JPS63248182A - Solar cell - Google Patents

Abstract

PURPOSE:To utilize the amount of light of incident beams maximally by forming an optical refraction region to a glass substrate or the surface of a cover glass and making incident beams reach to a region contributing to power generation. CONSTITUTION:Incident beams h1 projected toward a region, which does not contribute to power generation, such as a grid electrode are refracted in an optical refraction region A forming a recessed section in a glass 1, and projected to a photoelectric conversion section 3 contributing to power generation. Accordingly, the amount of light of incident beams can be utilized maximally, and the effective efficiency of a solar cell is improved. The recessed section may take a protruding shape, or the combination of the recessed section and the protruding section may be used.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a solar cell, and particularly to a solar cell that efficiently utilizes incident light energy.

[Conventional technology]

FIG. 10 is a partially cutaway side view showing a conventional example of a solar cell, FIG. 10(a) is an explanatory view showing a state in which light is incident from the glass substrate side, and FIG. 10(b) is a cover glass. In Figure 0, which is an explanatory diagram showing a state in which light is incident from the side, 1 is a glass substrate, 2 is a grid electrode on the light incident surface side of the solar cell, 3 is a photoelectric conversion unit, and 4 is a cover glass. Conventional solar cells have a structure in which a solar cell is formed on a glass substrate 1 (
FIG. 10(a)), covering the solar cell with a cover glass,
There is a sealing structure (FIG. 1(b)).

In any of the conventional solar cells described above, when light is incident, the grid electrode 2° on the light incident surface side or the gap between each solar cell when a plurality of solar cell elements are arranged side by side in the horizontal direction, ( Incident light that enters areas that do not contribute to power generation, such as (not shown), does not contribute to power generation and is lost as ineffective energy.

[Problem that the invention seeks to solve]

As described above, in the conventional example, there is a problem that when light is incident on the glass substrate or cover glass surface of a solar cell, the incident light on an area that does not contribute to the main area is lost as ineffective energy.

This invention was made in order to solve the problems of the conventional example as described above, and its purpose is to obtain a solar pond that can make maximum use of the amount of incident light.

[Means for solving problems]

Therefore, in the present invention, a light refraction region (A) is formed on the glass substrate or cover glass surface portion corresponding to a region such as a grid electrode that does not contribute to power generation, and the light refraction region (A) is
The above-mentioned problem is solved and the objective is achieved by refracting the light incident on A) at the light refraction region (A) and making it reach the region that contributes to power generation.

[Effect]

In this invention, light incident on a region of the solar cell that does not contribute to power generation is refracted by the light refraction region (A) and reaches a region that contributes to power generation.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a partially cutaway side view showing a state in which light enters a solar cell in which the light refraction region (A) is concave according to an embodiment of the present invention, and FIG. 2 is a side view showing the light refraction region of FIG. FIG. 3 is an explanatory diagram showing the path of incident light to (A), and is a graph showing data that affects 'fJ to power generation in FIG.
is the graph when the groove inclination angle θ=450, FIG. 3(b) is the graph when θ=600, and FIG. 4 is the graph when the light ray is directly incident on the solar cell in FIG. 2 is a graph showing data contributing to power generation of incident light. 5 to 9 are partially cutaway side views showing a state in which light enters a solar cell according to another embodiment of the present invention, and FIG. 5 shows a convex light refraction area (A) of a glass substrate. Figure 6 shows that the light refraction area (A) of the glass substrate is lens-shaped, and Figure 7 shows that the light refraction area (A) of the cover glass on the side opposite to the light incident side of the cover glass is shaped like a lens.
A) is convex, Figure 8 shows the light refraction area (A) in Figure 7 is concave, and Figure 9 shows the light refraction area (A) on the light incident surface of the cover glass.
FIG. 4 is an explanatory diagram of a combination of a concave light refractive region (A) and a convex light refraction region (A) on the opposite surface;

In the figure, 1 is a glass substrate, 2 is an area that does not contribute to power generation, grid electrodes 1 and 3 are areas that contribute to power generation, which is a photoelectric conversion section, 4 is a cover glass, and A is a grid electrode 2 that is an area that does not contribute to power generation. Glass substrate 1 or cover glass 4 corresponding to
A light refraction region formed on the surface portion, h, is incident light that enters the light refraction region, and h2 is direct light that enters a region that is close to direct power generation.

The same reference numerals throughout the drawings indicate the same or equivalent parts, and the same or equivalent components as in the conventional example are also represented by the same reference numerals.

Next, the operation of the solar cells of each of these embodiments will be explained using diagrams.

In the explanatory diagrams of Figures 1 and 2, glass J^
On the surface of the plate 1 corresponding to the grating electrode 2, a concave groove, particularly a V-shaped groove, which is a light refraction area A, is cut along the grating electrode 2. As shown in FIG. 1, the incident light h1 that has entered the light refraction region A is refracted by the light refraction region A and reaches the photoelectric conversion section 3, which is a region that contributes to power generation.

Next, the above operation will be explained in detail using FIG. 2.

In Fig. 2, θ is the inclination angle of the side surface of the 7-shaped groove, α is the incident angle indicating the inclination from the vertical direction of the incident light h1 that enters the corresponding battery, and θ' is the inclination angle of the incident light h1 to the corresponding battery. The refraction angle at the groove side surface according to Snell's law, n is the refractive index of the glass substrate, W is the width of the grating electrode 2, that is, the width of the figure 7 groove, and t is the distance from the bottom of the groove to the grating type J4i2.

As shown in FIG. 2, when a parallel incident light ray is incident on the solar cell at an angle of incidence α from the perpendicular direction, the angle of incidence of this light ray on the side surface of the groove is (θ+α).

If the refractive index of the glass substrate is n, then according to Snell's law, the refraction angle θ' of this ray is 0'=5in-'(-%1n(0+a))-
-----------Setup (1) is given by n.

Since the refractive index of the glass substrate is n > 1, the light incident on the side surface of the groove is refracted, and if the following condition (2) is satisfied, photoelectric conversion occurs in the area that contributes to power generation. Since the light reaches the grid electrode 2 and does not enter the grid electrode 2, the light that enters the solar cell is effectively used for power generation.

Figures 3(a) and 3(b) graph the results of calculating the values on the right side of equation (2) above, with the horizontal axis plotting Figure 3(a) for the case where the inclination angle is 0 = 450. Incident angle α=00~4
50, and FIG. 3(b) shows the values for the incident angle α=QO~300 for the case of the inclination angle θ=600, and each curve in the figure .2, 1.3
゜1.4, 1.5. The case is shown below.

When θ=450, from Fig. 3(a), α 12° is 1
7. That is, approximately 12 degrees from the direction perpendicular to the solar cell surface.
All the rays within the range reach the region where y occurs, and θ
= 60°, as shown in Figure 3(b), as long as the rays hit the side of the groove, all the points incident on the solar cell contribute to power generation.
You can see that it will lead you to the area where you want to go.

Figure 4 shows the value of the right side of equation (2) calculated for the inclination angle θ = 0 to 90L' in the case where the light is directly incident on the solar cell surface with Ir, that is, the incident angle α = 0. , and the horizontal axis is the inclination angle θ, and the vertical axis is the right side of equation (2), if θ>33°, it can be seen that all the light that perpendicularly enters the solar cell reaches the region that contributes to power generation.

From then on, 9h1! This is an embodiment in which the folding area (A) is V-shaped. Next, embodiments in which the light refraction region (A) has a different shape will be described with reference to FIG. 5 to JJI FIG. 9.

First, in FIG. 5, the light refraction area A is located on the glass substrate l.
It is formed as a convex chevron on the surface. In this case, the incident light h1 that has entered the light refraction region A is refracted in the direction of the arrow in the light refraction region A, and reaches the light center conversion section 3, which is a region that contributes to power generation.

Next, in the 61st % J, the light refraction area A is formed as a lens-like structure on the surface of the glass J^ plate 1. In this case, the light incident on the light refraction area A is refracted in the direction of the arrow and reaches the photoelectric conversion section 3.

Next, in FIG. 7, the light refraction @b3A is formed as a convex portion on the surface of the cover glass 4 on the side opposite to the light incident side. In this case, the light incident on the light refraction area A is refracted in the direction of the arrow and reaches the photoelectric conversion section 3.

Next, in FIG. 8, the light refraction area A is formed as a concave portion on the surface of the cover glass 4 on the side opposite to the light incident side. In this case, the light incident on the light refraction area A is refracted in the direction of the arrow and reaches the photoelectric conversion section 3.

Next, in FIG. 9, the light refraction area A is formed as a concave portion on the surface of the cover glass 4 on the light incident side and a convex portion on the surface opposite to the light incident side. In this case, the light incident on the light refraction area A is refracted in the direction of the arrow and reaches the photoelectric conversion section 3.

In any of the cases shown in FIGS. 1 and 5 to 9, the incident light on the light refraction area A contributes to power generation. It is effectively applied to the photoelectric conversion unit 3, which is the area where the photovoltaic power is measured, and increases the effective efficiency of the solar cell.

〔Effect of the invention〕

As explained above, this invention will greatly contribute to power generation.
Glass substrate b+ corresponding to 'Ki LJi'
< forms a light refraction area A on the cover glass surface, and refracts the incident light to the light refraction area 7.7i in the light refraction area A,
By reaching the region that contributes to power generation, the effective efficiency of the solar cell can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing a state in which light enters a solar cell according to an embodiment of the present invention, and FIG.
FIG. 3 is a graph showing data contributing to power generation in FIG. 2, and FIG.
a) is the graph when θ=450, and FIG. 3(b) is the graph when θ=450.
600, and FIG. 4 is a graph showing data contributing to power generation in the case of vertical incidence of light in FIG. 2. 5 to 9 are partially cutaway side views showing a state in which light enters a solar cell according to another embodiment of the present invention, in which the light refraction region is convex in FIG. The light refraction region is lens-shaped, FIG. 7 shows that the light refraction region of the cover glass is convex, and FIG. 8 shows that the light refraction region of the cover glass is concave.
Figure 9 is an explanatory diagram of each case in which the refraction area of the cover glass is a combination of concave and convex shapes, Figure 10 is a partially cutaway side explanatory diagram showing a conventional example of a solar cell, and Figure 10 (a) is an explanatory diagram showing a state in which light is incident from the glass substrate side, Fig. 10 (
b) is an explanatory diagram showing a state in which light is incident from the cover glass side. 1--Glass substrate 2--Grid electrode 3...Photoelectric conversion section 4--Cover glass 8--Light refraction area

Claims (3)

[Claims] (1) A light refraction region is formed on the glass substrate or cover glass surface corresponding to an area that does not contribute to power generation, such as a grid electrode, and the light incident on the light refraction region is refracted by the light refraction region, thereby contributing to power generation. A solar cell characterized in that it can reach an area where (2) The solar cell according to claim 1, wherein the light refraction region has a concave shape, a convex shape, or a combination thereof. (3) The solar cell according to claim 1, wherein the light refraction region has a lens-like structure.