201133869 六、發明說明： 【發明所屬之技術領域】 [0001] 本發明係有關於一種電極及其電池結構，特別係有 關於一種具金屬反光層之光電極及其染料敏化太陽能電 池結構。 【先前技術】 [0002] 如第1圖所示，習知染料敏化太陽能電池之光電極係 由一透明基板S、一透明導電層C及一吸附染料（Dye)之多 孔性半導體層P所構成，該多孔性半導體層P大都由二氧 〇 化鈦（Ti〇2)奈米粒子所组成。當太陽光照射於光電極時 ，染料會吸收太陽光，同時染料分子内的電子獲得足夠 能量從基態躍遷到高能階的激發態（Dye*)，染料分子中 處於高能階激發態的電子不穩定，故不穩定的電子易被 緊鄰的1^〇2奈米粒子所吸引，而選擇注入到Ti〇2奈米粒 子的導帶内，獲得額外電子的1^〇2奈米粒子則形成η-型 半導體，而失去電子的染料則轉為帶正電的離子而形成 氧化態，此外，失去電子的染料會從液態電解質中補充 ^ 電子，以使染料恢復電荷平衡而回到基態，而進入Ti〇2 奈米粒子導帶的傳導電子則匯集於該透明導電層C，並透 過外部迴路傳遞到對電極，其所產生流通的電流稱之為 光電流。然而，習知光電極之該多孔性半導體層P的厚度 只有數微米，其具有某種程度的透光性，因此，當太陽 光照射於光電極時，會有一部分的光被染料吸收，而另 有一部分光會穿透該多孔性半導體層P而無法被使用。 【發明内容】 099109476 表單編號A0101 第3頁/共13頁 0992016846-0 201133869 [0003] 本發明之主要目的係在於提供一種具金屬反光層之 光電極及其染料敏化太陽能電池結構，該光電極係包含 一透明基板、一透明導電層、一多孔性半導體層以及一 金屬反光層，該透明基板係具有一表面，該透明導電層 係形成於該透明基板之該表面，該多孔性半導體層係形 成於該透明導電層上，而該金屬反光層係覆蓋該多孔性 半導體層。該染料敏化太陽能電池結構係包含一光電極 、一對電極以及一電解質溶液，該光電極係包含一透明 基板、一透明導電層、一多孔性半導體層以及一金屬反 光層，該透明基板係具有一表面，該透明導電層係形成 於該透明基板之該表面，該多孔性半導體層係形成於該 透明導電層上，而該金屬反光層係覆蓋該多孔性半導體 層，該對電極係與該光電極呈相對設置，該電解質溶液 係設置於該光電極與該對電極之間，本發明係利用該金 屬反光層將穿透該多孔性半導體層之光反射回該多孔性 半導體層，以使染料再吸收反射光，其功效上可提昇光 電極之光吸收效率及提高染料敏化太陽能電池之光電轉 換效率。 【實施方式】 [0004] 請參閱第2圖，其係本發明之一較佳實施例，一種光 電極10係包含有一透明基板11、一透明導電層12、一多 孔性半導體層13以及一金屬反光層14，在本實施例中， 該透明基板11係可為玻璃基板或可撓式基板，且該透明 基板11係具有一表面11a，該透明導電層12係形成於該透 明基板11之該表面11a，而該透明導電層12之材質係可選 自於由SnOQ:F (FTO)、In9Oq:Sn (ΙΤΟ)、ΖηΟ:Α1201133869 VI. Description of the Invention: [Technical Field] [0001] The present invention relates to an electrode and a battery structure thereof, and more particularly to a photoelectrode having a metal reflective layer and a dye-sensitized solar cell structure thereof. [Prior Art] As shown in Fig. 1, the photoelectrode of a conventional dye-sensitized solar cell is composed of a transparent substrate S, a transparent conductive layer C, and a porous semiconductor layer P of a dye (Dye). In this configuration, the porous semiconductor layer P is mostly composed of titanium dioxide titanium dioxide (Ti〇2) nanoparticles. When sunlight is applied to the photoelectrode, the dye absorbs sunlight, and the electrons in the dye molecule gain sufficient energy to transition from the ground state to the excited state of the high energy level (Dye*), and the electrons in the dye molecule are excited by the high energy level excited state. Therefore, the unstable electrons are easily attracted by the adjacent 1^〇2 nanoparticle, and are selectively injected into the conduction band of the Ti〇2 nanoparticle, and the 1^〇2 nanoparticle which obtains additional electrons forms η- a type of semiconductor, and the dye that loses electrons is converted into a positively charged ion to form an oxidation state. In addition, the dye that loses electrons replenishes the electron from the liquid electrolyte, so that the dye restores charge balance and returns to the ground state, and enters Ti. The conduction electrons of the 〇2 nanoparticle conduction band are collected in the transparent conductive layer C and transmitted to the counter electrode through the external loop, and the current generated by the current is called photocurrent. However, the thickness of the porous semiconductor layer P of the conventional photoelectrode is only a few micrometers, and it has a certain degree of light transmittance. Therefore, when sunlight is irradiated to the photoelectrode, a part of the light is absorbed by the dye, and A part of the light penetrates the porous semiconductor layer P and cannot be used. SUMMARY OF THE INVENTION 099109476 Form No. A0101 Page 3 / Total 13 Pages 0992016846-0 201133869 [0003] The main object of the present invention is to provide a photoelectrode having a metal reflective layer and a dye-sensitized solar cell structure thereof, the photoelectrode The invention comprises a transparent substrate, a transparent conductive layer, a porous semiconductor layer and a metal reflective layer, the transparent substrate having a surface, the transparent conductive layer being formed on the surface of the transparent substrate, the porous semiconductor layer It is formed on the transparent conductive layer, and the metal reflective layer covers the porous semiconductor layer. The dye-sensitized solar cell structure comprises a photoelectrode, a pair of electrodes and an electrolyte solution, the photoelectrode comprising a transparent substrate, a transparent conductive layer, a porous semiconductor layer and a metal reflective layer, the transparent substrate And having a surface, the transparent conductive layer is formed on the surface of the transparent substrate, the porous semiconductor layer is formed on the transparent conductive layer, and the metal reflective layer covers the porous semiconductor layer, the pair of electrode systems Opposite the photoelectrode, the electrolyte solution is disposed between the photoelectrode and the counter electrode, and the present invention uses the metal reflective layer to reflect light that penetrates the porous semiconductor layer back to the porous semiconductor layer. In order to re-absorb the reflected light, the efficacy of the dye can improve the light absorption efficiency of the photoelectrode and improve the photoelectric conversion efficiency of the dye-sensitized solar cell. Embodiments [0004] Referring to FIG. 2, a photoelectrode 10 includes a transparent substrate 11, a transparent conductive layer 12, a porous semiconductor layer 13, and a preferred embodiment of the present invention. In the present embodiment, the transparent substrate 11 can be a glass substrate or a flexible substrate, and the transparent substrate 11 has a surface 11a formed on the transparent substrate 11. The surface 11a, and the material of the transparent conductive layer 12 may be selected from SnOQ:F (FTO), In9Oq:Sn (ΙΤΟ), ΖηΟ:Α1
L L O 099109476 表單編號A0101 第4頁/共13頁 0992016846-0 201133869 (AZO)、Sn〇2:Sb (ΑΤΟ)及ZnO:Ga (GZ0)所構成之群組 中的其中一種，該多孔性半導體層13係形成於該透明導 電層12上，且該多孔性半導體層13係包含有複數個吸附 染料之金屬氧化物半導體奈米粒子13a，在本實施例中， 該些金屬氧化物半導體奈米粒子13a係為二氧化鈦（Ti〇2) 奈米粒子，且較佳地，該多孔性半導體層13之厚度係介 於1微米至20微米之間，以防止電子在該多孔性半導體層 13中的擴散和復合阻抗過大而影響電池效能。 請再參閱第2圖，該金屬反光層14係覆蓋該多孔性半 Ο 導體層13，在本實施例中，該金屬反光層14係包含有複 數個金屬複合粒子Μ，各該金屬複合粒子M.係由一金屬微 粒Μ0及一包覆該金屬微粒Μ0之透明絕緣層Ml所構成，在 本實施例中，該些金屬微粒M0係為高反射率之金屬，其 材質係可選自於由銘、銅、錄、欽、金、銀及其合金所 構成之群組中的其中一種，此外，該些金屬微粒M0之幾 何形狀係可為圓球形或薄片形，較佳地，該些金屬微粒 M0係為薄片形，因其具有較佳之光遮蔽性，該些透明絕 〇 緣層Ml主要用以保護該些金屬微粒M0免於受到電解質溶 液之腐蝕及防止該些金屬微粒M0與該多孔性半導體層13 產生電性導通而造成電池失效，因此，該些透明絕緣層 Ml之材質須具備高透明度、低消光係數、高絕緣性及耐 化學性佳等特點，在本實施例中，該些透明絕緣層Ml之 材質係可選用二氧化矽（Si〇2)，且為避免影響透光性， 該些透明絕緣層Ml之厚度須控制在介於1奈米至100奈米 之間。又，在本實施例中，為避免因使用該金屬反光層 14而導致電池内阻增加，該金屬反光層14之厚度亦須控 099109476 表單編號A0101 第5頁/共13頁 0992016846-0 201133869 制付當’較佳地’該金屬反光層14之厚度係介於1微米至 1 5微米之間。 5清參閱第3圖，其係本發明之一種染料敏化太陽能電 池結構係包含有一光電極10、一對電極20以及一電解質 冷液30，該光電極10係包含有一透明基板11、一透明導 %層12、一多性半導體層is以及一金屬反光層14，在 本實施例中’該透明基板11係可為玻璃基板或可撓式基 板’且邊透明基板11係具有一表面11a，該透明導電層12 係形成於該透明基板11之該表 面11a，而該透明導電層12 之材貝係可選自於由SnO :F (FTO)、In2〇 :Sn (ITO) n (AZO)、sn〇2:Sb (ΑΤΟ)及ZnO:Ga (GZO)所 構成之群組中的其中一種，該多孔性半導體層i3係形成 於該透明導電層12上，且該多孔性半導體層13係包含有 複數個°及附染料之金屬氡化物半導體奈米粒子，在本 、例中’該些金屬氧化物半導體奈米粒子13a係為二氧 化欽（Ti〇、太、>、 係—2)不米粒子。請再參辆第3圖，該金屬反光層14 光5广該多孔性半導體層13、在本實施例中 ，該金屬反 子Mi*係包含有複數個金屬複合粒子M，各該金屬複合粒 層Μ、金屬微粒M0及-包覆該金屬微粒M〇之透明絕緣 射率構< 在本實施例中，該些金屬微粒M0係為高反 :金屬’其材質係可選自於由鋁、銅、鎳、鈦、金 金屬與上„ <蛘組中的其中一種，此外，該些 屬微粒M0之幾何形狀 … ,, '、了為圓球形或薄片形，較佳地 性 孩些金屬微粒M0係為薄 , ^ 导片形，因其具有較佳之光遮蔽 5亥些透明絕緣層Mi 於成 王要用以保護該些金屬微粒M0免 099109476 於文到電解質溶液之腐 表單編號麵 麵及防止該些金屬微粒M0與該多 0992016846-0 第6貢/共13頁 201133869 孔性半導體層13產生電性導通而造成電池失效，因此， 該些透明絕緣層M1之材質須具僙高透明.度、低消光係數 、南絕緣性及耐化學性佳等特點，在本實施例中 ，該些 透明絕緣層M1之材質係可選用二氧化矽（Si〇2) ，且為避 免影響透紐’該些透明絕緣㈣丨之厚度須控制在介於i 奈米至100奈米之間。又，在本實施例中，為避免因使用 該金屬反光層14而導致魏⑽增加，該金屬反光層14 之厚度亦須控制得當’較佳地，該金屬反光層14之厚度 係介於1微米至15微米之間。 请再參閱第3圖’尊對電極2〇係與該光電極丨〇呈相對 設置’且該對電極2〇係具有一朝向該光電極1〇之導電表 面20a及一形成於該導電表面2〇社之催化層21，在本實施 例中’其係可利用—密封間隔材40接合該對電極20與該 光電極10 ’而該電解質溶液30係設置於該光電極10與該 對電極20之間’其中該密封間隔材40係可防止該電解質 溶液30發生朗。本發明係湘該金屬反光層14將穿透 该多孔性半導體層13之光反射回該多孔性半導體層13， 以使染料再錢反料，其功效上可提昇光電極之光吸 收效率及提而染料敏化太陽能電池之光電轉換效率。 本發明之保護範圍當視後附之申請專利範圍所界定 者為準’任何熟知此項技藝者，在不脫離本發明之精神 和範圍内所作之任何變化與修改，均狀本發明之保護 範圍。 【圖式簡單說明】 [0005] 第1圖：習知染料敏化太陽能電池之光電極結構示意圖。 099109476 第2圖：依據本發明之 表單編號A0101 第7 一較佳實施例，一種具金屬反光層 頁/共 13 頁 0992016846-0 201133869 之光電極結構圖。 第3圖：依據本發明之一較佳實施例，一種染料敏化太陽 能電池結構圖。 【主要元件符號說明】 [0006] 10光電極 11透明基板 11a表面 12透明導電層 20a導電表面 40密封間隔材 Μ金屬複合粒子 Ml透明絕緣層 S透明基板 13多孔性半導體層 13a金屬氧化物半導體奈米粒子 14金屬反光層 20對電極 21催化層 30電解質溶液 C透明導電層 M0金屬微粒 P多孔性半導體層 099109476 表單編號A0101 第8頁/共13頁 0992016846-0LLO 099109476 Form No. A0101 Page 4 of 13 Page 0992016846-0 201133869 (AZO), Sn〇2: Sb (ΑΤΟ) and one of ZnO:Ga (GZ0), the porous semiconductor layer 13 is formed on the transparent conductive layer 12, and the porous semiconductor layer 13 is composed of a plurality of metal oxide semiconductor nanoparticles 13a adsorbing dye, in the embodiment, the metal oxide semiconductor nanoparticles 13a is titanium dioxide (Ti〇2) nanoparticles, and preferably, the thickness of the porous semiconductor layer 13 is between 1 micrometer and 20 micrometers to prevent diffusion of electrons in the porous semiconductor layer 13. And the composite impedance is too large to affect battery performance. Referring to FIG. 2 again, the metal reflective layer 14 covers the porous semiconductor layer 13. In the embodiment, the metal reflective layer 14 comprises a plurality of metal composite particles, each of the metal composite particles M. The metal particles Μ0 and a transparent insulating layer M1 covering the metal particles Μ0, in the embodiment, the metal particles M0 are high reflectivity metals, and the material thereof may be selected from One of a group consisting of Ming, Cu, Li, Qin, Jin, Silver, and alloys thereof. Further, the geometry of the metal particles M0 may be spherical or flaky, preferably, the metals The microparticles M0 are in the shape of a thin sheet. Because of their better light shielding properties, the transparent insulating margins M1 are mainly used to protect the metal microparticles M0 from corrosion by the electrolyte solution and prevent the metal microparticles M0 from being porous. The semiconductor layer 13 is electrically conductive and causes battery failure. Therefore, the materials of the transparent insulating layer M1 are required to have high transparency, low extinction coefficient, high insulation and chemical resistance. In this embodiment, Transparent The material of the edge layer M1 may be selected from cerium oxide (Si〇2), and in order to avoid affecting the light transmittance, the thickness of the transparent insulating layer M1 shall be controlled between 1 nm and 100 nm. Moreover, in this embodiment, in order to avoid an increase in internal resistance of the battery due to the use of the metal reflective layer 14, the thickness of the metal reflective layer 14 is also controlled by 099109476. Form No. A0101 Page 5 / Total 13 Page 0992016846-0 201133869 The thickness of the metal reflective layer 14 is preferably between 1 micrometer and 15 micrometers. 5, which is a dye-sensitized solar cell structure of the present invention, comprising a photoelectrode 10, a pair of electrodes 20, and an electrolyte cold liquid 30, the photoelectrode 10 comprising a transparent substrate 11 and a transparent In the embodiment, the transparent substrate 11 can be a glass substrate or a flexible substrate, and the transparent substrate 11 has a surface 11a. The transparent conductive layer 12 is formed on the surface 11a of the transparent substrate 11, and the shell of the transparent conductive layer 12 can be selected from SnO:F (FTO), In2〇:Sn (ITO) n (AZO) And one of a group consisting of: Sn2: Sb (ΑΤΟ) and ZnO: Ga (GZO), the porous semiconductor layer i3 is formed on the transparent conductive layer 12, and the porous semiconductor layer 13 is The metal oxide semiconductor nanoparticle containing a plurality of ° and dye-containing dyes, in the present example, the metal oxide semiconductor nanoparticles 13a are dioxide (Ti〇, Tai, >, system-2 ) not rice particles. Referring to FIG. 3 again, the metal reflective layer 14 is broadly covered with the porous semiconductor layer 13. In the embodiment, the metal counter-Mi* system comprises a plurality of metal composite particles M, each of the metal composite particles. The layer Μ, the metal particles M0 and the transparent insulating radiance of the metal particles M & are in the embodiment, the metal particles M0 are high-reverse: the metal 'the material is selected from the aluminum , copper, nickel, titanium, gold metal and one of the upper group, in addition, the geometrical shape of the particles M0..., ', is spherical or flaky, preferably child The metal particles M0 are thin, ^ guide-shaped, because they have better light shielding, and some transparent insulating layers Mi are used to protect the metal particles M0 from 099109476 to the rot form number of the electrolyte solution. And preventing the metal particles M0 from being electrically connected to the porous semiconductor layer 13 to cause battery failure, and therefore, the materials of the transparent insulating layers M1 are required to be high. Transparent, low extinction coefficient, south insulation and chemical resistance In this embodiment, the materials of the transparent insulating layer M1 are selected from cerium oxide (Si〇2), and in order to avoid affecting the transparent layer, the thickness of the transparent insulating layer (four) must be controlled between Between meters and 100 nm. Also, in this embodiment, in order to avoid an increase in Wei (10) due to the use of the metal reflective layer 14, the thickness of the metal reflective layer 14 must be properly controlled. Preferably, the metal is reflective. The thickness of the layer 14 is between 1 micrometer and 15 micrometers. Please refer to FIG. 3 again, 'the opposite electrode 2 is opposite to the photoelectrode '' and the pair of electrodes 2 has a light toward the light The conductive surface 20a of the electrode 1 and a catalytic layer 21 formed on the conductive surface 2, in the present embodiment, the sealing electrode 40 can be used to bond the pair of electrodes 20 and the photoelectrode 10'. The electrolyte solution 30 is disposed between the photoelectrode 10 and the counter electrode 20, wherein the sealing spacer 40 prevents the electrolyte solution 30 from occurring. The present invention is directed to the metal reflective layer 14 to penetrate the porous semiconductor. The light of layer 13 is reflected back to the porous semiconductor layer 13, In order to make the dye more expensive, the efficacy of the light absorption efficiency of the photoelectrode and the photoelectric conversion efficiency of the dye-sensitized solar cell can be improved. The scope of protection of the present invention is subject to the definition of the patent application scope attached thereto. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention are within the scope of the present invention. [Simplified Description] [0005] Figure 1: Conventional dye sensitivity Schematic diagram of the structure of the photoelectrode of a solar cell. 099109476 FIG. 2 is a view showing the structure of a photoelectrode having a metal reflective layer/13 pages of 0992016846-0 201133869 according to the seventh embodiment of the present invention. Figure 3 is a structural view of a dye-sensitized solar cell in accordance with a preferred embodiment of the present invention. [Major component symbol description] [0006] 10 photoelectrode 11 transparent substrate 11a surface 12 transparent conductive layer 20a conductive surface 40 sealing spacer material Μ metal composite particle M1 transparent insulating layer S transparent substrate 13 porous semiconductor layer 13a metal oxide semiconductor nai Rice particle 14 metal light reflecting layer 20 counter electrode 21 catalytic layer 30 electrolyte solution C transparent conductive layer M0 metal particle P porous semiconductor layer 099109476 Form No. A0101 Page 8 of 13 0992016846-0