JPH01219043A - Transparent conductive glass substrate and solar-cell module - Google Patents

Abstract

PURPOSE:To easily and stably form a rugged SnO2 conductive film layer with a reduced loss in the surface reflection of sunbeams on a substrate by growing an SnO2 film on the surface of a transparent glass substrate provided with fine and uniform ruggednesses by sandblast in the vapor phase. CONSTITUTION:The transparent conductive glass substrate 10 has three layers consisting of a transparent glass substrate 12, an SiO2 film layer 14, and an SnO2 film layer 16. Fine and uniform ruggednesses are formed on one side of the substrate 12 by sandblast, and the film layer 14 is formed on the rugged surface of the substrate 12 by the chemical vapor growth method, etc. Since the film layer 14 is used to prevent the elution of alkali from glass when the substrate 12 is based on the soda lime, the layer 14 is made as thin as possible, and the same ruggednesses as those formed on the substrate 12 are formed on its surface. When the SnO2 film layer 16 is formed on the rugged surface by the chemical vapor growth method, the layer is grown in the form of a hexagonal system, the crystal growth rate is varied by the ruggedness, and a rugged surface effective for light diffusion is formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an uneven glass substrate with a transparent conductive film layer that is effective for light diffusion, and more specifically, a glass substrate with fine uniform unevenness formed on the surface by sandblasting. a transparent glass substrate,
The present invention relates to a transparent conductive glass substrate combined with a 5n02 conductive film layer formed by vapor phase growth, and a solar cell module using the same.

[Prior Art] A transparent conductive glass substrate, which is a combination of a transparent glass substrate and a SnO□ conductive film layer, is used, for example, as a substrate for a solar cell module. In order to improve the efficiency of amorphous solar cells, it is important to reduce surface reflection loss so that as much sunlight as possible is absorbed. For this reason, the substrate is made uneven.

There are the following conventional techniques for forming such an uneven glass substrate. One of them is S, which forms the base layer on the glass substrate.
iO is a technique for creating unevenness by dipping, etc. when forming a film layer, and other techniques include 5no.
zl? Some attempts have been made to increase the grain size of crystal grains and provide unevenness by modifying the coating method and coating conditions when forming the W layer.

[Problems to be Solved by the Invention] However, with the above-mentioned conventional techniques, it is difficult to uniformly and stably form irregularities of appropriate dimensions.

Coating methods for forming precise films include chemical vapor deposition and sputtering, but these coating methods are originally intended to form uniform films, and the size of the particles usually formed is small. On the order of a few hundred particles, it is difficult to form particles larger than that. Particularly in the sputtering method, the particles become even finer. Therefore, it is difficult to make the grain size sufficiently large and form uniform unevenness only by changing the coating method and coating conditions, and if you intentionally try to increase the grain size, the efficiency of the coating will deteriorate significantly and it will be difficult to achieve uniformity. .

The purpose of the present invention is to eliminate the drawbacks of the prior art as described above, and to form a SnO2 conductive film layer formed on a transparent glass substrate into uniform irregularities with appropriate dimensions for scattering sunlight, which can be easily and reproducibly produced. An object of the present invention is to provide a transparent conductive glass substrate that can be manufactured stably with good performance.

Another object of the present invention is to provide a solar cell module that can enhance the scattering effect of incident light and achieve high efficiency by using such a transparent conductive glass substrate.

[Means for Solving the Problems] The present invention, which can achieve the above-mentioned objects, includes a transparent glass substrate whose surface has fine and uniform irregularities formed by sandblasting, and a transparent glass substrate formed by vapor phase growth on the irregular surface side. SnO whose crystal grains have a large uneven shape! This is a transparent conductive glass substrate comprising a conductive film layer.

If the transparent glass substrate is a normal glass material such as soda lime, the uneven surface is coated with a film layer of SiO to prevent alkali elution, and then SnO,
Form a conductive film layer.

If the transparent glass substrate is alkali-free, such as borosilicate glass, it is not necessary to provide the SiOx film layer.

The solar cell module has an amorphous silicon layer formed on the 5n02 conductive film layer side of the transparent conductive glass substrate as described above.

[Operation] The SnO film layer formed by chemical vapor deposition grows in a hexagonal system. By forming fine and uniform irregularities on the surface of a transparent glass substrate by sandblasting, SnO,
A speed change occurs in the crystal growth of the film, and the crystal grains exhibit a large uneven shape, making it possible to create a transparent conductive glass substrate that is effective in light diffusion.

A solar cell module using such a transparent conductive glass substrate and forming an amorphous silicon layer thereon has high efficiency because the internal scattering effect is enhanced by the unevenness of large crystal particles and a large amount of incident sunlight can be absorbed.

[Example] FIG. 1 is a sectional view showing an example of a transparent conductive glass substrate according to the present invention. This transparent conductive glass substrate 10 includes a transparent glass substrate 12, a SiO□ film layer 14, and a Snow film layer 1.
It has a three-layer structure with 6.

The transparent glass substrate 12 has fine and uniform irregularities formed on one side thereof by sandblasting. Sandblasting is 300# to 2000 depending on the degree of unevenness required.
An arbitrary particle size and material is selected from among abrasives with a particle size of # order (for example, carborundum, alundum, garnet, chilled steel, etc.). The 5iOt film layer 14 is formed on the uneven surface of the transparent glass substrate 12 by chemical vapor deposition, dipping, or the like. This is necessary when the transparent glass substrate 12 is made of soda lime, etc., and functions to prevent alkaline elution from the glass. Therefore, this SiOx film layer covers the uneven surface of the transparent glass substrate. It should be as thin as possible. As a result, the same irregularities as those formed on the transparent glass substrate 12 are formed on the surface of the S i Ox tIIll 14 as well.

The S n OZ conductive film layer 16 is formed on the uneven surface of the S i O film layer 14 by chemical vapor deposition.

The SnO film grown by chemical vapor deposition develops in a hexagonal system. When fine and uniform irregularities are formed on the substrate side, the speed of crystal growth of the Sn0w film changes,
The crystal grains grow in a large uneven shape, forming an uneven surface that is effective for light diffusion.

In order to effectively scatter sunlight, the pitch between peaks (valleys) should be about 0.1 to 1 μm, and the height (distance between peaks and valleys) should be about half that. It is important to form the unevenness uniformly.

Transparent glass substrate 1 with unevenness formed by sandblasting
The combination of 2 and the snow conductive film layer 16 formed by vapor phase growth fully satisfies these requirements.

FIG. 2 is a sectional view showing another embodiment of the present invention. In this embodiment, unlike the embodiment shown in FIG. 1, the intermediate Sin! If the transparent glass substrate 12 to be used, which is not provided with a film layer, is alkali-free such as borosilicate glass, it is not necessary to form a 340 g film as described above, and the production becomes easier.

FIG. 3 is a sectional view showing an example of a solar cell module using the transparent conductive glass substrate obtained in this manner.

Here, a transparent conductive glass substrate 10 as shown in FIG. 1 is used, and an amorphous silicon layer 18 is formed on the S n Oz conductive film layer 16 side.

Therefore, uniform irregularities with appropriate dimensions exist between the SnO conductive film layer 16 and the amorphous silicon layer 18. Therefore, the amorphous silicon layer 18
The incident light is scattered by the unevenness and is repeatedly reflected inside, increasing the light absorption effect and achieving high efficiency.

[Effects of the Invention] As described above, the present invention forms irregularities on a transparent glass substrate by sandblasting, and then forms S on the irregular surface side by vapor phase growth.
Since the nO conductive film is formed, the Snow crystal particles exhibit a large uneven shape, improving the light scattering effect. Since the unevenness is formed on the transparent glass substrate by the sandblasting method, uniform and fine unevenness can be easily formed. In addition, since it is easy to control the unevenness of the underlying transparent glass substrate, Sn
O, it becomes possible to easily control unevenness due to crystal growth to optimal conditions.

As a result, it is possible to uniformly manufacture irregularities of stable quality and appropriate dimensions, and a good light diffusion effect can be obtained.

Furthermore, since the present invention is a solar cell module in which an amorphous silicon layer is formed on such an appropriately conductive glass substrate, it has a large light scattering effect, increases internal reflection, absorbs as much incident light as possible, and achieves high efficiency. There is an effect that can be done.

[Brief Description of the Drawings] Fig. 1 is a sectional view showing one embodiment of a transparent conductive glass substrate according to the present invention, Fig. 2 is a sectional view showing another embodiment of the invention, and Fig. 3 is a sectional view showing an embodiment of the transparent conductive glass substrate according to the present invention. FIG. 2 is a sectional view showing an example of a solar cell module according to the present invention. DESCRIPTION OF SYMBOLS 10... Transparent conductive glass substrate, 12... Transparent glass substrate, 14-3 ift film layer, 16- SnOz conductive film layer, 18... Amorphous silicon layer. Patent applicant Nippon Sheet Glass Co., Ltd.

Claims (1)

[Claims] 1. A transparent glass substrate with fine and uniform irregularities formed on its surface by sandblasting, and SnO_2 with crystal grains formed by vapor phase growth on the irregular surface side and exhibiting a large irregular shape.
A transparent conductive glass substrate comprising a conductive film layer. 2. Si between the transparent glass substrate and the SnO_2 conductive film layer
The transparent conductive glass substrate according to claim 1, further comprising an O_2 film layer. 3. A solar cell module in which an amorphous silicon layer is formed on the SnO_2 conductive film layer side of the transparent conductive glass substrate according to claim 1 or 2.