KR20100037861A - Thin film type solar cell and method for manufacturing the same - Google Patents

Abstract

PURPOSE: A thin film type solar cell and a method for manufacturing the same are provided to reduce the size of an electrode by separating the thin film type solar cell into a plurality of cell units and serially connecting the cell units. CONSTITUTION: A first electrode(200) is formed on a substrate(100). A first semiconductor layer(300) is formed on the first electrode. A second electrode(400) is formed on the first semiconductor layer. The first electrode and the second electrode are composed of a transparent conductive material. A buffer layer and a second semiconductor layer(500) are successively formed between the first semiconductor layer and the second electrode. A pre-set pattern of a third electrode(600) is formed on the second semiconductor layer. The third electrode is electrically connected to the first electrode through a contact part(700).

Description

Thin film type solar cell and method for manufacturing same

The present invention relates to a solar cell, and more particularly to a thin film solar cell.

Solar cells are devices that convert light energy into electrical energy using the properties of semiconductors.

The structure and principle of the solar cell will be briefly described. The solar cell has a PN junction structure in which a P (positive) type semiconductor and a N (negative) type semiconductor are bonded to each other. Holes and electrons are generated in the semiconductor by the energy of the incident solar light. At this time, the holes (+) are moved toward the P-type semiconductor by the electric field generated in the PN junction. Negative (-) is the principle that the electric potential is generated by moving toward the N-type semiconductor to generate power.

Such solar cells may be classified into a substrate type solar cell and a thin film type solar cell.

The substrate type solar cell is a solar cell manufactured by using a semiconductor material such as silicon as a substrate, and the thin film type solar cell is a solar cell manufactured by forming a semiconductor in the form of a thin film on a substrate such as glass.

Substrate-type solar cells, although somewhat superior in efficiency compared to thin-film solar cells, there is a limitation in minimizing the thickness in the process and there is a disadvantage that the manufacturing cost is increased because of the use of expensive semiconductor substrates.

Although thin-film solar cells are somewhat less efficient than substrate-type solar cells, they can be manufactured in a thin thickness and inexpensive materials can be used to reduce manufacturing costs, making them suitable for mass production.

Hereinafter, a thin film solar cell according to the related art will be described with reference to the accompanying drawings.

1 is a schematic cross-sectional view of a conventional thin film solar cell.

As can be seen in FIG. 1, the conventional thin film solar cell includes a substrate 10, a front electrode layer 20, a semiconductor layer 30, a back reflection layer 50, and a back electrode layer 60.

The front electrode layer 20 is formed by using a transparent conductive material because it is a surface on which sunlight is incident.

The semiconductor layer 30 is formed using a semiconductor material such as silicon, and has a so-called PIN structure in which a P-type semiconductor layer, an I-type semiconductor layer, and an N-type semiconductor layer are sequentially stacked. Is formed.

The back reflection layer 50 is formed using a conductive material such as ZnO. The back reflection layer 50 scatters sunlight passing through the semiconductor layer 30 and proceeds at various angles to increase the proportion of light reflected from the back electrode layer 60 and re-incident to the semiconductor layer 30. It plays a role.

The back electrode layer 60 is formed by using an opaque metal such as Ag and Al to re-inject sunlight transmitted through the back reflection layer 50 into the semiconductor layer 30.

In the conventional thin film solar cell, holes and electrons are generated in the semiconductor layer 30 by incident sunlight, and the holes and electrons are collected in the front electrode layer 20 and the rear electrode layer 60 to generate current. Will be generated.

In the conventional thin film solar cell, the front electrode layer 20 formed on the incident surface of sunlight is formed of a transparent conductive material, but the back electrode layer 60 formed on the surface opposite to the incident surface of the sunlight is formed of an opaque conductive material. The reason for this was to reflect incident sunlight from the back electrode layer 60 and to re-inject into the semiconductor layer 30.

However, in the conventional thin film solar cell, although the back electrode layer 60 may be made of an opaque conductive material to re-enter sunlight into the semiconductor layer 30, the amount of the thin film solar cell may not be large, so it may have a great effect on efficiency improvement. Rather, the light may be incident on the surface opposite to the incident surface of the solar light, but such light is fundamentally blocked from being incident into the solar cell. In addition, the conventional thin film solar cell is formed of an opaque conductive material for the back electrode layer 60, and thus cannot be applied to a glass window of a building requiring light, and thus there is a limitation in its application.

The present invention has been devised to solve the above-mentioned problems, and the present invention improves battery efficiency by using light in all directions by allowing light to be incident not only on the incident surface of sunlight but also on the opposite side of the incident surface of sunlight. It is also an object of the present invention to provide a thin-film solar cell and a method of manufacturing the same, which can be applied to a glass window of a building that requires light.

The present invention, the first electrode formed on the substrate to achieve the above object; A first semiconductor layer formed on the first electrode; And a second electrode formed on the first semiconductor layer, wherein the first electrode and the second electrode are made of a transparent conductive material.

In this case, a buffer layer and a second semiconductor layer may be further formed in order between the first semiconductor layer and the second electrode.

The present invention comprises a first electrode formed in a predetermined pattern on the substrate; A first semiconductor layer formed with a contact portion in a predetermined region on the first electrode; A second electrode formed in a predetermined pattern on the first semiconductor layer; A second semiconductor layer formed with a contact portion in a predetermined region on the second electrode; And a third electrode formed on the second semiconductor layer in a predetermined pattern and electrically connected to the first electrode through the contact portion, wherein the first electrode, the second electrode, and the third electrode are transparent conductive materials. It provides a thin-film solar cell, characterized in that made of a material.

At this time, the thin-film solar cell according to an embodiment of the present invention, the insulating layer formed on the third electrode; A fourth electrode formed on the insulating layer; A third semiconductor layer formed on the fourth electrode; And a fifth electrode formed on the third semiconductor layer, wherein the fourth electrode and the fifth electrode may be made of a transparent conductive material.

The present invention includes a plurality of first electrodes spaced apart at predetermined intervals on the substrate; A first semiconductor layer formed with a contact portion in a predetermined region on the first electrode; A plurality of second electrodes spaced apart at predetermined intervals on the first semiconductor layer; A second semiconductor layer formed with a contact portion in a predetermined region on the second electrode; And a plurality of third electrodes spaced apart at predetermined intervals on the second semiconductor layer, wherein the third electrode is electrically connected to the first electrode and the neighboring second electrode through the contact portion. The first electrode, the second electrode, and the third electrode provides a thin film solar cell, characterized in that made of a transparent conductive material.

At this time, the thin-film solar cell according to an embodiment of the present invention, the insulating layer formed on the third electrode; Fourth electrodes spaced apart at predetermined intervals on the insulating layer; A third semiconductor layer formed on the fourth electrode and having a contact portion; And a fifth electrode connected to the fourth electrode through a contact portion provided in the third semiconductor layer and spaced apart at a predetermined interval, wherein the fourth electrode and the fifth electrode may be made of a transparent conductive material. .

In addition, the present invention is a thin film solar cell according to another embodiment, the third semiconductor layer formed on the third electrode; A plurality of fourth electrodes spaced apart at predetermined intervals on the third semiconductor layer; A fourth semiconductor layer formed on the fourth electrode; And a fifth electrode spaced apart from each other at predetermined intervals on the fourth semiconductor layer, wherein a contact portion is formed in a predetermined region of the third semiconductor layer and the fourth semiconductor layer, and the fifth electrode is the third electrode. The third electrode and the neighboring fourth electrode may be electrically connected to each other through contact portions formed in predetermined regions of the semiconductor layer and the fourth semiconductor layer, and the fourth electrode and the fifth electrode may be made of a transparent conductive material.

The first semiconductor layer may be formed of a PIN structure, the second semiconductor layer may be formed of a NIP structure, or the first semiconductor layer may be formed of a NIP structure, and the second semiconductor layer may be formed of a PIN structure.

The present invention provides a process for forming a first electrode on a substrate; Forming a first semiconductor layer on the first electrode; And forming a second electrode on the first semiconductor layer, wherein the first electrode and the second electrode are formed using a transparent conductive material. do.

At this time, between the step of forming the first semiconductor layer and the step of forming the second electrode, forming a buffer layer on the first semiconductor layer; And forming a second semiconductor layer on the buffer layer.

The present invention comprises the steps of forming a first electrode of a predetermined pattern on a substrate; Forming a first semiconductor layer on the first electrode; Forming a second electrode of a predetermined pattern on the first semiconductor layer; Forming a second semiconductor layer on the second electrode; Forming a contact portion by removing predetermined regions of the first semiconductor layer and the second semiconductor layer; And forming a third electrode having a predetermined pattern electrically connected to the first electrode through the contact portion, wherein the first electrode, the second electrode, and the third electrode are made of a transparent conductive material. It provides a method for producing a thin film solar cell, characterized in that forming.

At this time, the manufacturing method of the thin-film solar cell according to an embodiment of the present invention, forming an insulating layer on the upper portion of the third electrode; Forming a fourth electrode on the insulating layer; Forming a third semiconductor layer on the fourth electrode; And forming a fifth electrode on the third semiconductor layer, wherein the fourth electrode and the fifth electrode may be formed using a transparent conductive material.

The present invention is a step of forming a plurality of first electrodes spaced apart at predetermined intervals on the substrate; Forming a first semiconductor layer on the first electrode; Forming a plurality of second electrodes spaced apart at predetermined intervals on the first semiconductor layer; Forming a second semiconductor layer on the second electrode; Forming a contact portion by removing predetermined regions of the first semiconductor layer and the second semiconductor layer; And forming a plurality of third electrodes electrically connected to the first electrode and the neighboring second electrode through the contact portion and spaced apart from each other by a predetermined interval. The electrode and the third electrode provide a method of manufacturing a thin film solar cell, characterized in that formed using a transparent conductive material.

At this time, the manufacturing method of the thin-film solar cell according to an embodiment of the present invention, forming an insulating layer on the upper portion of the third electrode; Forming fourth electrodes spaced apart at predetermined intervals on the insulating layer; Forming a third semiconductor layer having a predetermined contact portion on the fourth electrode; And forming a fifth electrode connected to the fourth electrode through the contact portion provided in the third semiconductor layer and spaced apart by a predetermined interval, wherein the fourth electrode and the fifth electrode are transparent conductive materials. It can be formed using.

In addition, a method of manufacturing a thin film solar cell according to another embodiment of the present invention, the step of forming a third semiconductor layer on the third electrode; Forming a plurality of fourth electrodes spaced apart at predetermined intervals on the third semiconductor layer; Forming a fourth semiconductor layer on the fourth electrode; Forming a contact portion by removing predetermined regions of the third semiconductor layer and the fourth semiconductor layer; And a plurality of fifth electrodes electrically connected to the third electrode and the neighboring fourth electrode through contact portions formed by removing predetermined regions of the third semiconductor layer and the fourth semiconductor layer and spaced apart at predetermined intervals. Forming a step, wherein the fourth electrode and the fifth electrode may be formed using a transparent conductive material.

The process of forming the first semiconductor layer is a process of forming a PIN structure and the process of forming the second semiconductor layer is a process of forming a NIP structure, or the process of forming the first semiconductor layer is The process of forming the NIP structure and the process of forming the second semiconductor layer may be performed by the process of forming the PIN structure.

According to the present invention as described above has the following effects.

First, since the present invention forms the electrode constituting the solar cell with a transparent conductive material, the solar light can be incident on the opposite side as well as the solar light incident to increase the efficiency of the solar cell, and Since sunlight can penetrate the entire battery, it can be applied to glass windows of buildings that require light, and thus can be applied to various fields.

Second, the present invention relates to a combination of a first solar cell formed by a combination of a first electrode, a first semiconductor layer of a PIN structure, and a second electrode, and a combination of a second electrode, a second semiconductor layer of a NIP structure, and a third electrode. Since the second solar cells constituted by the second solar cells are connected in parallel, a process for current matching between the first solar cell and the second solar cell is not required. Therefore, the solar light incident on the substrate is absorbed by each of the first solar cell and the second solar cell without requiring a process for current matching, thereby improving the efficiency of the entire thin-film solar cell.

Third, the present invention has a configuration in which a thin-film solar cell is separated into a plurality of unit cells and each unit cell is connected in series, so that the size of the electrode can be reduced even if the substrate is large, thereby increasing the electrode resistance. Can be prevented to obtain the effect of improving the efficiency of the solar cell.

Fourth, the present invention by forming a separate third solar cell on top of the thin-film solar cell consisting of the first solar cell and the second solar cell, or by forming a combination of the first solar cell and the second solar cell up and down The effect of improving the efficiency of the solar cell can be obtained.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<Thin Film Solar Cell>

First embodiment

2 is a schematic cross-sectional view of a thin film solar cell according to a first embodiment of the present invention.

As can be seen in Figure 2, the thin-film solar cell according to the first embodiment of the present invention comprises a substrate 100, the first electrode 200, the first semiconductor layer 300 and the second electrode 400. .

The substrate 100 is formed using glass or transparent plastic.

Since the first electrode 200 is formed on the substrate 100 and is formed on the surface where sunlight is incident, ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F or ITO (Indium Tin Oxide) It may be formed using a transparent conductive material such as).

The first electrode 200 is preferably formed in the upper surface of the concave-convex structure through a texturing process so that the incident sunlight can be absorbed into the solar cell as much as possible. The texture processing process is a process of forming a surface of a material with an uneven structure and processing it into a shape like a surface of a fabric. An etching process using a photolithography method and an anisotropic etching process using a chemical solution are performed. Or through a groove forming process using mechanical scribing. When such a texture processing process is performed on the first electrode 200, the rate at which sunlight is absorbed into the solar cell is increased by scattering of incident sunlight, thereby improving efficiency of the solar cell.

The first semiconductor layer 300 is formed on the first electrode 200 and has a PIN structure in which a P-type semiconductor layer, an I-type semiconductor layer, and an N-type semiconductor layer are sequentially stacked. When the first semiconductor layer 300 is formed in the PIN structure as described above, the I-type semiconductor layer is depleted by the P-type semiconductor layer and the N-type semiconductor layer, and an electric field is generated therein, and Holes and electrons generated by the drift are drift by the electric field so that holes are collected to the first electrode 200 through the P-type semiconductor layer and electrons to the second electrode 400 through the N-type semiconductor layer. Is collected.

The second electrode 400 is formed on the first semiconductor layer 300 and is a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO). To form. As such, since the second electrode 400 formed on the uppermost layer is made of a transparent conductive material, sunlight may also be incident through the second electrode 400, thereby increasing efficiency of the solar cell.

Second embodiment

3 is a schematic cross-sectional view of a thin film solar cell according to a second embodiment of the present invention. The thin film type solar cell according to the second embodiment of the present invention relates to a thin film type solar cell having a tandem structure in which a PIN layer of semiconductor layers is laminated in two layers. The description will be omitted.

As can be seen in Figure 3, the thin film solar cell according to the second embodiment of the present invention is the substrate 100, the first electrode 200, the first semiconductor layer 300, the buffer layer 350, the second semiconductor layer ( 500 and the second electrode 400 are sequentially stacked.

The first semiconductor layer 300 and the second semiconductor layer 500 are both formed of a PIN structure in which a P-type semiconductor layer, an I-type semiconductor layer, and an N-type semiconductor layer are sequentially stacked.

The first semiconductor layer 300 may be made of an amorphous semiconductor material having a PIN structure, and the second semiconductor layer 500 may be made of a microcrystalline semiconductor material having a PIN structure.

Since the amorphous semiconductor material absorbs light of short wavelength well and the microcrystalline semiconductor material absorbs light of long wavelength well, light absorption efficiency may be enhanced when the amorphous semiconductor material and the microcrystalline semiconductor material are combined. . In addition, the amorphous semiconductor material has a problem that the degradation phenomenon is accelerated when exposed to light for a long time, when the amorphous semiconductor material is formed on the side where the sunlight is incident and the microcrystalline semiconductor material is formed on the opposite side of the solar cell deterioration There is an effect to reduce. Therefore, the first semiconductor layer 300 close to the surface where sunlight is incident may be formed of an amorphous semiconductor material, and the second semiconductor layer 500 far from the surface where sunlight is incident may be formed of a microcrystalline semiconductor material. . However, the present invention is not necessarily limited thereto, and various modifications such as amorphous semiconductor / germanium and microcrystalline semiconductor materials may be used as the first semiconductor layer 300, and amorphous semiconductor materials and amorphous semiconductors may be used as the second semiconductor layer 500. Various modifications such as germanium are available.

The buffer layer 350 serves to facilitate the movement of holes and electrons through the tunnel junction between the first semiconductor layer 300 and the second semiconductor layer 500, and is made of a transparent material such as ZnO.

The thin film solar cell according to the second embodiment of the present invention has a structure in which two solar cells are connected in series by forming a first semiconductor layer 300 having a PIN structure and a second semiconductor layer 500 having a PIN structure. Since the open voltage of the battery can be increased, there is an advantage that higher efficiency can be achieved.

Third embodiment

4A is a schematic cross-sectional view of a thin film solar cell according to a third exemplary embodiment of the present invention. Detailed description of the same configuration as in the above-described embodiment will be omitted.

As can be seen in Figure 4a, the thin film solar cell according to the third embodiment of the present invention is a substrate 100, the first electrode 200, the first semiconductor layer 300, the second electrode 400, the second semiconductor The layer 500 and the third electrode 600 are included.

The first electrode 200 is formed in a predetermined pattern on the substrate 100 and is formed using a transparent conductive material.

The first electrode 200 may be formed in an uneven structure at an upper surface thereof through a texturing process.

The first semiconductor layer 300 is formed on the first electrode 200, and the first semiconductor layer 300 may be electrically connected to the first electrode 200 and the third electrode 600. The contact portion 700 is formed in the predetermined region.

The first semiconductor layer 300 has a PIN structure in which a P-type semiconductor layer, an I-type semiconductor layer, and an N-type semiconductor layer are sequentially stacked. When the first semiconductor layer 300 is formed in the PIN structure as described above, the I-type semiconductor layer is depleted by the P-type semiconductor layer and the N-type semiconductor layer, and an electric field is generated therein, and Holes and electrons generated by the drift are drift by the electric field so that holes are collected to the first electrode 200 through the P-type semiconductor layer and electrons to the second electrode 400 through the N-type semiconductor layer. Is collected.

The second electrode 400 is formed in a predetermined pattern on the first semiconductor layer 300, and may be formed of ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO). It is formed using a transparent conductive material.

The second electrode 400 is formed between the first electrode 200 and the third electrode 600, collects electrons generated in the first semiconductor layer 300, as described above, and further described later The electrons generated in the second semiconductor layer 500 are collected.

The second semiconductor layer 500 is formed on the second electrode 400, so that the first electrode 200 and the third electrode 600 can be electrically connected to each other. The contact portion 700 is formed in the predetermined region.

The second semiconductor layer 500 is formed of a NIP structure in which an N-type semiconductor layer, an I-type semiconductor layer, and a P-type semiconductor layer are sequentially stacked. As described above, when the second semiconductor layer 500 is formed in the NIP structure, holes generated by sunlight are collected by the third electrode 600 through the P-type semiconductor layer, and electrons are formed by the second semiconductor layer through the N-type semiconductor layer. Collected to electrode 400.

The first semiconductor layer 300 may be made of an amorphous semiconductor material having a PIN structure, and the second semiconductor layer 500 may be made of a microcrystalline semiconductor material having a NIP structure. However, the present invention is not necessarily limited thereto, and various modifications such as amorphous semiconductor / germanium and microcrystalline semiconductor materials may be used as the first semiconductor layer 300, and amorphous semiconductor materials and amorphous semiconductors may be used as the second semiconductor layer 500. Various modifications such as germanium are available.

Meanwhile, the first semiconductor layer 300 is formed of a NIP structure in which an N-type semiconductor layer, an I-type semiconductor layer, and a P-type semiconductor layer are sequentially stacked, and the second semiconductor layer 500 is a P-type semiconductor layer. , The I-type semiconductor layer and the N-type semiconductor layer are formed in a stacked PIN structure in order, holes generated by sunlight are collected to the second electrode 400 through the P-type semiconductor layer and electrons are N-type semiconductor The first electrode 200 and the third electrode 600 may be collected through the layer.

The third electrode 600 is formed in a predetermined pattern on the second semiconductor layer 500 and through the contact portion 700 provided in the first semiconductor layer 300 and the second semiconductor layer 500. It is connected to the first electrode 200. The third electrode 600 is formed using a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO). As described above, since the third electrode 600 formed on the uppermost layer is made of a transparent conductive material, sunlight may also be incident through the third electrode 600, thereby increasing efficiency of the solar cell.

In the thin film solar cell according to the third embodiment of the present invention as described above, the first solar cell is configured by the combination of the first electrode 200, the first semiconductor layer 300, and the second electrode 400. The second solar cell is formed by the combination of the second electrode 400, the second semiconductor layer 500, and the third electrode 600, and the first electrode 200 and the third electrode 600 are connected to each other. As shown in FIG. 4B, the first solar cell and the second solar cell are connected in parallel.

The thin film solar cell according to the third embodiment of the present invention has a process for current matching between the first solar cell and the second solar cell as compared to the thin film solar cell according to the second embodiment. The advantage is that it is not required.

That is, the thin film solar cell according to the second embodiment described above requires a process for current matching between the first semiconductor layer 300 and the second semiconductor layer 500. The process is very difficult and if the current matching is not made correctly, there is a problem that can not achieve high efficiency.

More specifically, in the structure in which two solar cells are connected in series as in the above-described second embodiment, electrons generated in the first semiconductor layer 300 are moved to the second semiconductor layer 500. The tunneling process must be performed between the first semiconductor layer 300 and the second semiconductor layer 500. When such tunneling is maximized, current matching is performed. In this case, in order to maximize the tunneling, the thickness of the buffer layer 350, the thickness of the P layer of the second semiconductor layer 500, etc. should be optimized, which may require a lot of work time. If it is impossible to obtain the corrected dimensions, current matching may not be performed accurately, and thus high efficiency solar cells may not be realized.

In contrast, the thin-film solar cell according to the third embodiment of the present invention includes a first solar cell formed by a combination of a first electrode 200, a first semiconductor layer 300 having a PIN structure, and a second electrode 400. And a first solar cell having a configuration in which a second solar cell constituted by a combination of a second electrode 400, a second semiconductor layer 500 having a NIP structure, and a third electrode 600 is connected in parallel. There is no need for a process for current matching between the second solar cells. Therefore, the solar light incident on the substrate is absorbed by each of the first solar cell and the second solar cell without requiring a process for current matching, thereby improving the efficiency of the entire thin-film solar cell.

Fourth embodiment

FIG. 5A is a schematic cross-sectional view of a thin film solar cell according to a fourth embodiment of the present invention, in which a plurality of unit cells are connected in series using the thin film solar cell according to the third embodiment of the present invention as a unit cell It relates to a thin film solar cell. Hereinafter, detailed description of the same configuration will be omitted.

As can be seen in Figure 5a, the thin film solar cell according to the fourth embodiment of the present invention is the substrate 100, the first electrode 200, the first semiconductor layer 300, the second electrode 400, the second semiconductor The layer 500 and the third electrode 600 are included.

A plurality of first electrodes 200 are spaced apart from each other at predetermined intervals on the substrate 100.

The first semiconductor layer 300 is formed on the first electrode 200, and the first semiconductor layer 300 may be electrically connected to the first electrode 200 and the third electrode 600. The contact portion 700 is formed in the predetermined region.

A plurality of second electrodes 400 are formed on the first semiconductor layer 300 at predetermined intervals.

The second semiconductor layer 500 is formed on the second electrode 400, so that the first electrode 200 and the third electrode 600 can be electrically connected to each other. The contact portion 700 is formed in the predetermined region.

A plurality of third electrodes 600 are formed on the second semiconductor layer 500 at predetermined intervals. The third electrode 600 is connected to the first electrode 200 through a contact part 700 provided in the first semiconductor layer 300 and the second semiconductor layer 500, and is adjacent to the unit cell. Is connected to the second electrode 400.

Additional features of the thin film solar cell according to the fourth embodiment of the present invention are as follows.

First, each of the plurality of unit cells includes a first solar cell, a second electrode 400, and a second semiconductor layer formed by a combination of the first electrode 200, the first semiconductor layer 300, and the second electrode 400. It is made of a second solar cell by a combination of the 500 and the third electrode 600, the first electrode 200 and the third electrode 600 is connected, as shown in Figure 5b, each unit The first solar cell and the second solar cell are connected in parallel in the cell. Therefore, a process for current matching between the first solar cell and the second solar cell is not required.

Second, as the third electrode 600 in one unit cell is connected to the second electrode 400 of the neighboring unit cell, as shown in FIG. 5B, a plurality of unit cells are connected in series. Therefore, even if the substrate becomes large, the size of the electrode can be reduced, thereby reducing the electrode resistance.

Fifth Embodiment

FIG. 6 is a schematic cross-sectional view of a thin film solar cell according to a fifth embodiment of the present invention, which is further configured with a separate solar cell on top of the thin film solar cell according to the third embodiment of the present invention shown in FIG. 4A. will be. Hereinafter, detailed description of the same configuration will be omitted.

As shown in FIG. 6, an insulating layer 800 is formed on the third electrode 600, a fourth electrode 820 is formed on the insulating layer 800, and the fourth electrode ( The third semiconductor layer 840 is formed on the 820, and the fifth electrode 860 is formed on the third semiconductor layer 840. Accordingly, the third solar cell is configured by the combination of the fourth electrode 820, the third semiconductor layer 840, and the fifth electrode 860.

The insulating layer 800 is preferably made of a transparent insulating material such as SiO ₂ , TiO ₂ , SiN _x , or SiON.

The fourth electrode 820 is made of a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO).

The third semiconductor layer 840 may be formed of a PIN structure or a NIP structure, and may be formed of an amorphous semiconductor material or a microcrystalline semiconductor material.

The fifth electrode 860 is made of a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO). As described above, since the fifth electrode 860 formed on the uppermost layer is made of a transparent conductive material, sunlight may also be incident through the fifth electrode 860, thereby increasing efficiency of the solar cell.

Sixth embodiment

7 is a schematic cross-sectional view of a thin film solar cell according to a sixth embodiment of the present invention, which is a separate solar cell is further configured on top of the thin film solar cell according to the fourth embodiment of the present invention shown in FIG. will be. Detailed description of the same configuration will be omitted below.

As shown in FIG. 7, an insulating layer 800 is formed on the third electrode 600, a fourth electrode 820 is formed on the insulating layer 800, and the fourth electrode ( The third semiconductor layer 840 is formed on the 820, and the fifth electrode 860 is formed on the third semiconductor layer 840. Accordingly, the third solar cell is configured by the combination of the fourth electrode 820, the third semiconductor layer 840, and the fifth electrode 860.

The insulating layer 800 is preferably made of a transparent insulating material such as SiO ₂ , TiO ₂ , SiN _x , or SiON.

The fourth electrode 820 is made of a transparent conductive material, and a plurality of fourth electrodes 820 are spaced at predetermined intervals.

The third semiconductor layer 840 has a PIN structure or a NIP structure, and is formed with a contact portion 845 in a predetermined region.

The fifth electrode 860 is made of a transparent conductive material, and a plurality of fifth electrodes 860 are spaced at predetermined intervals. In addition, the fifth electrode 860 is electrically connected to the neighboring fourth electrode 820 through the contact portion 845. Accordingly, a third solar cell constituted by a combination of the fourth electrode 820, the third semiconductor layer 840, and the fifth electrode 860 is formed of a plurality of unit cells connected in series.

Seventh embodiment

FIG. 8 is a schematic cross-sectional view of a thin film solar cell according to a seventh embodiment of the present invention, which is a structure in which the thin film solar cell shown in FIG.

As shown in FIG. 8, a third semiconductor layer 810 is formed on the third electrode 600, and a fourth electrode 830 is formed on the third semiconductor layer 810. A fourth semiconductor layer 850 is formed on the fourth electrode 830, and a fifth electrode 870 is formed on the fourth semiconductor layer 850.

Contact portions 700 are formed in the third semiconductor layer 810 and the fourth semiconductor layer 850 so that the third electrode 600 and the fifth electrode 870 can be electrically connected to each other.

The fourth electrode 830 is made of a transparent conductive material such as ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F or ITO (Indium Tin Oxide), and the third semiconductor layer 810 and the fourth The electrons or holes generated in the semiconductor layer 850 are collected. The fourth electrode 830 is connected to the fifth electrode 870 in the neighboring unit cell so that the plurality of unit cells are connected in series.

The fifth electrode 870 is made of a transparent conductive material and is connected to the third electrode 600 through the contact portion 700 provided in the third semiconductor layer 810 and the fourth semiconductor layer 850. do.

Accordingly, the first solar cell is formed by the combination of the first electrode 200, the first semiconductor layer 300, and the second electrode 400, and the second electrode 400, the second semiconductor layer 500, and The second solar cell is configured by the combination of the third electrodes 600, and the third solar cell is configured by the combination of the third electrode 600, the third semiconductor layer 810, and the fourth electrode 830. The fourth solar cell is formed by the combination of the fourth electrode 830, the fourth semiconductor layer 850, and the fifth electrode 870.

When the first semiconductor layer 300 is formed of a PIN structure, the second semiconductor layer 500 is formed of a NIP structure, the third semiconductor layer 810 is formed of a PIN structure, and the fourth semiconductor The layer 850 is formed in a NIP structure so that electrons generated by sunlight are collected at the second electrode 400 and the fourth electrode 830, and holes generated by sunlight are formed on the first electrode 200. , The third electrode 600 and the fifth electrode 870 are collected. In addition, when the first semiconductor layer 300 is formed of a NIP structure, the second semiconductor layer 500 is formed of a PIN structure, the third semiconductor layer 810 is formed of a NIP structure, The fourth semiconductor layer 850 is formed in a PIN structure so that the holes generated by sunlight are collected at the second electrode 400 and the fourth electrode 830, and the electrons generated by the sunlight are transferred to the first electrode ( 200, the third electrode 600, and the fifth electrode 870.

As described above, the thin film solar cell according to the seventh exemplary embodiment of the present invention shown in FIG. 8 is a structure in which the thin film solar cell according to FIG. 5A is formed up and down, but the present invention is not limited thereto. The thin film solar cell according to 5a may be formed in triple or more up and down.

<Method of manufacturing thin film solar cell>

9A to 9C are cross-sectional views illustrating a manufacturing process of a thin film solar cell according to an embodiment of the present invention, which relates to the manufacturing process of the thin film solar cell according to FIG.

First, as shown in FIG. 9A, the first electrode 200 is formed on the substrate 100.

The substrate 100 may be formed of glass or transparent plastic, and the first electrode 200 may be formed of a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO). It is formed using a material, and the upper surface of the first electrode 200 is formed in a concave-convex structure through a texturing process.

Next, as can be seen in Figure 9b, to form a first semiconductor layer 300 on the first electrode.

The first semiconductor layer 300 may have a PIN structure in which a P-type semiconductor layer, an I-type semiconductor layer, and an N-type semiconductor layer are sequentially stacked. The first semiconductor layer 300 is formed of amorphous silicon or microcrystalline silicon using a plasma CVD process or the like.

Next, as can be seen in Figure 9c, by forming a second electrode 400 on the first semiconductor layer 300, to complete a thin-film solar cell.

The second electrode 400 is formed using a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO).

Although not shown, before forming the second electrode 400, a buffer layer is formed on the first semiconductor layer 300 and a second semiconductor layer is formed on the buffer layer to form a thin film as shown in FIG. 3. Solar cells can be manufactured.

The buffer layer may be formed of a transparent material such as ZnO by using a MOCVD method, and the second semiconductor layer may be formed of amorphous silicon or microcrystalline silicon by using a PECVD process. The second semiconductor layer has a PIN structure.

10A to 10F are cross-sectional views illustrating a manufacturing process of a thin film solar cell according to another embodiment of the present invention, which relates to the manufacturing process of the thin film solar cell according to FIG. 4A.

First, as shown in FIG. 10A, the first electrode 200 having a predetermined pattern is formed on the substrate 100.

The first electrode 200 may be formed by sputtering a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO) on the entire surface of the substrate 100. After stacking using a sputtering method or a metal organic chemical vapor deposition (MOCVD) method, the first electrode 200 may be formed using a laser scribing method.

Next, as shown in FIG. 10B, a first semiconductor layer 300 is formed on the first electrode 200.

The first semiconductor layer 300 may be formed in a PIN structure by using a plasma CVD method.

Next, as shown in FIG. 10C, a second electrode 400 having a predetermined pattern is formed on the first semiconductor layer 300.

The process of forming the second electrode 400 may include a transparent conductive material, such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, or Indium Tin Oxide (ITO), on the entire surface of the first semiconductor layer 300. The material may be stacked using a sputtering method, a metal organic chemical vapor deposition (MOCVD) method, or the like to form a second electrode 400 having a predetermined pattern using a laser scribing method.

Next, as shown in FIG. 10D, a second semiconductor layer 500 is formed on the second electrode 400.

The second semiconductor layer 500 may form an amorphous semiconductor material, a microcrystalline semiconductor material, or an amorphous semiconductor / germanium in a NIP structure using a plasma CVD method or the like.

Next, as shown in FIG. 10E, the contact portion 700 is formed by removing predetermined regions of the first semiconductor layer 300 and the second semiconductor layer 500.

The process of forming the contact portion 700 may use a laser scribing process, in which the contact portion 700 is formed to expose the first electrode 200.

Next, as shown in FIG. 10F, the third electrode 600 having a predetermined pattern electrically connected to the first electrode 200 is formed through the contact portion 700.

The third electrode 600 may be formed by sputtering or MOCVD (ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F or ITO (Indium Tin Oxide)). Metal Organic Chemical Vapor Deposition) and the like may be laminated, and the third electrode 600 having a predetermined pattern may be formed by using a laser scribing method.

Although not shown, an insulating layer 800 is formed on the third electrode 600 after the process of forming the third electrode 600, and a fourth electrode is formed on the insulating layer 800. 6 by forming a 820, forming a third semiconductor layer 840 on the fourth electrode 820, and forming a fifth electrode 860 on the third semiconductor layer 840. According to the present invention, a thin film solar cell may be manufactured.

11A to 11F are cross-sectional views illustrating a manufacturing process of a thin film solar cell according to still another embodiment of the present invention, which relates to the manufacturing process of the thin film solar cell according to FIG. 5A.

First, as shown in FIG. 11A, a plurality of first electrodes 200 are formed on the substrate 100 at predetermined intervals.

Next, as shown in FIG. 11B, a first semiconductor layer 300 is formed on the first electrode 200.

Next, as can be seen in FIG. 11C, a plurality of second electrodes 400 are formed on the first semiconductor layer 300 at predetermined intervals.

Next, as shown in FIG. 11D, a second semiconductor layer 500 is formed on the second electrode 400.

Next, as shown in FIG. 11E, the contact portion 700 is formed by removing predetermined regions of the first semiconductor layer 300 and the second semiconductor layer 500.

Next, as can be seen in FIG. 11F, the plurality of electrodes are electrically connected to the first electrode 200 and the second electrode 400 of the neighboring unit cell through the contact part 700, and are formed at predetermined intervals. Third electrodes 600 are formed.

Although not shown, after the process of forming the third electrode 600, the insulating layer 800 is formed on the third electrode 600, and the insulating layer 800 is formed at predetermined intervals. Forming a fourth electrode 820 spaced apart from each other, forming a third semiconductor layer 840 having a predetermined contact portion 845 on the fourth electrode 820, and forming the third semiconductor layer 840. By forming the fifth electrode 860 electrically connected to the neighboring fourth electrode 820 through the contact portion 845, the thin film solar cell of FIG. 7 may be manufactured.

In addition, after the process of forming the third electrode 600, a third semiconductor layer 810 is formed on the third electrode 600, the predetermined distance on the third semiconductor layer 810. Forming a fourth electrode 830 spaced apart from each other, forming a fourth semiconductor layer 850 on the fourth electrode 830, and forming a predetermined portion of the third semiconductor layer 810 and the fourth semiconductor layer 850. The contact portion 700 is formed by removing a region, and the fifth electrode electrically connected to the third electrode 600 and the fourth electrode 830 of a neighboring unit cell through the contact portion 700. By forming 870, the thin film solar cell according to FIG. 8 may be manufactured.

1 is a schematic cross-sectional view of a conventional thin film solar cell.

2 is a schematic cross-sectional view of a thin film solar cell according to a first embodiment of the present invention.

3 is a schematic cross-sectional view of a thin film solar cell according to a second embodiment of the present invention.

Figure 4a is a schematic cross-sectional view of a thin film solar cell according to a third embodiment of the present invention, Figure 4b is a schematic circuit configuration of the thin film solar cell according to Figure 4a.

Figure 5a is a schematic cross-sectional view of a thin film solar cell according to a fourth embodiment of the present invention, Figure 5b is a schematic circuit configuration of the thin film solar cell according to Figure 5a.

6 is a schematic cross-sectional view of a thin film solar cell according to a fifth embodiment of the present invention.

7 is a schematic cross-sectional view of a thin film solar cell according to a sixth embodiment of the present invention.

8 is a schematic cross-sectional view of a thin film solar cell according to a seventh embodiment of the present invention.

9A to 9D are cross-sectional views illustrating a manufacturing process of a thin film solar cell according to an embodiment of the present invention.

10A to 10F are cross-sectional views illustrating a manufacturing process of a thin film solar cell according to another embodiment of the present invention.

11A to 11F are cross-sectional views illustrating a manufacturing process of a thin film solar cell according to still another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: substrate 200: first electrode

300: first semiconductor layer 400: second electrode

500: second semiconductor layer 600: third electrode

700, 845: contact portion 800: insulating layer

810 and 840: third semiconductor layer 820 and 830: fourth electrode

850: fourth semiconductor layer 860, 870: fifth electrode

Claims (16)

A first electrode formed on the substrate; A first semiconductor layer formed on the first electrode; And It comprises a second electrode formed on the first semiconductor layer, The thin film solar cell of claim 1, wherein the first electrode and the second electrode are made of a transparent conductive material. The method of claim 1, The thin film solar cell of claim 1, wherein a buffer layer and a second semiconductor layer are further formed in sequence between the first semiconductor layer and the second electrode. A first electrode formed in a predetermined pattern on the substrate; A first semiconductor layer formed with a contact portion in a predetermined region on the first electrode; A second electrode formed in a predetermined pattern on the first semiconductor layer; A second semiconductor layer formed with a contact portion in a predetermined region on the second electrode; And It is formed in a predetermined pattern on the second semiconductor layer, and comprises a third electrode electrically connected to the first electrode through the contact portion, The thin film solar cell of claim 1, wherein the first electrode, the second electrode, and the third electrode are made of a transparent conductive material. The method of claim 3, An insulating layer formed on the third electrode; A fourth electrode formed on the insulating layer; A third semiconductor layer formed on the fourth electrode; And It further comprises a fifth electrode formed on the third semiconductor layer, The fourth electrode and the fifth electrode is a thin film solar cell, characterized in that made of a transparent conductive material. A plurality of first electrodes spaced apart at predetermined intervals on the substrate; A first semiconductor layer formed with a contact portion in a predetermined region on the first electrode; A plurality of second electrodes spaced apart at predetermined intervals on the first semiconductor layer; A second semiconductor layer formed with a contact portion in a predetermined region on the second electrode; It comprises a plurality of third electrodes spaced apart at predetermined intervals on the second semiconductor layer, The third electrode may be electrically connected to the first electrode and the neighboring second electrode through the contact portion, and the first electrode, the second electrode, and the third electrode may be made of a transparent conductive material. Solar cells. The method of claim 5, An insulating layer formed on the third electrode; Fourth electrodes spaced apart at predetermined intervals on the insulating layer; A third semiconductor layer formed on the fourth electrode and having a contact portion; And And a fifth electrode connected to the fourth electrode through the contact portion provided in the third semiconductor layer and spaced apart at a predetermined interval. The fourth electrode and the fifth electrode is a thin film solar cell, characterized in that made of a transparent conductive material. The method of claim 5, A third semiconductor layer formed on the third electrode; A plurality of fourth electrodes spaced apart at predetermined intervals on the third semiconductor layer; A fourth semiconductor layer formed on the fourth electrode; And Further comprising a fifth electrode spaced apart at predetermined intervals on the fourth semiconductor layer, A contact portion is formed in a predetermined region of the third semiconductor layer and the fourth semiconductor layer, and the fifth electrode is adjacent to the third electrode through a contact portion formed in the predetermined region of the third semiconductor layer and the fourth semiconductor layer. Electrically connected to the fourth electrode, The fourth electrode and the fifth electrode is a thin film solar cell, characterized in that made of a transparent conductive material. The method according to any one of claims 3 to 7, Thin film type, characterized in that the first semiconductor layer is formed of a PIN structure and the second semiconductor layer is formed of a NIP structure, or the first semiconductor layer is formed of a NIP structure and the second semiconductor layer is formed of a PIN structure Solar cells. Forming a first electrode on the substrate; Forming a first semiconductor layer on the first electrode; And And forming a second electrode on the first semiconductor layer, The first electrode and the second electrode is a thin film solar cell manufacturing method characterized in that formed using a transparent conductive material. 10. The method of claim 9, Between the step of forming the first semiconductor layer and the step of forming the second electrode, Forming a buffer layer on the first semiconductor layer; And The method of manufacturing a thin film solar cell further comprising the step of forming a second semiconductor layer on the buffer layer. Forming a first electrode of a predetermined pattern on the substrate; Forming a first semiconductor layer on the first electrode; Forming a second electrode of a predetermined pattern on the first semiconductor layer; Forming a second semiconductor layer on the second electrode; Forming a contact portion by removing predetermined regions of the first semiconductor layer and the second semiconductor layer; And And forming a third electrode having a predetermined pattern electrically connected to the first electrode through the contact portion. The method of claim 1, wherein the first electrode, the second electrode, and the third electrode are formed using a transparent conductive material. The method of claim 11, Forming an insulating layer on the third electrode; Forming a fourth electrode on the insulating layer; Forming a third semiconductor layer on the fourth electrode; And Further comprising forming a fifth electrode on the third semiconductor layer, The fourth electrode and the fifth electrode is a method of manufacturing a thin film solar cell, characterized in that formed using a transparent conductive material. Forming a plurality of first electrodes spaced apart at predetermined intervals on the substrate; Forming a first semiconductor layer on the first electrode; Forming a plurality of second electrodes spaced apart at predetermined intervals on the first semiconductor layer; Forming a second semiconductor layer on the second electrode; Forming a contact portion by removing predetermined regions of the first semiconductor layer and the second semiconductor layer; And And forming a plurality of third electrodes electrically connected to the first electrode and the neighboring second electrode through the contact portion and spaced apart at predetermined intervals. The method of claim 1, wherein the first electrode, the second electrode, and the third electrode are formed using a transparent conductive material. The method of claim 13, Forming an insulating layer on the third electrode; Forming fourth electrodes spaced apart at predetermined intervals on the insulating layer; Forming a third semiconductor layer having a predetermined contact portion on the fourth electrode; And The method may further include forming a fifth electrode connected to the fourth electrode through the contact portion provided in the third semiconductor layer and spaced apart at a predetermined interval. The fourth electrode and the fifth electrode is a thin film solar cell manufacturing method characterized in that formed using a transparent conductive material. The method of claim 13, Forming a third semiconductor layer on the third electrode; Forming a plurality of fourth electrodes spaced apart at predetermined intervals on the third semiconductor layer; Forming a fourth semiconductor layer on the fourth electrode; Forming a contact portion by removing predetermined regions of the third semiconductor layer and the fourth semiconductor layer; And A plurality of fifth electrodes electrically connected to the third electrode and the neighboring fourth electrode and spaced apart at predetermined intervals through a contact part formed by removing predetermined regions of the third semiconductor layer and the fourth semiconductor layer; Forming process, The fourth electrode and the fifth electrode is a method of manufacturing a thin film solar cell, characterized in that formed using a transparent conductive material. The method according to any one of claims 11 to 15, The process of forming the first semiconductor layer is a process of forming a PIN structure and the process of forming the second semiconductor layer is a process of forming a NIP structure, or the process of forming the first semiconductor layer is The method of forming a NIP structure and the step of forming the second semiconductor layer is a method of manufacturing a thin film solar cell, characterized in that the step of forming a PIN structure.

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