KR100853245B1 - Solar cell and manufacturing method thereof - Google Patents

Abstract

A solar cell is provided to fabricate a light condensing apparatus of high efficiency by embodying a transparent electrode and/or a light condensing layer by an inkjet method wherein the transparent electrode and/or the light condensing layer is made of a micro hemispherical lens shape. A transparent electrode of a micro lens shape is formed on one surface of a transparent substrate by an inkjet method(100). An n-type semiconductor and a p-type semiconductor are sequentially coated to cover the transparent electrode(110). Electrodes are deposited on the transparent electrode and the p-type semiconductor(120). A light condensing layer of a micro lens shape can be stacked on the other surface of the transparent substrate wherein the light condensing layer can be printed by an inkjet method(130).

Description

Solar cell and manufacturing method thereof

1 is a flow chart showing a solar cell manufacturing method according to a first embodiment of the present invention.

Figure 2 is a photograph showing the impact ink droplets according to an embodiment of the present invention.

3 is a flow chart showing a solar cell manufacturing process according to a first embodiment of the present invention.

Figure 4 is a flow chart showing a solar cell manufacturing method according to a second embodiment of the present invention.

5 is a cross-sectional view showing a solar cell according to a first embodiment of the present invention.

6 is an enlarged cross-sectional view of the solar cell illustrated in FIG. 5.

7 is a sectional view showing a solar cell according to a second embodiment of the present invention.

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

1 transparent substrate 2 core substrate

10 transparent electrode 12, 52 first ink droplet

14, 54: second ink droplet 20: n-type semiconductor

30 p-type semiconductor 40, 41 electrode

50, 51: light collecting layer

The present invention relates to a solar cell and a method of manufacturing the same.

Recently, due to the rapid development of the flat panel display industry, liquid crystal display (LCD) and plasma display panel (PDP) are showing growth over the market size of the semiconductor industry, and organic light emitting diode (EL) and field emission (FED) displays are also expected as next-generation displays.

Korea has already solidified its position as a production base for flat panel displays in the world due to its large-scale investment and mass production technology. Recently, Korea is leading the development of new technology and new products. However, despite these outward developments, manufacturing equipment, core parts, and material technology still have gaps with developed countries.

In particular, the entire process field of equipment technology is mostly dependent on imports despite the efforts of many domestic equipment companies. One of the recent attentions of these equipment technologies is inkjet printing technology that can directly form a desired pattern without going through a conventional complicated photolithography process. Inkjet printing technology is expected to be one of the most competitive process technologies, especially in the organic EL field, and its application to LCD, PDP, FED, etc. is also actively progressing.

Inkjet technology was developed for industrial use by 'drop on demand (DOD)' by 'Kyzer' and 'Zaltan' in 1970.In early 1980, HP and Canon used thermal inkjet heads. After that, Epson began developing piezo inkjet heads for full-fledged office automation (OA) printers.

Industrial inkjet technology is currently used in various fields, and the most widely used fields are display and solar cells. The display field may be applied to a process of filling a color filter into a black matrix, and the solar cell field may be used to form a masking pattern for patterning. Inkjet technology has the advantages of time and space and cost savings by eliminating the intermediate process.

Conventional solar cells have been manufactured in two types, a superstrate type using a transparent substrate such as a glass substrate and a substrate type using a silicon substrate.

Substrate-type solar cells have been manufactured in the form of high-efficiency solar cells using silicon semiconductor processes, and have a disadvantage in that the process is complicated and material costs are high, but the energy efficiency is higher than that of other solar cells, and thus they are used for mass production.

The superstrate type solar cell is a method of forming a p-n junction by depositing a transparent electrode on one surface using a glass substrate and sequentially depositing n-type and p-type semiconductors, respectively. In this case, the light incident through the glass substrate is absorbed by the p-type semiconductor through the transparent electrode and the n-type semiconductor, and the electrons are excited, and the excited electrons flow by the electromotive force to obtain power.

The present invention forms a microspherical transparent electrode and / or a condenser lens using an inkjet, thereby realizing a high efficiency light concentrating device without losing light and increasing the interfacial surface area of the transparent electrode, thereby contributing to many electron excitations. It is to provide a solar cell and a method of manufacturing the same.

According to an aspect of the invention, the step of printing a transparent electrode on one surface of the transparent substrate by an inkjet method, the step of sequentially coating the n- type semiconductor and p-type semiconductor to cover the transparent electrode, and the transparent electrode and p- A solar cell manufacturing method comprising the step of depositing an electrode on a type semiconductor is provided.

The printing step may include forming a transparent electrode in a micro lens shape, in which case, discharging a first ink droplet containing a material constituting the transparent electrode on the transparent substrate, and curing the first ink droplet. And ejecting a second ink droplet containing a material constituting the transparent electrode adjacent to the first ink droplet.

After the depositing step, the method may further include laminating a light collecting layer having a microlens shape on the other surface of the transparent substrate. The laminating step may include printing the light collecting layer by an inkjet method, in which case, discharging a first ink droplet containing a material constituting the light collecting layer to a transparent substrate, and curing the first ink droplet. And ejecting a second ink droplet containing a material constituting the light collecting layer adjacent to the first ink droplet.

Further, according to another aspect of the invention, providing a core substrate in which n-type semiconductor and p-type semiconductor is sequentially stacked, forming an electrode for electrically connecting the n-type semiconductor and p-type semiconductor And, and providing a solar cell manufacturing method comprising the step of laminating a light collecting layer of a micro lens shape on the surface of the core substrate.

The core substrate may be formed by printing a transparent electrode on one surface of the transparent substrate by an inkjet method, and sequentially coating an n-type semiconductor and a p-type semiconductor to cover the transparent electrode.

The electrode forming step may include depositing an electrode on the transparent electrode and the p-type semiconductor.

The printing step may include forming a transparent electrode in a microlens shape, in this case, discharging a first ink droplet containing a material constituting the transparent electrode on the transparent substrate, and curing the first ink droplet. And ejecting a second ink droplet containing a material constituting the transparent electrode adjacent to the first ink droplet.

The laminating step may include printing the light collecting layer by an inkjet method, in this case, discharging a first ink droplet containing a material constituting the light collecting layer on the core substrate, and curing the first ink droplet. And ejecting a second ink droplet containing a material constituting the light collecting layer adjacent to the first ink droplet.

According to another aspect of the present invention, a transparent substrate, a transparent electrode laminated on one surface of the transparent substrate by an inkjet method, an n-type semiconductor covering the transparent electrode, and a p-type semiconductor covering the n-type semiconductor And a solar cell including a transparent electrode and an electrode deposited on a p-type semiconductor. The transparent electrode may be formed in a micro lens shape.

The light emitting layer may further include a microlens-shaped light collecting layer laminated on the other surface of the transparent substrate by an inkjet method.

In addition, according to another aspect of the invention, a plurality of n-type semiconductor and a p-type semiconductor is sequentially stacked stacked on the core substrate, a plurality of electrically connected n-type semiconductor and p-type semiconductor Provided is a solar cell including an electrode and a light collecting layer having a microlens shape stacked on a surface of a core substrate.

The core substrate may include a transparent substrate, a transparent electrode laminated on one surface of the transparent substrate by an inkjet method, an n-type semiconductor covering the transparent electrode, and a p-type semiconductor covering the n-type semiconductor.

The plurality of electrodes may include electrodes that are respectively deposited on the transparent electrode and the p-type semiconductor. The transparent electrode may be formed in a micro lens shape.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

Hereinafter, a preferred embodiment of a solar cell and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings, in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals Duplicate description thereof will be omitted.

1 is a flowchart illustrating a method of manufacturing a solar cell according to a first embodiment of the present invention, Figure 2 is a photograph showing a droplet of impact ink according to a preferred embodiment of the present invention, Figure 3 is a preferred embodiment of the present invention 1 is a flowchart illustrating a solar cell manufacturing process according to an embodiment. Referring to FIG. 3, the transparent substrate 1, the transparent electrode 10, the first ink droplets 12 and 52, the second ink droplets 14 and 54, the n-type semiconductor 20, and the p-type semiconductor 30, an electrode 40, and a light collecting layer 50 are shown.

This embodiment is a novel solar cell manufacturing method, characterized in that the transparent electrode 10 is manufactured in the shape of a micro lens using an inkjet method, rather than the conventional transparent electrode deposition method.

When the ink droplets are ejected from the inkjet head as shown in FIG. 2, droplets of several tens of micro-sizes are ejected and adhered to the substrate, thereby forming a hemispherical lens having a diameter of several tens of micro-sizes on the substrate. That is, it can be seen that the microlenses can be manufactured by the inkjet method.

In the present embodiment, the transparent electrode 10 is manufactured in a micro lens shape using an inkjet method in a superstrate type solar cell, thereby reducing the loss of incident light and acting as a light collecting device, thereby manufacturing a high performance solar cell. It is possible.

In order to manufacture a superstrate type solar cell according to the present embodiment, first, a transparent electrode is formed on the surface of a transparent substrate 1 such as a glass substrate as shown in FIG. (TCO) 10 prints (100). In the superstrate type solar cell, the transparent electrode 10 serves to transmit the light passing through the transparent substrate 1 to the n-type semiconductor 20 without being reflected, and is transparent and electrically conductive such as ITO and ZnO. Material is used. Unlike the deposition of the transparent electrode 10 by a conventional deposition method, this embodiment contains a material constituting the transparent electrode 10 through an inkjet head as shown in FIG. The droplet of one ink is discharged, that is, the transparent electrode 10 is printed on the transparent substrate 1 by an inkjet method.

The transparent electrode 10 printed according to the present embodiment may be formed as a micro lens, that is, a hemispherical shape of a micro size, as shown in FIG. As described below, the microlens transmits incident light without loss and increases the surface area of the interface between the transparent electrode 10 and the n-type semiconductor 20 to allow more electrons to be excited. Such a micro lens-shaped transparent electrode 10 can be easily formed by an inkjet method.

That is, in the process of printing the ink containing the material constituting the transparent electrode 10 by the inkjet method, the first ink droplet 12 and the second ink droplet 14 adjacent to the difference in the ejection time, the first The second ink droplets 14 are discharged while the ink droplets 12 are cured to maintain a hemispherical shape.

Therefore, in order to form the microlens-shaped transparent electrode 10 according to the present embodiment, the first ink droplet 12 is discharged 102 and the first ink droplet 12 adhered to the transparent substrate 1. After it is made to cure (104), the second ink droplet 14 is ejected (106) adjacent to the first ink droplet 12.

The curing of the ink droplets may be performed by simply ejecting the droplets at predetermined time intervals, or drying the adhered ink droplets by heating the substrate or irradiating the ink droplets with ultraviolet rays. In order to discharge the second ink droplets 14 after the first ink droplets 12 have been cured, a time interval such that the first ink droplets 12 are cured as shown in FIG. Ink droplets may be discharged to the first ink droplets 12 so as to be spaced apart by a predetermined interval, and after the first ink droplets 12 have been cured, the second ink droplets may be discharged into the spaces between the first ink droplets 12. It is also possible to discharge 14).

After discharging the ink droplets so as to be spaced apart by a predetermined interval, in order to discharge the ink droplets again between the adhering ink droplets in consideration of the ejection interval of the ink droplets, the size of the space between the adhering ink droplets, the curing time of the ink droplets, and the like. It is good to determine the most efficient discharge method.

Next, the n-type semiconductor 20 is coated to cover the transparent electrode 10 stacked on the transparent substrate 1 as shown in FIG. 3D, and the n-type semiconductor as shown in FIG. 3E. P-type semiconductor 30 is deposited 110 to cover 20. As a result, a p-n bond of the solar cell is formed, and a method of coating or depositing the n-type and p-type semiconductors 20 and 30 may be a conventional general method, and thus a detailed description thereof will be omitted.

Next, as shown in FIG. 3F, a metal to be used as the electrode 40 is deposited on the transparent electrode 10 and the p-type semiconductor 30 (120). A method of depositing the metal of the electrode 40 may also be used because a conventional general method may be omitted.

As a result, the solar cell having the basic structure of the solar cell according to the present embodiment, that is, the microlens-shaped transparent electrode 10 easily formed by the inkjet method is completed. Furthermore, the condenser lens may also be easily implemented by forming the condensing layer 50 by applying the microlens forming process using the inkjet method.

That is, as shown in FIG. 3G, an inkjet method is applied to the surface of the transparent substrate 1 to stack the light collecting layer 50 having a microlens shape (130). In order to stack the light collecting layer 50 having a microlens shape according to the present embodiment, similarly to the above-described process of forming the transparent electrode 10, a first material containing a material constituting the light collecting layer 50, such as a transparent polymer ink, is included. After discharging the ink droplets 52 (132) and allowing the first ink droplets 52 adhering on the transparent substrate 1 to harden (134), the second ink is adjacent to the first ink droplets 52. The droplet 54 is discharged (136).

As a result, a transparent hemispherical microlens condensing lens layer is formed. As will be described later, by forming hemispherical micro lenses on both sides of the transparent substrate 1, the performance of the solar cell is improved by preventing the loss of incident light and allowing more electrons to be excited without using a separate light collecting device. You can.

4 is a flowchart illustrating a method of manufacturing a solar cell according to a second embodiment of the present invention.

The above-described first embodiment is characterized in that the microelectrode-shaped transparent electrode 10 is formed by using the inkjet method, and the present embodiment forms the microlens-shaped light collecting layer 50 by using the inkjet method. It is characterized by one. Therefore, the present embodiment can be applied not only to the superstrate type but also to the substrate type solar cell in which the transparent electrode 10 is not used.

That is, in order to manufacture a solar cell according to the present embodiment, a core substrate in which n-type semiconductors 20 and p-type semiconductors 30 are sequentially stacked is provided (200), and n-type semiconductors 20 and After forming the electrode 40 electrically connecting the p-type semiconductor 30 (210), the light collecting layer 50 having a microlens shape is laminated by discharging transparent polymer ink or the like on the surface of the core substrate by an inkjet method ( 220).

Here, the core substrate is a basic structure of the solar cell before the light collecting layer 50 is stacked. In the case of the super straight type, the transparent electrode 10, the n-type semiconductor 20, The p-type semiconductor 30 is stacked, and in the case of the substrate type, the p-type semiconductor 31 is stacked on the silicon substrate 21 in FIG. 7 to be described later, which will be described later with reference to FIG. 7.

In the case of the super-straight type, the core substrate prints the transparent electrode 10 on the surface of the transparent substrate 1 by inkjet method 202 and covers the transparent electrode 10 as described above. ) And the p-type semiconductor 30 is coated to cover the n-type semiconductor 20 (206), and then the electrode 40 is deposited on the transparent electrode 10 and the p-type semiconductor 30. By forming (210).

In addition, as described above, in the process of printing the transparent electrode 10 on the transparent substrate 1 by an inkjet method, the transparent electrode 10 may be implemented in the form of a micro lens, which is a material constituting the transparent electrode 10. The first ink droplets 12 containing 203 were discharged (203), and the first ink droplets 12 stuck on the transparent substrate 1 were cured (204), and then the first ink droplets 12 were It can be realized by ejecting (205) the second ink droplet 14 adjacently.

After the core substrate is formed as described above, the light collecting layer 50 having the microlens shape is laminated by applying an inkjet method to the surface of the core substrate according to the present embodiment. That is, the first ink droplet 52 containing the material constituting the light collecting layer 50, such as transparent polymer ink, is discharged (222), and the first ink droplet 52 adhering on the core substrate is cured. Thereafter, the second ink droplet 54 is discharged 226 adjacent to the first ink droplet 52 (226). As a result, a transparent hemispherical microlens condensing lens layer is formed.

5 is a cross-sectional view showing a solar cell according to a first embodiment of the present invention, Figure 6 is an enlarged cross-sectional view of the solar cell shown in FIG. 5 and 6, a transparent substrate 1, a transparent electrode 10, an n-type semiconductor 20, a p-type semiconductor 30, an electrode 40, and a light collecting layer 50 are illustrated. have.

The present embodiment is a super-straight type solar cell manufactured according to the above-described solar cell manufacturing method, the micro-lens-shaped transparent electrode 10 and the light collecting layer 50 are stacked on both sides of the transparent substrate 1, The n-type semiconductor 20 and the p-type semiconductor 30 are sequentially stacked on the transparent electrode 10. Each of the transparent electrode 10 and the light collecting layer 50 may be easily implemented in a micro lens shape by an inkjet method.

By forming the microlens-shaped transparent electrode 10 and the light collecting layer 50 on both sides of the transparent substrate 1 as described above, the loss of incident light is prevented and more electrons are excited to improve the performance of the solar cell. have.

That is, as shown in FIG. 6 in which the path of light incident is indicated by an arrow, the incident light is condensed without diffuse reflection due to the light condensing layer 50 formed in the lens shape on the surface of the transparent substrate 1 to increase the incident efficiency. Light transmitted through the transparent substrate 1 is not only transmitted to the n-type semiconductor 20 again without diffuse reflection due to the lens-shaped transparent electrode 10, but also the n-type semiconductor 20 and the p-type semiconductor ( 30) Since the interfacial surface area between the substrates increases, more electrons can be excited, thereby increasing the efficiency of the solar cell.

7 is a cross-sectional view showing a solar cell according to a second preferred embodiment of the present invention. Referring to FIG. 7, a core substrate 2, a silicon substrate 21, a p-type semiconductor 31, an electrode 41, and a light collecting layer 51 are illustrated.

The present embodiment is characterized in that the light collecting efficiency is improved by laminating a light collecting layer 51 having a microlens shape on a substrate type solar cell. That is, after the silicon substrate 21 is used as the n-type semiconductor and the p-type semiconductor 31 is stacked thereon to form the core substrate 2, the surface of the core substrate 2 is condensed in a micro lens shape. Layer 51 is laminated.

As described above, the light collecting layer 51 having a microlens shape may be embodied by discharging ink containing a material constituting the light collecting layer 51 such as a transparent polymer ink by an inkjet method. Manufacturing of the solar cell is completed by depositing and electrically connecting the electrodes 41 to the silicon substrate 21 and the p-type semiconductor 31, respectively.

Meanwhile, in the case of the super straight type, the core substrate may be formed by stacking the transparent electrode 10, the n-type semiconductor 20, and the p-type semiconductor 30 on the transparent substrate 1, and the transparent electrode 10. As described above, the silver inkjet method may be implemented in a micro lens shape.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention.

According to a preferred embodiment of the present invention as described above, by implementing the transparent electrode and / or the light collecting layer in a micro hemispherical lens shape using the inkjet method can form a high efficiency light collecting device, and transmits light without loss In addition, the interfacial surface area of the transparent electrode can be increased to contribute to many electron excitations.

In addition, it is possible to reduce the solar cell manufacturing cost by forming a condenser lens and a transparent electrode using an inkjet method rather than a conventional deposition process.

Claims (20)

Forming a microlens-shaped transparent electrode on one surface of the transparent substrate by an inkjet method; Sequentially coating an n-type semiconductor and a p-type semiconductor to cover the transparent electrode; And And depositing an electrode on the transparent electrode and the p-type semiconductor. delete The method of claim 1, Forming the transparent electrode, Ejecting a first ink droplet containing a material constituting the transparent electrode on the transparent substrate; Curing the first ink droplets; And And discharging a second ink droplet containing a material constituting the transparent electrode adjacent to the first ink droplet. The method of claim 1, After the deposition step, And stacking a light collecting layer having a microlens shape on the other surface of the transparent substrate. The method of claim 4, wherein The lamination step, A solar cell manufacturing method comprising the step of printing the light collecting layer by an inkjet method. The method of claim 5, The lamination step, Ejecting a first ink droplet containing a material constituting the light collecting layer onto the transparent substrate; Curing the first ink droplets; And And discharging a second ink droplet containing a material constituting the light collecting layer adjacent to the first ink droplet. providing a core substrate in which n-type semiconductors and p-type semiconductors are sequentially stacked; Forming an electrode electrically connecting the n-type semiconductor and the p-type semiconductor; And Forming a light collecting layer of the micro-lens shape on the surface of the core substrate by an inkjet method. The method of claim 7, wherein The core substrate, Printing a transparent electrode on one surface of the transparent substrate by an inkjet method; And a step of sequentially coating the n-type semiconductor and the p-type semiconductor to cover the transparent electrode. The method of claim 8, The electrode forming step, And depositing the electrode on the transparent electrode and the p-type semiconductor. The method of claim 8, The printing step, Forming the transparent electrode in the shape of a micro lens solar cell manufacturing method comprising the. The method of claim 10, The printing step, Ejecting a first ink droplet containing a material constituting the transparent electrode on the transparent substrate; Curing the first ink droplets; And And discharging a second ink droplet containing a material constituting the transparent electrode adjacent to the first ink droplet. delete The method of claim 7, wherein Forming the light collecting layer, Discharging a first ink droplet containing a material constituting the light collecting layer onto the core substrate; Curing the first ink droplets; And And discharging a second ink droplet containing a material constituting the light collecting layer adjacent to the first ink droplet. A transparent substrate; A micro lens-shaped transparent electrode stacked on one surface of the transparent substrate by an inkjet method; An n-type semiconductor covering the transparent electrode; A p-type semiconductor covering the n-type semiconductor; A solar cell comprising the electrode deposited on the transparent electrode and the p-type semiconductor. delete The method of claim 14, The solar cell further comprises a micro-lens condensing layer stacked on the other surface of the transparent substrate by an inkjet method. a core substrate in which n-type semiconductors and p-type semiconductors are sequentially stacked; A plurality of electrodes deposited on the core substrate and electrically connecting the n-type semiconductor and the p-type semiconductor; A solar cell comprising a light collecting layer of a microlens shape formed on the surface of the core substrate by an inkjet method. The method of claim 17, The core substrate, A transparent substrate; A transparent electrode stacked on one surface of the transparent substrate by an inkjet method; An n-type semiconductor covering the transparent electrode; And a p-type semiconductor covering the n-type semiconductor. The method of claim 18, The plurality of electrodes, A solar cell comprising electrodes deposited on the transparent electrode and the p-type semiconductor, respectively The method of claim 18, The transparent electrode is a solar cell, characterized in that formed in the shape of a micro lens.

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