JP2014086576A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply stress capable of enhancing photoelectric conversion efficiency to a non-light receiving surface side of a solar cell element.SOLUTION: A solar cell module includes: a solar cell element having a light receiving surface and a non-light receiving surface; and light transmissive stress application means that has a plurality of protrusions at a principal plane and contacts the plurality of protrusions to the light receiving surface of the solar cell element.

Description

  The present invention relates to a solar cell module.

  Conventionally, in order to improve the mechanical strength of a solar cell element, a solar cell module in which a peripheral portion of the solar cell element is reinforced with a frame is known.

  For example, as in Patent Document 1, a structure of a solar cell module that fixes a solar cell element to a frame by pressing the peripheral portion of the solar cell element from the front and back with a holding portion of the frame is known.

JP 2006-1000063 A

  On the other hand, it is known that when a strain is applied to a semiconductor by applying a stress from the outside, the electrical characteristics change.

  For example, by applying an appropriate stress to the CuO-based solar cell element from the outside by four-point bending or the like, the Schottky barrier changes and the maximum output in photoelectric conversion can be improved. Are known.

  However, in the structure of the solar cell module in which the solar cell element as in Patent Document 1 is simply fixed to the frame, only the central portion of the solar cell module is warped by its own weight. It is difficult to sufficiently increase the photoelectric conversion efficiency of the module.

  The solar cell module of the present invention has a solar cell element having a light receiving surface and a non-light receiving surface, a plurality of convex portions on a main surface, and the plurality of convex portions are brought into contact with the light receiving surface of the solar cell element. Translucent stress applying means.

  According to the solar cell module of the present invention, a stress capable of increasing the photoelectric conversion efficiency can be applied to the light receiving surface side of the solar cell element.

It is a cross-sectional schematic diagram of the solar cell element and stress application means in one embodiment of the solar cell module of the present invention. It is the plane schematic diagram which planarly viewed the stress application means in one Embodiment of the solar cell module of this invention from the main surface side. It is the plane schematic diagram which planarly viewed the stress application means in other embodiment of the solar cell module of this invention from the main surface side. In the solar cell module using the stress application means of FIG. 2, it is a plane schematic diagram when the light-receiving surface side of a solar cell element is observed with an interferometer. In the solar cell module using the stress application means of FIG. 3, it is a plane schematic diagram when the light-receiving surface side of a solar cell element is observed with an interferometer. It is an expanded cross-sectional schematic diagram of the main surface vicinity of the stress application means in one Embodiment of the solar cell module of this invention.

(Solar cell module)
Hereinafter, an embodiment of a solar cell module of the present invention will be described with reference to the drawings.

<Solar cell element>
As the solar cell element used in the present embodiment, for example, a thin film solar cell element having a configuration including a substrate, a first electrode layer, a light absorption layer, a semiconductor layer, and a second electrode layer. (Not shown), but is not limited to this, and may be a silicon-based solar cell or the like.

  Here, the substrate is used to support the solar cell element, and only needs to satisfy rigidity and smoothness. Examples of the material used for the substrate include glass, ceramics, hard resin, sapphire, and SUS. The metal etc. are mentioned.

  And a frame etc. are provided so that the peripheral part of a solar cell element may be enclosed, and what combined a solar cell element and a flame | frame becomes a solar cell module.

<Solar cell module>
According to the embodiment of the solar cell module of the present invention, the solar cell element having the light receiving surface and the non-light receiving surface, the plurality of convex portions on the main surface, and the plurality of convex portions on the light receiving surface of the solar cell element. A translucent stress applying means in contact therewith.

  As shown in FIG. 1, a solar cell element 1 having a light receiving surface 1a and a non-light receiving surface 1b, and a plate-like stress applying means 2 having a plurality of convex portions 2a on the main surface are prepared separately.

  And it arrange | positions with respect to the light-receiving surface 1a of the solar cell element 1 so that the some convex part 2a of the stress application means 2 may be pressed.

  Here, the solar cell element 1 and the stress applying means 2 may be those in which the light receiving surface 1a of the solar cell element 1 and the main surface of the stress applying means 2 are fixed by an adhesive, or the solar cell. The outer edge portion of the element 1 and the outer edge portion of the stress applying means 2 may be fixed by a frame or the like.

  Thereby, the stress which can improve a photoelectric conversion efficiency can be applied from the light-receiving surface 1a side of the solar cell element 1. FIG.

  This is by applying an appropriate stress to the solar cell element 1 to impart a strain and thereby lowering the resistance value of the semiconductor film of the solar cell element 1 (piezoresistance effect), whereby the photoelectric conversion efficiency of the solar cell element 1 is reduced. This is thought to be due to the fact that

  In order to arrange such a stress applying means 2 on the light receiving surface 1a side of the solar cell element 1, it is necessary not to prevent the incidence of light on the light receiving surface 1a side of the solar cell element 1, and stress It is necessary that the convex part 2a of the applying means 2 does not damage the upper electrode layer of the solar cell element 1.

  For this reason, in particular, if the stress applying means is a light receiving surface side panel that covers the light receiving surface side, the stress applying means and the light receiving surface side panel can be integrated with each other. This is preferable in that it can be reduced.

  Furthermore, according to the embodiment of the solar cell module of the present invention, it is preferable that the solar cell element is distorted at a position where the plurality of convex portions are in contact with the light receiving surface of the solar cell element.

  That is, the strain 3 is uniformly applied on the solar cell element 1 as shown in FIG. 4 corresponding to the plurality of convex portions 2a provided on the main surface of the plate-like stress applying means 2 as shown in FIG. Therefore, high photoelectric conversion efficiency can be obtained. Alternatively, corresponding to the plurality of convex portions 2a provided on the main surface of the plate-like stress applying means 2 as shown in FIG. 3, the strain 3 is uniformly applied on the solar cell element 1 as shown in FIG. Therefore, high photoelectric conversion efficiency can be obtained.

  In addition, about the form of arrangement | positioning of the some convex part 2a, if the distortion 3 of a suitable magnitude | size can be obtained more, it will not be restrict | limited to these arrangement | positioning.

  Furthermore, according to the embodiment of the solar cell module of the present invention, it is preferable that the pressure at which each of the plurality of convex portions comes into contact with the light receiving surface of the solar cell element is substantially uniform within the light receiving surface.

  That is, the stress 3 due to the plurality of convex portions 2a is uniformly distributed not only to a specific portion of the solar cell element 1 but also to the solar cell element 1, so that the magnitude of the strain 3 due to the stress is constant in the plane. Can be.

  For example, in FIGS. 2 and 3, the convex portions 2a are regularly formed on the main surface of the stress applying means 2 for the purpose of making the stress distribution applied from the stress applying means 2 to the solar cell element 1 uniform. It is arranged.

  Thereby, photoelectric conversion efficiency can be improved uniformly in a state where there is no bias in the in-plane direction of the solar cell element 1.

  For such a stress distribution, the distribution of the strain 3 can be observed by using an interferometer, for example.

  In this case, light 3 is applied from the light receiving surface 1 a side, and the distortion 3 is observed by interference fringes (not shown) on the light receiving surface 1 a of the solar cell element 1.

  The interval between the interference fringes is determined by the wavelength of the light source and the incident angle, and can be used as a contour line. Therefore, the degree of the magnitude of the strain 3 can be observed from the light receiving surface side of the solar cell element 1.

  Furthermore, according to embodiment of the solar cell module of this invention, it is preferable that a convex part is so high that it is located in the outer edge part side of a solar cell module.

  As the solar cell element 1 becomes closer to the center, the weight due to its own weight increases, so that the height H of the convex portion 2a becomes higher as it is located on the outer edge side of the solar cell module 10, as shown in FIG. That is, by setting the height H1> the height H2> the height H3, the stress from each convex portion 2a can be made constant.

Thereby, even if the own weight of the solar cell element 1 is a relatively light outer edge side, the same level of stress as that of the central part side where the own weight of the solar cell element 1 is relatively heavy is obtained by increasing the convex portion 2a. Therefore, the same strain 3 can be obtained.

  The height H of the convex portion 2a is in the range of 0.1 to 1 mm, so that no unnecessary gap is formed between the solar cell element 1 and the stress applying means 2, and the solar cell module 10 is not thickened. Is preferable.

  Furthermore, according to embodiment of the solar cell module of this invention, it is preferable that the space | interval of vertex is so wide that a some convex part is located in the outer edge part side of a solar cell module.

  As the solar cell element 1 becomes closer to the center, the weight due to its own weight increases. Therefore, as shown in FIG. 6, the interval W between the vertices of the convex portions 2 a becomes wider as it is located on the outer edge side of the solar cell module 10. That is, when the distance W1 <the distance W2 <the distance W3, the stress at each convex portion 2a can be made constant.

  Thereby, even if the own weight of the solar cell element 1 is relatively light on the outer edge side, by increasing the interval W between the vertices of the protrusions 2a, the solar cell element 1 has the same heavy weight as the central part side. Since a certain degree of stress can be obtained, the strain 3 having the same magnitude can be obtained in the plane of the solar cell element 1.

  Here, the interval W depends on the size of the substrate, but is preferably in the range of 10 to 100 mm because the stress can be easily controlled uniformly.

  As described above, by stabilizing the magnitude of the strain 3 on the light receiving surface 1a side of the solar cell element 1, the resistance value of the semiconductor film of the solar cell element 1 can be maintained low, and the photoelectric conversion efficiency can be improved. Can do.

(Production method)
Hereinafter, the manufacturing method of the solar cell module of this invention is demonstrated.

  The stress applying means 2 may be made of a translucent resin such as a glass plate, an epoxy resin, or a polycarbonate resin, and masking for controlling the height H and the interval W of the convex portions 2a on the main surface of the stress applying means 2. Then, after the main surface is blasted, the convex portion 2a is formed by etching with nitric acid or the like.

  Or the light-receiving surface panel 2 which has the convex part 2a in the main surface of the stress application means 2 can also be formed by metal mold | die shaping | molding.

  Next, the solar cell module is obtained by combining the solar cell element 1 and the stress applying means 2 with a frame or the like in a state where the main surface of the stress applying means 2 is pressed against the light receiving surface 1a side of the solar cell element 1. 10

  Alternatively, the solar cell element 1 and the stress applying means 2 are bonded by EVA or the like while the main surface of the stress applying means 2 is pressed against the light receiving surface 1a side of the solar cell element 1 to form the solar cell module 10. Also good.

  Note that the values of the height H and the interval W of the convex portions 2a described above do not need to be observed in the cross section of the stress applying means 2 as shown in FIG. 6, and the convex portions 2a on the main surface of the stress applying means 2 are described above. What is necessary is just to observe and measure a predetermined range with an interferometer or an AFM.

1: solar cell element 1a: light receiving surface 1b: non-light receiving surface 2: stress applying means (light receiving surface panel)
2a: Convex part 3: Strain 10: Solar cell module H: Height W: Interval

Claims (6)

A solar cell element having a light receiving surface and a non-light receiving surface;
A solar cell module comprising: a plurality of convex portions on a main surface; and translucent stress applying means in which the plurality of convex portions are brought into contact with the light receiving surface of the solar cell element.   The solar cell module according to claim 1, wherein the stress applying means is a light receiving surface side panel covering the light receiving surface side.   The solar cell module according to claim 1 or 2, wherein the solar cell element is distorted at a position where the plurality of convex portions are in contact with the light receiving surface of the solar cell element.   The solar cell module according to any one of claims 1 to 3, wherein a pressure at which each of the plurality of convex portions comes into contact with the light receiving surface of the solar cell element is substantially uniform within the light receiving surface.   The said convex part is a solar cell module in any one of Claims 1-4 whose height is so high that it is located in the outer edge part side of the said solar cell module.   The solar cell module according to any one of claims 1 to 5, wherein the plurality of convex portions have a wider interval between vertices as they are positioned on an outer edge side of the solar cell module.