Patent Publication Number: US-2013240020-A1

Title: Ultraviolet light-absorbing solar module and fabricating method thereof

Description:
RELATED APPLICATIONS 
     This application claims priority to China Application Serial Number 201210080613.1, filed Mar. 16, 2012, which is herein incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a solar module and a fabricating method thereof, and more particularly, to an ultraviolet light-absorbing solar module and a fabricating method thereof. 
     2. Description of Related Art 
     Because the oil reserves in the world have been gradually reducing year by year, energy shortage becomes the global focus problem. Concerning the resource depletion, it is imperative to develop and utilize various kinds of alternative energies. With the rise of environmental awareness, solar energy that has advantages of zero pollution and inexhaustibility receives the most attention in the fields of the alternative energies. Accordingly, solar energy panels are increasingly installed in the locations with ample sunshine such as roofs of buildings, squares, etc. 
     SUMMARY 
     The disclosure provides an ultraviolet light-absorbing solar module for improving power generation efficiency and preventing degradation of a back plate caused by being exposed of ultraviolet light. 
     According to an embodiment of the disclosure, an ultraviolet light-absorbing solar module includes a transparent substrate, a back plate, a plurality of solar cells, a first sealant, and a second sealant. The solar cells are capable of absorbing ultraviolet light, and are disposed between the transparent substrate and the back plate. The light-receiving surfaces of the solar cells face the transparent substrate. The first sealant is located between the transparent substrate and the solar cells. The second sealant is located between the back plate and the solar cells. The first sealant has an ultraviolet light transmission greater than that of the second sealant. 
     According to another embodiment of the disclosure, a fabricating method of an ultraviolet light-absorbing solar module includes providing a transparent substrate; disposing a first sealant on the transparent substrate; disposing a plurality of solar cells on the first sealant; disposing a second sealant on the solar cells; disposing a back plate on the second sealant; and laminating the transparent substrate, the first sealant, the solar cells, the second sealant, and the back plate. The light-receiving surfaces of the solar cells face the transparent substrate, and the solar cells are capable of absorbing ultraviolet light. The first sealant has an ultraviolet light transmission greater than that of the second sealant. 
     Because the ultraviolet light transmission of the first sealant between the solar cells and the transparent substrate is greater than the ultraviolet light transmission of the second sealant between the solar cells and the back plate, the ultraviolet light that passes through the first sealant can be absorbed and utilized by the solar cells, and the ultraviolet light that passes through gaps among the solar cells can be absorbed by the second sealant, thereby preventing degradation of the back plate caused by being exposed of ultraviolet light. 
     It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the disclosure as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1  is a partial sectional view of a first embodiment of an ultraviolet light-absorbing solar module of the disclosure; 
         FIG. 2  is a partial sectional view of a second embodiment of the ultraviolet light-absorbing solar module of the disclosure; 
         FIG. 3  is a partial sectional view of a third embodiment of the ultraviolet light-absorbing solar module of the disclosure; 
         FIG. 4  is a partial sectional view of a fourth embodiment of the ultraviolet light-absorbing solar module of the disclosure; 
         FIG. 5  is a partial sectional view of a fifth embodiment of the ultraviolet light-absorbing solar module of the disclosure; 
         FIG. 6  is a partial sectional view of a sixth embodiment of the ultraviolet light-absorbing solar module of the disclosure; 
         FIG. 7  is a block diagram of an embodiment of a fabricating method of an ultraviolet light-absorbing solar module of the disclosure; and 
         FIG. 8  is a block diagram of another embodiment of a fabricating method of an ultraviolet light-absorbing solar module of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     In order to improve the power generation efficiency of solar panels, an improved solar module that is capable of absorbing certain part of ultraviolet light is provided. Particularly, the ultraviolet light-absorbing solar module provided by the disclosure can prevent degradation of a back plate in the ultraviolet light-absorbing solar module caused by of the exposure under ultraviolet light. 
       FIG. 1  is a partial sectional view of a first embodiment of an ultraviolet light-absorbing solar module of the disclosure. 
     The ultraviolet light-absorbing solar module  100  includes a transparent substrate  110 , a back plate  120 , a plurality of solar cells  130 , a first sealant  140 , and a second sealant  150 . The solar cells  130  are disposed between the transparent substrate  110  and the back plate  120 . The light-receiving surfaces  132  of the solar cells  130  (i.e., surfaces of the solar cells  130  used for receiving solar radiation) face the transparent substrate  110 . The first sealant  140  is located between the transparent substrate  110  and the solar cells  130 . The second sealant  150  is located between the back plate  120  and the solar cells  130 . The transparent substrate  110 , the solar cells  130 , and the back plate  120  can be adhered to each other by the first sealant  140  and the second sealant  150  after heated and laminated. Meanwhile, the solar cells  130  are located between the first sealant  140  and the second sealant  150 , and a portion of the first sealant  140  contacts a portion of the second sealant  150 . 
     The solar cells  130  are capable of absorbing ultraviolet light. In order to allow the ultraviolet light to get into the solar cells  130 , the first sealant  140  located between the transparent substrate  110  and the solar cells  130  preferably has a high ultraviolet light transmission, so as to allow most of the ultraviolet light to pass through the first sealant  140 . In order to protect the back plate  120  from degradation caused by being exposed of the ultraviolet light or prevent the adhesive force between the back plate  120  and the second sealant  150  from decreasing, the second sealant  150  preferably has a low ultraviolet light transmission. In other words, the ultraviolet light transmission of the first sealant  140  is greater than the ultraviolet light transmission of the second sealant  150 . 
     The transparent substrate  110  can be a glass substrate. The back plate  120  can be a plastic substrate. The first sealant  140  and the second sealant  150  include adhesive members that have the same material or different materials. The materials of the adhesive members can include at least one of EVA (ethylene vinyl acetate resin), LDPE (low density polyethylene), HDPE (high density polyethylene), silicone, epoxy, PVB (Polyvinyl Butyral), and TPU (Thermoplastic Polyurethane, TPU), but the disclosure is not limited in this regard. In the embodiment of the disclosure, the first sealant  140  has the adhesive member but does not have any ultraviolet light absorbent. Besides the adhesive member, the second sealant  150  further includes a first ultraviolet light absorbent  160 . The second sealant  150  absorbs the ultraviolet light by the first ultraviolet light absorbent  160 , so as to reduce the radiation dose of the ultraviolet light transmitted to the back plate  120  and thus reduce the affect of the ultraviolet light applying to the back plate  120 . 
       FIG. 2  is a partial sectional view of a second embodiment of the ultraviolet light-absorbing solar module of the disclosure. 
     The ultraviolet light-absorbing solar module  100  includes a transparent substrate  110 , a back plate  120 , a plurality of solar cells  130 , a first sealant  140 , and a second sealant  150 . The solar cells  130  are disposed between the transparent substrate  110  and the back plate  120 . The first sealant  140  is located between the transparent substrate  110  and the solar cells  130 . The second sealant  150  is located between the back plate  120  and the solar cells  130 . 
     The solar cells  130  are capable of absorbing ultraviolet light. The ultraviolet light transmission of the first sealant  140  is greater than the ultraviolet light transmission of the second sealant  150 . In the embodiment of the disclosure, the first sealant  140  and the second sealant  150  can include adhesive members that have the same material or different materials. Both of the first sealant  140  and the second sealant  150  have a first ultraviolet light absorbent  160 . The distribution density of the first ultraviolet light absorbent  160  of the first sealant  140  is smaller than the distribution density of the first ultraviolet light absorbent  160  of the second sealant  150 , so that most of the ultraviolet light can pass through the first sealant  140  and be absorbed and utilized by the solar cells  130 , but is not easy to pass through the second sealant  150  to reach the back plate  120 . In a case, the first sealant  140  directly contact the second sealant  150 , so the first ultraviolet light absorbent  160  of the first sealant  140  can be formed by a portion of the first ultraviolet light absorbent  160  of the second sealant  150  that is spread to the first sealant  140  during the processes of heating and laminating, but the disclosure is not limited in this regard. 
       FIG. 3  is a partial sectional view of a third embodiment of the ultraviolet light-absorbing solar module of the disclosure. 
     The ultraviolet light-absorbing solar module  100  includes a transparent substrate  110 , a back plate  120 , a plurality of solar cells  130 , a first sealant  140 , and a second sealant  150 . The solar cells  130  are disposed between the transparent substrate  110  and the back plate  120 . The first sealant  140  is located between the transparent substrate  110  and the solar cells  130 . The second sealant  150  is located between the back plate  120  and the solar cells  130 . 
     The solar cells  130  are capable of absorbing ultraviolet light. The ultraviolet light transmission of the first sealant  140  is greater than the ultraviolet light transmission of the second sealant  150 . In the embodiment of the disclosure, the second sealant  150  includes an adhesive member and a first ultraviolet light absorbent  160 , and the first sealant  140  includes an adhesive member and a second ultraviolet light absorbent  170 . The adhesive member of the first sealant  140  and the adhesive member of the second sealant  150  can include the same material or different materials. The overlapping range between the absorption band of the first ultraviolet light absorbent  160  and the wave band of the ultraviolet light is greater than the overlapping range between the absorption band of the second ultraviolet light absorbent  170  and the wave band of the ultraviolet light. For example, the wave band of the ultraviolet light that can be absorbed and utilized by a solar module is 300-400 nm. The overlapping range between the absorption band of the second ultraviolet light absorbent  170  in the first sealant  140  and the foregoing wave band of the ultraviolet light that can be absorbed and utilized by a solar module is less, so the ultraviolet light with the wave band of 300-400 nm is rarely absorbed by the second ultraviolet light absorbent  170 . The ultraviolet light with the wave band of 300-400 nm can pass through the first sealant  140  and be absorbed and utilized by the solar cells  130 . The overlapping range between the absorption band of the first ultraviolet light absorbent  160  in the second sealant  150  and the foregoing wave band of the ultraviolet light is more, so the back plate  120  can be prevented from exposing to the ultraviolet light. 
       FIG. 4  is a partial sectional view of a fourth embodiment of the ultraviolet light-absorbing solar module of the disclosure. 
     Besides a transparent substrate  110 , a back plate  120 , a plurality of solar cells  130  capable of absorbing ultraviolet light, a first sealant  140 , and a second sealant  150 , the ultraviolet light-absorbing solar module  100  further includes a third sealant  180  that is disposed between the solar cells  130  and the second sealant  150 . The ultraviolet light transmission of the third sealant  180  is greater than the ultraviolet light transmission of the second sealant  150 . The third sealant  180  acts as a buffer layer between the first sealant  140  and the second sealant  150 , so as to prevent the first ultraviolet light absorbent  160  in the second sealant  150  from directly spreading to the first sealant  140  and being located at light-receiving surfaces  132  of the solar cells  130  after the processes of heating and laminating. Therefore, the ultraviolet light transmission of the first sealant  140  does not be reduced, and the performances of the solar cells  130  do not be affected. 
     The solar cells  130  are located between the first sealant  140  and the third sealant  180 . A portion of the first sealant  140  contacts a portion of the third sealant  180 . The ultraviolet light transmission of the first sealant  140  is greater than the ultraviolet light transmission of the second sealant  150 , so the ultraviolet light can get into the solar cells  130  to be absorbed and utilized. 
     Relationships between the first sealant  140  and the second sealant  150  can be referred to embodiments in  FIG. 1  to  FIG. 3 . In all embodiments introduced below, only changes of the third sealant  180  will be discussed. 
     In the embodiment of the disclosure, the third sealant  180  has an adhesive member but does not have any ultraviolet light absorbent, and the second sealant  150  includes an adhesive member and the first ultraviolet light absorbent  160 . The adhesive member of the third sealant  180  and the adhesive member of the second sealant  150  may have the same material or different materials. The second sealant  150  absorbs the ultraviolet light by the first ultraviolet light absorbent  160 , so as to reduce the radiation dose of the ultraviolet light transmitted to the back plate  120  and thus reduce the affect of the ultraviolet light applying to the back plate  120 . Furthermore, in a case, the thickness of the third sealant  180  is greater than the second sealant  150 , so as to prevent the risk that the first ultraviolet light absorbent  160  gradually spreading to the first sealant  140  after long-term use of the solar module  100 . 
       FIG. 5  is a partial sectional view of a fifth embodiment of the ultraviolet light-absorbing solar module of the disclosure. 
     The ultraviolet light-absorbing solar module  100  includes a transparent substrate  110 , a back plate  120 , a plurality of solar cells  130  capable of absorbing ultraviolet light, a first sealant  140 , a second sealant  150 , and a third sealant  180 . The ultraviolet light transmission of the third sealant  180  is greater than the ultraviolet light transmission of the second sealant  150 . The solar cells  130  are located between the first sealant  140  and the third sealant  180 . The third sealant  180  acts as a buffer layer between the first sealant  140  and the second sealant  150 . Furthermore, in a case, the thickness of the third sealant  180  is greater than the second sealant  150 , so as to prevent the risk that the first ultraviolet light absorbent  160  is gradually spread to the first sealant  140  after long-term use of the solar module  100 . 
     In the embodiment of the disclosure, the third sealant  180  and the second sealant  150  can include adhesive members that have the same material or different materials. Both of the second sealant  150  and the third sealant  180  have a first ultraviolet light absorbent  160 . The distribution density of the first ultraviolet light absorbent  160  of the third sealant  180  is smaller than the distribution density of the first ultraviolet light absorbent  160  of the second sealant  150 , so that most of the ultraviolet light can pass through the third sealant  180  which acts as a buffer layer, but is not easy to pass through the second sealant  150  to reach the back plate  120 . In a case, the third sealant  180  directly contact the second sealant  150 , so the first ultraviolet light absorbent  160  of the third sealant  180  can be formed by a portion of the first ultraviolet light absorbent  160  of the second sealant  150  that is spread to the third sealant  180  during the processes of heating and laminating. Because the third sealant  180  acts as a buffer layer, the probability that the first ultraviolet light absorbent  160  is spread to the first sealant  140  is reduced under restrictions of the third sealant  180 , so that the utilization efficiency of the ultraviolet light of the solar cells  130  do not be affected. 
       FIG. 6  is a partial sectional view of a sixth embodiment of the ultraviolet light-absorbing solar module of the disclosure. 
     The ultraviolet light-absorbing solar module  100  includes a transparent substrate  110 , a back plate  120 , a plurality of solar cells  130  capable of absorbing ultraviolet light, a first sealant  140 , a second sealant  150 , and a third sealant  180 . The ultraviolet light transmission of the third sealant  180  is greater than the ultraviolet light transmission of the second sealant  150 . The solar cells  130  are located between the first sealant  140  and the third sealant  180 . The third sealant  180  acts as a buffer layer between the first sealant  140  and the second sealant  150 . Furthermore, in a case, the thickness of the third sealant  180  is greater than the second sealant  150 , so as to prevent the risk that the first ultraviolet light absorbent  160  is gradually spread to the first sealant  140  after long-term use of the solar module  100 . 
     In the embodiment of the disclosure, the second sealant  150  includes an adhesive member and a first ultraviolet light absorbent  160 , and the third sealant  180  includes an adhesive member and a second ultraviolet light absorbent  170 . The adhesive member of the third sealant  180  and the adhesive member of the second sealant  150  can have the same material or different materials. The overlapping range between the absorption band of the first ultraviolet light absorbent  160  and the wave band of the ultraviolet light is greater than the overlapping range between the absorption band of the second ultraviolet light absorbent  170  and the wave band of the ultraviolet light. The overlapping range between the absorption band of the first ultraviolet light absorbent  160  in the second sealant  150  and the wave band of the ultraviolet light is more, so the back plate  120  can be prevented from exposing to the ultraviolet light. 
     Because the third sealant  180  acts as a buffer layer, the probability that to the first ultraviolet light absorbent  160  is spread to the first sealant  140  is reduced under restrictions of the third sealant  180 , so that the utilization efficiency of the ultraviolet light of the solar cells  130  do not be affected. 
     According to practical test results, the power of the third embodiment of the solar module  100  (i.e., the solar module  100  does not have the third sealant  180 , and the first sealant  140  and the second sealant  150  have different ultraviolet light absorbents) is 265.989 watt, whereas the power of the sixth embodiment of the solar module  100  (i.e., the solar module  100  further includes third sealant  180 ) is 266.819 watt. Accordingly, the third sealant  180  that acts as a buffer layer can really reduce the probability that the first ultraviolet light absorbent  160  is spread to the first sealant  140  under restrictions of the third sealant  180 . 
       FIG. 7  is a block diagram of an embodiment of a fabricating method of an ultraviolet light-absorbing solar module of the disclosure. 
     In step s 10 , a transparent substrate is provided. The transparent substrate can be a glass substrate. 
     In step s 12 , a first sealant is disposed on the transparent substrate. The first sealant  140  preferably has a high ultraviolet light transmission, so as to allow most of the ultraviolet light to pass through the first sealant  140 . The first sealant  140  includes an adhesive member, and materials of the adhesive member can include at least one of EVA (ethylene vinyl acetate resin), LDPE (low density polyethylene), HDPE (high density polyethylene), silicone, epoxy, PVB (Polyvinyl Butyral), and TPU (Thermoplastic Polyurethane, TPU), but the disclosure is not limited in this regard. 
     In step s 14 , a plurality of solar cells are disposed on the first sealant. The solar cells are capable of absorbing ultraviolet light, and light-receiving surfaces of the solar cells face the transparent substrate. 
     In step s 16 , a second sealant is disposed on the solar cells. The solar cells are located between the first sealant and the second sealant. The light-receiving surfaces of the solar cells directly contact the first sealant, and other surfaces opposite to the light-receiving surface of the solar cells directly contact the second sealant. 
     The second sealant  16  includes an adhesive member, and materials of the adhesive member can include at least one of EVA (ethylene vinyl acetate resin), LDPE (low density polyethylene), HDPE (high density polyethylene), silicone, epoxy, PVB (Polyvinyl Butyral), and TPU (Thermoplastic Polyurethane, TPU), but the disclosure is not limited in this regard. The second sealant can further include a first ultraviolet light absorbent. 
     The ultraviolet light transmission of the first sealant is greater than the ultraviolet light transmission of the second sealant, so that the solar cells can absorb and utilize the ultraviolet light. The first sealant can have an adhesive member but does not have any ultraviolet light absorbent. Alternatively, the first sealant can include a first ultraviolet absorbent, and the distribution density of the first ultraviolet light absorbent of the first sealant is smaller than the distribution density of the first ultraviolet light absorbent of the second sealant. Alternatively, the first sealant can include a second ultraviolet absorbent, and the overlapping range between the absorption band of the first ultraviolet light absorbent of the second sealant and the wave band of the ultraviolet light is greater than the overlapping range between the absorption band of the second ultraviolet light absorbent of the first sealant and the wave band of the ultraviolet light. 
     In step s 18 , a back plate is disposed on the second sealant. The back plate can be a plastic substrate. The second sealant can absorb most of the ultraviolet light and thus reduce the radiation dose of the ultraviolet light transmitted to the back plate, so as to prevent the back plate from degradation caused by being exposed of the ultraviolet light or prevent the adhesive force between the back plate and the second sealant from decreasing. 
     Finally, in step s 20 , the transparent substrate, the first sealant, the solar cells, the second sealant, and the back plate are laminated. In step s 20 , the transparent substrate is further heated. That is, the transparent substrate is the component that is directly heated in step s 20 . In a case, the heating temperature is about 140-160 degrees Celsius. Because the solar cells are arranged separately, a portion of the first sealant directly contacts a portion of the second sealant after laminating. 
       FIG. 8  is a block diagram of another embodiment of a fabricating method of an ultraviolet light-absorbing solar module of the disclosure. 
     In step s 30 , a transparent substrate is provided. The transparent substrate can be a glass substrate. 
     In step s 32 , a first sealant is disposed on the transparent substrate. The first sealant  140  preferably has a high ultraviolet light transmission, so as to allow most of the ultraviolet light to pass through the first sealant  140 . The first sealant  140  includes an adhesive member, and materials of the adhesive member can include at least one of EVA (ethylene vinyl acetate resin), LDPE (low density polyethylene), HDPE (high density polyethylene), silicone, epoxy, PVB (Polyvinyl Butyral), and TPU (Thermoplastic Polyurethane, TPU), but the disclosure is not limited in this regard. 
     In step s 34 , a plurality of solar cells are disposed on the first sealant. The solar cells are capable of absorbing ultraviolet light, and light-receiving surfaces of the solar cells face the transparent substrate. 
     In step s 36 , a third sealant is disposed on the solar cells. The solar cells are located between the first sealant and the third sealant. The light-receiving surfaces of the solar cells directly contact the first sealant, and other surfaces opposite to the light-receiving surface of the solar cells directly contact the third sealant. 
     The third sealant includes an adhesive member, and materials of the adhesive member can include at least one of EVA (ethylene vinyl acetate resin), LDPE (low density polyethylene), HDPE (high density polyethylene), silicone, epoxy, PVB (Polyvinyl Butyral), and TPU (Thermoplastic Polyurethane, TPU), but the disclosure is not limited in this regard. 
     In step s 38 , a second sealant is disposed on the third sealant. The third sealant acts as a buffer layer between the first sealant and the second sealant. The second sealant include an adhesive member, and materials of the adhesive member can include at least one of EVA (ethylene vinyl acetate resin), LDPE (low density polyethylene), HDPE (high density polyethylene), silicone, epoxy, PVB (Polyvinyl Butyral), and TPU (Thermoplastic Polyurethane, TPU), but the disclosure is not limited in this regard. The second sealant can further include a first ultraviolet light absorbent. 
     The ultraviolet light transmission of the first sealant is greater than the ultraviolet light transmission of the second sealant, so that the solar cells can absorb and utilize the ultraviolet light. The ultraviolet light transmission of the third sealant that acts as a buffer layer is greater than the ultraviolet light transmission of the second sealant, so that most of the ultraviolet light is absorbed by the second sealant. 
     The first sealant or the third sealant can have an adhesive member but does not have any ultraviolet light absorbent. Alternatively, the first sealant or the third sealant can include a first ultraviolet absorbent, and the distribution density of the first ultraviolet light absorbent of the first sealant or the third sealant is smaller than the distribution density of the first ultraviolet light absorbent of the second sealant. Alternatively, the first sealant or the third sealant can include a second ultraviolet absorbent, and the overlapping range between the absorption band of the first ultraviolet light absorbent of the second sealant and the wave band of the ultraviolet light is greater than the overlapping range between the absorption band of the second ultraviolet light absorbent of the first sealant or the third sealant and the wave band of the ultraviolet light. 
     In step s 40 , a back plate is disposed on the second sealant. The back plate can be a plastic substrate. The second sealant can absorb most of the ultraviolet light and thus reduce the radiation dose of the ultraviolet light transmitted to the back plate, so as to prevent the back plate from degradation caused by being exposed of the ultraviolet light or prevent the adhesive force between the back plate and the second sealant from decreasing. 
     Finally, in step s 42 , the transparent substrate, the first sealant, the solar cells, the third sealant, the second sealant, and the back plate are laminated. In step s 42 , the transparent substrate is further heated. That is, the transparent substrate is the component that is directly heated in step s 42 . In a case, the heating temperature is about 140-160 degrees Celsius. Because the solar cells are arranged separately, a portion of the first sealant directly contacts a portion of the third sealant after laminating. Accordingly, the third sealant  180  that acts as a buffer layer can really reduce the probability that the first ultraviolet light absorbent  160  is spread to the first sealant  140  under restrictions of the third sealant  180 , so that the utilization efficiency of the ultraviolet light of the solar cells  130  do not be affected. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims.