Patent Publication Number: US-2011061727-A1

Title: Dye-sensitized solar cells and mobile device including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Patent Application No. 10-2009-0086934, filed with the Korean Intellectual Property Office on Sep. 15, 2009, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a dye-sensitized solar cell and a mobile phone including the same. 
     2. Description of the Related Art 
     A solar cell, which generates electric energy by using solar energy, provides infinite energy and is durable and environmentally friendly. Some examples of solar cells include silicon solar cells, semiconductor compound solar cells and dye-sensitized solar cells. 
     Here, the dye-sensitized solar cell is a solar cell in which a dye molecule interposed between a pair of electrodes converts sunlight to electrons by absorbing the sunlight. 
     The dye-sensitized solar cell can form a specific pattern that can be viewed from the outside by properly disposing dye molecules. Nevertheless, the pattern may not be identified from the outside by external factors such as the viewing angle. 
     SUMMARY 
     The present invention provides a dye-sensitized solar cell that can effectively identify a specific pattern formed by a dye when viewed from the outside, and a mobile device including the same. 
     An aspect of the present invention provides a dye-sensitized solar cell that includes a first substrate, which is transparent, a first electrode, which is formed on a rear surface of the first substrate, a second electrode, which is formed apart from the first electrode and in which the second electrode faces the first electrode, a catalytic layer, which is formed on a rear surface of the first electrode, a light absorption layer, which is formed on a front surface of the second electrode and includes a dye which is absorbed into metal oxide such that the dye forms a specific pattern with the metal oxide, an electrolyte, which is interposed between the first electrode and the second electrode, a base layer, which is formed on a rear surface of the second electrode and forms a background against the pattern formed by the dye such that the pattern can be identified when viewed from the outside, and a second substrate, which is formed on a rear surface of the base layer. 
     The base layer can be formed by including a fluorescent or phosphorescent substance. 
     The base layer can be translucent, and the second substrate can be a metal substrate having a reflective surface formed on its front surface. 
     The dye-sensitized solar cell can further include a secondary base layer, which is formed on a rear surface of the second substrate. Here, the base layer can be translucent, and the second substrate can be transparent. 
     The secondary base layer can be formed by including a fluorescent or phosphorescent substance. 
     The secondary base layer can be formed by including a dye or pigment with a specific color. 
     The dye-sensitized solar cell can further include a metal coating layer, which is interposed between the base layer and the second substrate and provides a reflective surface. Here, the base layer can be translucent. 
     The dye-sensitized solar cell can further include a metal coating layer, which is formed on a rear surface of the second substrate and provides a reflective surface. Here, the base layer can be translucent, and the second substrate can be transparent. 
     The base layer can be formed by including a dye or pigment with a specific color. 
     The base layer can be translucent, and the second substrate can be a metal substrate having a reflective surface formed on its front surface. 
     The dye-sensitized solar cell can further include a secondary base layer, which is formed on a rear surface of the second substrate. Here, the base layer can be translucent, and the second substrate can be transparent. 
     The secondary base layer can be formed by including a fluorescent or phosphorescent substance. 
     The secondary base layer can be formed by including a dye or pigment with a specific color. 
     The dye-sensitized solar cell can further include a metal coating layer, which is interposed between the base layer and the second substrate and provides a reflective surface. Here, the base layer can be translucent. 
     The dye-sensitized solar cell can further include a metal coating layer, which is formed on a rear surface of the second substrate and provides a reflective surface. Here, the base layer can be translucent, and the second substrate can be transparent. 
     Another aspect of the present invention provides a dye-sensitized solar cell that includes a first substrate, which is transparent, a first electrode, which is formed on a rear surface of the first substrate, a second electrode, which is formed apart from the first electrode and in which the second electrode faces the first electrode, a light absorption layer, which is formed on a rear surface of the first electrode and in which the light absorption layer includes a dye which is absorbed into metal oxide such that the dye forms a specific pattern with the metal oxide, a catalytic layer, which is formed on a front surface of the second electrode, an electrolyte, which is interposed between the first electrode and the second electrode, a base layer, which is formed on a rear surface of the second electrode and forms a background against the pattern formed by the dye such that the pattern can be identified when viewed from the outside, and a second substrate, which is formed on a rear surface of the base layer. 
     The base layer can be formed by including a dye or pigment with a specific color. 
     The base layer can be translucent, and the second substrate can be a metal substrate having a reflective surface formed on its front surface. 
     The dye-sensitized solar cell can further include a secondary base layer, which is formed on a rear surface of the second substrate. Here, the base layer can be translucent, and the second substrate can be transparent. 
     The secondary base layer can be formed by including a fluorescent or phosphorescent substance. 
     The secondary base layer can be formed by including a dye or pigment with a specific color. 
     The dye-sensitized solar cell can further include a metal coating layer, which is interposed between the base layer and the second substrate and provides a reflective surface. Here, the base layer can be translucent. 
     The dye-sensitized solar cell can further include a metal coating layer, which is formed on a rear surface of the second substrate and provides a reflective surface. Here, the base layer can be translucent, and the second substrate can be transparent. 
     Another aspect of the present invention provides a dye-sensitized solar cell that includes a first substrate, which is transparent, a first electrode, which is formed on a rear surface of the first substrate, a second electrode, which is formed apart from the first electrode and in which the second electrode faces the first electrode, a light absorption layer, which is interposed between the first electrode and the second electrode and in which the light absorption layer includes a dye which is absorbed into metal oxide such that the dye forms a specific pattern with the metal oxide, a catalytic layer, which is interposed between the first electrode and the second electrode and in which the catalytic layer is formed apart from the light absorption layer and the catalytic layer faces the light absorption layer, an electrolyte, which is interposed between the first electrode and the second electrode, and a second substrate, which is formed on a rear surface of the second electrode and forms a background against the pattern formed by the dye such that the pattern can be identified when viewed from the outside. 
     The second substrate is a metal substrate and can have a colored reflective surface formed on its front surface. 
     Another aspect of the present invention provides a dye-sensitized solar cell that includes a first substrate, which is transparent, a first electrode, which is formed on a rear surface of the first substrate, a second electrode, which is formed apart from the first electrode and in which the second electrode faces the first electrode, a catalytic layer, which is formed on a rear surface of the first electrode, a light absorption layer, which is formed on a front surface of the second electrode and in which the light absorption layer includes a dye which is absorbed into metal oxide such that the dye forms a specific pattern with the metal oxide, an electrolyte, which is interposed between the first electrode and the second electrode, a second substrate, which is formed on a rear surface of the second electrode and in which the second substrate is transparent, and a base layer, which is formed on a rear surface of the second electrode and forms a background against the pattern formed by the dye such that the pattern can be identified when viewed from the outside. 
     The base layer can be formed by including a fluorescent or phosphorescent substance. 
     The base layer can be formed by including a dye or pigment with a specific color. 
     Another aspect of the present invention provides a dye-sensitized solar cell that includes a first substrate, which is transparent, a first electrode, which is formed on a rear surface of the first substrate, a second electrode, which is formed apart from the first electrode and in which the second electrode faces the first electrode, a light absorption layer, which is formed on a rear surface of the first electrode and in which the light absorption layer includes a dye which is absorbed into metal oxide such that the dye forms a specific pattern with the metal oxide, a catalytic layer, which is formed on a front surface of the second electrode, an electrolyte, which is interposed between the first electrode and the second electrode, a second substrate, which is formed on a rear surface of the second electrode and in which the second substrate is transparent, and a base layer, which is formed on a rear surface of the second electrode and forms a background against the pattern formed by the dye such that the pattern can be identified when viewed from the outside. 
     The base layer can be formed by including a dye or pigment with a specific color. 
     Another aspect of the present invention provides a mobile device that includes a body and the above dye-sensitized solar cell, which is mounted on the body. 
     Additional aspects and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  briefly shows a structure of a dye-sensitized solar cell in accordance with an embodiment of the present invention. 
         FIG. 2  shows a pattern formed by a dye included in a dye-sensitized solar cell in accordance with an embodiment of the present invention. 
         FIGS. 3 to 12  briefly show a respective structure of a dye-sensitized solar cell in accordance with different embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Certain embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. Those components that are the same or are in correspondence are rendered the same reference numeral regardless of the figure number, and redundant descriptions are omitted. 
       FIG. 1  briefly shows a structure of a dye-sensitized solar cell in accordance with an embodiment of the present invention. Referring to  FIG. 1 , a dye-sensitized solar cell  100  according to the present embodiment can be constituted by a first substrate  111 , a first electrode  113 , a second electrode  127 , a catalytic layer  115 , a light absorption layer  125 , an electrolyte  119 , a base layer  130  and a second substrate  140 . 
     The first substrate  111  is transparent and can allow a ray of sunlight incident from the front to pass through. The first substrate  111  can be made of glass or high polymer such as PET. 
     The first electrode  113  can be formed on a rear surface of the first substrate  111 . The second electrode  127  can be formed apart from the first electrode  113 , facing the first electrode  113 . The first electrode  113  and the second electrode  127  can each be formed by including Indium Tin Oxide (ITO), Fluorine-doped Tin Oxide (FTO), Carbon Nano Tube (CNT) or Graphene. The first electrode  113  and the second electrode  127  can have conductivity. The first electrode  113  and the second electrode  127  can be transparent. 
     The catalytic layer  115  can be formed on a rear surface of the first electrode  113 . The catalytic layer  115  can be formed by including platinum (Pt), carbon, Carbon Nano Tube (CNT) or Graphene. 
     Referring to  FIG. 1 , the light absorption layer  125  can be formed on a front surface of the second electrode  127 . The light absorption layer  125  can be formed by including metal oxide  121  and a dye  123 , which is absorbed into the metal oxide  121 . When the sunlight is absorbed in the dye  123 , the dye  123  transfers electrons from a ground state to an excited state. The excited state electron is injected into a conduction band of an interface between particles of the metal oxide  121 , and the injected electron is transferred to the first electrode  113  along the interface between particles of the metal oxide  121  and is moved to the second electrode  127  through an external circuit (not shown). 
     The dye  123 , which is oxidized by electronic transmission, can be deoxidized by an iodine oxidation-reduction pair (I 3   − /I − ) in an electrolyte  119 , which will be described later. The oxidized iodine oxidation-reduction pair makes a reduction reaction with electrons arrived at an interface of the second electrode  127  to achieve charge neutrality so that the dye-sensitized solar cell can be operated. 
     In this embodiment, the dye  123  included in the light absorption layer  125  forms a specific pattern. Here, the pattern encompasses a shape formed by disposing the dye and a color of the dye, and the specific pattern is a pattern that is predetermined when the dye-sensitized solar cell is manufactured. 
       FIG. 2  shows a pattern formed by a dye included in a dye-sensitized solar cell in accordance with an embodiment of the present invention. Referring to  FIG. 2 , the dye-sensitized solar cell  100  of the present embodiment can have the color of, for example, red (not shown) by the dye  123  (refer to  FIG. 1 ) when viewed from the front and can form a specific pattern P formed in the shape of a heart. 
     Meanwhile, the electrolyte  129  can be interposed between the first electrode  113  and the second electrode  127 . The electrolyte  119  can be made of an iodine oxidation-reduction liquid electrolyte, that is, an electrolyte aqueous solution of I 3   − /I −  in which 1-vinyl-3-methyl-imidazolium iodide, 0.1 mol LiI, 40 m-mol I 2  (iodine) and 0.2 mol tert-butyl pyridine are dissolved in 3-methoxypropionitrile. However, the electrolyte  119  is not limited to this example. 
     The electrolyte  119  can be sealed by a partition wall  117  that is interposed between the first electrode  113  and the second electrode  127 . The partition wall  117  can be made of, for example, a thermoplastic high polymer membrane such as Surlyn and can have a thickness of about 30˜50 μm and a width of about 1˜4 mm. 
     In this embodiment, the base layer  130  can be formed on a rear surface of the second electrode  127 . The base layer  130  forms a background against a pattern formed by the dye  123  such that the pattern can be effectively identified when viewed from the outside. 
     The base layer  130  can be formed by including a fluorescent or phosphorescent substance. The base layer  130  can absorb the sunlight transmitted through the second electrode  127  and can emit light. In this case, the light-emitting base layer  130  is disposed behind the light absorption layer  125 , and thus the light-emitting base layer  130  forms a background against the pattern formed by the dye  123  when viewed from the front of the first substrate  111 . In this way, the pattern, formed by the dye  123 , on the base layer  130  that functions as a background can be effectively identified from the outside. 
     Particularly, if the base layer  130  is made of a phosphorescent material, the light-emitting base layer  130  that is exposed to sunlight can emit light for a certain period of time even in a dark space so that the pattern formed by the dye  123  can be effectively seen in the dark space. 
     Furthermore, since the light-emitting base layer  130  is disposed adjacent to the light absorption layer  125 , the light emitted by the base layer  130  can directly reach the dye  123  so that the pattern formed by the dye  123  can be identified more clearly from the outside. 
     Meanwhile, the base layer  130  can be formed by including a dye or pigment with a specific color, instead of a fluorescent or phosphorescent material. Here, the specific color is the color of a background against a pattern formed by the dye  123  included in the light absorption layer  125  to make the pattern stand out. 
     In one example, the base layer  130  can be formed by including a dye or pigment with the color of white or pale yellow. Since the base layer  130  including a dye or pigment with such specific color is disposed behind the light absorption layer  125 , the pattern formed by the dye  123  can be effectively identified against its background when viewed from the front of the first substrate  111 . 
     In this embodiment, the second substrate  140  can be formed on a rear surface of the base layer  130 . The second substrate  140  supports other components of the dye-sensitized solar cell  100 . 
     The second substrate  140  can be a metal substrate having a reflective surface  141  formed thereon. In this case, it is preferable that the base layer  130  is translucent. To make the base layer  130  translucent, the base layer  130  can be formed in the shape of a thin-film or the concentration of a fluorescent substance included in the base layer  130  can be lowered. 
     In this case, a portion of the sunlight transmitted through the second electrode  127  transmits through the translucent base layer  130 . The sunlight transmitted through the base layer  130  can be reflected to the base layer  130  by the reflective surface  141  of the second substrate  140 . 
     The light reflected by the second substrate  140  strikes a rear surface of the translucent base layer  130  so that the base layer  130  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  123  to be identified more clearly. 
     While this embodiment presents an example in which the second substrate  140  is a metal substrate and the base layer  130  is translucent, it shall be apparent that a second substrate of various materials and shapes and an opaque base layer can be employed. 
       FIG. 3  briefly shows a structure of a dye-sensitized solar cell in accordance with another embodiment of the present invention. Referring to  FIG. 3 , a dye-sensitized solar cell  200  according to the present embodiment can be constituted by a first substrate  211 , a first electrode  213 , a second electrode  227 , a catalytic layer  215 , a light absorption layer  225 , an electrolyte  219 , a base layer  230 , a second substrate  240  and a secondary base layer  250 . 
     Compared to the dye-sensitized solar cell  100  of the previously described embodiment, the dye-sensitized solar cell  200  of the present embodiment further includes the secondary base layer  250 , which is formed on a rear surface of the second substrate  240 . Thus, the difference between the dye-sensitized solar cell  200  of the present embodiment and the dye-sensitized solar cell  100  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the base layer  230  forms a background against a pattern formed by a dye  223  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. In this case, the base layer  230  can be translucent. 
     The second substrate  240  can be formed on a rear surface of the base layer  230 . In this case, the second substrate  240  is a transparent substrate and can be made of glass or high polymer. 
     The secondary base layer  250  can be formed on a rear surface of the second substrate  240 . The secondary base layer  250  with the base layer  230  forms a background against the pattern formed by the dye  223 . 
     More specifically, the secondary base layer  250  can be formed by including a fluorescent or phosphorescent substrate. In this case, the secondary base layer  250  can absorb the sunlight transmitted through the transparent second substrate  240  after having passed through the translucent base layer  230  and can emit light. 
     Since light is emitted from the secondary base layer  250  located at the bottom of the translucent base layer  230 , the secondary base layer  250  forms a background against a pattern formed by the dye  223  with the base layer  230  such that the pattern can be effectively identified when viewed from the front of the first substrate  211 . 
     Meanwhile, the secondary base layer  250  can be formed by including a dye or pigment with a specific color. Here, the specific color is the color of a background against a pattern formed by the dye  223  included in the light absorption layer  225  to make the pattern stand out. In one example, the secondary base layer  250  can be formed by including a dye or pigment with white or pale yellow color. 
     Since the secondary base layer  250  is disposed behind the translucent base layer  230 , the secondary base layer  250  forms a background with the base layer  230  that allows the pattern formed by the dye  223  to be effectively identified when viewed from the front of the first substrate  211 . 
     Meanwhile, the dye-sensitized solar cell  200  of the present embodiment can further include a metal coating layer (not shown), which is formed on a rear surface of the secondary base layer  250  and provides a reflective surface. In this case, the secondary base layer  250  can be translucent. 
     The sunlight transmitted through the translucent secondary base layer  250  can be reflected to the secondary base layer  250  by the metal coating layer (not shown). The light reflected by the metal coating layer (not shown) strikes a rear surface of the translucent base layer  230  and the translucent secondary base layer  250  so that the base layer  230  and the secondary base layer  250  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  223  to be identified more clearly. 
       FIG. 4  briefly shows a structure of a dye-sensitized solar cell in accordance with yet another embodiment of the present invention. Referring to  FIG. 4 , a dye-sensitized solar cell  300  according to the present embodiment can be constituted by a first substrate  311 , a first electrode  313 , a second electrode  327 , a catalytic layer  315 , a light absorption layer  325 , an electrolyte  319 , a base layer  330 , a second substrate  340  and a metal coating layer  360 . 
     Compared to the dye-sensitized solar cell  100  of the previously described embodiment, the dye-sensitized solar cell  300  of the present embodiment further includes the metal coating layer  360 , which is interposed between the base layer  330  and the second substrate  340 . Thus, the difference between the dye-sensitized solar cell  300  of the present embodiment and the dye-sensitized solar cell  100  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the base layer  330  forms a background against a pattern formed by a dye  323  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. In this case, the base layer  330  can be translucent. 
     The metal coating layer  360  can be interposed between the base layer  330  and the second substrate  340 . The metal coating layer  360  forms a reflective surface. In this case, the light transmitted through the translucent base layer  330  can be reflected to the base layer  330  by the reflective surface of the metal coating layer  360 . 
     The light reflected by the metal coating layer  360  strikes a rear surface of the translucent base layer  330  so that the base layer  330  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  323  to be identified more clearly. 
       FIG. 5  briefly shows a structure of a dye-sensitized solar cell in accordance with still another embodiment of the present invention. Referring to  FIG. 5 , a dye-sensitized solar cell  400  according to the present embodiment can be constituted by a first substrate  411 , a first electrode  413 , a second electrode  427 , a catalytic layer  415 , a light absorption layer  425 , an electrolyte  419 , a base layer  430 , a second substrate  440  and a metal coating layer  460 . 
     Compared to the dye-sensitized solar cell  100  of the previously described embodiment, the dye-sensitized solar cell  400  of the present embodiment further includes the metal coating layer  460 , which is formed on a rear surface of the second substrate  440 . Thus, the difference between the dye-sensitized solar cell  400  of the present embodiment and the dye-sensitized solar cell  100  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the base layer  430  forms a background against a pattern formed by a dye  423  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. In this case, the base layer  430  can be translucent. 
     In this embodiment, the second substrate  440  can be formed on a rear surface of the base layer  430 . In this case, the second substrate  440  can be a transparent substrate. 
     The metal coating layer  460  can be disposed on a rear surface of the transparent second substrate  440 . The metal coating layer  460  forms a reflective surface. In this case, the light transmitted through the transparent second substrate  440  after having passed the translucent base layer  430  can be reflected to the base layer  430  by the metal coating layer  460 . 
     The light reflected by the metal coating layer  460  strikes a rear surface of the translucent base layer  430  so that the base layer  430  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  423  to be identified more clearly. 
       FIG. 6  briefly shows a structure of a dye-sensitized solar cell in accordance with still another embodiment of the present invention. Referring to  FIG. 6 , a dye-sensitized solar cell  500  according to the present embodiment can be constituted by a first substrate  511 , a first electrode  513 , a second electrode  527 , a catalytic layer  515 , a light absorption layer  525 , an electrolyte  519 , a base layer  530  and a second substrate  540 . 
     Compared to the dye-sensitized solar cell  100  of the previously described embodiment, the dye-sensitized solar cell  500  of the present embodiment is different in that the positions of the catalytic layer  515  and the light absorption layer  525  are different from those of the catalytic layer  115  and the light absorption layer  125  of the dye-sensitized solar cell  100  of the previously described embodiment. Thus, the difference between the dye-sensitized solar cell  500  of the present embodiment and the dye-sensitized solar cell  100  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the catalytic layer  515  is formed on a front surface of the second electrode  527 , and the light absorption layer  525  is disposed on a rear surface of the first electrode  513 . In this case, the base layer  530  can be formed on a rear surface of the second electrode  527 . 
     The base layer  530  forms a background against a pattern formed by a dye  523  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. 
     In this embodiment, the second substrate  540  can be formed on a rear surface of the base layer  530 . The second substrate  540  supports other components of the dye-sensitized solar cell  500 . 
     The second substrate  540  can be a metal substrate having a reflective surface  541  formed thereon. In this case, it is preferable that the base layer  530  is translucent. In this case, a portion of the sunlight transmitting through the second electrode  527  transmits through the translucent base layer  530 . The sunlight transmitted through the base layer  530  can be reflected to the base layer  530  by the reflective surface  541  of the second substrate  540 . 
     The light reflected by the second substrate  540  strikes a rear surface of the translucent base layer  530  so that the base layer  530  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  523  to be identified more clearly. 
     While this embodiment presents an example in which the second substrate  540  is a metal substrate and the base layer  530  is translucent, it shall be apparent that a second substrate of various materials and shapes and an opaque base layer can be employed. 
       FIG. 7  briefly shows a structure of a dye-sensitized solar cell in accordance with still another embodiment of the present invention. Referring to  FIG. 7 , a dye-sensitized solar cell  600  according to the present embodiment can be constituted by a first substrate  611 , a first electrode  613 , a second electrode  627 , a catalytic layer  615 , a light absorption layer  625 , an electrolyte  619 , a base layer  630 , a second substrate  640  and a secondary base layer  650 . 
     Compared to the dye-sensitized solar cell  200  of the previously described embodiment, the dye-sensitized solar cell  600  of the present embodiment is different in that the positions of the catalytic layer  615  and the light absorption layer  625  are different from those of the catalytic layer  215  and the light absorption layer  225  of the dye-sensitized solar cell  200  of the previously described embodiment. Thus, the difference between the dye-sensitized solar cell  600  of the present embodiment and the dye-sensitized solar cell  200  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the base layer  630  forms a background against a pattern formed by a dye  623  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. In this case, the base layer  630  can be translucent. The transparent second substrate  640  can be formed on a rear surface of the translucent base layer  630 . The secondary base layer  650  can be formed on a rear surface of the transparent second substrate  640 . The secondary base layer  650  forms a background with the base layer  630  against the pattern formed by the dye  623 . 
     The secondary base layer  650  can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. Since the secondary base layer  650  is disposed with the translucent base layer  630  behind the light absorption layer  625 , the secondary base layer  650  forms a background with the base layer  630  that allows the pattern formed by the dye  623  to be effectively identified when viewed from the front of the first substrate  611 . 
     Meanwhile, the dye-sensitized solar cell  600  of the present embodiment can further include a metal coating layer (not shown), which is formed on a rear surface of the secondary base layer  650  and provides a reflective surface. In this case, the secondary base layer  650  can be translucent. 
     In this case, the sunlight transmitted through the translucent secondary base layer  650  can be reflected to the secondary base layer  650  by the metal coating layer (not shown). The light reflected by the metal coating layer (not shown) strikes a rear surface of the translucent base layer  630  and the translucent secondary base layer  650  so that the base layer  630  and the secondary base layer  650  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  623  to be identified more clearly. 
       FIG. 8  briefly shows a structure of a dye-sensitized solar cell in accordance with still another embodiment of the present invention. Referring to  FIG. 8 , a dye-sensitized solar cell  700  according to the present embodiment can be constituted by a first substrate  711 , a first electrode  713 , a second electrode  727 , a catalytic layer  715 , a light absorption layer  725 , an electrolyte  719 , a base layer  730 , a second substrate  740  and a metal coating layer  760 . 
     Compared to the dye-sensitized solar cell  300  of the previously described embodiment, the dye-sensitized solar cell  700  of the present embodiment is different in that the positions of the catalytic layer  715  and the light absorption layer  725  are different from those of the catalytic layer  315  and the light absorption layer  325  of the dye-sensitized solar cell  300  of the previously described embodiment. Thus, the difference between the dye-sensitized solar cell  700  of the present embodiment and the dye-sensitized solar cell  300  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the base layer  730  forms a background against a pattern formed by a dye  723  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. In this case, the base layer  730  can be translucent. 
     In this embodiment, the metal coating layer  760  can be interposed between the translucent base layer  730  and the second substrate  740 . The metal coating layer  760  forms a reflective surface. In this case, the light transmitted through the translucent base layer  730  can be reflected to the base layer  730  by the reflective surface of the metal coating layer  760 . 
     The light reflected by the metal coating layer  760  strikes a rear surface of the translucent base layer  730  so that the base layer  730  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  723  to be identified more clearly. 
       FIG. 9  briefly shows a structure of a dye-sensitized solar cell in accordance with still another embodiment of the present invention. Referring to  FIG. 9 , a dye-sensitized solar cell  800  according to the present embodiment can be constituted by a first substrate  811 , a first electrode  813 , a second electrode  827 , a catalytic layer  815 , a light absorption layer  825 , an electrolyte  819 , a base layer  830 , a second substrate  840  and a metal coating layer  860 . 
     Compared to the dye-sensitized solar cell  400  of the previously described embodiment, the dye-sensitized solar cell  800  of the present embodiment is different in that the positions of the catalytic layer  815  and the light absorption layer  825  are different from those of the catalytic layer  415  and the light absorption layer  425  of the dye-sensitized solar cell  400  of the previously described embodiment. Thus, the difference between the dye-sensitized solar cell  800  of the present embodiment and the dye-sensitized solar cell  400  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the base layer  830  forms a background against a pattern formed by a dye  823  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. In this case, the base layer  830  can be translucent. 
     In this embodiment, the second substrate  840  can be formed on a rear surface of the translucent base layer  830 . In this case, the second substrate  840  can be a transparent substrate. 
     The metal coating layer  860  can be disposed on a rear surface of the transparent second substrate  840 . The metal coating layer  860  forms a reflective surface. In this case, the light transmitted through the transparent second substrate  840  after having passed the translucent base layer  830  can be reflected to the base layer  830  by the metal coating layer  860 . 
     The light reflected by the metal coating layer  860  strikes a rear surface of the translucent base layer  830  so that the base layer  830  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  823  to be identified more clearly. 
       FIG. 10  briefly shows a structure of a dye-sensitized solar cell in accordance with still another embodiment of the present invention. Referring to  FIG. 10 , a dye-sensitized solar cell  900  according to the present embodiment can be constituted by a first substrate  911 , a first electrode  913 , a second electrode  927 , a catalytic layer  915 , a light absorption layer  925 , an electrolyte  919  and a second substrate  940 . 
     In the description of the dye-sensitized solar cell  900  according to the present embodiment, certain detailed descriptions of the previously described embodiments will be omitted. 
     In this embodiment, the catalytic layer  915  and the light absorption layer  925  can be interposed between the first electrode  913  and the second electrode  927 . In this case, as illustrated in  FIG. 10 , the light absorption layer  925  can be formed on a rear surface of the first electrode  913 , and the catalytic layer  915  can be formed on a front surface of the second electrode  927 . 
     Although the light absorption layer  925  and the catalytic layer  915  are formed on a rear surface of the first electrode  913  and a front surface of the second electrode  927 , respectively, this configuration is only one example, and the light absorption layer  925  and the catalytic layer  915  can be formed on the front surface of the second electrode  927  and the rear surface of the first electrode  913 , respectively. 
     The second substrate  940  can be disposed on a rear surface of the second electrode  927 . In this embodiment, the second substrate  940  forms a background against a pattern formed by a dye  923  such that the pattern can be effectively identified when viewed from the outside. 
     The second substrate  940  can have a specific color. Here, the specific color is the color of a background against a pattern formed by the dye  923  included in the light absorption layer  925  to make the pattern stand out. In one example, the second substrate  940  can have white or pale yellow color. 
     In this embodiment, since the second substrate  940  with a specific color is disposed behind the light absorption layer  925 , the pattern formed by the dye  923  can be effectively identified against its background when viewed from the front of the first substrate  911 . 
     Meanwhile, the second substrate  940  can be a metal substrate. In this case, the second substrate  940  can have a colored reflective surface  941  formed on its front surface. The Femto pulse laser can be used to color the reflective surface  941 . The color of the reflective surface  941  is the color of a background against the pattern formed by the dye  923 . The reflective surface  941  of the second substrate  940  reflects light to the light absorption layer  925  and also forms a background against the pattern of the dye  923 , and thus the pattern formed by the dye  923  can be effectively identified when viewed from the front of the first substrate  911 . 
       FIG. 11  briefly shows a structure of a dye-sensitized solar cell in accordance with still another embodiment of the present invention. Referring to  FIG. 11 , a dye-sensitized solar cell  1000  according to the present embodiment can be constituted by a first substrate  1011 , a first electrode  1013 , a second electrode  1027 , a catalytic layer  1015 , a light absorption layer  1025 , an electrolyte  1019 , a second substrate  1040  and a base layer  1030 . 
     Compared to the dye-sensitized solar cell  100  of the previously described embodiment, the dye-sensitized solar cell  1000  of the present embodiment is different in that the positions of the second substrate  1040  and the base layer  1030  are different from those of the second substrate  140  and the base layer  130  of the dye-sensitized solar cell  100  of the previously described embodiment. Thus, the difference between the dye-sensitized solar cell  1000  of the present embodiment and the dye-sensitized solar cell  100  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the second substrate  1040  can be formed on a rear surface of the second electrode  1027 . In this case, the second substrate  1040  can be transparent. The base layer  1030  can be formed on a rear surface of the transparent second substrate  1040 . 
     The base layer  1030  forms a background against a pattern formed by a dye  1023  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. 
     In this embodiment, since the base layer  1030  is disposed behind the light absorption layer  1025 , the pattern formed by the dye  1023  can be effectively identified against its background when viewed from the front of the first substrate  1011 . 
     Meanwhile, the dye-sensitized solar cell  1000  of the present embodiment can further include a metal coating layer (not shown), which is formed on a rear surface of the base layer  1030  and provides a reflective surface. In this case, the base layer  1030  can be translucent. 
     In this case, the sunlight transmitted through the translucent base layer  1030  can be reflected to the base layer  1030  by the metal coating layer (not shown). The light reflected by the metal coating layer (not shown) strikes a rear surface of the translucent base layer  1030  so that the base layer  1030  can be identified more clearly when viewed from the outside. This allows the pattern formed by the dye  1023  to be identified more clearly. 
       FIG. 12  briefly shows a structure of a dye-sensitized solar cell in accordance with still another embodiment of the present invention. Referring to  FIG. 12 , a dye-sensitized solar cell  1100  according to the present embodiment can be constituted by a first substrate  1111 , a first electrode  1113 , a second electrode  1127 , a catalytic layer  1115 , a light absorption layer  1125 , an electrolyte  1119 , a second substrate  1140  and a base layer  1130 . 
     Compared to the dye-sensitized solar cell  500  of the previously described embodiment, the dye-sensitized solar cell  1100  of the present embodiment is different in that the positions of the second substrate  1140  and the base layer  1130  are different from those of the second substrate  540  and the base layer  530  of the dye-sensitized solar cell  500  of the previously described embodiment. Thus, the difference between the dye-sensitized solar cell  1100  of the present embodiment and the dye-sensitized solar cell  500  of the previously described embodiment will be mainly described hereinafter, and redundant descriptions are omitted. 
     In this embodiment, the second substrate  1140  can be formed on a rear surface of the second electrode  1127 . In this case, the second substrate  1140  can be transparent. The base layer  1130  can be formed on a rear surface of the transparent second substrate  1140 . 
     The base layer  1130  forms a background against a pattern formed by a dye  1123  such that the pattern can be effectively identified when viewed from the outside and can be formed by including a fluorescent or phosphorescent substance or by including a dye or pigment with a specific color. 
     In this embodiment, since the base layer  1130  is disposed behind the light absorption layer  1125 , the pattern formed by the dye  1123  can be effectively identified against its background when viewed from the front of the first substrate  1111 . 
     Meanwhile, the dye-sensitized solar cell  1100  of the present embodiment can further include a metal coating layer (not shown), which is formed on a rear surface of the base layer  1130  and provides a reflective surface. 
     Meanwhile, a dye-sensitized solar cell in accordance with certain embodiments described above can be used in a mobile device. That is, the mobile device can be constituted by a body (not shown) and a dye-sensitized solar cell, which is mounted on the body in accordance with the previously described embodiments of the present invention. Here, the mobile device collectively refers to mobile phones, laptop computers, PMPs, PDAs and the like. 
     By a mobile device, for example, a mobile phone, in which a dye-sensitized solar cell according to the above embodiments of the present invention is included, a pattern formed by a dye included in the dye-sensitized solar cell can be effectively viewed. This can improve the aesthetic attractiveness of the mobile phone that includes the dye-sensitized solar cell. 
     While the spirit of the present invention has been described in detail with reference to particular embodiments, the embodiments are for illustrative purposes only and shall not limit the present invention. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention. 
     As such, many embodiments other than those set forth above can be found in the appended claims.