CN101312220B - Double-sided light-absorbing power generation thin film solar cell - Google Patents

Abstract

A double-sided light-absorbing power generation thin film solar cell. The thin film solar cell comprises a first transparent substrate, a second transparent substrate, a first solar cell module, a second solar cell module and an insulating layer. The first solar cell module is positioned on the first transparent substrate, and is also provided with a metal layer which is used as one of the electrodes of the first solar cell module and is used as a light reflecting layer. The insulating layer is located on the metal layer of the first solar cell module. The second solar cell module is positioned between the insulating layer and the second transparent substrate.

Description

Thin-film solar cells capable of absorbing light and generating electricity on both sides

technical field

The invention relates to a solar cell, and in particular to a solar cell capable of absorbing light on both sides to generate electricity.

Background technique

With the promotion of government policies and the trend of carbon dioxide reduction, there will be more and more trends to integrate solar cells in buildings in the future. Solar cells can be placed on the roof, but in narrow and densely populated urban areas, the space is limited and the installation area will not be too large. However, the glass curtain wall on the facade of the building has a large area, which is an area that can be used by solar cells in the future. Among them, thin-film solar cells in particular can obtain electricity without losing their appearance. However, how to increase the power of a single solar cell module will be an important issue.

Contents of the invention

In order to solve the above problems, the present invention provides a double-sided thin-film solar cell capable of absorbing light and generating electricity, which includes first and second transparent substrates, first and second solar cell modules, and an insulating layer. The first solar cell module is located on the first transparent substrate, and there is a metal layer therein as one of the electrodes of the first solar cell module and as a light reflection layer. The insulating layer is on the metal layer of the first solar cell module. The second solar cell module is located between the insulating layer and the second transparent substrate. In addition, the above insulating layer may also be replaced by an adhesive layer.

The above-mentioned first and second transparent substrates may be, for example, transparent plastic substrates or transparent glass substrates. The first and/or solar cell unit may be made of amorphous silicon, or a stacked structure made of amorphous silicon and microcrystalline silicon, for example. In addition, the aforementioned gluing step can be performed using ethyl vinylacetate (EVA).

With the above-mentioned structure, the light passes through the transparent plastic substrate or the glass substrate and irradiates the solar battery unit to perform the process of converting light energy into electric energy. In addition, the unabsorbed light can be reflected by the metal layer, so that the light can return to the solar cell unit, and then undergo the process of converting light energy into electrical energy. Therefore, since the metal layer reflects incident light (sunlight and indoor light, etc.), the utilization rate of sunlight and indoor light will be increased, and the power generation efficiency will be further improved.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

1A to 1H are schematic diagrams illustrating the manufacturing process of an embodiment of the present invention;

Figure 2 shows an application example of the double-sided thin-film solar cell capable of absorbing light to generate electricity according to the present invention;

3A to 3H are schematic diagrams illustrating the manufacturing process of another embodiment of the present invention.

Description of main component symbols

100, 200: transparent substrate

102, 202: transparent conductive layer (electrode)

104, 204: the first solar battery unit

106, 206: metal layer (electrode)

108, 208: insulating layer

110, 216: conductive layer/transparent conductive layer (electrode)

112, 214: second solar battery unit

114, 212: transparent conductive layer (electrode)

120, 210: second transparent substrate

130, 220: ethyl vinyl acetate (EVA)

Detailed ways

The present invention mainly proposes a double-sided light-absorbing thin-film solar cell, which uses a reflective metal layer as one of the electrodes of the solar cell to reflect incident light beams to increase the use efficiency of light and increase power generation. efficiency. Embodiments of the present invention will be described in detail below.

As shown in FIG. 1 , firstly, a transparent substrate 100 is provided, and the transparent substrate 100 can be a plastic substrate or a glass substrate. Next, a transparent conductive layer 102, such as a transparent conductive oxide layer (TCO layer) 102, is formed on the transparent substrate 100, and then the transparent conductive layer 102 is patterned to serve as an electrode of a solar cell unit. . The material of the transparent conductive layer may be, for example, ZnO, SnO ₂ or any other suitable material. After the transparent conductive layer is formed on the substrate 100 , the transparent conductive layer can be patterned by means of laser scriber or the like to form the patterned transparent conductive layer 102 .

Next, as shown in FIG. 1B , a plurality of solar cell units 104 are formed on the patterned transparent conductive layer 102 . The solar battery unit 104 is, for example, a three-layer thin film of P-type, I-type (ie, intrinsic type (intrinsic)) and N-type grown amorphous silicon. The solar battery unit 104 can also be a stacked (tandem) structure of six layers (2 groups of P, I and N types) of amorphous silicon and microcrystalline silicon or amorphous silicon (1 group of P, I and N types) Three-layer stack structure with amorphous silicon germanium (2 groups of P, I and N types) or six layers of amorphous silicon and microcrystalline silicon germanium (2 groups of P, I and N types) stacked type (tandem) structure. The solar cell unit 104 is then patterned by means of laser scriber or the like to isolate it from adjacent solar cell units.

Next, as shown in FIG. 1C , after the solar battery unit 104 is formed, a metal layer 106 is continuously formed thereon. The metal layer 106 is then patterned by means of laser scriber or the like to isolate it from adjacent metal electrodes. The metal layer 106 serves as the other electrode of each solar battery unit 104 mentioned above on the one hand, and also serves as a reflective light source on the other hand, which will be described later. For the convenience of description, the transparent conductive layer 102 , the solar cell unit 104 and the metal layer 106 will be referred to as a first solar cell module in some cases below.

The metal layer 106 and the transparent conductive layer 102 are respectively used as electrodes of each solar battery unit 104 after patterning, so that each solar battery unit 104 performs the function of converting light energy into electrical energy. In addition, the patterned electrodes of the metal layer 106 and the transparent conductive layer 102 correspond to each solar battery unit 104 . The corresponding manner here can be performed according to the design, for example, in series or in parallel. Taking FIG. 1C as an example, one solar cell unit 104 corresponds to two adjacent electrodes formed on the transparent conductive layer, and the electrode corresponding to the metal layer of the solar cell unit 104 is not only formed on the solar cell unit 104, but also connected to the corresponding electrode. The electrodes (transparent conductive layer 102 ) corresponding to adjacent solar cells are electrically connected to form a series arrangement.

Next, an insulating layer 108 is formed on the entire metal layer 106, as shown in FIG. 1D. The insulating layer 108 can electrically isolate the electrodes of the metal layer 106 , and can also electrically isolate the first solar cell module and the subsequently formed second solar cell module from each other. The method of forming the insulating layer can be performed using generally known techniques such as deposition, and is not particularly limited. The insulating layer may be, for example, a non-conductive oxide layer, but its material is not particularly limited as long as it can achieve the purpose of electrical insulation.

As shown in FIG. 1E , a conductive layer 110 is continuously formed on the insulating layer 108 . The conductive layer is then patterned to form a plurality of electrodes. These electrodes are easily used as electrodes of solar cells described later. In addition, as mentioned above, the conductive layer 110 may be a transparent conductive oxide layer. In addition, the conductive layer 110 can also be a metal layer, and the metal layer also has a reflective function, which can reflect sunlight back to the solar cell unit.

As shown in FIG. 1F , a plurality of second solar cell units 112 are formed on the patterned conductive layer 110 (electrodes). Likewise, the solar battery unit 112 is, for example, a three-layer film of P-type, I-type (ie, intrinsic type (intrinsic)) and N-type grown amorphous silicon. The solar battery unit 112 can also be a stacked (tandem) structure of six layers (2 groups of P, I and N types) of amorphous silicon and microcrystalline silicon or amorphous silicon (1 group of P, I and N types) Three-layer stack structure with amorphous silicon germanium (2 groups of P, I and N types) or six layers of amorphous silicon and microcrystalline silicon germanium (2 groups of P, I and N types) stacked type (tandem) structure. In this embodiment, the type of the first and second solar battery units 104 and 112 is not limited, and any type of solar battery unit can be used.

Afterwards, a transparent conductive layer 114 is formed on each solar cell unit 112 and patterned into an electrode, as shown in FIG. 1G .

Finally, as shown in FIG. 1H , the second transparent substrate 120 is glued to the transparent conductive layer 114 to complete the packaging of the double-sided thin-film solar cell capable of absorbing light and generating electricity in this embodiment. The second transparent substrate may be a transparent glass substrate. In the above-mentioned gluing step, the second transparent substrate 120 can be glued to the transparent conductive layer 114 by using, for example, an gluing layer of ethyl vinyl acetate (EVA) 130 to complete the package, or other suitable gluing materials can be used. .

FIG. 2 shows an application example of the double-sided thin-film solar cell capable of absorbing light and generating electricity according to the present invention. As shown in Figure 2, the double-sided thin-film solar cells capable of absorbing light and generating electricity are used, for example, as glass curtain walls of buildings.

In the example of FIG. 2 , the glass substrate 120 can be regarded as the outer wall of the glass curtain wall, and the plastic substrate or glass substrate 100 can be regarded as the indoor wall. In the outdoor part, the sunlight passes through the glass substrate 120 and irradiates the solar battery unit 112 to perform a process of converting light energy into electrical energy. In addition, the unabsorbed sunlight can be reflected by the metal layer 106, so that the light returns to the solar cell unit 112, and then undergoes the process of converting light energy into electrical energy.

In the same way, it also has the same effect in the indoor part. The light in the room passes through the transparent plastic substrate or the glass substrate 100 and irradiates the solar battery unit 104 to perform the process of converting light energy into electric energy. In addition, the unabsorbed indoor light can be reflected by the metal layer 106, so that the light returns to the solar cell unit 104, and then undergoes the process of converting light energy into electrical energy. Therefore, since the metal layer can reflect sunlight and indoor light, the utilization rate of sunlight and indoor light will increase, and the power generation efficiency will also be further improved.

In terms of structure, the above purpose can be achieved by using a metal layer, but the above-mentioned conductive layer 110 can also be formed by using a metal layer to improve the reflectivity.

As mentioned above, there is no special limitation on the selection of solar cells. But generally speaking, solar cells made of amorphous silicon have better photoelectric conversion efficiency under low light intensity; The solar cell made of amorphous silicon and microcrystalline silicon can be used for the solar cell unit 112 .

In addition, when considering the weight reduction in the selection of substrates, a transparent plastic substrate can be used on one side and a glass substrate on the other side.

Next, the manufacturing method of another embodiment of the present invention will be described using FIGS. 3A to 3H . In the previous embodiment, each layer of the thin film solar cell is stacked and formed in a continuous process. The next embodiment is to fabricate solar cell modules on a transparent substrate, and then glue two groups of solar cell modules into a double-sided thin-film solar cell capable of absorbing light and generating electricity.

Referring first to FIG. 3A , firstly, a transparent substrate 200 is provided, and the transparent substrate 200 can be a plastic substrate or a glass substrate. Next, a transparent conductive layer 202 is formed on the transparent substrate 200, and then the transparent conductive layer 202 is patterned to serve as an electrode of a solar battery unit. The material of the transparent conductive layer may be, for example, ZnO, SnO ₂ or any other suitable material. Same as the previous embodiment, the transparent conductive layer 202 can be patterned by means of laser engraving or the like to form electrode patterns.

Next, as shown in FIG. 3B , a plurality of solar cell units 204 are formed on the transparent conductive layer 202 . The solar cell unit 204 is, for example, a three-layer thin film of P, I and N types grown on amorphous silicon. The solar battery unit 204 can also be a stacked structure of six layers (two groups of P, I and N types) of amorphous silicon and microcrystalline silicon. Next, as shown in FIG. 3C , after the formation of the solar battery unit 204 , a metal layer or a metal plating film 206 is continuously formed thereon. The metal layer 206 serves as another electrode of the solar battery unit 204 on the one hand, and serves as a reflective light source on the other hand.

Similarly, as shown in FIGS. 3D to 3F , a transparent conductive layer 212 , a plurality of solar cell units 214 and a conductive layer 216 are sequentially formed on the second transparent substrate 210 . The structures and materials of the transparent conductive layer 212 and the solar battery unit 214 are also the same as those described in FIGS. 3A to 3C , and will not be further described here. In addition, the conductive layer 216 of FIG. 3F may be formed of a transparent conductive oxide layer. The conductive layer 216 can also be formed as a reflective metal layer, so that sunlight can be reflected back to the solar battery unit 214 to increase power generation efficiency.

Finally, as shown in FIG. 3G , the two sets of solar cell modules in FIG. 3C and 3F are packaged together by gluing to complete a double-sided light-absorbing thin-film solar cell as shown in FIG. 3H . As in the previous embodiment, this gluing step can utilize ethyl vinyl acetate (EVA) 220 to complete the encapsulation.

To sum up, with the double-sided thin-film solar cell capable of absorbing light and generating electricity of the present invention, light can pass through the transparent plastic substrate or glass substrate and irradiate the solar cell unit to perform the process of converting light energy into electric energy. In addition, the unabsorbed light can be reflected by the metal layer, so that the light can return to the solar cell unit, and then undergo the process of converting light energy into electrical energy. Therefore, since the metal layer can reflect sunlight and/or indoor light, etc., the utilization rate of sunlight and indoor light will be increased, and the power generation efficiency will be further improved.

In addition, the present invention can take advantage of the advantages that amorphous silicon can still absorb most of the spectrum in visible light and generate electricity, and integrate amorphous silicon and amorphous silicon (a-Si)/microcrystalline silicon (μc-Si) two thin-film solar The battery is one, becoming a solar cell element that can absorb light on both sides.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. , so the protection scope of the present invention shall prevail as defined by the appended claims.

Claims (23)

1. A double-sided thin-film solar cell capable of absorbing light and generating electricity, comprising: a first and a second transparent substrate; The first solar cell module is located on the first transparent substrate, and further has a first metal layer, which serves as one of the electrodes of the first solar cell module and serves as a light reflection layer; an insulating layer on the metal layer of the first solar cell module; and The second solar cell module is located between the insulating layer and the second transparent substrate. 2 . The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 1 , wherein the first transparent substrate is a transparent plastic substrate or a transparent glass substrate. 3. The thin-film solar cell capable of absorbing light and generating electricity on both sides as claimed in claim 1, wherein the second transparent substrate is a transparent glass substrate. 4. The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 1, wherein the first solar cell module further comprises: The first transparent conductive layer is patterned into a plurality of electrodes; A plurality of first solar cell units are configured correspondingly to the electrodes; and The first metal layer is patterned into a plurality of electrodes, respectively corresponding to the first solar cell units. 5. The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 1, wherein the second solar cell module comprises: a second transparent conductive layer, patterned into a plurality of electrodes, and located on the insulating layer; A plurality of second solar cell units are located on the second transparent conductive layer and are respectively arranged corresponding to the electrodes of the second transparent conductive layer; and The third transparent conductive layer, patterned into a plurality of electrodes, is located on the second solar battery units and corresponding to the second solar battery units. 6 . The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 5 , further comprising an adhesive layer for bonding the third transparent conductive layer and the second transparent substrate. 7 . The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 6 , wherein the adhesive layer is an ethyl vinyl acetate layer. 8. The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 1, wherein the second solar cell module comprises: a second metal layer patterned into a plurality of electrodes and located on the insulating layer; a plurality of second solar cell units, located on the second metal layer, and respectively corresponding to the electrodes of the second metal layer; and The transparent conductive layer is patterned into a plurality of electrodes, located on the second solar battery units and respectively corresponding to the second solar battery units. 9 . The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 8 , further comprising an adhesive layer for bonding the transparent conductive layer and the second transparent substrate. 10 . The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 9 , wherein the adhesive layer is an ethyl vinyl acetate layer. 11 . 11 . The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 4 , wherein each of the first solar cell units is composed of amorphous silicon, or a stacked structure composed of amorphous silicon and microcrystalline silicon. 12 . The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 5 , wherein each of the second solar cell units is composed of amorphous silicon, or a stacked structure composed of amorphous silicon and microcrystalline silicon. 13 . The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 6 , wherein each of the second solar cell units is composed of amorphous silicon, or a stacked structure composed of amorphous silicon and microcrystalline silicon. 14 . 14. A double-sided thin-film solar cell capable of absorbing light and generating electricity, comprising: a first and a second transparent substrate; The first solar cell module is located on the first transparent substrate, and further has a first metal layer, which serves as one of the electrodes of the first solar cell module and serves as a light reflection layer; a glue layer on the metal layer of the first solar cell module; and The second solar cell module is located between the adhesive layer and the second transparent substrate. 15. The thin-film solar cell with double-sided light absorption and power generation as claimed in claim 14, wherein the first transparent substrate is a transparent plastic substrate or a transparent glass substrate. 16. The double-sided light-absorbing and generating thin-film solar cell as claimed in claim 14, wherein the second transparent substrate is a transparent glass substrate. 17. The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 14, wherein the first solar cell module further comprises: The first transparent conductive layer is patterned into a plurality of electrodes; A plurality of first solar cell units are configured correspondingly to the electrodes; and The first metal layer is patterned into a plurality of electrodes, respectively corresponding to the first solar cell units. 18. The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 14, wherein the second solar cell module comprises: a second transparent conductive layer, patterned into a plurality of electrodes, and located on the adhesive layer; A plurality of second solar cell units are located on the second transparent conductive layer and are respectively arranged corresponding to the electrodes of the second transparent conductive layer; and The third transparent conductive layer, patterned into a plurality of electrodes, is located on the second solar battery units and corresponding to the second solar battery units. 19. The thin-film solar cell capable of absorbing light and generating electricity on both sides as claimed in claim 14, wherein the second solar cell module comprises: a second metal layer patterned into a plurality of electrodes and located on the glued layer; a plurality of second solar cell units, located on the second metal layer, and respectively corresponding to the electrodes of the second metal layer; and The transparent conductive layer is patterned into a plurality of electrodes, located on the second solar battery units and respectively corresponding to the second solar battery units. 20. The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 17, wherein each of the first solar cell units is made of amorphous silicon, or a stacked structure of amorphous silicon and microcrystalline silicon. 21. The thin-film solar cell capable of absorbing electricity on both sides as claimed in claim 18, wherein each of the second solar cells is made of amorphous silicon, or a stacked structure of amorphous silicon and microcrystalline silicon. 22. The double-sided thin-film solar cell capable of absorbing light and generating electricity as claimed in claim 19, wherein each of the second solar cell units is made of amorphous silicon, or a stacked structure made of amorphous silicon and microcrystalline silicon. 23. The thin-film solar cell capable of absorbing light and generating electricity on both sides as claimed in claim 14, wherein the adhesive layer is an ethyl vinyl acetate layer.

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