KR101077833B1 - Tandem Solar Cell and Method of Manufacturing the Same - Google Patents

Abstract

The present invention, a substrate, a transparent electrode formed on the substrate, a super-straight type chalcogenide-based solar cell formed on the transparent electrode, a connection electrode formed on the super-straight type chalcogenide-based solar cell, the connection An inverted organic solar cell formed on an electrode, and a tandem solar cell including a metal electrode formed on the inverted organic solar cell.

Solar cell, tandem type, organic solar cell

Description

Tandem Solar Cell and Method of Manufacturing the Same

The present invention relates to a tandem solar cell in which two cells are stacked and a method of manufacturing the same.

There is a need for clean and unlimited energy that is different from the existing energy, such as a sense of crisis of exhaustion of oil resources, the entry into force of the Kyoto Protocol's climate change agreement, and the explosive demand for energy due to the economic growth of emerging BRICs. This is going on. Among the renewable energy, solar cells (Solar Cells or Photovoltaic Cells) are the core elements of photovoltaic power generation that converts sunlight directly into electricity, and are widely used for power supply from space to home. In the early days when solar cells were first made, they were mainly used for space use, but after two oil surges in the 1970s, they were attracting attention for their potential as ground power sources. It started to use for dragon. Recently, it has been used in aviation, meteorology, and communication fields, and solar vehicles and solar air conditioners are also attracting attention.

An object of the present specification is to provide a tandem solar cell having high photoelectric conversion efficiency.

In addition, the present specification has an object to provide a tandem solar cell excellent in properties and easy to manufacture.

In one aspect, the present invention, the substrate; A transparent electrode formed on the substrate; A super-straight type chalcogenide solar cell formed on the transparent electrode; A connection electrode formed on the super-straight type chalcogenide solar cell; An inverted organic solar cell formed on the connection electrode; It provides a tandem solar cell comprising a metal electrode formed on the inverted organic solar cell.

In another aspect, the present invention, forming a transparent electrode on the substrate; Forming a super-straight type chalcogenide-based solar cell on the transparent electrode; Forming a connection electrode on the super-straight type chalcogenide-based solar cell; Forming an inverted organic solar cell on the connection electrode; And it provides a tandem solar cell manufacturing method comprising the step of forming a metal electrode on the inverted organic solar cell.

The tandem solar cell according to the present embodiments has a high photoelectric conversion efficiency.

In addition, the tandem solar cell according to the present embodiments is excellent in properties and easy to manufacture.

  Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used to refer to the same components as much as possible even if displayed on different drawings. In the following description 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.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but between components It will be understood that may be "connected", "coupled" or "connected".

The solar cells mainly use silicon or compound semiconductors, but they are manufactured by semiconductor device manufacturing process, so the manufacturing cost is high. Also, silicon solar cells, which occupy the main part of solar cells, have difficulty in supplying silicon raw materials. . Under these circumstances, chalcogenide-based solar cells such as CIGS and CdTe, which do not use silicon materials at all, and organic solar cells using low-molecular organic materials or polymers have begun to be studied in earnest. It is possible to process and manufacture flexible solar cell regardless of the shape, which is attracting much attention now.

Chalcogenide refers to a compound containing chalcogen (S, Se, Te), a chalcogen element, and the chalcogenide compound that is widely applied in the solar cell field is an IB-IIIA-VIA element or an IIB-VIA element. CuInS ₂ (CIS), CuGaS ₂ (CGS), CuInSe ₂ (CISe), CuGaSe ₂ (CGSe), CuAlSe ₂ (CASe), CuInTe ₂ (CITe), CuGaTe ₂ (CGTe), Cu (In, Ga) S ₂ (CIGS), Cu (In, Ga) Se ₂ (CIGSe), Cu ₂ ZnSnS ₄ (CZTS), CdTe and the like. The chalcogenide-based compound or thin film has a band gap energy of 1 to 2 eV, which has the best light absorption coefficient (1 x 10 ⁵ cm ^-1 ) among semiconductors and is very optically stable, so that the light absorption layer of the solar cell It is a very ideal material.

Another chalcogenide compound used in the solar cell industry is CdS, which is composed of IIB-VIA group elements, and is suitable as a buffer material located at an interface where a PN junction is formed. Typical chalcogenide-based solar cells use CIGSe as a light absorption layer, CdS as a buffer layer, and various physicochemical manufacturing methods are used as a thin film formation method.

A method of manufacturing a chalcogenide-based (CIGSe) solar cell by a vacuum method will be described with reference to FIG. 1.

In general, the chalcogenide-based thin film solar cell 100 is a substrate 110 / P-side electrode 120 / P-type semiconductor layer (absorption layer, 130) / buffer layer 140 / N-type semiconductor layer 150 / N side Electrode 160.

In the case of the substrate 110, soda ash glass is most commonly used, and flexible substrates such as polymers such as copper tape, stainless steel, titanium, and polyimide are also used to reduce the cost and diversify the use of the process. Mo (molybdenum) is most commonly used for the P-side electrode 120, and is deposited on a substrate cleaned by DC sputtering (DC sputtering) under vacuum to a thickness of about 1 μm. In addition to Mo, various metals and transparent electrodes may be used as the P-side electrode 120.

The P-type semiconductor layer (absorption layer) 130, which is the most important functional layer in the chalcogenide-based solar cell 100, is formed in two ways.

As a first method, the three-step process of evaporating and evaporating four metal elements (Cu, In, Ga, Se) has the advantage of easy control of the composition of the four components. However, it is recognized that it is not suitable for manufacturing large-area modules. The second method is a method of forming a P-type semiconductor layer (absorption layer) by a two-step process, which is formed by first forming a precursor layer and then performing heat treatment under a reactive atmosphere. That is, the precursor thin film is formed by evaporation, sputtering, or electrodeposition, and then selenized under H ₂ Se atmosphere to form a P-type semiconductor layer (absorption layer 130).

Recently, a P-type semiconductor layer (absorption layer) 130 may be manufactured by rapidly forming a selenium thin film on the metal precursor thin film by vacuum deposition and then rapidly thermally treating the thin film. A buffer layer 140 is formed on the P-type semiconductor layer (absorption layer) 130, and CdS is mainly used by a chemical bath deposition (CBD) method. An N-type semiconductor layer 150 is formed on the buffer layer 140, and ZnO is most frequently used by a sputtering method. Al-doped ZnO (ZnO: Al) is mainly used for the N-side electrode 160, and ITO (Indium-Tin Oxide) is also applied.

The chalcogenide-based solar cell 100 is classified into a substrate type and a superstrate type according to the stacked structure.

The substrate type chalcogenide-based solar cell 100 has a substrate 110, a P-side electrode (Mo, 120), a P-type semiconductor layer (CIGSe absorption layer, 130), and a buffer layer (CdS, 140) / N, as shown in FIG. It is composed of a mold semiconductor layer (ZnO, 150) / N-side electrode (ZnO: Al transparent electrode, 160), the structure in which sunlight is incident on the opposite side of the substrate (110).

In contrast, the super straight type chalcogenide-based solar cell 200 has a substrate 210 / N side electrode (ZnO: Al transparent electrode, 260) / N-type semiconductor layer (ZnO, 250) / buffer layer (CdS) as shown in FIG. , 240) / P-type semiconductor layer (CIGSe absorbing layer, 230) / P-side electrode (Mo, Au, etc.) 220, the structure of the sunlight is incident on the substrate 210 side, the material and process used It is almost the same as the subtrace type chalcogenide solar cell 100.

Meanwhile, as another candidate to replace the silicon solar cell, an organic solar cell using an organic material such as a low molecule or a polymer has been studied. The core material of the organic solar cell is a conjugated polymer. Unlike silicon solar cells, conjugated polymers have a high absorption coefficient and can absorb sunlight even with a thin film (about 100 nm), so they can be manufactured as thin devices. It has the advantage that there are various application fields other than buildings where silicon solar cells are mainly used.

The organic solar cell is composed of a junction structure of a hole acceptor (D) and an electron acceptor (A) material. When absorbing visible light, an electron-hole pair is generated at the hole acceptor. As the electrons move to the electron acceptor, electron-hole separation is performed, resulting in a photovoltaic effect. In 1986, Eastman Kodak's C. Tang first proposed the feasibility of using solar cells as a heterojunction structure using copper pthalocyanine (CuPc) and perylene tetra carboxylic derivatives. A solar cell generating electricity using a mixed film of a conjugated polymer and a fullerene derivative as a photoactive layer has been reported, and the efficiency was improved to 3% by developing a fullerene-modified fullerene derivative (PCBM). Since then, various studies have been conducted to obtain highly efficient organic solar cells, and photoelectric conversion efficiency of up to 6.5% has been announced.

The structure of such a conventional organic solar cell is shown in FIG.

Referring to FIG. 3, the organic solar cell 300 includes a transparent substrate 310, a transparent electrode (anode 320), a buffer layer 330, a photoactive layer 340, and a metal electrode (cathode 350). do.

The conventional organic solar cell 300 uses indium tin oxide (ITO), which is a transparent electrode having a high work function, as a cathode material, and Al or Ca having a low work function as a cathode material. The photoactive layer 340 uses a two-layer structure or a mixed thin film [(D + A) blend] structure having a hole acceptor (D) material and an electron acceptor (A) material having a thickness of about 100 nm. Therefore, a structure [D / (D + A) / A] in which the latter mixed thin film is sandwiched between the hole acceptor (P-type semiconductor) and the electron acceptor (N-type semiconductor) layers is also used.

In addition, an anode planarization layer or a hole transport layer is provided between the anode ITO electrode 320 and the photoactive layer 340 as a buffer layer 330, and an electron transport layer is formed between the cathode and the photoactive layer. It can also be inserted.

The operating principle of the conventional organic solar cell 300 is as follows. When the organic solar cell 300 is exposed to light, the light is absorbed by the hole acceptor through the substrate 310, the anode 120, and the anode layer planarization layer to form an electron-hole pair (exciton) in an excited state. The electron-hole pair diffuses in any direction and encounters an interface with the electron acceptor material, separating it into electrons and holes. That is, electrons move toward the electron acceptor material having a high electron affinity, and holes remain on the hole acceptor side and are separated into respective charge states. They are collected and moved to the respective electrodes by the difference in concentration between the internal magnetic field and the accumulated charge formed by the work function difference between the two electrodes 320 and 350, and finally flow through the external circuit in the form of current.

The conventional organic solar cell 300 has a structure of a transparent substrate 310 / transparent electrode 320 / buffer layer 330 / photoactive layer 340 / metal electrode 350 as shown in Figure 3, the transparent electrode ( 320 serves as an anode, and the metal electrode 350 serves as a cathode.

On the other hand, the inverted organic solar cell 400 is a transparent substrate 410 / transparent electrode 420 / transparent electrode modification layer 425 / photoactive layer 440 / buffer layer 430 / as shown in FIG. A metal electrode 450 is included. The transparent electrode modification layer 425 of the transparent electrode 420 / chalcogenide-based compound serves as a cathode, and the metal electrode 450 serves as an anode. That is, the transparent electrode modified layer 425 of the chalcogenide-based compound having the n-type characteristic is formed on the p-type transparent electrode 420 to impart a function as a cathode, and the metal electrode 450 serves as an anode. Will be performed.

Since there is an advantage that the non-silicon solar cell can be manufactured at low cost as described above, active development is being progressed in many institutions, but the chalcogenide-based solar cell (100, 200) and the organic solar cell (300, 400) Has a problem in that photoelectric conversion efficiency is lower than that of a conventional bulk silicon solar cell, which is an obstacle to commercialization. In order to increase the photoelectric conversion efficiency, it is required to develop new high-performance materials and new structures such as tandem solar cells.

In particular, the tandem solar cell is designed to maximize the efficiency by absorbing the sunlight reaching the earth as much as possible, to manufacture each solar cell using a material with a different band gap and take the form of stacked up and down. have.

However, in the case of the chalcogenide-based solar cells 300 and 400, since the chalcogenide compound used as the absorption layer is weak in heat, it is impossible to manufacture a tandem solar cell. That is, when manufacturing a tandem solar cell composed of a lower cell and an upper cell, the lower cell already formed when forming the upper cell may be deteriorated by heat.

On the other hand, in the case of organic solar cells (mainly polymer solar cells) manufactured by the solution process, the type of connection layer for connecting the upper cell and the lower cell is limited, and the characteristics are also low, making it difficult to manufacture various types of tandem cells. Can be. That is, it is difficult to manufacture a tandem solar cell because it does not affect the lower cell by the solvent when forming the upper cell, and almost no material having excellent conductivity is used.

The present specification provides a tandem solar cell having a super-straight type chalcogenide-based solar cell and an inverted organic solar cell, and a manufacturing method thereof.

More specifically, the present specification relates to a tandem solar cell having a structure in which a transparent substrate / transparent electrode / superstrattal chalcogenide solar cell / connection electrode / inverted organic solar cell / metal electrode are sequentially stacked. Provides a technique relating to the manufacturing method.

In the tandem solar cell 500 according to the exemplary embodiment, as illustrated in FIG. 5, the substrate 510, the transparent electrode 520 formed on the substrate 510, and the super-straight type chalcogenide system formed on the transparent electrode 520. The solar cell 530, the connection electrode 538 formed on the super-straight type chalcogenide-based solar cell 530, the inverted organic solar cell 540 formed on the connection electrode 538, the inverted organic type The metal electrode 550 formed on the solar cell 540 is included.

Referring to FIG. 5, in another aspect, a method of manufacturing a tandem solar cell according to another embodiment may include (1) forming a transparent electrode 520 on a substrate 510 by a wet method such as vacuum deposition or electroplating. (2) forming a super-straight type chalcogenide-based solar cell 530 on the transparent electrode 520 by a vacuum method or a wet method, (3) the super-straight type chalcogenide-based solar cell (4) forming an inverted organic solar cell 540 on the connection electrode 538 by forming a connection electrode 538 in a vacuum method or a wet method on the connection electrode 538; And forming the metal electrode 550 on the inverted organic solar cell 540 in a vacuum method or a wet method.

At this time, the manufacturing method of each layer may be a vacuum method, it does not matter even if a wet method is applied. The vacuum method means forming a corresponding unit thin film in a vacuum chamber, and thermal deposition, sputter deposition, chemical vapor deposition, and electron beam deposition may be applied according to the type of each layer. have. In addition, the wet method refers to inkjet printing, screen printing, gravure printing, flexography, doctor blade coating method, after dissolving or dispersing a corresponding material in a liquid medium. It means forming the foil by the electroplating method.

In the following embodiment, a tandem solar cell implementation method combining a super-straight type chalcogenide-based solar cell and an inverted organic-based solar cell is embodied using the structure of FIG. 6, but this is to help understanding of the present invention. The present invention is only presented, but is not limited to the following examples.

   Referring to FIG. 6, the tamdom-type solar cell 600 according to an embodiment includes a substrate 610, a transparent electrode 620 formed on the substrate 610, and a super-straight type chalkage formed on the transparent electrode 620. Nide-based solar cell 630, the connection electrode 638 formed on the super-straight type chalcogenide-based solar cell 630, inverted organic solar cell 640 formed on the connection electrode 638, invert It includes a metal electrode 650 formed on the type organic solar cell 640.

Meanwhile, the super-straight type chalcogenide-based solar cell 630 includes an N-type semiconductor layer 632 formed on the transparent electrode 620 and a first buffer layer 634 formed on the N-type semiconductor layer 632. The P-type semiconductor layer 636 formed on the one buffer layer 634 is included. The connection electrode 638 is formed on the P-type semiconductor layer 636.

In addition, the inverted organic solar cell 640 formed between the connection electrode 638 and the metal electrode 650 is formed on the connection electrode reforming layer 642 and the connection electrode reforming layer 642 formed on the connection electrode 638. And a second buffer layer 646 formed on the photoactive layer 644.

5 and 6, the substrates 510 and 610 may be used as long as they are transparent substrates such as soda lime silica glass or flexible plastics such as amorphous glass and polyimide. The substrates 510 and 610 undergo a cleaning process immediately before use, and are immersed in acetone, alcohol, water, or a mixed solution thereof, and then ultrasonically cleaned.

The transparent electrodes 520 and 620 may be formed of both transparent and electrically conductive materials. However, the transparent electrodes 520 and 620 are capable of ohmic bonding with superstrat type chalcogenide-based solar cells and require a material having excellent transparency. In ₂ O ₃ , ITO (indium-tin oxide), indium-gallium-zinc oxide (IGZO), ZnO, aluminum-zinc oxide (ZnO: Al), SnO ₂ , Fluorine-doped tin oxide (STO ₂ : F), ATO (ATO) Aluminium-tin oxide, such as SnO ₂ : Al, may be used alone or in combination with a metal such as indium (In), tin (Sn), gallium (Ga), zinc (Zn), and aluminum (Al). For example, ZnO: Al (ZnO, Al ₂ O ₃ composite oxide) is suitable. The transparent electrodes 520 and 620 may be formed by DC sputtering or otherwise by chemical vapor deposition (CVD), atomic layer deposition (ALD), sol-gel coating, or the like. The transparent electrodes 520 and 620 may have a thickness of about 100 nm to about 1,000 nm.

Referring to FIGS. 5 and 6, the super-straight type Carl Cogenide-based solar cells 530 and 630 are formed on the transparent electrodes 520 and 620, and the ZnO thin film, which is the N-type semiconductor layer 632, and the P-type. The chalcogenide-based compound thin film, which is the semiconductor layer 636, is bonded to each other, and the N-type semiconductor layer 632 is formed on the transparent electrodes 520 and 620, and the P-type semiconductor layer 636 is formed thereon. In addition, when the first buffer layer 634 is formed between the N-type semiconductor layer 632 and the P-type semiconductor layer 636, the efficiency may be improved, but not necessarily required.

The N-type semiconductor layer 632 may be ZnO, but ZnO including In, Ga, or the like may be used. The N-type semiconductor layer 632 may form a thin film by a sputter method, or may form a thin film by a wet method such as a printing process using ZnO nanoparticles, and may have a thickness of 10 to 500 nm.

As a chalcogenide compound for P-type semiconductors, it absorbs sunlight from the outside, and CuInS ₂ (CIS), CuGaS ₂ (CGS), CuInSe ₂ (CISe), CuGaSe ₂ (CGSe), CuAlSe ₂ (CASe), CuInTe ₂ (CITe), CuGaTe ₂ (CGTe), Cu (In, Ga) S ₂ (CIGS), Cu (In, Ga) Se ₂ (CIGSe), Cu ₂ ZnSnS ₄ (CZTS), CdTe, etc. For example. Among them, the most representative CIGSe thin film may be deposited using a co-evaporation method using four metal elements (Cu, In, Ga, Se) as a starting element, and sputtering and selenization of these metal elements or compounds to form a thin film. It may be formed. In addition, a thin film may be formed by using a wet method such as a printing process after preparing chalcogenide compounds or precursor nanoparticles without using a vacuum device as described above. The thickness of the P-type semiconductor layer 636 may be about 0.5 to 10 μm, but is not limited thereto.

Since the energy gap between the ZnO thin film 632 of the N-type semiconductor layer 632 and the CIGSe thin film of the P-type semiconductor layer 636 is large and the lattice constant is large, a first buffer layer 634 may be formed therebetween. By alleviating the difference in lattice constant, better PN junction is achieved, which helps to improve efficiency. Cadmium sulfide (CdS) may be used as the material for the first buffer layer, but ZnS, MnS, Zn (O, S), ZnSe, (Zn, In) Se, In (OH, S), which does not use Cd, which is a heavy metal. ), In ₂ S ₂ and the like can be used. As a method for forming the first buffer layer 634, a chemical bath deposition method, an ion layer gas reaction method, or a vacuum deposition method may be used, and the thickness may be 10 to 500 nm. have. The first buffer layer 634 helps in terms of efficiency, but is not necessary for the operation of the solar cell.

5 and 6, in order to implement a tandem solar cell, the role of the connection electrodes 538 and 638 connecting the upper and lower solar cells is very important. The connection electrodes 538 and 638 receive electrons from the inverted organic solar cells 540 and 640 and transmit electrons to the super straight chalcogenide solar cells 530 and 630. The connection electrodes 538 and 638 must also have excellent transparency in order for incident light to pass through the super straight chalcogenide solar cell 630 to the inverted organic solar cell 640.

The super-straight type chalcogenide-based solar cell 630, specifically, the connection electrode material formed on the P-type semiconductor layer 636 may be In ₂ O ₃ , indium-tin oxide (ITO), or indium-IGZO (IGZO). gallium-zinc oxide), ZnO, aluminum-zinc oxide (AZO: Al), SnO ₂ , Fluorine-doped tin oxide (SnO ₂ : F), Aluminum-tin oxide (SnO ₂ : Al), etc. Likewise, single or complex oxides of metals such as indium (In), tin (Sn), gallium (Ga), zinc (Zn), and aluminum (Al) may also be used, as well as their nanoparticles and metal nanoparticles. But may not be limited to about 400 nm. More specifically, the thin film on the super-straight type chalcogenide-based solar cell 630 by vacuum deposition (sputter method, thermal deposition, CVD method) using materials such as ITO, IGZO, AZO, FTO, ATO, etc. It may be formed, and may also be formed by a wet method such as a printing process using nanoparticles, such as ITO, IGZO, AZO, FTO, ATO, Au nanoparticles, Ni nanoparticles, Ag nanoparticles. Of course, if the metal electrode is formed very thin (several to several tens nm) in a vacuum method, light may be transmitted, and thus may be used as the connection electrodes 538 and 638.

In addition, the connection electrodes 538 and 638 may have a multilayer structure by applying a plurality of materials described above. That is, in order to more smoothly transfer electrons from the inverted organic solar cell 640 to the super straight chalcogenide solar cell 630, a stacked structure such as a two-layer structure and a three-layer structure may be used.

5 and 6, inverted organic solar cells 540 and 640 are formed on the connection electrodes 538 and 638. The inverted organic solar cells 540 and 640 include a connection electrode reforming layer 642, a photoactive layer 644, and a second buffer layer 646 as shown in FIG. 6.

The connection electrode reforming layer 642 serves to modify the characteristics of the connection electrodes 538 and 638. That is, when the connection electrodes 538 and 638 exhibit p-type semiconductor characteristics, the connection electrodes 538 and 638 have a role of changing the characteristics of the connection electrodes 538 and 638 by forming the connection electrode modification layer 642 having the n-type semiconductor characteristics. Do it. If the photoactive layer 644 is formed directly on the p-type connection electrode, there is a problem in that the function of the solar cell is significantly degraded since the ohmic junction is not made. Therefore, by forming a connection electrode reformed layer 642 having n-type semiconductor characteristics between the connection electrodes 538 and 638 and the photoactive layer 644 having p-type semiconductor characteristics, ohmic contact is possible to induce smooth electron flow. . Of course, when the connection electrodes 538 and 638 are semiconductors that exhibit n-type characteristics by themselves, the formation of the connection electrode modification layer 642 is not necessary.

As the material for the connection electrode reforming layer, any material that is transparent and modifies the connection electrodes 538 and 638 to have an n-type characteristic can be used. As a representative example, TiOx (1 <x <2) sol (nanoparticle) , ZnO nanoparticles, titanium (diisoproxide) bis (2,4-pentadionate), tetrakis (dimethylamino) ethylene, poly (ethylene oxide), self assembly monolayer (hexadecanthiol, 1H, 1H, 2H, 2H-perfluoro decanethiol), n- type nano thin film, n-type nanoparticles, and the like, but is not limited thereto. Using these materials, the connection electrode reformed layer 642 may be formed by performing vacuum deposition or wet coating on the connection electrodes 538 and 638.

The photoactive layer 644 may be embodied in various forms. (1) The photoactive layer 644 may have a single layer structure of a mixed thin film [(A + D) blend] layer of an electron acceptor (A) material and a hole acceptor (D) material. (2) It may have a two-layer structure in which the electron acceptor (A) material and the hole acceptor (D) material are laminated (A / D), respectively. (3) In some cases, the electron acceptor (A) and the hole acceptor. It is also possible to have a three-layer structure [A / (A + D) / D] in which the mixed thin film is sandwiched between the layers (D).

As the hole acceptor (D) material, compounds such as phthalocyanine pigments such as copper phthalocyanine (CuPc), indigo, thioindigo pigments, melocyanine compounds, and cyanine compounds, and polyparaphenylene vinylene (poly- ρ- ) phenylenevinylene-based polymer derivatives such as phenylenevinylene), polythiophene, poly [2,6- (4,4-bis- (2-ethylhexyl) -4H-cyclopenta [2,1-b; 3,4 -b1] dithiophene) -alt-4,7- (2,1,3-benzothiadiadiazole)] (PCPDTBT), a conductive polymer including a thiophene-based polymer derivative such as poly (3-hexylthiophene) (P3HT), etc. can be used. have.

The electron acceptor (A) is fullerene (C ₆₀ ), [6,6] -phenyl-C ₆₁ -butyric acid methyl ether (PCBM), [6,6] -phenyl-C ₇₁ -butyric acid methyl ether (PC Fullerene derivatives such as ₇₀ BM), perylene derivatives such as perylene and 3,4,9,10-perylenetetracarboxylic bisbenzimidazole (PTCBI), semiconductor nanoparticles such as CdS, CdSe, or ZnSe.

The second buffer layer 646 is formed above the photoactive layer 644 and under the metal electrodes 550 and 650, and smoothly flows electrons by controlling interface energy between the metal electrodes 550 and 650 and the photoactive layer 644. However, solar cells are not necessary to operate. As the material for the second buffer layer, conductive polymers such as phthalocyanine derivatives, naphthalocyanine derivatives, aromatic amine compounds, polyethylenedioxythiophene (PEDOT: PSS), polyaniline, and the like may be used. The hole acceptor, electron acceptor and the second buffer layer of the organic solar cell may be prepared in a solution state, such as spin coating, spray coating, screen printing, bar coating, or doctor blade coating. Etc. may be applied and may be formed by thermal evaporation under vacuum. The thickness of the hole acceptor, the electron acceptor, and the second buffer layer may be about 5 nm to about 300 nm, but is not limited thereto.

5 and 6, the metal electrodes 550 and 650 formed on the second buffer layer 646 serve to collect holes (that is, to transfer electrons to the second buffer layer 646). In addition, high electrical conductivity and ohmic bonding with the second buffer layer 646 or the photoactive layer 644 and excellent stability of silver (Ag), platinum (Pt), tungsten (W), copper (Cu) and molybdenum Metal electrodes 550 and 650 such as denium (Mo), gold (Au), nickel (Ni), and the like are good, and the thickness may be about 0.1 to 5 μm, but is not limited thereto. The metal electrodes 550 and 650 may be formed by DC sputtering, thermal evaporation, or by wet methods such as chemical vapor deposition (CVD), atomic layer deposition (ALD), electroplating, and various printing techniques.

Embodiments have been described above with reference to the drawings, but the present invention is not limited thereto.

In the tandem solar cells 500 and 600 described above, a grid electrode may be additionally formed above (or below) the transparent electrode. The grid electrode is mainly composed of a metal contact layer and can be formed through an electron beam system or another method, and mainly Ni, Al, Ag, or the like can be used.

In addition, an antireflection layer may be additionally formed inside or outside the transparent substrate. Anti-reflective layer that functions to reduce the reflection loss of sunlight incident on the solar cell to further increase efficiency is generally used MgF ₂ , silicon nitride (SiNx), etc., the thickness of the electron beam evaporation, chemical vapor deposition (CVD), etc. It can be used to form about 600 ~ 1000Å.

In addition, the terms "comprise", "comprise" or "having" described above mean that the corresponding component may be included, unless otherwise stated, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a cross-sectional view of an organic solar cell.

2 is a cross-sectional view of an inverted organic solar cell according to one embodiment.

3 is a cross-sectional view of a substrate type chalcogenide-based solar cell according to another embodiment.

4 is a cross-sectional view of a super straight chalcogenide-based solar cell according to another embodiment.

5 and 6 are cross-sectional views of a tandem solar cell according to another embodiment.

Claims (17)

Forming a transparent electrode on the substrate; Forming a super-straight type chalcogenide-based solar cell on the transparent electrode; Forming a connection electrode on the super-straight type chalcogenide-based solar cell; Forming an inverted organic solar cell on the connection electrode; And Tandem solar cell manufacturing method comprising the step of forming a metal electrode on the inverted organic solar cell. The method of claim 1, The substrate is a tandem solar cell manufacturing method, characterized in that the transparent substrate selected from soda ash glass, plastic substrate. The method of claim 1, The transparent electrode is In ₂ O ₃ , ITO (indium-tin oxide), IGZO (indium-gallium-zinc oxide), ZnO, AZO (Aluminium-zinc oxide; ZnO: Al), SnO ₂ , FTO (Fluorine-doped tin SnO ₂ : F), ATO (Aluminium-tin oxide; SnO ₂ : Al one or more selected from the group consisting of Al tandem solar cell manufacturing method characterized in that. The method of claim 1, The super-straight type chalcogenide-based solar cell is an N-type semiconductor layer, CuInS ₂ (CIS), CuGaS ₂ (CGS), CuInSe ₂ (CISe), CuGaSe ₂ (CGSe), CuAlSe ₂ (CASe), CuInTe ₂ One selected from the group consisting of (CITe), CuGaTe ₂ (CGTe), Cu (In, Ga) S ₂ (CIGS), Cu (In, Ga) Se ₂ (CIGSe), Cu ₂ ZnSnS ₄ (CZTS), CdTe or Tandem solar cell manufacturing method, characterized in that the one or more stacked P-type semiconductor layer structure. 5. The method of claim 4, Further comprising a first buffer layer between the N-type semiconductor layer and the P-type semiconductor layer, the first buffer layer is CdS, ZnS, MnS, Zn (O, S), ZnSe, (Zn, In) Se, In ( OH, S), In ₂ S ₂ One or more selected from the group consisting of tandem solar cell manufacturing method. The method of claim 1, The connection electrode is In ₂ O ₃ , ITO (indium-tin oxide), IGZO (indium-gallium-zinc oxide), ZnO, AZO (Aluminium-zinc oxide; ZnO: Al), SnO ₂ , FTO (Fluorine-doped tin SnO ₂ : F), ATO (Aluminium-tin oxide; SnO ₂ : Al) One or more selected from the group consisting of tandem solar cell manufacturing method characterized in that.  The method of claim 1, The inverted organic solar cell is a tandem solar cell manufacturing method, characterized in that the connection electrode reformed layer, photoactive layer, the second buffer layer is sequentially stacked. The method of claim 7, wherein The connection electrode modifying layer is a self assembly monolayer such as hexadecanthiol, 1H, 1H, 2H, 2H-perfluoro decanethiol, TiOx (1 <x <2) sol (nanoparticle), ZnO nanoparticle, titanium (diisoproxide) bis (2,4) -pentadionate), tetrakis (dimethylamino) ethylene, poly (ethylene oxide) one or more selected from the group consisting of tandem solar cell manufacturing method. The method of claim 7, wherein The second buffer layer is a tandem solar cell, characterized in that one or more selected from the group consisting of phthalocyanine derivatives, naphthalocyanine derivatives, aromatic amine compounds, polyethylene dioxythiophene (PEDOT: PSS), polyaniline (Polyaniline) Way.  The method of claim 7, wherein The photoactive layer comprises (1) a single layer structure of a mixed thin film [(A + D) blend] layer of an electron acceptor (A) material and a hole acceptor (D) material, (2) an electron acceptor (A) material and a hole acceptor ( D) A two-layered structure in which materials are laminated (A / D), respectively (3) A three-layered structure in which the mixed thin film is sandwiched between the electron acceptor (A) and the hole acceptor (D) layers [A / (A + D) / D] tandem solar cell manufacturing method characterized in that one selected from. The method of claim 10, The hole receptor (D) is a copper phthalocyanine (CuPc) phthalo cyanine-based pigments, indigo, thioindigo pigments, marshmallow, not compounds, alkylene compound as polyparaphenylene vinylene of the cyanine compound (poly- ρ -phenylenevinylene), such as Phenylene vinylene-based polymer derivatives, polythiophene, poly [2,6- (4,4-bis- (2-ethylhexyl) -4H-cyclopenta [2,1-b; 3,4-b1] dithiophene) -alt-4,7- (2,1,3-benzothiadiadiazole)] (PCPDTBT), poly (3-hexylthiophene) (P3HT), or one or more selected from the group consisting of polymer derivatives Tandem solar cell manufacturing method. The method of claim 10, The electron acceptor (A) is fullerene (C ₆₀ ), [6,6] -phenyl-C ₆₁ -butyric acid methyl ether (PCBM), [6,6] -phenyl-C ₇₁ -butyric acid methyl ether ( PC ₇₀ BM) fullerene derivatives, perylene and perylene derivatives of 3,4,9,10-perylenetetracarboxylic bisbenzimidazole (PTCBI), one or more selected from the group consisting of semiconductor nanoparticles of CdS, CdSe, or ZnSe Tandem solar cell manufacturing method. The method of claim 1, The inverted organic solar cell is a tandem solar cell manufacturing method, characterized in that the photoactive layer and the second buffer layer is sequentially stacked. The method of claim 1, The inverted organic solar cell manufacturing method of a tandem solar cell, characterized in that the connection electrode reforming layer and the photoactive layer is sequentially stacked. The method of claim 1, Tandem solar cell manufacturing method, characterized in that the inverted organic solar cell comprises a photoactive layer. The method of claim 1, The metal electrode is one or more selected from the group consisting of silver (Ag), platinum (Pt), tungsten (W), copper (Cu), molybdenum (Mo), gold (Au), nickel (Ni). Tandem solar cell manufacturing method characterized in that. delete

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