KR20150138966A - Organic solar cell with nano particle array layer and manufacturing method thereof - Google Patents

Abstract

Disclosed are an organic solar cell having a surface plasmon effect and a manufacturing method thereof. In the organic solar cell, a metal particle array having various patterns can be formed on an anode by using block copolymer. After a block copolymer layer is formed on the anode, a hole having, a dot pattern, a line patter, or a dot-line pattern is formed by solvent annealing. And then, the block copolymer layer is dipped into a metal powder solution to remove the block copolymer layer after arraying metal particles with a pattern of the hole formed in the block copolymer. Therefore, a metal particle array layer which is uniformly distributed on the anode can be formed.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic solar cell having a nanoparticle array layer and a method of manufacturing the same.

The present invention relates to a field of organic solar cells, and more particularly, to an organic solar cell having a nanoparticle array layer formed on an anode using a morphology of a block copolymer and a method of manufacturing the same.

A typical bulk heterojunction (BHJ) organic solar cell adopts tin-doped indium oxide (ITO) as a transparent electrode (anode). PEDOT: PSS (poly (3,4-ethylene dioxythiophene): poly (styrenesulfonate)] having a charge transporting / collecting function and a buffer layer function is coated thereon, and then poly (3-hexylthiophene-2,5-diyl (P3HT) and phenyl-C61-butyric acid methyl ester (PC ₆₁ BM)} are sequentially coated on the active layer to form an active layer.

In order to obtain a plasmon effect in such an organic solar cell, metal particles are disposed on the upper surface of the anode. The following two methods are widely used for the arrangement of the metal particles. One of them is a method in which Au or Ag, which is a metal material, is spin-coated on the top surface of an ITO substrate, which is an anode, by dispersing PEDOT: PSS [poly (3,4-ethylene dioxythiophene) Are deposited on the ITO surface using a thermal deposition process.

In the case of the former, it is difficult to disperse the metals in the PEDOT: PSS, so a surfactant must be added, or a problem of aggregation between metals occurs during spin coating. In the latter case, there is a problem that a thermal deposition process having various difficulties in the process progress is basically used.

Korean Patent Publication No. 10-2007-0044145

The present invention provides an organic solar cell having a nanoparticle array layer formed to have high dispersibility by using a block copolymer in view of the above-mentioned conventional problems.

The present invention provides an organic solar cell having various patterns of nanoparticle array layers formed on an anode using a block copolymer.

The present invention provides a method for producing an organic solar cell having a nanoparticle array layer on an anode using a block copolymer.

The present invention provides an organic solar cell having a nanoparticle array layer, comprising: a first electrode; A second electrode; An organic layer disposed between the first electrode and the second electrode; And a metal nanoparticle alignment layer disposed on an upper surface of the first electrode between the organic layers on a surface of the first electrode, wherein the metal nanoparticle alignment layer is arranged in a predetermined pattern.

The metal nanoparticle array layer may be a metal nanoparticle arrayed in a dot pattern, a line pattern, or a mixed pattern of dots and lines.

The present invention also provides a method of manufacturing an organic solar cell having a nanoparticle array layer comprising: forming a block copolymer film on a first electrode; Forming a predetermined pattern of holes by solvent annealing the block copolymer film; Dipping the block copolymer film in a solution containing the metal powder so that the hole is filled with the solution containing the metal powder; And removing the block copolymer film to leave a metal nanoparticle alignment layer having a predetermined pattern on the first electrode.

And forming an organic layer on the entire surface of the first electrode including the metal nanoparticle array layer.

The block copolymer may be one comprising pyridine.

The metal powder may be a powder of a metal capable of bonding with pyridine.

According to the present invention, there is provided an organic solar cell having a surface plasmon effect by a metal nanoparticle array layer and a method of manufacturing the same. In the present invention, a block copolymer is formed on an anode and solvent annealing is performed to form a hole pattern. The metal nanoparticles are arranged in a dot pattern, a line pattern, or a mixed pattern of dots and lines by dipping a block copolymer film having such a hole pattern into a solution containing a metal powder. Then, when the block copolymer film is removed, the metal nanoparticle array layer is formed on the anode in a well dispersed state. This process not only solves the problems of the dispersion method or the thermal deposition method in which metal is dispersed in the conventional solution, but also the manufacturing process is very easy. For example, by forming a pattern of holes in the block copolymer film through solvent annealing and dipping into a metal powder solution, the metal particles can be dispersed in a very good state depending on the pattern. Further, since the present invention uses a solution process rather than a thermal deposition as described above, the process is simple and easy. Further, in the manufacturing method of the present invention, the amount of the metal particles can be adjusted according to the pattern, and such pattern can be adjusted according to the solvent and the annealing time.

1 to 3 are sectional views schematically showing organic solar cells according to first to third embodiments of the present invention, respectively.
4 (a) to 4 (c) are photographs showing hole patterns formed in the block copolymer film employed in the production method of the present invention.
5 (a) to 5 (c) are photographs showing the metal nanoparticle array layers formed in the method of the present invention.
6 is a graph showing the efficiencies of Examples 1 to 3 and Comparative Example of the present invention.
7 is a view schematically showing the process of the organic solar cell manufacturing method of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Briefly, in the present invention, a block copolymer is used in the production of an organic solar cell having a plasmon effect. First, a block copolymer film is formed on the anode, followed by solvent annealing to form a hole pattern in the block copolymer. The block copolymer membrane is immersed in a solution containing the metal powder to bind the metal nanoparticles with the components of the block copolymer in the nano-pores. Thereafter, when the block copolymer is removed, a well-dispersed arrangement of metal nanoparticle alignment layers is disposed on the anode. By selecting and adjusting the solvent and annealing time, the hole pattern is obtained as a dot pattern, a line pattern, or a mixed pattern of dots and lines, and the formed metal nanoparticle array layers are formed on the anode in the same or similar pattern. This manufacturing process of the present invention can solve the problems of the conventional method using thermal deposition, dispersion, and the like.

1 to 3 are cross-sectional views schematically showing organic solar cells according to first to third embodiments of the present invention.

1 to 3, the organic solar battery of the present invention includes a first electrode 11, a second electrode 12, and an organic layer (not shown) disposed between the first electrode 11 and the second electrode 12 13, and metal nanoparticle array layers 141, 142, and 143 formed on the first electrode 11. Here, the first electrode 11 may be a positive electrode, and the second electrode 12 may be a negative electrode.

The organic solar cell according to the first embodiment has a dot pattern in which the metal nanoparticle array layer 141 includes a plurality of dots as schematically shown in FIG. As can be seen from the electron microscope (AFM) photograph of FIG. 5 (a), the dot pattern has a plurality of dot-shaped metal nanoparticles arranged on the first electrode 11.

The organic solar cell according to Example 2 has a mixed pattern in which the metal nanoparticle array layer 142 includes a plurality of dots and a plurality of lines as schematically shown in FIG. As shown in the electron micrograph of FIG. 5 (b), this mixed pattern is a state in which a plurality of dot-shaped metal nanoparticles and a plurality of line-shaped metal nanoparticles are mixed and arranged.

The organic solar cell according to Example 3 has a line pattern in which the metal nanoparticle array layer 143 includes a plurality of lines as schematically shown in FIG. As can be seen from the electron micrograph of FIG. 5 (c), the line pattern is a state in which the metal nanoparticles are arranged in a plurality of lines.

The patterns of the metal nanoparticle array layers 141, 142, and 143 of Examples 1 to 3 are prepared by using a block copolymer film that is invisible in FIGS. 1 to 3 The above-mentioned kinds of patterns can be obtained by solvent annealing of the block copolymer film depending on the type of solvent and annealing time (see FIGS. 4 (a) to 4 (c)).

Referring again to FIGS. 1 to 3, the first electrode 11 may be, for example, indium tin oxide (ITO), but is not limited thereto.

The metal nanoparticle array layers 141, 142, and 143 may be formed of a metal including, for example, Au, Pt, Ag, and the like, but are not limited thereto. Metals can be applied.

The organic layer 13 disposed between the first electrode 11 and the second electrode 12 may include an active layer 132 and a buffer layer 131. Here, for example, PEDOT: PSS is applied to the buffer layer 131 to perform buffer and hole conduction.

The second electrode 12 may have a structure in which an Al layer 121 and a LiF layer 122 are stacked.

Hereinafter, the manufacturing method of the present invention will be described in detail with reference to FIGS. 1 to 7. FIG.

First, the organic solar cell manufacturing method of the present invention performs a step of forming a block copolymer film on the first electrode 11 (step 110). Here, ITO may be applied to the first electrode 11. The block copolymer film may be a block copolymer containing pyridine, for example, polystyrene-block-poly (2-vinylpyridine) copolymers (S2VP). The block copolymer film is formed, for example, by spin coating on the first electrode 11.

In step 120, the block copolymer film is solvent annealed to form a hole pattern in the block copolymer film. 4 (a) to 4 (c) show holes formed in the block copolymer film. The hole pattern formed here is a dot pattern, a line pattern, or a mixed pattern in which dots and lines are mixed, depending on the applied solvent and annealing time. For example, solvents can be Tetrahydrofuran (THF), chloroform.

In step 130, the block copolymer film having the hole pattern formed therein is dipped into the solution containing the metal powder. By this dipping, the solution is filled with holes, for example, the metal is covalently bonded to the pyridine. Therefore, the metal nanoparticles are arranged in the same or similar pattern as the hole pattern.

In step 140, the block copolymer film is removed to leave the metal nanoparticle alignment layers 141, 142, and 143 identical or similar to the hole pattern on the first electrode 11. Removal of the block copolymer film can be performed using, for example, O ₂ -plasma.

As described above, the metal nanoparticle array layers 141, 142, and 143 are the same as or similar to the patterns of the holes formed in the block copolymer film, and the metal nanoparticle array layers 141, 142, For example, ITO. As can be seen from FIGS. 1A to 1C and FIGS. 5A to 5C, the dot pattern, the dot-line pattern, and the line pattern are formed on the first electrode 11, Patterned metal nanoparticle array layers 141, 142, and 143 are formed.

Thereafter, a buffer layer 131 is formed on the entire surface of the first electrode 11 including the metal nanoparticle array layers 141, 142, and 143 using PEDOT: PSS (Step 150). Subsequently, an active layer 132 is formed on the buffer layer 131 (Step 160), and a LiF layer 122 and an Al layer 121 are formed thereon as a second electrode 12.

The method of the present invention for forming an organic solar cell as described above is characterized in that metal nanoparticle array layers capable of obtaining a surface plasmon effect on an ITO electrode are formed to be well dispersed in a dot pattern, a line pattern, can do.

Particularly, in the case of the dot pattern of Example 1, the Au nanoparticles accounted for about 30% of the entire upper surface of the ITO substrate, and in the case of the dot-line mixed pattern of Example 2, In the case of the line pattern of Example 3, Au nanoparticles account for about 50% of the entire upper surface of the ITO substrate. It is possible to compare how the surface plasmon effect depending on the content of Au nanoparticles formed on the first electrode affects the organic solar cell.

Hereinafter, Examples 1 to 3 and Comparative Examples of the production method of the present invention will be described in detail.

Example 1

In Example 1, an organic solar cell having a dot patterned metal nanoparticle array layer 141 was produced (FIG. 1).

First, a preparation process including cleaning and UV-O ₃ irradiation on the ITO substrate applied as the first electrode 11 was performed. Then, an S2VP block copolymer film was formed on the upper surface of the ITO substrate. To this end, S2VP was dissolved in toluene at a concentration of 1 wt%, stirred for 24 hours, and then spin-coated on the ITO substrate at a speed of about 2000 rpm for about 60 seconds.

Solvent annealing was carried out using Tetrahydrofuran (THF) for about 2 hours and 20 minutes to form holes in the dot pattern on the spin-coated S2VP block copolymer film (see Fig. 4 (a)).

Next, the S2VP block copolymer film having the holes of the dot pattern was dipped in methanol dissolved with Au nanopowder for about 1 minute.

After the dipping, the washing process was performed using the third distilled water, and the S2VP film was removed through an O ₂ -plasma treatment for about 30 minutes. The metal nanoparticle array layer 141 having a dot pattern remained on the ITO substrate (Fig. 4 (a)).

PEDOT: PSS was spin-coated on the entire upper surface of the ITO substrate including the metal nanoparticle array layer 141 at a speed of about 4000 rpm for about 40 seconds and annealed in a hot plate heated at about 150 캜 for about 10 minutes to form a buffer layer 131).

The crystalline polymer donors P3HT and PC61BM were mixed with chlorobenzene in a ratio of 5: 3 at a ratio of 4.3 wt%, spin-coated on the buffer layer 131 for about 900 rpm / 5 seconds, annealed at about 150 DEG C for about 30 minutes An active layer 132 was formed.

The lithium fluoride (LiF) layer 122 is deposited on the upper surface of the active layer 132 to a thickness of about 0.3 nm at a rate of about 0.2 A / sec under a high vacuum of about 3.0 × 10 ^-6 Torr . Then, the aluminum (Al) layer 121 was laminated at a rate of about 1 ANGSTROM / sec at a high vacuum of about 3.0 X 10 < ^-6 > Torr to about 100 nm by thermal evaporation.

Example 2

In Example 2, an organic solar cell including a metal nanoparticle alignment layer 142 having a dot-line hybrid pattern was prepared (FIG. 2).

Example 2 was carried out in the same manner as in Example 1 except that chloroform was used as the solvent in the solvent annealing step and annealing time was performed for about 1 hour and 10 minutes. As can be seen from FIG. 4 (b), holes are formed in the block copolymer film in a dot pattern and a line pattern. 5 (b), the metal nanoparticle alignment layer 142 in which the dot pattern and the line pattern are mixed is formed on the upper surface of the ITO substrate, which is the first electrode 11.

Example 3

In Example 3, an organic solar cell including a metal nanoparticle array layer 143 having a line pattern was prepared (FIG. 3).

Example 3 was carried out in the same manner as in Example 1 except that chloroform was used as the solvent in the solvent annealing step and the annealing time was performed for about 2 hours and 20 minutes. As can be seen in FIG. 4 (c), holes of line pattern are formed in the block copolymer film. 5 (c), the metal nanoparticle array layer 143 having a line pattern was formed on the upper surface of the first electrode 11, that is, the ITO substrate.

Comparative Example

In the comparative example, an organic solar cell without the metal nanoparticle array layers 141, 142, and 143 was fabricated, and other components were the same as those in Example 1.

Efficiency was measured using a solar simulator in order to evaluate the organic solar cells of Examples 1 to 3 and Comparative Examples.

Table 1 and Fig. 6 show the efficiencies of Examples 1 to 3 and Comparative Example of the present invention.

In Fig. 6, A corresponds to the comparative example, B corresponds to the dot pattern example 1, C corresponds to the dot-line mixed pattern example 2, and D corresponds to the line pattern example 3, respectively.

Referring to Table 1 and FIG. 6, when the Au nanoparticles were present on the ITO surface as in Examples 1 to 3 of the present invention, the efficiency of the organic solar cell was increased by the optical amplification due to the surface plasmon effect. The reason for the increase in efficiency is that as the exciton generation rate increases, the short circuit current rises. In particular, it can be seen that the efficiency tends to increase as the content of gold nanoparticles increases. Example 1 having a dot pattern of about 30% gold nanoparticle content on the entire upper surface of the ITO substrate, Example 2 having a gold content of 40%, and Example 3 having a gold nanoparticle content of 50% It can be seen that it increases considerably.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

11: first electrode 12: second electrode
121: Al layer 122: LiF layer
13: organic layer 131: buffer layer
132: active layer 141, 142, 143: metal nanoparticle array layer

Claims (11)

A first electrode;
A second electrode;
An organic layer disposed between the first electrode and the second electrode; And
And a metal nanoparticle alignment layer disposed on an upper surface of the first electrode between the organic layers on the surface of the first electrode,
Wherein the metal nanoparticle array layer has metal nanoparticles arranged in a predetermined pattern.
The method according to claim 1,
Wherein the metal nanoparticle array layer comprises metal nanoparticles arranged in a dot pattern.
The method according to claim 1,
Wherein the metal nanoparticle array layer comprises metal nanoparticles arranged in a line pattern.
The method according to claim 1,
Wherein the metal nanoparticle alignment layer is arranged in a mixed pattern in which metal nanoparticles are mixed with dots and lines.
Forming a block copolymer film on the first electrode;
Forming a predetermined pattern of holes by solvent annealing the block copolymer film;
Dipping the block copolymer film into a solution containing a metal powder so that the hole is filled with a solution containing a metal powder; And
And removing the block copolymer film to leave the metal nanoparticle alignment layer having the predetermined pattern on the first electrode.
The method of claim 5,
And forming an organic layer on the entire surface of the first electrode including the metal nanoparticle array layer.
The method of claim 5,
Wherein the predetermined pattern is a dot pattern of a plurality of dots.
The method of claim 5,
Wherein the predetermined pattern is a line pattern composed of a plurality of lines.
The method of claim 5,
Wherein the predetermined pattern is a mixed pattern in which a plurality of dots and a plurality of lines are mixed.
The method of claim 5,
Wherein the block copolymer comprises pyridine. ≪ RTI ID = 0.0 > 21. < / RTI >
The method of claim 10,
Wherein the metal powder is a powder of a metal capable of binding to the pyridine.

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