KR101112676B1 - Large area and high energy conversion efficiency OPVs using nano particle and high conducting novel organic/inorganic hydrid buffer layer and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a large-area high efficiency organic solar cell using nanoparticles and a highly conductive organic / inorganic composite buffer layer, and a method for manufacturing the same, and to introducing metal nanoparticles into the organic / inorganic composite buffer layer to improve plasmon resonance and conductivity. It is possible to provide large area organic solar cells which exhibit high energy conversion efficiency without the introduction of further layers.

Description

Large area and high energy conversion efficiency OPVs using nano particle and high conducting novel organic / inorganic hydrid buffer layer and manufacturing method

The present invention relates to a large-area high efficiency organic solar cell using nanoparticles and a highly conductive organic / inorganic hybrid buffer layer, and a method of manufacturing the same. More specifically, the metal nanoparticles are applied to increase light absorption through plasmon resonance. The present invention relates to a large-area organic solar cell exhibiting high energy conversion efficiency by introducing a highly conductive organic / inorganic composite buffer layer and increasing current density.

Solar cells are being reassessed from the viewpoint of global environmental preservation due to their no pollution, and research as a next-generation clean energy source is being actively conducted.

The types of solar cells known to date include solar cells using monocrystalline or polycrystalline bulk silicon, thin film solar cells using amorphous, microcrystalline or polycrystalline silicon, compound semiconductor solar cells, dye-sensitized solar cells and organic polymer solar cells. Varies.

Solar cells using commercially available single crystal bulk silicon have not been actively utilized due to high manufacturing cost and installation cost. In order to solve such a cost problem, researches on thin film solar cells using organic materials are underway, and various attempts have been made to manufacture high efficiency solar cells.

Organic thin film solar cell technology converts solar energy into electrical energy using polymer or low molecular organic semiconductor. Its thin-film device, large-area device, and roll- It is a next-generation technology with both ultra-low cost and versatile mass production specifications such as flexible devices by a roll-to-roll method.

In general, an organic solar cell is composed of a junction structure of an electron donor and an electron acceptor material. When light is incident on the photoelectric conversion layer, electrons and hole pairs are excited in the electron donor, and electrons are electrons. By moving to the receptor, separation of electrons and holes occurs. Therefore, the carriers generated by the light generate power as they move to the external circuit through the phenomenon of electron-hole separation.

For the same reason as above, in recent years, interest in bulk heterojunction organic solar cells that can be applied to flexible substrates with low cost has been improved. US Patent Publication No. 2006-0011233 discloses poly-3-hexylthiophene (P3HT) as an electron donor and [6,6] -phenyl- C ₆₁ -butyl acid methyl ester as an electron acceptor ( Organic solar cells using a [6,6] -phenyl- C ₆₁ -butyric acid methyl ester (PCBM) and a photoelectric conversion layer introduced by spin coating have been disclosed, but their energy conversion efficiency is not high. There was.

In order to solve this problem, many studies are underway to increase the efficiency through the introduction of a buffer layer having improved conductivity. Representatively, Korean Patent Publication No. 10-2007-0108040 introduces G-PEDOT: PSS containing glycerol in the buffer layer of an organic solar cell, but still shows low energy conversion efficiency, and Korean Patent Publication No. 10-2009-0019609 The issue introduces a solar cell with a structure containing nanoparticle layers using Surface Plasomon Resonance (SPR). The solar cell of the above structure had the effect of amplifying the wavelength of light to obtain a solar cell with higher efficiency than the conventional solar cell, but its application was limited to the amorphous / microcrystalline silicon tandem structure.

In spite of the above-described technology, in order to commercialize an organic solar cell, it is necessary to develop a device showing higher energy conversion efficiency.

Accordingly, the present invention has been made to solve the above problems, the main object of the present invention by applying metal nanoparticles to increase the light absorption through the plasmon resonance effect, by introducing a highly conductive organic / inorganic composite buffer layer The present invention provides a large-area organic solar cell and a method for manufacturing the same, which exhibit high energy conversion efficiency by increasing the current density.

In order to achieve the above object, the present invention is a solar cell comprising a first electrode, an organic / inorganic composite buffer layer, a photoelectric change layer and a second electrode formed on a transparent substrate, the metal nanoparticles in the organic / inorganic composite buffer layer It provides a large-area high efficiency organic solar cell incorporating nanoparticles and a highly conductive organic / inorganic composite buffer layer comprising a.

In the present invention, the metal nanoparticles included in the organic / inorganic composite buffer layer are gold (Au), silver (Ag), platinum having a particle size of several tens to several hundred nanometers (nm), preferably 30 to 80 nm. It is preferably at least one selected from the group consisting of (Pt), palladium (Pd), aluminum (Al), copper (Cu), nickel (Ni), zinc (Zn), and iron (Fe).

The present invention also provides a method for producing a large-area high efficiency organic solar cell incorporating nanoparticles and a highly conductive organic / inorganic composite buffer layer comprising metal nanoparticles in the organic / inorganic composite buffer layer.

Specifically, the preparation method of the present invention comprises the steps of: (1) mixing a conductive polymer and a derivative solution thereof and an aprotic polar solvent; (2) adding metal nanoparticles to the mixed solvent; And (3) filtering the metal nanoparticle solution to form a thin film.

The present invention is to provide a large-area organic solar cell showing a high energy conversion efficiency without introducing another layer through the introduction of metal nanoparticles in the organic / inorganic composite buffer layer through the plasmon resonance effect and conductivity enhancement.

In addition, the organic / inorganic composite buffer layer of the present invention has excellent energy conversion efficiency, and can form a thin film by a relatively simple process such as inkjet printing, screen printing, and gravure printing, thereby making it possible to obtain a large area and high efficiency organic solar cell at a low price. Can be produced with

1 is a structure of an organic solar cell according to the present invention.
2 is a UV-Vis absorbance according to the reaction time of the gold nanoparticles according to an embodiment of the present invention.
Figure 3 is a FE-SEM picture of the reaction time of the gold nanoparticles according to an embodiment of the present invention (A: 6 hours; B: 12 hours; C: 36 hours; D: 48 hours and E: 72 hours).
4A to 4D are graphs of current density-voltage (JV) characteristics of organic solar cells according to examples and comparative examples of the present invention.
5A to 5D are graphs of IPCEs of organic solar cells according to examples and comparative examples of the present invention.
6 is an FE-SEM photograph of an organic / inorganic hybrid buffer layer according to an embodiment of the present invention.
7A is an AFM image of an organic / inorganic composite buffer layer according to an embodiment of the present invention (A: PH500, RMS 1.44 nm; B: PH500 + Au10%, RMS 2.959 nm; C: PH500 + Au20%, RMS 4.239 nm; And D: PH500 + Au30%, RMS 5.840 nm).
7B is an AFM image of an organic / inorganic composite buffer layer according to another embodiment of the present invention (A: PH500 + DMSO, RMS 3.861 nm; B: PH500 + DMSO + Au10%, RMS 9.224 nm; C: PH500 + DMSO + Au20%, RMS 12.402 nm; and D: PH500 + DMSO + Au30%, RMS 14.163 nm).
7C is an AFM image of an organic / inorganic composite buffer layer according to another embodiment of the present invention (A: PH500 + EG, RMS 5.189 nm; B: PH500 + EG + Au10%, RMS 7.135 nm; C: PH500 + EG + Au20%, RMS 6.595 nm; and D: PH500 + EG + Au30%, RMS 8.449 nm).

Hereinafter, the present invention will be described in detail.

1 is a schematic structure of an organic solar cell manufactured according to a preferred embodiment of the present invention, as shown, the substrate 110, the first electrode 120, the organic / inorganic complex buffer layer 130, The light conversion layer 140 and the second electrode 15 are stacked.

In the present invention, the substrate 110 used in the device fabrication is not only glass and quartz plate but also PET (polyethylene terephthalate), PEN (polyethylene naphthelate), PP (polyperopylene), PI (polyimide), PC (polycarbornate), PS (polystylene) ), POM (polyoxyethlene), AS resins, ABS resins and triacetyl cellulose (TAC) and the like can be made of a flexible and transparent material such as plastic.

The first electrode 120 is sputtered, E-Beam, thermal evaporation, spin coating, screen printing, inkjet printing, doctor blade or gravure printing method using a transparent electrode material on one side of the substrate or coated in the form of a film It is formed by. The first electrode 120 serves as an anode, and any material having transparency and conductivity may be used as a material having a larger work function than the second electrode 150 described later. For example, indium tin oxide (ITO), gold, silver, fluorine doped tin oxide (FTO), aluminum doped zink oxide (AZO), indium zink oxide ), ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O _3, antimony tin oxide (ATO), and the like, and preferably ITO is used.

The patterned ITO substrate is washed sequentially with a detergent, acetone and isopropanol (IPA), and then dried for 1 to 30 minutes at 100 to 150 ° C., preferably at 120 ° C. for 10 minutes on a heating plate to remove moisture, and the substrate is thoroughly cleaned. The surface of the substrate is modified to be hydrophilic.

Through the surface modification as described above, the bonding surface potential can be maintained at a level suitable for the surface potential of the hole injection layer, and when opened, the formation of the polymer thin film on the ITO substrate is facilitated and the quality of the thin film is improved. Pretreatment techniques for this are a) surface oxidation using parallel planar discharge, b) oxidation of the surface through ozone generated using UV ultraviolet light in a vacuum state, and c) oxygen radicals generated by plasma. There is a method to oxidize, etc., depending on the state of the substrate to select one of the above methods, whichever method is commonly used to prevent the oxygen escape of the surface of the substrate and to minimize the residual of moisture and organic matters practical effect of pretreatment You can expect.

In the embodiment of the present invention, a method of oxidizing the surface through ozone generated by using UV was used. After ultrasonic cleaning, the patterned ITO substrate was baked on a hot plate, dried well, and then put into a chamber. The UV lamp is operated to clean the ITO substrate patterned by ozone generated by the reaction of oxygen gas with UV light.

However, the surface modification method of the patterned ITO substrate in this invention does not need to be specifically limited, Any method may be used as long as it is a method of oxidizing a substrate.

The organic / inorganic composite buffer layer 130 is introduced to the upper portion of the pretreated first electrode 120 through spin coating or dip coating. In the present invention, poly (3,4-ethylenedioxyti) is used as the conductive polymer solution. It is preferable to use a mixed liquid containing offen) [PEDOT] and poly (4-styrenesulfonate) [PSS] in a weight ratio of 1: 2.5 to 1:20 in water or alcohol in an amount of 1.0 to 3.0 wt%.

In order to make the conductive polymer solution into a highly conductive polymer solution, acetone, acetonitrile, dimethyl acetamide (DMAc), dimethyl formamide (DMF), and dimethyl sulfoxide are aprotic polar solvents. Dimetheyl sulfoxise (DMSO), methyl ethyl ketone, methyl n-propyl ketone, N-methylpyrrolidone (NMP), propylene carbonate (propylene carbornate) Conductive polymer by mixing one or two or more selected from nitromethane, sulforane, ethylene glycol and hexamethylphophoramide (HMP) in various weight ratios (wt%). Mix to contain 0.5-30% by weight, preferably 1-10% by weight, based on the solution.

In addition, to prepare the organic / inorganic composite buffer layer containing the metal nanoparticles, 5 to 50% by weight, preferably 10 to 30% by weight of the metal nanoparticles dispersed in deionized water is added to the conductive polymer solution. At this time, the metal nanoparticles are gold (Au), silver (Ag), platinum (Pt), palladium (Pd), aluminum (Al), copper (Cu), nickel (Ni), having a particle size of 30 to 80 nm After adding at least one selected from zinc (Zn) and iron (Fe), preferably gold nanoparticles, blending is performed for 10 minutes to 24 hours, preferably 1 to 6 hours, for homogeneous mixing. good. Further, in order to obtain a uniform thin film, it is filtered using a PTFE syringe filler of 5 μm, and then heat-treated by coating to a thickness of 10 to 150 nm, preferably 20 to 60 nm.

The heat treatment temperature of the thin film is preferably in the range below the boiling point of the aprotic polar solvent. In the embodiment of the present invention, it is preferable to perform drying in a temperature range of 80 to 150 ° C. by using dimethyl sulfoxide (DMSO) or ethylene glycol (EG) as an aprotic polar solvent. At the temperature below the boiling point of the solvent, the higher the temperature, the higher the solubility of PEDOT and the more active the polar solvent. Therefore, the polar solvent can be more uniformly intercalated in the PEDOT: PSS chain. The effect seems to increase. However, when the drying temperature is 60 ℃ or less, it is not preferable because the drying time takes too long, and on the contrary, when the drying temperature is higher than the boiling point of the polar solvent, the polar solvent rapidly evaporates and thus it is not preferable to contribute to the increase of the electrical conductivity. .

In addition, the metal nanoparticles may be used both chemically synthesized compounds or commercially available.

In order to synthesize metal nanoparticles to be introduced into the organic / inorganic composite buffer layer according to the present invention, the hydrothermal reaction is performed at 100 to 150 ° C., preferably at 110 to 130 ° C. for 3 to 80 hours, preferably 6 to 72 hours. It is preferable to use the synthesis, wherein the synthesized metal nanoparticles preferably have a size of 30 to 80 nm.

The photoelectric conversion layer 14 of the present invention is a poly-3-hexylthiophene (P3HT) and a CT type polymer and its derivatives as electron donors, [6,6] -phenyl- C ₆₁ -butyl acid methyl ester ( PCBM (C ₆₀ )) and [6,6] -phenyl- C ₇₁ -butyl acid methyl ester (PC ₇₁ BM) are used as the electron acceptor, and the ratio is 1: 0.5 to 1: 2, preferably 1: 0.6. Photoelectric conversion material mixed in a weight ratio of 1 to 1.0 can be used.

Such photoelectric conversion materials are dissolved in an organic solvent. Preferably, a solution obtained by dissolving two or more boiling points in an organic solvent having a different boiling point is 10 to 150 nm, preferably 60 to 120 nm thick by spin coating or the like. A conversion layer is introduced. In this case, the photoelectric conversion layer may be applied to methods such as dip coating, screen printing, spray coating, doctor blade, brush painting, and the like.

In addition, the electron acceptor may include other fullerene derivatives such as C ₇₀ , C ₇₆ , C ₇₈ , C ₈₀ , C ₈₂ , C ₈₄ , including PCBM (C ₆₀ ), and the coated thin film is 80 to 160 ° C. Preferably, the annealed at 90 to 140 ℃ to improve the crystallinity of the conductive polymer.

The second electrode 150 is deposited inside the thermal evaporator exhibiting a vacuum degree of 5 × 10 ⁻⁷ torr or less when the photoelectric conversion layer 140 is introduced. The electrode materials usable here include lithium fluoride / aluminum, lithium fluoride / calcium / aluminum, calcium / aluminum, barium fluoride / aluminum, barium fluoride / barium / aluminum, barium / aluminum, aluminum, gold, silver, magnesium: silver, Or lithium: aluminum, and it is preferable to use an electrode made of a barium fluoride / barium / aluminum structure.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these examples are for illustrative purposes only and that the scope of the present invention is not construed as being limited by these examples.

Example  One. Patterned ITO  Substrate Cleaning

In order to clean the surface of a patterned ITO glass (surface resistance: ˜15 μs / sq ² , Samsung Corning, Korea) having a large area active area of 15 × 15 mm (2.25 cm 2), a cleaning agent (Alconox, Aldtrich, USA), acetone, and isopropanol (IPA) were sequentially subjected to ultrasonic cleaning for 20 minutes each, followed by completely blowing water with nitrogen and drying at 120 ° C. for 10 minutes on a heating plate to completely remove moisture.

Once the cleaning of the patterned ITO substrate was completed, the surface was hydrophilically modified for 10 minutes in a UVO cleaner (UVO cleaner, Ahtech LTS, Korea).

Example  2. Synthesis of Gold Nanoparticles

To synthesize the gold nanoparticles to be introduced into the organic / inorganic composite buffer layer, 9.7 ml distilled water, 0.055 g CTAB (cetyltrimethylammonium bromide; 99%, Aldrich, USA) and 0.01 M HAuCl ₂ 3H ₂ O ( 250 μl of hydrogen tetrachloroaurate; 99%, Aldrich, USA) was added, followed by stirring by adding 50 μl of 0.1 M Na ₃ C ₆ H ₅ O ₇ 2H ₂ O (trisodium citrate; 99%, Aldrich, USA). The vial was wrapped in aluminum foil and placed in an oven preheated to 120 ° C. for hydrothermal reaction for 6, 12, 24, 36, 48, and 72 hours.

Samples taken out of the oven were cooled to room temperature, and absorbance was measured using UV-Visible spectroscopy (Agilent 8453, Agilent Technology, USA), and the results are shown in FIG. 2.

In addition, the FE-SEM (Field emission scanning electron microscope; JSM 6701F, Jeol, Japan) photograph of each sample is shown in FIG.

Table 1 shows the average size of the gold nanoparticles according to the hydrothermal reaction time.

6 hours 12 hours 36 hours 48 hours 72 hours Particle size ~ 30 nm ~ 40 nm ~ 50 nm ˜70 nm ~ 80 nm

Example  3-1. Organic / Inorganic Complex Buffer layer  Manufacture (1)

In the present invention, the ratio of PEDOT and PSS is 1: 2.5, and gold nanoparticles dispersed at an arbitrary concentration in a PEDOT: PSS solution (Clevios ^™ PH500, Clevios, Germany) mixed with water or alcohol at 1.0 to 1.3 wt%. After the particles were added at 5, 10, 20, 30% by weight, spin-coated to form a thin film and heat-treated for 20 minutes at 120 ℃ to measure the specific resistance and conductivity.

For comparison with the sample, spin the conventional PEDOT: PSS solution (Clevios ^TM AI4083, Clevios, Germany) for OPV with a weight ratio of PEDOT and PSS of 1: 6 and 1.3 to 1.7% by weight in water or alcohols. After coating to form a thin film, heat treatment was performed for 20 minutes at 120 ℃ to measure the specific resistance and conductivity.

Table 2 shows the results of the specific resistance and conductivity of the organic / inorganic composite buffer layer according to the content of the gold nanoparticles.

AI4083 PH500 PH500
+ Au 5% PH500
+ Au 10% PH500
+ Au 20% PH500
+ Au 30% Specific resistance (Ω? Cm) 4221 6.32 7.12 5.431 5.261 6.216 Conductivity (S / cm) 0.00023 0.15 0.14 0.18 0.19 0.16

Example  3-2. Organic / Inorganic Complex Buffer layer  Manufacture (2)

In order to greatly improve the conductivity of the organic / inorganic composite buffer layer, 1 to 7% by weight of DMSO was added to the mixture of Example 3-1 and spin-coated, followed by heat treatment at 120 ° C. for 20 minutes, and then the specific resistance and conductivity were measured.

Tables 3 to 5 show specific resistance and conductivity of the organic / inorganic composite buffer layer according to the content of gold nanoparticles and DMSO.

PH500 + Au 10%
+ DMSO 1% PH500 + Au 10%
+ DMSO 3% PH500 + Au 10%
+ DMSO 5% PH500 + Au 10%
+ DMSO 7% Specific resistance (Ω? Cm) 0.0492 0.0036 0.0014 0.0028 Conductivity (S / cm) 20 276 724 355

PH500 + Au 20%
+ DMSO 1% PH500 + Au 20%
+ DMSO 3% PH500 + Au 20%
+ DMSO 5% Specific resistance (Ω? Cm) 0.0224 0.003 0.0012 Conductivity (S / cm) 44.5 333 833

PH500 + Au 30%
+ DMSO 1% PH500 + Au 30%
+ DMSO 3% PH500 + Au 30%
+ DMSO 5% Specific resistance (Ω? Cm) 0.0272 0.0034 0.0016 Conductivity (S / cm) 36 294 625

Example  3-3. Organic / Inorganic Complex Buffer layer  Manufacture (3)

In addition, 1% by weight and 3% by weight of ethylene glycol (EG) was added to the mixture of Example 3-1, followed by spin coating and heat treatment at 120 ° C. for 20 minutes to measure specific resistance and conductivity. 7 is shown.

PH500 + Au 10%
+ EG 1% PH500 + Au 20%
+ EG 1% PH500 + Au 30%
+ EG 1% Specific resistance (Ω? Cm) 1.404 0.450 0.795 Conductivity (S / cm) 0.712 2.22 1.257

PH500 + Au 10%
+ EG 3% PH500 + Au 20%
+ EG 3% PH500 + Au 30%
+ EG 3% Specific resistance (Ω? Cm) 0.0053 0.0031 0.0042 Conductivity (S / cm) 188 325 237

Example  4. Fabrication of Organic Solar Cells (1)

10 weights of gold nanoparticles dispersed at any concentration in a PEDOT: PSS solution (Clevios ^TM PH500, Clevios, Germany), in which the ratio of PEDOT and PSS is 1: 2.5 and is mixed with water or alcohol at 1.0 to 1.3% by weight. % And DMSO 1% by weight was spin-coated to a thickness of 40 nm on the patterned ITO prepared in Example 1, and then heat-treated at 120 ° C for 20 minutes on a hot plate to remove the residual solvent to complete the buffer layer.

The photoelectric conversion layer material mixed with P3HT and PCBM in a weight ratio of 1: 0.8 was dissolved in a chlorobenzene solvent at a concentration of 1.5% by weight, spin-coated on the ITO substrate to which the buffer layer was introduced, and then heat-treated at 120 ° C. for 10 minutes. 100 nm thick photoelectric conversion layer was introduced.

Subsequently, barium fluoride (BaF ₂ ) is 2 nm at a rate of 0.1 mW / s, barium (Ba) is 2 nm at a rate of 0.2 mW / s, and aluminum in a thermal evaporator having a vacuum degree of 5 × 10 ⁻⁷ torr or less. (Al) was deposited at 100 nm at a rate of 5 mA / s to manufacture an organic solar cell.

The device thus manufactured was introduced with a moisture and oxygen absorbent to the inner surface of the encapsulating glass in order to prevent decomposition by moisture and oxygen, and then sealed using an ultraviolet curing agent.

Example  5. Manufacture of Organic Solar Cells (2)

An organic solar cell was manufactured by the same method and conditions as in Example 4, except that 20 wt% of the gold nanoparticles were added to prepare the buffer layer.

Example  6. Fabrication of Organic Solar Cells (2006.01)

An organic solar cell was manufactured in the same manner and in the same manner as in Example 4, except that 30 wt% of the gold nanoparticles were added during the preparation of the buffer layer.

Example  7. Fabrication of Organic Solar Cells (4)

An organic solar cell was manufactured according to the same method and condition as in Example 4, except that 3 wt% of DMSO was added to prepare a buffer layer.

Example  8. Fabrication of Organic Solar Cell (5)

An organic solar cell was manufactured according to the same method and condition as in Example 5, except that 3 wt% of DMSO was added to prepare a buffer layer.

Example  9. Fabrication of Organic Solar Cell (6)

An organic solar cell was manufactured according to the same method and condition as in Example 6, except that 3 wt% of DMSO was added to prepare a buffer layer.

Example  10. Fabrication of Organic Solar Cell (7)

An organic solar cell was manufactured according to the same method and condition as in Example 4, except that 1 wt% of ethylene glycol (EG) was added in place of DMSO to prepare a buffer layer.

Example  11. Fabrication of Organic Solar Cells (8)

An organic solar cell was manufactured by the same method and condition as in Example 5, except that 1 wt% of ethylene glycol (EG) was added in place of DMSO to prepare a buffer layer.

Example  12. Fabrication of Organic Solar Cell (9)

An organic solar cell was manufactured by the same method and condition as in Example 6, except that 1 wt% of ethylene glycol (EG) was added in place of DMSO to prepare a buffer layer.

Example  13. Fabrication of Organic Solar Cell (10)

An organic solar cell was manufactured according to the same method and condition as in Example 4, except that 3 wt% of ethylene glycol (EG) was added in place of DMSO to prepare a buffer layer.

Example  14. Fabrication of Organic Solar Cell (11)

An organic solar cell was manufactured by the same method and condition as in Example 5, except that 3 wt% of ethylene glycol (EG) was added in place of DMSO when preparing the buffer layer.

Example  15. Fabrication of Organic Solar Cell (12)

An organic solar cell was manufactured by the same method and conditions as in Example 6, except that 3 wt% of ethylene glycol (EG) was added in place of DMSO when preparing the buffer layer.

Comparative example  1. Fabrication of Organic Solar Cells (13)

An organic solar cell was manufactured by the same method and conditions as in Example 4, except that only a conventional OPD PEDOT: PSS solution (Clevios ^™ AI4083, Clevios, Germany) was used as a buffer layer.

Comparative example  2. Fabrication of Organic Solar Cells (14)

An organic solar cell was manufactured by the same method and condition as in Example 4, but gold nanoparticles and DMSO were not added when the buffer layer was prepared.

Experimental Example  1. Characterization of Organic Solar Cell

In order to measure the electro-optical characteristics of the organic solar cells prepared in Examples 4 to 15 and Comparative Examples 1 and 2, standard conditions (Air) using a Keithley 2400 source meter and a solar simulator (Oriel 150W solar simulator) Mass 1.5 Global, 100 mA / cm 2, 25 ° C.), current-voltage density was measured.

Optical short-circuit current density (Jsc), photo-opening voltage (Voc), Fill Factor (FF) and energy conversion efficiency of the organic solar cells are shown in Table 8 below.

At this time, the Fill Factor (FF) is the voltage value Vmax × current density Jmax / (Voc × Jsc) at the maximum power point, and the energy conversion efficiency is FF × (Jsc × Voc) / Pin, Pin = 100 [㎽ / Cm 2].

Optical short circuit current density
Jsc (㎃ / ㎠) Photo-opening voltage
Voc (V) Fill factor
(%) Energy conversion efficiency
(%) Example 4 6.8 0.595 48.5 2.0 Example 5 8.1 0.616 49.4 2.6 Example 6 7.9 0.595 50.9 2.4 Example 7 8.0 0.575 36.2 1.7 Example 8 8.2 0.575 39.2 1.9 Example 9 8.2 0.555 38.2 1.8 Example 10 7.8 0.595 44.2 2.0 Example 11 7.9 0.595 47.5 2.2 Example 12 7.6 0.595 45.7 2.1 Example 13 7.1 0.555 35.1 1.4 Example 14 7.3 0.575 35.4 1.5 Example 15 6.6 0.555 32.3 1.2 Comparative Example 1 6.6 0.575 37.6 1.4 Comparative Example 2 7.3 0.595 37.3 1.6

4 is a graph showing current density-voltage (JV) characteristics of the organic solar cells, FIG. 5 is a graph of incident photon-to-current conversion efficiency (IPCE) of incident photons, and FIG. It is an FE-SEM photograph of the manufactured buffer layer.

As can be seen from Table 8 and FIGS. 4 and 5, the photoelectric conversion efficiency in Comparative Example is 1.4% in Comparative Example 1 and 1.6% in Comparative Example 2, respectively, 2.6% in Example 5, up to 85%. Showed an increase.

At this time, the amount of gold nanoparticles diluted to an arbitrary concentration was about 20% by weight compared to PEDOT: PSS solution (hereinafter referred to as 'PH500'), which is mixed 1.0 to 1.3% by weight in water or alcohols. Rather, the photoelectric conversion efficiency decreased. This can be interpreted through the roughness of the thin film surface measured by the atomic force microscope (AFM) of FIG.

The surface roughness of the surface containing 10% by weight of PH500, DMSO, and gold (Au) nanoparticles is 9.224 nm, the surface roughness of the surface containing 20% by weight of gold nanoparticles is 12.402 nm, and the surface roughness of 14.163 nm is included. It can be seen that increased to (see Fig. 7). However, although the increase in the gold nanoparticles leads to an increase in the plasmon resonance effect, the increase in the roughness hinders the movement of the hole, so the resonance effect and roughness can be said to be a trade-off relationship. Therefore, the optimal concentration of gold nanoparticles can be said to 20% by weight.

In addition, the efficiency of energy change efficiency through doping of the aprotic polar solvent was the best when 1 wt% of DMSO and EG were added. When 3, 5, 7 wt% of DMSO was added compared to PH500, the conductivity was increased, and a maximum of 833 S / cm was added when 5 wt% was added. However, the energy conversion efficiency was only 0.6% (not shown), but rather lower. This may be interpreted as a result of the thin film acting as an electrode rather than a buffer layer. In general, compared with the conductivity of an ITO electrode having a conductivity of 6,000 to 8,000 S / cm, the electrode acts as a relatively low conductivity electrode. It is considered that energy conversion efficiency is shown.

As described above, specific portions of the contents of the present invention have been described in detail, and for those skilled in the art, these specific techniques are merely preferred embodiments, and the scope of the present invention is not limited thereto. Will be obvious. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (10)

A solar cell comprising a first electrode, an organic / inorganic composite buffer layer, a photovoltaic layer, and a second electrode formed on a transparent substrate,
Metal nanoparticles and acetone (aceton), acetonitrile, dimethyl acetamide, dimethyl formamide, dimethyl sulfoxise, methyl ethyl ketone methyl ethyl ketone, methyl n-propyl ketone, N-methylpyrrolidone (NMP), propylene carbonate (propylene carbornate), nitromethane, sulfolane Introducing nanoparticles and highly conductive organic / inorganic composite buffer layer, characterized in that it comprises at least one selected from the group consisting of ethylene glycol (ethylene glycol) and hexamethylphophoramide (HMP) Area high efficiency organic solar cell. The method of claim 1,
The metal nanoparticles have a particle size of 30 to 80 nm (Au), silver (Ag), platinum (Pt), palladium (Pd), aluminum (Al), copper (Cu), nickel (Ni), zinc (Zn), an organic solar cell, characterized in that any one or more selected from the group consisting of iron (Fe). (1) mixing a conductive polymer, a derivative solution thereof, and an aprotic polar solvent;
(2) adding metal nanoparticles to the mixed solvent; And
(3) filtering the metal nanoparticle solution to form a thin film; and a method of manufacturing a large-area high efficiency organic solar cell, comprising the nanoparticles and the highly conductive organic / inorganic composite buffer layer. The method of claim 3,
The aprotic polar solvent is acetone, acetonitrile, dimethyl acetamide (DMAc), dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), methyl ethyl ketone (methyl ethyl ketone), methyl n-propyl ketone, N-methylpyrrolidone (NMP), propylene carbonate (propylene carbornate), nitromethane, sulfolane ), Ethylene glycol (ethylene glycol) and hexamethylphosphoramide (hexamethylphophoramide; HMP) is any one or two or more selected from the method of manufacturing an organic solar cell. The method of claim 3,
The aprotic polar solvent is a method of manufacturing an organic solar cell, characterized in that the mixing so as to contain 0.5 to 3% by weight of the conductive polymer solution. The method of claim 3,
The metal nanoparticles have a particle size of 30 to 80 nm (Au), silver (Ag), platinum (Pt), palladium (Pd), aluminum (Al), copper (Cu), nickel (Ni), zinc (Zn), a method for producing an organic solar cell, characterized in that at least one selected from iron (Fe). The method of claim 6,
The metal nanoparticles are added to the gold (Au) nanoparticles having a particle size of 30 to 80 nm, and then blended for 10 minutes to 24 hours to homogeneously mix, the method of manufacturing an organic solar cell. The method of claim 3,
The metal nanoparticles of the organic solar cell manufacturing method characterized in that the addition of 5 to 50% by weight of the conductive polymer solution. The method of claim 8,
The metal nanoparticles of the organic solar cell manufacturing method characterized in that the addition of 10 to 30% by weight of the conductive polymer solution. The method of claim 3,
The thin film is coated with a thickness of 10 to 150 nm method for producing an organic solar cell, characterized in that the heat treatment.

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