electrodes, copper electrodes, aluminum electrodes, and the like.
It will be understood by those skilled in the art that the foregoing is only an exemplary embodiment of the present invention, and is not intended to limit the invention to the particular forms disclosed, since various modifications, substitutions and improvements within the spirit and scope of the invention are possible and within the scope of the appended claims.

Claims (7)

1. A perovskite solution with a controllable and adjustable operating time window, characterized in that the composition comprises:
perovskite ABX 3 A site is methylamine ion, B site is lead ion, X site is one or more of iodide ion, bromide ion and chloride ion,
an acetonitrile solvent, and a solvent, wherein the acetonitrile solvent,
the coordination type solvent is selected from a plurality of dimethyl sulfoxide, N-methylpyrrolidone and 4-tert-butylpyridine, and the addition of the coordination type solvent enables the intermediate phases in the perovskite nucleation process to have a plurality of types, and the competition and the synergistic effect of the plurality of intermediate phases exist, so that the time window of crystallization is prolonged,
perovskite ABX 3 Is changed from solid state into liquid state after being fumigated by methylamine gas, or perovskite ABX 3 Is in a state of being dissolved by methylamine ethanol solution,
the mass concentration of the methylamine ethanol is 25-41 wt.%, the volume ratio of the methylamine ethanol solution with the mass concentration of 25-41 wt.% to acetonitrile is 1.8-1.2,
the volume ratio of the coordination type solvent to the acetonitrile solvent is 1.
2. A method for preparing a perovskite solution with a controlled adjustment of the operating time window as claimed in claim 1, characterized in that it comprises the following steps:
firstly, perovskite single crystal obtained by inverse temperature crystallization in advance or iodomethylamine and lead iodide powder prepared by stoichiometric ratio are placed in methylamine atmosphere to obtain viscous yellow perovskite precursor solution, or
Dissolving perovskite single crystal obtained by inverse temperature crystallization in advance or iodomethylamine and lead iodide powder prepared by stoichiometric ratio in methylamine ethanol solution to obtain viscous yellow perovskite precursor solution,
then, after a coordination solvent and acetonitrile are mixed uniformly, the perovskite precursor liquid is diluted to obtain perovskite ink,
wherein the coordination solvent is selected from dimethyl sulfoxide, N-methyl pyrrolidone and 4-tert-butyl pyridine.
3. A perovskite solar cell employing as a functional layer a perovskite solution controllably adjusted in an operating time window as claimed in claim 1.
4. The perovskite solar cell according to claim 3, wherein the cell structure comprises a conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer and a gold electrode which are sequentially laminated, wherein the overall thickness of the electron transport layer is 100nm to 140nm, the thickness of the perovskite thin film is 400nm to 600nm, the thickness of the hole transport layer is 150nm to 250nm, and the thickness of the gold electrode is 60nm to 100nm.
5. The perovskite solar cell as claimed in claim 4, wherein the conductive substrate is FTO conductive glass, ITO conductive glass or a flexible conductive substrate,
the material of the electron transmission layer is any one of titanium oxide, zinc oxide, tin oxide, niobium pentoxide and fullerene derivatives,
the perovskite has the chemical general formula of MAPbI 3 、MAPb(I 1-x Cl x ) 3 Or MApB (I) 1-x Br x ) 3 The value range of X is less than 0 < X < 1,
the hole transport layer material is selected from one or more of 2,2', 7' -tetra [ N, N-di (4-methoxyphenyl) amino ] -9,9' -spirobifluorene, poly 3, 4-ethylenedioxythiophene/polystyrene sulfonate, poly 3-hexylthiophene and poly [ bis (4-phenyl) (2, 4, 6-trimethylphenyl) amine ].
6. A method of manufacturing the perovskite solar cell as defined in any one of claims 4 to 5, comprising the steps of:
s1: coating the electron transport layer precursor solution on a clean conductive substrate, annealing to form a compact electron transport layer film,
s2: diluting the mesoporous slurry by using a solvent, uniformly stirring, coating the solution on the electronic transmission layer film prepared in the step S1, sintering to obtain the mesoporous layer electronic transmission film,
s3: depositing a perovskite precursor solution on the mesoporous layer electron transport film prepared in the step S2, annealing to obtain a perovskite film, wherein the annealing temperature is 100-120 ℃, the annealing time is 10-20 min,
s4: preparing a hole transport layer on the perovskite thin film,
s5: and preparing a gold electrode on the hole transport layer.
7. Use of the perovskite solar cell according to any one of claims 4 to 5, for producing a continuously stable photovoltage and photocurrent under a standard sunlight exposure for use in solar electric vehicles, solar water heaters, wearable flexible solar watches.
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