JPS62101084A - Optical confinement solar battery - Google Patents

Abstract

PURPOSE:To obtain an optical confinement solar battery with a high energy conversion factor by providing concave spaces in the surface part of the solar battery. CONSTITUTION:Spherical spaces 6 which can confine at least a part of incident light and have fine holes are formed near the surface of the P-N semiconductor 1 of a solar battery and a P-N junction 2 is provided along those spheres. Electrodes 3 are provided on the top part and the bottom part of the semiconductor. A light converging member 5 is provided at the position apart a little from the electrodes. The light is converged by the light converging member so as to focus at the light inlet of the concave space 6. Whole light converged by the light converging member is introduced into the concave space 6 and confined in it. The light introduced into the concave space through the light inlet is reflected and absorbed by the inside wall in the concave space repeatedly and the whole light or a part of the light is converted into electrical energy and almost no part of the light escapes outside.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to solar cells, and more particularly to light confinement type solar cells.

(Prior art and its problems) Solar fuel oil is a device that converts light energy into electrical energy, and has achieved effective use of the almost inexhaustible light energy. Nibi is used.

However, the energy conversion efficiency of solar cells is only about 13% in practical use, and there is active research into increasing the energy conversion rate by a small amount.

Typically, a solar cell has a structure in which electrodes (3) are provided on the top and bottom surfaces of a p-n type semiconductor (1), as shown in FIG. In order to achieve high efficiency in such solar cells, the energy collection rate on the surface of the solar cell is controlled.
1, by providing an anti-reflection film (4) or by selectively etching (texturing) the surface layer as shown in Figure 3.・Multiple reflections were used.

However, with these methods it is essentially impossible to get all the light into the solar cell.

In particular, in the portion of the electrode (3) located at γj on the light-receiving surface, light does not reach the semiconductor portion and does not contribute to power generation at all.

(Objective of the Invention) The purpose of the present invention is not to obtain a solar cell that does not have the above-mentioned drawbacks, that is, has a high energy conversion rate (means for solving the problem). Provided is a light confinement type solar cell having a recess space in which at least a part of incident light can be confined in a surface layer part.

The present invention will be explained using the drawings.

FIG. 1 is a diagram showing a schematic cross section of one embodiment of the light confinement type solar cell of the present invention.

In Figure 1, a spherical space with a minute hole that can confine at least part of the incident light is formed near the p-n semiconductor surface of the solar cell, and the p-n junction is formed along this spherical surface. establish. TL poles (3) are provided on the top and bottom of the semiconductor. A light condensing member (5
) is provided. The condensing member is usually preferably a lens or the like.

The light collected from the light collecting member (5) is focused at the light entrance of the recessed space (6). All the light collected by the light collecting member is guided into the recessed space (6), where the light is confined. Since the light that enters the recess space from the light entrance is repeatedly reflected and absorbed by the inner walls of the recess space, all or part of it is converted into electrical energy, and there is almost no escape to the outside.

The semiconductor (1) is usually a pn type semiconductor, and the pn junction (2) is present near the surface layer. Other types of semiconductors may be used as this semiconductor. It is sufficient to use other types of semiconductors to function as solar cells, and the type of semiconductor does not affect it at all. As a p-n type semiconductor, generally used is a type in which the surface of an n-type silicon plate is changed to p-type by a diffusion method. The semiconductor (1) of the present invention can be obtained by the usual method of forming an a-zigzag type silicone plate in the recessed space, and then converting the upper layer surface portion to p-type by a diffusion method.

The recessed space is generally preferably spherical, but may have other shapes. If the concave space is spherical, ideally it will repeat the reflection and absorption of sunlight infinitely (principle of integrating sphere). The condensing member (5) may be a member such as a lens as in the above embodiment, but the light from the condensing member (5) is once received by an optical fiber, and the other end of this fiber is connected to a spherical space. By introducing the light receiving section into the power generating section, the light receiving section and the power generating section can be separated. That is, it is possible to put the semiconductor parts of the solar cell together in a box part and place only the light collecting part in a place that receives good light.

(Effects of the Invention) According to the present invention, by forming a light confinement type solar cell, the light energy incident on the solar cell can be effectively used with considerable efficiency without escaping to the outside. Since the light-receiving area on the surface of solar heavy oil is small, the electrode area can be relatively large, which is advantageous in that the electrode thickness can be made thinner for the same electrode resistance. Since a low-priced material can be used, costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a light confinement type solar cell of the present invention. FIGS. 2 and 3 are schematic cross-sectional views showing conventional solar cells. In the figure, the numbers are as follows: (1)・"o-nノζ1ノhalfin('))---n-n
6 in J (3)... Electrode (4)... Anti-reflection film (5)... Light collecting member (6)... Concave space.

Claims (1)

[Scope of Claims] 1. A light confinement solar cell having a concave space that can confine at least a portion of incident light in the surface layer of the solar cell. 2. The solar cell according to item 1, wherein the recessed space is spherical. 3. The solar cell according to item 1, further comprising a light condensing member provided above the recessed space to collect light at the light entrance of the recessed space.