KR101750275B1 - Method of manufacturing perovskite film using electricity spinning - Google Patents

Abstract

The introduction of the solution process using the electrospinning method not only significantly improves the conversion rate to the perovskite structure but also enables the PbX ₂ to be produced in the form of nanofibers and the grain can be regularly distributed to improve the photocurrent efficiency A method for producing a perovskite film will be described.
The method of manufacturing a perovskite film using electrospinning according to the present invention comprises the steps of: (a) adding PbX ₂ and a polymer resin to a solvent and stirring to form a spinning solution; (b) electrospinning the spinning solution on a substrate, followed by drying to form a nanofiber composite layer; And (c) immersing the nanofiber composite layer in a coating solution and reacting the nanofiber composite layer, followed by washing to form a perovskite film.

Description

Technical Field [0001] The present invention relates to a method for manufacturing a perovskite film using electrospinning,

The present invention relates to a method for producing a perovskite film, and more particularly, to a method for producing a perovskite film, which not only has a considerably high conversion rate to a perovskite structure, but also produces a nanofiber PbX ₂ , And more particularly, to a method for producing a perovskite film.

In order to solve the environmental problems caused by the use of fossil energy, researches on renewable and clean alternative energy sources such as solar energy, wind power, and hydro power are being actively conducted.

Of these, there is a great interest in solar cells that change electrical energy directly from sunlight. A solar cell is a cell that generates a current-voltage by using a photovoltaic effect that absorbs light energy from sunlight and generates electrons and holes.

It is possible to fabricate an np diode type silicon single crystal based solar cell with a photoelectric conversion efficiency of more than 20%, which is used in actual photovoltaic power generation. In addition, solar cells using compound semiconductors such as gallium arsenide (GaAs) There is also.

However, since inorganic semiconductor-based solar cells require highly refined materials for high efficiency, a great deal of energy is consumed in the purification of raw materials, and in the process of making single crystals or thin films using raw materials, expensive process equipment is required Thereby reducing the manufacturing cost of the solar cell.

In recent years, in order to manufacture a solar cell at a low cost, it is necessary to drastically reduce the cost of materials or manufacturing processes used as the core of the solar cell. As an alternative to inorganic semiconductor-based solar cells, Type solar cells and organic solar cells have been actively studied.

On the other hand, studies showing high efficiency using a perovskite as a dye-sensitized solar cell or an organic solar cell have been carried out, but the efficiency is still unsatisfactory.

Perovskite thin film solar cells can achieve high efficiency photoelectric conversion characteristics even with a thin light absorbing layer thickness. Unlike dye-sensitized solar cells, they can produce solar cells economically because they use a solid conductive layer. Can be solved.

In the conventional perovskite solar cell, a perovskite light absorbing layer is formed on a substrate using a spin coating method, a sputtering deposition method, or the like, and then an organic material hole transporting layer is formed thereon to produce a solar cell have.

However, in a conventional perovskite thin film solar cell, when a perovskite light absorbing layer is formed by a spin coating method or a sputtering deposition method on a substrate without a porous scaffold, MAI (metylammonium iodide) It is difficult to penetrate into the PbX ₂ film which is a light absorbing layer, so that the synthesis time is reduced and the conversion rate to the perovskite crystal structure is low.

A related prior art is Korean Patent Laid-Open Publication No. 10-2014-0003998 (published on Jan. 10, 2014), which discloses a perovskite based mesoporous thin film solar cell manufacturing technology.

It is an object of the present invention to provide a method for manufacturing a perovskite film which not only has a remarkably high conversion rate to a perovskite structure but also PbX ₂ is produced in a nanofiber shape and grains are regularly distributed to improve photocurrent efficiency .

According to an aspect of the present invention, there is provided a method of manufacturing a perovskite film using electrospinning, comprising: (a) adding PbX ₂ and a polymer resin to a solvent and stirring to form a spinning solution; (b) electrospinning the spinning solution on a substrate, followed by drying to form a nanofiber composite layer; And (c) immersing the nanofiber composite layer in a coating solution and reacting the nanofiber composite layer, followed by washing to form a perovskite film.

The method of manufacturing a perovskite film using electrospinning according to the present invention comprises the steps of adding PbX ₂ and a polymer resin to a solvent and stirring the resulting solution to form a spinning solution on the substrate through a solution process using an electrospinning method, After the nanofiber composite layer is immersed in the coating solution and reacted for 5 to 15 minutes, cleaning is performed only once to produce a perovskite film.

As a result, the method for producing a perovskite film using the electrospinning method according to the present invention not only has a remarkably high conversion rate to a perovskite structure, but also PbX ₂ is produced in the form of nanofiber and the grains are regularly distributed, Can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing a process for producing a perovskite film using electrospinning according to an embodiment of the present invention; FIG.
FIG. 2 and FIG. 3 are schematic views illustrating a process for manufacturing a perovskite film using electrospinning according to an embodiment of the present invention. FIG.
4 is a photograph showing microstructure after electrospinning and after immersion in Example 1. Fig.
5 is a photograph showing the microstructure after electrospinning and after immersion for Example 2. Fig.
6 is a photograph showing microstructure after electrospinning and after immersion in Example 3, respectively.
7 is a photograph showing microstructure after electrospinning and after immersion in Example 4, respectively.
8 is a photograph showing the final microstructure for Example 2. Fig.
Figs. 9 and 10 are photographs showing the results of element mapping in Example 2. Fig.
11 is a photograph showing the final microstructure for Example 2 taken by AFM.
12 is a graph showing the XRD measurement results of the perovskite film produced according to Example 2 and Comparative Examples 1 to 3;

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a method for manufacturing a perovskite film using electrospinning according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Manufacturing method of perovskite film

FIG. 1 is a process flow diagram illustrating a method of manufacturing a perovskite film using an electrospinning method according to an embodiment of the present invention. FIGS. 2 and 3 are views showing a process for manufacturing a perovskite film by electrospinning according to an embodiment of the present invention And Fig.

Referring to FIG. 1, a method for manufacturing a perovskite film using electrospinning according to an embodiment of the present invention includes forming a spinning solution (S110), an electrospinning step (S120), and a perovskite film forming step (S130) .

Spinning solution formation

In the spinning solution forming step (S110), PbX ₂ and the polymer resin are added to a solvent and stirred to form a spinning solution.

In PbX ₂ , X may include any one selected from I and CI. These PbX ₂ is preferred that is added to 2 ~ 10mmol of the total concentration of the spinning solution, which is the concentration of PbX ₂ have a too low or high concentration out of the range, page lobe perovskite crystal manufacturing Sky agent film This is because the structure can not be uniformly distributed over the entire surface.

As the polymer resin, at least one selected from polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), and epoxy resin may be used. At this time, it is preferable to use PVP (polyvinylpyrrolidone) as the polymer resin, because it is possible to secure excellent physical properties in terms of flexibility, elasticity and the like due to fiber shape safety when using PVP. As described above, when PVP, a hydrophobic polymer material, is used as a polymer resin, stable operation can be performed in an electrospinning process which is a process extremely sensitive to humidity.

It is preferable that the polymer resin is added in an amount of 2.0-5.0% by weight of the total weight of the spinning solution. If the content of the polymer resin is out of the above range, the viscosity of the polymer resin is too weak or too thick, This is because of concerns.

In this step, as the solvent, 2-methoxyethanol, acetylacetone, dimethylformamide (DMF), octanol, ethoxy ethanol, tetradecane, pentane At least one selected from pentanol, dipropylene glycol monomethyl ether, ethylene glycol, and the like may be used.

The mixing is preferably carried out at a speed of 100 to 500 rpm using a stirrer. If the stirring speed is less than 100 rpm, there is a fear that uniform mixing between the PZT precursor solution and the polymer resin may not be achieved. On the contrary, when the stirring speed exceeds 500 rpm, there is a problem that the manufacturing cost is increased without any further effect.

Electric radiation

Referring to FIGS. 1 and 2, in the electrospinning step S120, the spinning solution 10 is electrospun on a substrate S and dried to form a nanofiber composite layer.

2, the electrospinning includes a syringe 110 in which a spinning solution 10 is filled, a base S as a spinning object disposed on the lower side spaced apart from the syringe 110, And a power control unit 120 for controlling the driving of the display unit 110.

At this time, the electrospinning is performed by injecting the spinning solution 10 into the syringe 110 and then discharging it onto the base material S at a rate of 1 to 10 μl / min.

In particular, it is preferable that the electrospinning is performed under the conditions of a radiation voltage of 7 to 10 kV and a radiation distance of 5 to 15 cm, and the nozzle diameter of the syringe 110 is preferably 20 to 30 G. Here, the radiation distance means a separation distance between the base material S as the object to be radiated and the nozzles of the syringe 110.

Thus, the fiber diameter of the nanofiber composite layer can be controlled by controlling the discharge speed, the radiation voltage, the nozzle diameter, and the like.

When the radiation voltage is less than 7 kV, the manufacturing time is excessively increased, which may increase the manufacturing cost, and it may be difficult to form a uniform film quality. Conversely, when the radiation voltage exceeds 10 kV, it can not be economical since it can only cause a rise in the cost of effect increase. When the spinning distance is less than 5 cm, there is a possibility that the film quality characteristic is lowered due to the interference by the nozzles of the syringe 110. Conversely, if the spinning distance exceeds 15 cm, it may be difficult to obtain a uniform film.

In this step, drying is preferably carried out at 60 to 80 ° C for 15 to 30 hours. If the drying temperature is lower than 60 ° C or less than 15 hours, there is a possibility that sufficient drying is not achieved. On the other hand, when the drying temperature exceeds 80 ° C or the drying time exceeds 30 hours, it may become a factor that raises the manufacturing cost without increasing the effect any more, which is not economical.

Perovskite film formation

Referring to FIGS. 1 and 3, in the perovskite film forming step S130, the substrate S having the nanofiber composite layer P formed thereon is immersed in the coating solution C, reacted, To form a skate film.

Such an immersion reaction may be carried out by dipping or spin coating a substrate S on which a nanofiber composite layer P is formed in a coating vessel 130 filled with a coating solution C therein have. The time for the coating solution (C) to penetrate the nanofiber composite layer (P) can be controlled by immersing the coating solution in the dipping or spin coating method, thereby optimizing the perovskite conversion depending on the thickness .

At this time, the coating solution (C) is preferably an organic solvent in which 0.1 M of MAI (methyl anmine idoine) is dissolved.

The organic solvent is selected from the group consisting of isopropyl alcohol (IPA), acetylacetone, propylene glycol methyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PM) Or more species.

In this step, the immersion reaction is preferably carried out for 5 to 15 minutes. If the immersion reaction time is less than 5 minutes, the conversion to the perovskite crystal structure may not be smoothly performed. On the contrary, when the immersion reaction time exceeds 15 minutes, it is converted into perovskite structure and there is a problem that it is decomposed again.

In the case of spin coating, it is preferably carried out at a speed of 250 to 2000 rpm for 10 to 60 seconds. If the spin-coating speed is less than 250 rpm, the coated surface may have a wavy pattern and the coating quality may be deteriorated. On the contrary, when the spin coating rate exceeds 2000 rpm, there is a problem that the perovskite structure conversion ratio may be low.

Further, it is preferable to perform cleaning only once. Isopropyl alcohol (IPA) may be used for this cleaning, but is not limited thereto.

At this time, it is preferable that the number of rinsing is limited to one, because as the number of rinsing is increased, the Pb ₂ peak is strongly observed again due to the decomposition and decomposition of the perovskite structure.

The method of manufacturing the perovskite film using the electrospinning method according to the embodiment of the present invention is characterized in that PbX ₂ and the polymer resin are added to a solvent and stirred to prepare a spinning solution by a solution process using electrospinning After forming the nanofiber composite layer, the nanofiber composite layer is immersed in the coating solution, reacted for 5 to 15 minutes, and then subjected to cleaning only once to produce a perovskite film.

As a result, the method of manufacturing a perovskite film using the electrospinning method according to the embodiment of the present invention not only has a considerably high conversion rate to the perovskite structure, but also produces PbX ₂ in nanofiber form, So that the photocurrent efficiency can be improved.

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

1. Manufacture of perovskite film

Example 1

2.71 mmol of PbI ₂ was dissolved in DMF, and PVP was added to 3.0 wt% of the total weight to form a spinning solution.

Next, the spinning solution was injected into the syringe, and then electrospun on the base material using a syringe pump at a rate of 5 / / min, followed by drying at 70 째 C for 24 hours to form a nanofiber composite layer.

Subsequently, the substrate having the nanofiber composite layer formed was immersed in IPA dissolved in 0.1 M of MAI, allowed to react for 10 minutes, and washed once with IPA to prepare a perovskite film.

Example 2

A perovskite film was prepared in the same manner as in Example 1, except that PVP was added in an amount of 3.5 wt% of the total weight of the spinning solution.

Example 3

A perovskite film was prepared in the same manner as in Example 1, except that PVP was added at 4.0 wt% of the total weight of the spinning solution.

Example 4

A perovskite film was prepared in the same manner as in Example 1, except that PVP was added at 4.5 wt% of the total weight of the spinning solution.

Comparative Example 1

A perovskite film was prepared in the same manner as in Example 2, except that the substrate was subjected to an immersion reaction for 10 minutes and then washed twice with IPA.

Comparative Example 2

A perovskite film was prepared in the same manner as in Example 2, except that the substrate was immersed for 20 minutes and then washed once with IPA.

Comparative Example 3

A perovskite film was prepared in the same manner as in Example 2, except that the substrate was immersed for 20 minutes and then washed twice with IPA.

2. Property evaluation

Figs. 4 to 7 are photographs showing microstructure after electrospinning and after immersion for Examples 1 to 4, respectively. Fig.

As shown in Figs. 4 to 7 (a), in the case of Examples 1 to 4, the fiber diameters of the nanofiber composite after electrospinning were measured. As a result, it was found that 463.8 nm, 560.1 nm, 657.9 nm and 735.7 nm .

As described above, in Examples 1 to 4, it was confirmed that the fiber diameter of the nanofiber composite increases as the amount of PVP added increases.

Also, as shown in Figs. 4 to 7 (b), in the case of Examples 1 and 2, a certain degree of fibrous phase was maintained even after immersion, and particles were observed rather than fibrous form because of the PVP content.

On the other hand, in Examples 3 to 4 in which the amount of PVP added was 4.0 wt% or more, it can be confirmed that the particles after immersion show a shape that is embedded.

FIG. 8 is a photograph showing the final microstructure of Example 2, and FIGS. 9 and 10 are photographs showing the results of element mapping in Example 2. FIG.

As shown in FIG. 8 to FIG. 10, in the case of Example 2 where the amount of PVP added was 3.5 wt%, element mapping of C, Pb, N and I was performed. As a result, And the distribution was uniform throughout.

11 is a photograph showing the final microstructure of Example 2 taken by AFM.

As shown in FIG. 11, it can be seen from the atomic force microscope (AFM) photographs that nano-sized grains are uniformly distributed on the fibrous phase in the case of Example 2. FIG.

On the other hand, FIG. 12 is a graph showing the XRD measurement results of the perovskite film produced according to Example 2 and Comparative Examples 1 to 3.

As shown in FIG. 12, in the case of Example 2 (a) in which the sample was washed once with IPA after immersion for 10 minutes, PbI ₂ peak was hardly observed and the crystal structure of CH ₃ NH ₃ PbI ₃ was It can be seen that the best formed.

That is, the perovskite can be synthesized and decomposed by the mechanism described in the following formula (1).

As can be seen from Equation 1 above, it can be seen that the perovskite is very easily decomposed as well as the synthesis takes place.

That is, as in the case of Comparative Example 1 (b), Comparative Example 2 (c) and Comparative Example 3 (d), as the immersion reaction time and the number of rinsing cycles were increased, the perovskite structure was changed to decompose again, PbI ₂ peak is strongly observed.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. These changes and modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

S110: spinning solution forming step
S120: electrospinning step
S130: perovskite film forming step

Claims (12)

(a) adding PbX ₂ and a polymer resin to a solvent and stirring to form a spinning solution;
(b) electrospinning the spinning solution on a substrate, followed by drying to form a nanofiber composite layer; And
(c) forming a perovskite film by immersing the nanofiber composite layer in a coating solution which is an organic solvent in which 0.1 M of MAI (methyl anmine idone) is dissolved,
In the above PbX ₂ , X may include any one selected from I and CI,
The PbX ₂ is added in an amount of 2 to 10 mmol of the total concentration of the spinning solution, the polymer resin is added in an amount of 3.0 to 4.5 wt% of the total weight of the spinning solution,
In the step (b), the electrospinning is carried out on the substrate at a rate of 1 to 10 μl / min, and the electrospinning is carried out under conditions of a radiation voltage of 7 to 10 kV and a radiation distance of 5 to 15 cm and,
Wherein the immersion reaction is carried out for 5 to 15 minutes in the step (c), and the cleaning is performed only once, and the perovskite film is produced by the electrospinning method.
delete delete The method according to claim 1,
The polymer resin
Wherein the at least one selected from the group consisting of polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), and epoxy resin is contained in the perovskite film.
delete delete delete The method according to claim 1,
In the step (b)
The drying
At 60 to 80 DEG C for 20 to 30 hours. ≪ RTI ID = 0.0 > 8. < / RTI >
delete The method according to claim 1,
The organic solvent
At least one of isopropyl alcohol (IPA), acetylacetone, propylene glycol methyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PM) The method of manufacturing a perovskite film using electrospinning according to claim 1,
delete delete

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