KR20100137614A - High photovoltaic efficiency optical film for solar cell system - Google Patents

Abstract

PURPOSE: The optical film for the solar power generation module with a superior photoelectric efficiency can consider the photoelectric efficiency. CONSTITUTION: The transparent film(20) is unwound. The ultraviolet hardening-type resin is spread in the embo roll impressed to the configurated side. The shape side is transferred in the transparent film. The baking step operates with the ultra-violet ray lamp apparatus. The adhesive film and protection film are adhered in the up down side.

Description

High Photovoltaic Efficiency Optical Film for Solar Cell System

The present invention relates to an optical film for a photovoltaic module, and more particularly, is attached to at least one side of the front or back surface of the upper glass surface when manufacturing the photovoltaic module and the 2D or 3D Micro Geometric Array shape surface is inscribed An optical film having excellent photoelectric efficiency and a method of manufacturing the same.

A solar cell is a photovoltaic cell that converts photons into electrical energy using a semiconductor, and the principle of converting solar light into electrical energy in a solar cell uses the p-n junction principle of the semiconductor. The structure of a photovoltaic module that is generally used is shown in FIG.

As solar power module costs are a big part of the solar power generation system, and other costs such as module installation cost, land price, and maintenance cost for installing the system are proportional to the total area of the solar cell. Increasing the efficiency of the solar cells also lowers the manufacturing cost of the photovoltaic power generation system, but it is an important variable that lowers the cost of power generation. Therefore, the improvement of the photoelectric efficiency of the solar cell is an important core technology.

A lot of research is being conducted to increase the efficiency of solar cells, and one method is to use a method of maximizing light absorption by texturing the wafer surface. As the texturing method, a chemical etching method, a plasma etching method, a mechanical scribing method, a photolithography method, and the like are used.

Many efforts have been made to improve photovoltaic efficiency in photovoltaic modules, and the representative method is solar cell texturing, but it is not yet applied due to problems of high cost, low efficiency and mass production.

In the photovoltaic module, the top glass is an important material that serves to protect the solar cell (solar cell) by being located on the top surface of the module, but there is a problem in that photoelectric efficiency is lowered by surface reflection. In the glass material for photovoltaic module, low iron tempered glass is used to prevent the module's efficiency from being reduced by iron stain and to maintain the transmittance of visible light more than 91%. There is a problem of not reaching efficiency.

The present invention is to solve the above problems, an optical film produced by applying a UV-curable resin to the embossing roll of the 2D or 3D Micro Geometric Array shape surface is imprinted and hardened after transfer to the transparent film of the shape surface Is attached to at least one side of the front or rear surface of the upper glass surface when manufacturing the solar power module to provide excellent photoelectric efficiency.

In order to achieve the above object, the present invention is a 2D or 3D Micro produced by applying a UV-curable resin to the embossing roll of the 2D or 3D Micro Geometric Array shape surface and transfer the cured to the transparent film based on the shape surface Provided are an optical film in which a geometric array shape is inscribed and a method of manufacturing the same.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The structured shape surface being engraved in the present invention is shown in Figure 3 and is characterized by having a 2D or 3D Micro Geometric Array shape. Here, 2D refers to the shape of a long line in one direction, and 3D refers to the form in which the 3D structure is arranged on the surface. Preferably, the 2D or 3D shaped structure is several nanometers to several millimeters. If it is smaller than a few nanometers, there is a difficulty in manufacturing, and if it is larger than a few millimeters, there is a problem that the optical properties are degraded. For this reason, it is more preferable that the 2D or 3D shaped structure is several micro to several hundred micrometers.

The manufacturing process of the optical film produced according to the present invention is shown in Figure 4 and described in more detail the step of unwinding the transparent film 40 as a substrate; Applying an ultraviolet curable resin to the embossing roll 42 stamped into the structured shape surface by using an ultraviolet curable resin supply device 41 and transferring the shape surface to a transparent film as a base material; Curing by the ultraviolet lamp device 44 after the transfer; Desorption using the strip roll 45; Adhesive laminating the upper and lower surfaces with the adhesive film 46 and the protective film 47 using the lamination (lamination) device 48; And finally, an optical film in which a 2D or 3D Micro Geometric Array shape surface is inscribed and wound by using the winding device 49 is wound. In addition, in the manufacturing of the optical film, the step of applying the UV curable resin to the transparent film as a substrate using a coating apparatus; Stamping the structured shape surface of the embossing roll by pressing the embossing roll with the structured shape surface after application; Curing after being removed by ultraviolet lamp device; Desorption and the step of adhesive lamination on the upper and lower surfaces with an adhesive film and a protective film; And finally manufacturing and winding the optical film in which the 2D or 3D Micro Geometric Array shape surface is indented may be applied.

The transparent film, which is the substrate to be unwound, generally has a thickness of 50 micrometers to 250 micrometers, and preferably a polyester film and a transparent film corresponding thereto, which include excellent light transmittance, transparency, durability, and the like.

In addition, the UV curable resin coated on the embossing roll having a shape surface and cured after being transferred to a transparent film as a substrate is generally characterized in that it comprises a resin alone or a mixture having a refractive index of 1.40 or more.

The transparent glass surface, which has not been treated before, causes 4% to 15% of light loss due to the surface reflection between the light incident surface and the light emitting surface with cells. In addition, photons entering the cell causing photoelectric efficiency are incident almost vertically and pass through the shortest distance corresponding to the thickness of the cell. Due to the characteristics of the cell that absorbs light and generates electricity, the longer the cell passing distance of the photons, the greater the photoelectric efficiency.

As shown in FIG. 2, in the case of the optical film including the structured shape surface of the present invention, the path through the cell can be maximized by minimizing reflection at the surface and changing the path of photons at various angles. This is how the cell can absorb more light.

As described above, in the present invention, the UV-curable resin is applied to the embossing roll of the 2D or 3D Micro Geometric Array shape surface, and the shape surface can be prepared by transferring the cured film to the transparent film as a base material and then hardening it. The optical film thus obtained has an increased photoelectric efficiency than the conventional method (Flat). Therefore, it is possible to manufacture a photovoltaic module having excellent photoelectric efficiency using the optical film produced by the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail. These examples are only some preferred embodiments of the present invention, but the present invention is not limited to the embodiments described below.

Example 1

Like the manufacturing method described above, UV curable resin is applied to the embossing roll having a shape surface, and the shape surface is transferred to a transparent film as a base material and then cured. The shape surface of the 2D Prism having a pitch of 100um and a height of 50um is textured An optical film was prepared.

The prepared optical film was attached to the front surface of the glass plate and finally the photovoltaic module was manufactured. The evaluation of the photoelectric efficiency was measured by the relative photoelectric efficiency compared to 100% of the conventional method. Shown in

[Example 2]

The only difference is that the shape textured on the optical film is a 2D spherical lens having a radius of curvature of 50 μm and a height of 50 μm, and the rest was performed in the same manner as in Example 1.

Example 3

The only thing different from the 3D Prism having a shape textured on the optical film is 100 μm in width and length and 50 μm in height, respectively, and the rest was performed in the same manner as in Example 1.

Example 4

The only difference is that the shape textured on the optical film is a 3D spherical lens having a radius of curvature of 50 μm and a height of 50 μm, and the rest was performed in the same manner as in Example 1.

Comparative Example 1

The conventional method for comparison with the embodiment is only the point of the flat shape of the upper surface of the glass surface having a general thickness of 5 mm or less, and the rest was carried out in the same manner as in Example 1.

The photoelectric efficiency of the optical film for photovoltaic module manufactured by the method of Examples 1 to 4 and Comparative Example 1 was measured, and the results are shown in Table 1 below.

Photoelectric Efficiency (Max Gain) Example 1 132.1% Example 2 112.5% Example 3 149.2% Example 4 119.6% Comparative Example 1 100.0%

From the results of Table 1, the optical film for photovoltaic module manufactured by the method of Examples 1 to 4 has a photoelectric efficiency of about 113% to 149% higher than that of Comparative Example 1 to produce a highly efficient photovoltaic module Can be.

Figure 1 shows the structure of a photovoltaic module that is commonly used.

2 is a cross-sectional view showing an optical film structure manufactured according to the present invention.

Figure 3 is a picture of a 2D or 3D Micro Geometric Array shape made in accordance with the present invention.

Figure 4 illustrates a method of manufacturing an optical film produced according to the present invention.

Claims (5)

The present invention is an optical film for photovoltaic module having excellent photoelectric efficiency and attached to at least one side of the front or rear surface of the upper glass surface when manufacturing the photovoltaic module and the production thereof It is about a method. The optical film of claim 1, wherein the 2D or 3D shaped structure is several nanometers to several millimeters, and more preferably several micrometers to several hundred micrometers. The method of claim 1, wherein the manufacturing of the optical film comprises: unwinding a transparent film as a substrate; Applying an ultraviolet curable resin to an embossing roll imprinted into a structured shape surface using an ultraviolet curing resin supply device and transferring the shape surface to a transparent film as a substrate; Curing after being transferred by an ultraviolet lamp device; Desorption using a strip roll; Adhesive lamination on the upper and lower surfaces with an adhesive film and a protective film using a lamination (lamination) device; And finally winding the optical film in which the 2D or 3D Micro Geometric Array shape surface is imprinted by using a winding device. The method of claim 1, wherein the transparent film is characterized in that the thickness of the film satisfying the properties such as excellent light transmittance, transparency, durability, such as 50 to 250 micrometers polyester film and the corresponding transparent film. The method of claim 1, wherein the UV curable resin comprises a predetermined amount of UV curable oligomer resin, dilution monomer, photoinitiator, dispersant, light stabilizer, solvent, etc., and includes a resin alone or a mixture having a refractive index of 1.40 or more. Characterized in that.

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