WO2015064959A1

WO2015064959A1 - Solar cell and manufacturing method thereof

Info

Publication number: WO2015064959A1
Application number: PCT/KR2014/010028
Authority: WO
Inventors: 전영권
Original assignee: 전영권
Priority date: 2013-10-31
Filing date: 2014-10-23
Publication date: 2015-05-07

Abstract

The present invention relates to a structure of a solar cell that can enhance photoelectric conversion efficiency of the solar cell and a manufacturing method thereof. An implemented embodiment of a solar cell according to the present invention provides a solar cell comprising charged particle material between two electrodes disposed to face each other. The charged particles or charged particle material layer is installed adjacent to a light-absorption layer of the solar cell so that an inner electric field is formed by the electric charge of the charged particles, which makes it possible to reduce recombination of electrons and holes generated in a semiconductor and improve collection efficiency of the electrodes at the same time, thereby increasing efficiency. In addition, the solar cell technology according to the present invention can also be applied to existing crystalline solar cells as well as thin film solar cells.

Description

Solar cell and manufacturing method

The present invention relates to a solar cell and a method of manufacturing the same, and more particularly, to the charge particles for forming a built-in electric field in silicon-based solar cells such as crystalline and amorphous silicon as well as thin film solar cells such as CIGS-based, dye-sensitized and organic By disposing a material layer, the present invention relates to a structure of a solar cell and a method of manufacturing the same, which improve the photoelectric conversion efficiency of the solar cell.

Thin film solar cell technology is a next-generation solar cell technology compared to crystalline Si solar cells, which currently has the largest market share. Thin film solar cells are more efficient and cheaper to manufacture than crystalline Si solar cells.

Various types of thin film solar cells are being developed, and a typical example thereof is CIGS (Cu (In, Ga) Se ₂ ) solar cell.

A CIGS solar cell is a cell composed of a substrate, a back electrode, a light absorbing layer, a buffer layer, a front transparent electrode, etc., using a common glass substrate, among which a light absorbing layer absorbing sunlight is CIGS or CIS (CuIn (S, Se) ₂ ). It means a battery consisting of). Since CIGS is more widely used among the CIGS or CIS, a CIGS solar cell will be described below.

CIGS is a chalcopyrite-based compound semiconductor of Group I-III-VI, has a direct transition energy band gap, and has a light absorption coefficient of about 1 × 10 ⁵ cm ^-1 , which is the highest among semiconductors, and has a thickness of 1 μm. Even a thin film having a thickness of 2 μm is a material capable of manufacturing a high efficiency solar cell.

CIGS solar cells are suitable for spacecraft solar cells because they have excellent long-term stability and excellent resistance to radiation.

Such CIGS solar cells generally use glass as a substrate, but may be manufactured in the form of a flexible solar cell by being deposited on a polymer (eg polyimide) or metal thin film (eg stainless steel, Ti) substrate in addition to the glass substrate. Particularly, as the energy conversion efficiency of 19.5%, which is the highest among thin film solar cells, is realized, a low-cost, high-efficiency thin-film solar cell that can replace a silicon crystalline solar cell is known as a solar cell having a high commercial potential.

Meanwhile, in the conventional thin film solar cell, a technology for further increasing efficiency through fusion with a piezoelectric device has been developed.

For example, Patent Document 1 (US Patent No. US 7,705,523 (2010.04.27) by Wang et al.) Discloses an electrode of a dye-sensitized solar cell in a hybrid solar nanogenerator. A method for improving efficiency by installing piezoelectric nanogenerators using ZnO nanowires in series or in parallel to collect charges generated by mechanical vibration and contributing to the amount of power generation with photocurrent is presented. have. However, the technique disclosed in Patent Document 1 has a disadvantage in that economic efficiency is inferior because energy and an apparatus for generating mechanical vibration are incidentally required.

In addition, Patent Document 2 (Korean Unexamined Patent Publication No. 2011-0087226 (2011.08.02)) discloses a solar cell technology capable of exhibiting improved light conversion efficiency by an electric field improving effect, which is a thin film solar cell. By installing a field emission layer including nanostructures having a form of nanorods, nanowires or nanotubes having a field emission effect on the electrodes of the battery, electrons and holes generated from the photoactive layer by light are effectively transmitted to each electrode. In order to improve the photoelectric conversion efficiency of the solar cell, but as a result of applying to various thin film solar cells, the efficiency improvement effect is insignificant, but the process cost required for the fabrication of the nanostructure increases, similar to the technique disclosed in Patent Document 1 There is a problem of low economic efficiency.

An object of the present invention for solving the problems of the prior art described above is to provide a material layer including charged particles that can form a built-in electric field in a solar cell adjacent to a light absorbing layer. And a solar cell structure capable of increasing the photoelectric conversion efficiency by reducing the recombination of electrons and holes generated in the pn junction semiconductor by light absorption and improving the collection efficiency at the electrode. It is to provide a manufacturing method.

Another object of the present invention is to provide a method of manufacturing a solar cell including a material layer including charged particles.

The first aspect of the present invention for achieving the above object is a solar cell having a light absorption layer formed between the cathode and the anode disposed to face each other, is disposed inside or adjacent to the cathode or anode, positive (+ The present invention provides a solar cell in which a charge layer having a negative or negative charge amount is formed.

In the first aspect of the present invention, a charge layer having a positive charge amount may be formed inside the cathode, a side of the cathode not facing the light absorbing layer, or between the cathode and the light absorbing layer.

In the first aspect of the present invention, a charged layer having a negative charge amount may be formed inside the anode, a side of the anode not facing the light absorbing layer, or between the anode and the light absorbing layer.

In the first aspect of the present invention, a first charge including charged particles having a positive amount of charge inside the cathode, one of the cathodes that does not face the light absorbing layer, or between the cathode and the light absorbing layer. An entire layer is formed, and at the same time, a second charged layer including charged particles having a negative charge amount is formed inside the anode, on the side of the anode not facing the light absorbing layer, or between the anode and the light absorbing layer. Can be.

In the first aspect of the present invention, the size of the charged particles included in the charged layer may be 0.1nm ~ 100nm.

In the first aspect of the present invention, the light absorption layer may be any one of a p-n junction semiconductor, a p-type semiconductor, an n-type semiconductor, and an intrinsic (i-type) semiconductor.

The second aspect of the present invention for solving the above another problem is a manufacturing method of a solar cell having a light absorption layer formed between the cathode and the anode disposed to face each other, having a positive (+) or negative (-) amount of charge Provided is a method for manufacturing a solar cell, wherein the charge layer is formed to be inside or adjacent to the cathode or the anode.

In the second aspect of the present invention, the charged layer may be formed by ion implantation, plasma doping or wet method.

In the second aspect of the present invention, the charged layer may be formed by coating and drying a colloidal solution in which charged particles are dispersed in a fluid.

In the second aspect of the present invention, the charged particles included in the charged layer may have a positive (+) or a negative (-) amount of charge.

In the solar cell according to the present invention, a charged layer including charged particles is disposed adjacent to a light absorbing layer of the solar cell to form an internal electric field in the solar cell through the charged layer, thereby forming electrons and holes in the pn junction semiconductor. The efficiency of the solar cell can be increased by reducing the recombination and improving the collection efficiency to the electrode.

The solar cell technology according to the present invention can be applied to conventional crystalline silicon solar cells as well as thin film solar cells.

1 is a view schematically showing a cross-sectional structure of a solar cell including a charged particle material according to an embodiment of the present invention.

2 is a schematic view for explaining the movement of electrons and holes in the solar cell according to an embodiment of the present invention.

3 is a schematic cross-sectional view of a solar cell including a charged particle material according to another embodiment of the present invention.

It is a schematic diagram for demonstrating the movement of an electron and a hole in the solar cell which concerns on other embodiment of this invention.

Hereinafter, the configuration and operation of the present invention will be described with reference to the accompanying drawings.

In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

The present invention is the result of research on a method for improving photoelectric conversion efficiency while minimizing additional cost. According to the present invention, when a charged layer having a positive (+) or a negative (-) amount of charge is inserted between a light absorbing layer and an electrode of a solar cell, the charged layer is formed between the light absorbing layer and the 'built-in electric'. field), which reduces the recombination of electrons and holes generated in the pn junction semiconductor by light absorption, and improves the collection efficiency of the electrode, thereby improving the photoelectric conversion efficiency of the solar cell. Can be.

1 is a view schematically showing a cross-sectional structure of a solar cell including a charged particle material according to an embodiment of the present invention. As shown in FIG. 1, a substrate 10, a lower electrode 20 formed on the substrate 10, a light absorbing layer 30 formed on the lower electrode 20, and the light absorbing layer 30 are formed. The upper electrode 40 is formed on the (), and the charge layer (C) formed between the light absorption layer 30 and the upper electrode 40.

In this case, the charged layer C may be formed between the lower electrode 20 and the light absorbing layer 30.

In addition, the charged layer (C) may be formed in a form embedded in the lower electrode 20, the upper electrode 40 or the light absorbing layer, the light absorbing layer and the surface of the lower electrode 20 or the upper electrode (40). It may be formed on the outside that does not.

2 is a schematic view for explaining the movement of electrons and holes in the solar cell according to an embodiment of the present invention. As shown in FIG. 2, the solar cell according to the exemplary embodiment is a case where a charged layer having a positive charge is disposed between an n-type semiconductor and a cathode in a p-n junction solar cell. In this case, since a built-in electric field is formed between the charged layer having a positive charge and the n-type semiconductor, electrons generated in the semiconductor absorption layer by the absorption of sunlight accelerate in the cathode direction, and the holes in the opposite direction. Accelerated by, reduces recombination between electrons and holes and increases the collection speed, thereby increasing the light conversion current. In this way, the charged layer having a positive charge amount in the direction toward the cathode where electrons are collected and the charged layer having a negative charge amount in the direction toward the anode where the holes are collected have the effect of a built-in electric field. It can be maximized. In addition to a p-n junction semiconductor, a charged particle layer is provided between a light absorption layer and an electrode in a p-type semiconductor, an n-type semiconductor, an intrinsic semiconductor, and the like to obtain the same internal electric field increase effect.

3 is a schematic cross-sectional view of a solar cell including a charged particle material according to another embodiment of the present invention. As shown in FIG. 3, a substrate 10, a lower electrode 20 formed on the substrate 10, a light absorbing layer 30 formed on the lower electrode 20, and the light absorbing layer 30 are formed. ) Two charge layers C formed on the upper electrode 40 and the lower electrode 20 and the light absorbing layer 30, and between the light absorbing layer 30 and the upper electrode 40, respectively. ) That is, according to another embodiment of the present invention, two charge layers C are formed with the light absorption layer 30 interposed therebetween. At this time, a charged layer C having a negative charge amount is formed between the lower electrode 20 and the light absorbing layer 30, which are anodes, and a positive amount between the upper electrode 40 and the light absorbing layer 30, which are cathodes. The charged layer C having a positive charge amount is formed.

It is a schematic diagram for demonstrating the movement of an electron and a hole in the solar cell which concerns on other embodiment of this invention. As shown in FIG. 4, when a positively charged layer is provided between an n-type semiconductor and a cathode, a negatively charged layer is disposed between a p-type semiconductor and an anode. The positively charged layer is formed between the n-type semiconductor and the charged layer, and the negatively-charged layer forms a built-in electric field between the p-type semiconductor and the anode, respectively. Since the electrons are accelerated toward the cathode and the holes are accelerated toward the anode, the recombination between the electrons and the holes is reduced and the collection speed is further increased, thereby increasing the light conversion current. As such, when a plurality of charge layers having different polarities are installed in one solar cell, the effect of strengthening the built-in electric field may be increased.

In the present invention, the 'charged layer' is a layer having a positive (+) or negative (-) charge amount, and includes charged particles, and the layer is formed continuously or in a form in which charged particles are discontinuously dispersed. Formed, or the portion containing the charged particles is formed on the island (island), and all that is injected or diffused in the anode, cathode or light absorbing layer and the like.

The substrate 10 may be any one used in the art, such as a glass substrate including soda-lime glass (SLG), a ceramic substrate, a metal substrate including a stainless steel substrate, a polymer substrate, and the like. .

The lower electrode 20 and the upper electrode 40 are electrodes for receiving electrons and holes generated by the photoelectric effect and transferring them to the outside, and the upper electrode 40 is a transparent electrode formed of a transparent transparent material. It is more preferable to form. For example, a transparent conductive oxide such as ITO, FTO, ZnO, ATO, PTO, AZO, IZO, or a material such as chalcogenide may be used as the transparent electrode, and the lower electrode 20 and the upper electrode ( There is no limitation on the material as long as it can realize the characteristics of 40).

The light absorbing layer 30 is formed by stacking at least one n-type semiconductor layer and at least one p-type semiconductor layer, and an additional light absorbing layer is additionally formed between the n-type semiconductor layer and the p-type semiconductor layer. It may be provided. The n-type semiconductor layer and the p-type semiconductor layer may include a compound semiconductor including an inorganic material, an organic material, an organometallic compound, an organic-inorganic composite, or a combination thereof, but are not limited thereto.

The charged layer (C) is a layer having positive (+) or negative (-) charges, including charged particles that are positively (+) or negative (-), between the light absorbing layer (30) By forming a built-in electric field in the, it is a layer that serves to reduce the mutual recombination between the electrons and holes by applying an electric field in the forward direction to the electrons or holes that are charge carriers generated in the semiconductor of the light absorption layer 30. The charged layer is not limited to any form as long as it has a positive (+) or negative (-) form. For example, the film or charged particles in which the charged particles are dispersed may have the light absorbing layer 30 and the lower electrode ( 20) or may be formed in a dispersed form between the upper electrodes 40.

As the method of forming the charged layer, for example, a method such as an ion implantation method, a plasma doping method, a colloidal solution coating method, or the like can be used, and any method that can apply the charged particles between the light absorption layer and the electrode is particularly limited. It doesn't work.

In the ion implantation method, an ion generating device for generating ions from a solid phase material including a metal or a nonmetal at room temperature may be used, and a target that is a solid phase material including basic particles of ions to be generated at room temperature. ) To emit the basic particles, and ionize the basic particles by bombarding the electrons emitted using the ionizer to the basic particles, and to give the generated ions in the plasma state a constant direction and speed A method of implanting ions may be applied including an ion acceleration step of applying a high voltage to the ions so as to be ion beams. At this time, the ionizer is a mechanism that emits hot electrons by heating the filament. In this case, as the ionic material target of the cation, general metals such as Na, Mg, Al, and Si, and transition metal materials such as Ti, Cr, Zn, Ti, Cr, Fe, Ni, Cu, and Zn may be used. As the ionic material target, nonmetallic materials such as O, P, S, As, and Se may be used. Specifically, in order to release the basic particles from the ionic material target, to generate a plasma by accelerating an inert gas of low chemical reactivity, such as oxygen, nitrogen, helium, neon, argon, etc. to a high voltage and impinge the plasma of the inert gas to the ionic material target To release the basic particles. When the ionic material target is a metal, a direct current (DC) voltage may be applied to generate plasma, and in the case of a non-metal, it is preferable to apply an alternating voltage having a repetitive cycle, in particular RF power, instead of the direct voltage. Then, in order to form a charged particle material layer in the solar cell, it is necessary to allow ions in a plasma state such as an ionic gas to be ion beams having a constant directivity and velocity. In order to form the ion beam, ions may be implanted by applying a voltage in the range of 80 to 150 kW using an ion acceleration electrode composed of at least two electrodes. The higher the acceleration voltage, the higher the speed of the metal ion beam and thus the deeper the ion implantation depth. In addition, forming a charged layer by ion implantation of metal ions or nonmetal ions, etc. includes forming a light absorption layer, forming a transparent electrode on the entire surface, and then performing ion implantation. In this case, the implantation depth is adjusted by selecting an acceleration voltage so that an ion implantation layer can be formed in the interface between the upper transparent electrode layer and the lower light absorbing layer or in the transparent electrode in consideration of the ion beam transmission characteristic of the transparent electrode material. .

In the case of the plasma doping method, a plasma is formed by using a precursor gas containing a base material for preparing charged particles as a raw material to form a charged layer, and the ion doping method also in the plasma doping method. Similarly, a precursor gas containing a general metal such as Na, Mg, Al, and Si and transition metal materials such as Ti, Cr, Fe, Ni, Cu, and Zn may be used for plasma generation. As a nonmetal material, O, P Precursor gases including materials such as S, As, Se, and the like may be used, but are not necessarily limited to these materials. In addition, heat treatment may be further performed after the plasma doping. At this time, the heat treatment may be a method of heating for at least 1 minute at a temperature of 300 ℃ or more in N ₂ , Ar and / or air atmosphere.

In the colloidal solution coating method, the colloidal solution may be formed by coating and drying a solution in which charged particles are dispersed in a fluid and present in a colloidal state, and the charged particles may be positively charged black particles or negative charges. White particles may be used, but are not necessarily limited thereto. At this time, the charged particles may have a diameter of about 10nm ~ 100nm, preferably has a diameter of 30nm ~ 50nm.

The charged particles are charged so that the black and white base particles have a charge, so that a polymer binder including a backbone and a side chain bonded to the main chain may be formed to surround the base particles. Can be. The binder consisting of the main chain and the side chain gives a charge to the basic particles and determines the type of charge of the particles. The binder allows the basic particles to be charged with positive or negative charges. do. In this case, the charged particles have the same polar group of the main chain and the side chain, or have a polar group having the opposite polarity, at least of the number of polar groups of the main chain and the side chain and the polarity and amount of the charge control agent (CCA) By setting one condition, the charging polarity and the charge amount of the particles can be controlled. That is, by setting the polarity of the charge control agent to be positive (+) or negative (-), the charging polarity of the finally-charged charged particles can be controlled to be positive (+) or negative (-), respectively. In addition, the amount of charge control agent can be increased to increase the amount of charge of the finally obtained charged particles, and the amount of charge of the finally charged particles can be increased by increasing the number of polar groups in the main chain and the side chain, and the polar groups in the main chain and the side chain can be increased. It is also possible to control the charging polarity positively or negatively through the number of.

Titanium oxide (TiO ₂ ), zinc oxide (ZnO), tungsten oxide (WO ₃ ), zirconium oxide (ZrO), silicon oxide (SiO ₂ ), and the like may be used as basic particles for forming charged particles. It is preferable to use titanium oxide (TiO ₂ ) which has ease of handling and low price. However, since titanium oxide (TiO ₂ ) causes photochemical activity with respect to ultraviolet rays, discoloration and deterioration are promoted when the ultraviolet rays are exposed to the ultraviolet rays themselves. The UV blocking layer includes applying an oxide semiconductor such as silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), tungsten oxide (WO ₃ ), molybdenum oxide (MoO ₃ ), or the like. can do.

The process for producing the titanium oxide charged particles is as follows. First, a polymer resin including a main chain and a side chain and a titanium oxide basic particle are first dispersed in a solvent to form a colloidal solution.

Here, the polymer resin may serve as a binder, and for this purpose, a polymer resin having thermoplasticity or having a low molecular weight is easy to mold. Here, the polymer resin constituting the main chain is polystyrene, acrylic resin, urethane ester, polyamide, polymethmethyl acrylate, unsaturated polyester It may be made of an unsaturated polyester, water dispersive polyester and the like, and may be used in combination of one or two or more of them.

In addition, the side chain bonded to the main chain may be formed of the same material as the main chain or have a different polar group, and may be polyvinyl alcohol, polycarbonate, silicone, sulfonyl ) May further include one kind, such as a metal salt or an amine. Such a main chain and a side chain have an uncrosslinked state backbone and side chain in which a polar group capable of reacting with a charge control agent is partially bonded to each other, or have polar groups having opposite polarities to each other.

At this time, by controlling the number of polar groups in the main chain and side chain, it is possible to control the amount of charge of the particles finally obtained. That is, since the amount of charge of the particles can be controlled by the amount of charge of the charge control agent bonded through the main chain and the side chain, the amount of charge of the charge control agent bonded to each other through the main and side chains by controlling the number of polar groups in the main and side chains. By controlling the amount of charge of the particles can be adjusted. In addition, the amount of charge of the particles may be controlled by the amount of charge of the charge control agent bonded to the main chain and the side chain itself. Here, the polar group of the main chain and the side chain may be formed to include 1 to 10% by weight based on the total weight of the polymer resin.

The colloidal solution is formed by mixing a polymer resin, a solvent, and a dispersant, using an ultrasonic dispersion method, a ball mill method, a mediamill method, a stirring dispersion method, and the like.

Here, as a solvent, a polar solvent consisting of ethyl acetate, water, alcohols, ethylene glycol, dimethylformamide, or a mixture thereof, or halogenated hydrocarbon oil, galden, isopar-based substance, or a mixture thereof. A nonpolar solvent consisting of, or a mixture of a polar solvent and a nonpolar solvent can be used. Most binders can be dispersed in a polar or nonpolar solvent, but an appropriate solvent can be selected according to the physical properties of the binder. The dispersant is a surfactant having a hydrophile lipophile balance (HLB) of 3 or more. Preferably, when a polar solvent is used, a byk ^TM -190, byk ^TM -183 or a tween-based surfactant is used as the dispersant. When using a non-polar solvent, as the dispersant, byk ^TM -110, byk ^TM -161, byk ^TM -183, or tween, span, OLOA series (manufactured by Chevron oronite Inc.), Ganex series ( Dispersants from ISP Inc. may be used.

The next step is to form a colloidal solution containing charged particles as follows.

The charge control agent is secondaryly dispersed in the colloidal solution in which the polymer resin including the main chain and the side chain and the color pigment are first dispersed. At this time, the charge control agent is formed to be included in an amount of 0.5 to 50% by weight based on the total weight of the colloidal solution according to the number of polar groups in the main chain and the side chain. In this case, when the content of the charge control agent is insufficient, there may be a problem that the charging speed is low and the charging amount is not large. When the content is more than 50%, the amount of the charge is excessively increased, resulting in a drop in stability of the particles. The charge control agent includes at least one of a positive charge control agent and a negative charge control agent. Examples of the charge control agent that can be used in the present embodiment include metal soap, Ganex series, and the like. At this time, by selectively adjusting the polarity of the charge control agent, it is possible to control the charging polarity of the finally obtained particles positive or negative.

For example, when the main chain and the side chain of the polymer resin have a positive polar group, when the charge control agent having a negative polarity is dispersed, the main chain and the side chain may be formed around the negative charge of the charge control agent. The particles form enclosing shapes, and the particles become polar in the negative charge of the charge control agent. And, by adjusting the amount of the charge control agent, it is possible to control the amount of charge coupled to the polar groups of the main chain and side chain, it is possible to control the amount of charge of the polarity of the particles. That is, charged particles having a desired amount of charge are obtained by controlling the number of polar groups in the main and side chains and the amount of the charge control agent.

In addition, the negative charge can be combined with other negative charges through the positive (+) polar group of the main chain and side chain, thereby controlling the amount of charge of the particles. That is, when the number of polar groups in the main chain and the side chain is large, a large amount of negative charges can be bonded to each other, thereby increasing the amount of charge of the particles. At this time, the amount of charge of the particles may be controlled by adjusting the amount of the charge control agent.

Then, the colloidal solution in which the charged particles are dispersed is coated on the surface of the CIGS light absorbing layer. The method of forming the colloidal solution may include chemical bath deposition (CBD), spin coating, doctor-blade coating, drop-casting, and screen printing. ) And wet coating methods such as inkjet printing can be used.

On the other hand, in addition to the above-described oxide or oxide semiconductor, inorganic pigments such as carbon black, titanium black, or organic pigments such as aniline black are added to the reaction vessel with ion-exchanged water as the basic particles for preparing charged particles. After the formation of the precipitate, the precipitate may be separated, and then subjected to condensation polymerization and drying.

EXAMPLE

CIGS-based thin film solar cell including a charge layer according to an embodiment of the present invention can be manufactured through the following process.

First, on the SLG glass substrate, a Mo layer is deposited to a thickness of about 1 μm using a sputtering method to form a lower electrode. Subsequently, a CIGS thin film having a p-n junction structure or any conductive type is deposited to a thickness of about 2 μm to form a light absorption layer. Here, the semiconductor substrate having any conductivity type includes using one or a combination of n-type, p-type, and i-type (intrinsic) semiconductor materials.

The method for forming the CIGS thin film may be applied to all known methods, and is not particularly limited. For example, one of the non-vacuum coating methods including the spray method, the ultrasonic spray method, the spin coating method, the doctor blade method, the screen printing method and the inkjet printing method, or the sputtering method, the simultaneous sputtering method and the evaporation deposition method, etc. It can be carried out by selecting one of the vacuum coating method. Thereafter, in some cases, a process of improving the physical properties of the thin film may be performed by promoting the diffusion of atoms or crystal growth in the CIGS thin film by applying a selenization heat treatment step.

Next, a ZnO layer is deposited on the surface of the CIGS light absorbing layer with a window layer of about 0.5 μm, and then a charged particle layer is formed within the range from the interface between the ZnO layer and the CIGS light absorbing layer to the inside of the ZnO layer by using an ion implantation method. Ion implantation of metal cations as possible. At this time, Cu ions are preferably implanted at a concentration of 1 × 10 ¹⁷ to 1 × 10 ²⁰ ions / cm 2 at an acceleration voltage of 100 to 120 mA.

Thereafter, an Al grid layer having a thickness of about 0.5 μm is formed on the window layer to form an upper electrode, thereby completing a CIGS thin film solar cell.

In the embodiment of the present invention has been described an example of forming a charge layer between the electrode and the light absorbing layer in the solar cell, it can be applied by connecting the charge layer in series to the outside of the solar cell. That is, in a general solar cell structure consisting of a substrate, a lower electrode, a light absorption layer (or a pn junction semiconductor layer), and an upper electrode, a charged layer is connected in series to an electrode below or below the lower electrode, or both. When formed so as to be able to obtain the effect of applying a built-in electric field to the electrons and holes collected in the solar cell using the electric field generated from the charge layer. In addition, similar effects can be obtained by installing a charged layer inside the upper electrode or the lower electrode.

In this way, the above-described method of forming the charged layer can also be applied to the case where the charged layer is provided inside or adjacent to the electrode. That is, a positive charged layer is provided inside the cathode or in the direction of the cathode, and a negative charged layer is provided inside the anode or in the direction of the anode.

In the above embodiment, the CIGS-based thin film solar cell (where CIGS-based solar cell is a light absorbing layer material is a compound semiconductor material M1, M2, X (M1 is Cu, Ag or a combination thereof, M2 is In, Ga, Al, Zn , Ge, Sn, or a combination thereof, X is Se, S, or a combination thereof), but a method of forming a built-in electric field by introducing a charged particle material is described. Thin film solar cells such as dye-sensitized, organic solar cells, as well as Si-based solar cells (where Si-based solar cells are light-absorbing layer materials are monocrystalline, polycrystalline and amorphous Si materials, or a combination thereof). Can be.

[Description of the code]

10: Substrate

20: lower electrode

30: light absorption layer

40: upper electrode

C: charged layer

Claims

A solar cell formed with a light absorption layer between the cathode and the anode disposed to face each other,

A solar cell disposed inside or adjacent to the cathode or anode and having a charged layer having a positive (+) or negative (−) charge amount.
The method of claim 1,

The charge cell having a positive charge amount is formed inside the cathode, the side of the cathode that does not face the light absorption layer, or between the cathode and the light absorption layer.
The method of claim 1,

The charge cell having a negative (-) charge amount is formed inside the anode, the side of the anode that does not face the light absorbing layer, or between the anode and the light absorbing layer.
The method of claim 1,

A first charged layer having a positive charge amount is formed inside the cathode, a side of the cathode not facing the light absorbing layer, or between the cathode and the light absorbing layer,

And a second charged layer having a negative charge amount inside the anode, a side of the anode not facing the light absorbing layer, or between the anode and the light absorbing layer.
The method of claim 1,

The solar cell, characterized in that the charge layer is formed in series on the inner side facing the light absorption layer of the cathode or anode or the outer side not facing the light absorption layer of the cathode or anode.
The method of claim 1,

The charged layer is a solar cell, characterized in that charged particles having a diameter of 0.1nm ~ 100nm.
The method of claim 1,

The light absorbing layer is a solar cell, characterized in that any one of p-n junction semiconductor, p-type semiconductor, n-type semiconductor and intrinsic (i-type) semiconductor.
In the manufacturing method of the solar cell formed with a light absorption layer between the cathode and the anode disposed to face each other,

A method of manufacturing a solar cell, characterized in that the charge layer having a positive or negative charge amount is formed to be inside or adjacent to the cathode or anode.
The method of claim 8,

The charged layer is a method of manufacturing a solar cell, characterized in that formed by ion implantation, plasma doping, or wet method.
The method of claim 9,

The wet method is a method of manufacturing a solar cell, characterized in that the colloidal solution coating method.
The method according to any one of claims 8 to 10,

The charged layer is a manufacturing method of a solar cell, characterized in that it comprises charged particles having a positive (+) or negative (-) amount of charge.