200810134 九、發明說明： 【發明所屬之技術領域】 H明係關於一種轉換裝置，特別關於一種光電轉換 裝置及其光電轉換元件。 【先前技術】 隨著地球能源資源逐漸地短缺，開發新能源已成為科 技業以及產業矚目的焦點之一，替代性能源產品例如太陽 電池即成為開發的標的之一。太陽電池係為一種利用光伏 特效應(photovoltaic effect)將光能轉換成電能的光電轉換 裝置，即利用p-n接合半導體吸收光能量後產生自由電子 與電洞，在p-n接合半導體接面附近的内建電場驅使下， 使自由電子向η型半導體移動，而自由電洞向p型半導體 移動，進而產生電流，最後經由電極將電流引出形成可供 使用或儲存之電能。 請參照圖1所示，習知之一種太陽電池1的基本結構 主要係包含一基板10、一 ρ-η接合半導體η、一抗反射層 12以及一金屬電極對13。其中，基板1〇為太陽電池i之 基底，一般即以p-n接合半導體n之一 n型半導體層m 或一 P型半導體層112直接作為基板1〇，而p-n接合半導 體11係為將光能轉換為電能之作用區；抗反射層12係設 置於太陽電池1之入光面，用以降低入射光的反射；金屬 電極對13包含—第—電極131與—第二電極132分別連 接於n型半導體層111與P型半導體層112,並用以與- 200810134 外界電路連接’其中為使光能有效入射，設置於入光面之 第一電極131係呈指插狀（Finger)結構。 為提高光電流量與光電轉換效率，習知在太陽電池1 結構之背面即第二電極132旁利用印刷或蒸空鍍膜方式形 成一鋁（A1)金屬層14，如圖2所示，其係為鄰近第二電 極132結構的放大圖，金屬層14之鋁離子對p型半導體 層112進行内部擴散，而形成有一 p+型半導體層ι41，其 中P+型半導體層141與p型半導體層112接合所產生之内 ⑩建電場即稱為背面電場（back surface field, BSF)，藉由 BSF之形成而得以使往第二電極132移動之電子往η型半 導體層111移動，因此提高了光電流量；此外，對往第二 電極132移動之電洞而言，ρ+型半導體層141提供了一低 電阻之歐姆性接觸，因此有效助益光電轉換效率之提升。 習知銘（Α1)金屬層14以及金屬電極對13之形成皆 須經:過高溫燒結之步驟，由於燒結過程發生收縮，及由於 ⑩金屬材質與矽材料的熱膨脹係數之差，因此在燒結過程中 會使太陽電池1發生翹曲的現象’且此現象在現今薄化石夕 基板的趨勢下更甚顯著，甚而導致後續製程發生破片的 •能性。 ° 有鐘於此，如何提供一種避免發生勉曲現象進而提古 光電轉換效率之光電轉換裝置及其光電轉換元件，實為^ 今的重要課題之一。 【發明内容】 200810134 有鑑於上述課題，本發明之目的為提供一種避免發生 翹曲現象進而提高光電轉換效率之光電轉換裝置及其光 電轉換元件。 緣是，為達上述目的，依據本發明之一種光電轉換元 件，其係與一第一電極與一第二電極電性連接，光電轉換 元件包含一第一半導體層、一第二半導體層以及一金屬 層。其中，第二半導體層係與第一半導體層相連接，金屬 ‘層係設置於第二半導體層之一側，金屬層係具有至少一第 • 一溝槽與至少一第二溝槽，第一溝槽係將金屬層區分為複 數個區塊，第二電極係設置於第二溝槽内。 為達上述目的，依據本發明之一種光電轉換裝置包含 一光電轉換元件、一第一電極以及一第二電極。其中’光 電轉換元件係具有一第一半導體層、一第二半導體層及一 金屬層，第二半導體層係與第一半導體層相連接，金屬層 係設置於第二半導體層之一侧，金屬層係具有至少一第一 ^ 溝槽與至少一第二溝槽，第一溝槽係將金屬層區分為複數 個區塊；第一電極係與第一半導體層相連結；第二電極係 設置於第二溝槽内，並與第二半導體相連結。 承上所述，因依據本發明之一種光電轉換裝置及其光 * 電轉換元件係利用溝槽（即第一溝槽）將金屬層區分為複 數個區塊，即金屬層可例如為一網狀結構，於此藉由溝槽 分散金屬層於高溫燒結過程中所產生的應力，而有效降低 金屬層因高溫所發生的翹曲現象，因此，包含本發明之金 屬層結構的光電轉換裝置，除了具有增加光電流以及降低 200810134 阻抗的效果下，更提高了光電轉換裝置之製作良率。 【實施方式】 以下將參照相關圖式，說明依本發明較佳實施例之光 電轉換裝置及其光電轉換元件，其中相同的元件將以相同 的參照符號加以說明。 請參照圖3所示，依據本發明較佳實施例之一種光電 轉換裝置2係包含一光電轉換元件21、一第一電極22以 ⑩及一第二電極23。本實施例中，光電轉換裝置2係為一太 陽電池。 光電轉換元件21係具有一第一半導體層211、一第二 半導體層212及一金屬層213。 第一半導體層211與第二半導體層212係相互連接以 形成一接面’以作為光能產生電子/電洞對之分離作用區。 如圖3所示，在本實施例中，第一半導體層211係為一打 ❿型半導體，第二半導體層212係為一 ρ型半導體，並作為 太陽電池之基板。當然，第一半導體層211亦可為一 ρ型 ★半導體，而第二半導體層212為一 η型半導體。其中，ρ 型半導體係以例如硼(boron)與鎵(gallium)等之摻質，摻雜 於石夕基板中而形成’而n型半導體係以例如磷 與砷(arsenic)等之摻質，摻雜於p型半導體内而形成，摻 雜之方式例如可以為擴散法或離子植入法。 金屬層213係以印刷或蒸空鍍膜方式形成於第二半導 體層212之一侧，在本實施例中，金屬層213之材質係包 9 200810134 含鋁，如圖4所示，其係顯示本實施例之光電轉換裝置2 的仰視圖，金屬層213係具有至少一第一溝槽214與至少 一第二溝槽215，第一溝槽214係將金屬層213區分為複 數個區塊2131，該等區塊2131係相互電性連接，藉由複 數第一溝槽214之圖案化而使金屬層213形成複數區塊 2131，且第一溝槽214或第二溝槽21.5係可穿設或不穿設 金屬層213,即分別形成彼此分離之該等區塊2131或藉由 ^ 第一溝槽214之底部相連接之該等區塊2131，其中彼此分 • 離之該等區塊2131則可藉由一導電元件216相互連接俾 使該等區塊2131電性連接，本實施例之導電元件216係 可由區塊2131之一侧延設形成。在本實施例中，第一溝 槽214之寬度範圍係約為0.1mm至10mm，較佳地，第一 溝槽214之寬度係約為3mm，區塊2131之面積係 20mm><22.5mm 〇 如圖4所示，在本實施例中，該等區塊2131之形狀 巍 係不限定，區塊2131可呈圓形、橢圓形或多邊形，而使 金屬層213呈一網狀結構或一蜂巢狀結構，以缓衝金屬層 213於高溫燒結過程中收縮之應力作用，避免發生翹曲之 現象。 如圖3所示，第一電極22係為一表面電極’即設置 於光電轉換裝置2之入光面，且第一電極22係與第一半 導體層211相連結，而為增加入射光之入射面積，第一電 極22係呈條狀、指狀或網狀；第二電極23則係為一背面 電極，設置於第二溝槽215中而與第二半導體層212相連 200810134 結，藉由第一電極22與第二電極23而得以輸出作用區所 產生之電流。其中，第一電極22或第二電極23以包含銀、 鋁、鈦或鉑之導電膠利用例如網印法形成。 另外’如圖3所示，本實施例之光電轉換裝置2更可 包含一抗反射層24設置於第一半導體層211之一侧，即 入光面之一侧，本實施例中，抗反射層24之材質係包含200810134 IX. Description of the invention: [Technical field to which the invention pertains] H is related to a conversion device, and more particularly to a photoelectric conversion device and a photoelectric conversion element thereof. [Prior Art] With the gradual shortage of the earth's energy resources, the development of new energy has become one of the focuses of science and industry and industry, and alternative energy products such as solar cells have become one of the development targets. A solar cell is a photoelectric conversion device that converts light energy into electrical energy by utilizing a photovoltaic effect, that is, a pn junction semiconductor absorbs light energy to generate free electrons and holes, and is built in near the pn junction semiconductor junction. The electric field drives the free electrons toward the n-type semiconductor, and the free holes move toward the p-type semiconductor, which in turn generates a current, and finally draws current through the electrodes to form electrical energy for use or storage. Referring to FIG. 1, a basic structure of a conventional solar cell 1 mainly includes a substrate 10, a p-n junction semiconductor η, an anti-reflection layer 12, and a metal electrode pair 13. The substrate 1 is a substrate of the solar cell i. Generally, the n-type semiconductor layer m or the p-type semiconductor layer 112 is directly used as the substrate 1 pn, and the pn junction semiconductor 11 is used to convert the light energy. The action area of the electric energy; the anti-reflection layer 12 is disposed on the light incident surface of the solar cell 1 to reduce the reflection of the incident light; the metal electrode pair 13 includes the first electrode 131 and the second electrode 132 respectively connected to the n-type The semiconductor layer 111 and the P-type semiconductor layer 112 are connected to the external circuit of the -200810134, wherein the first electrode 131 disposed on the light incident surface has a finger-like structure for effective light incident. In order to improve the photoelectric flow rate and the photoelectric conversion efficiency, it is known to form an aluminum (A1) metal layer 14 by printing or vapor deposition coating on the back side of the solar cell 1 structure, that is, the second electrode 132, as shown in FIG. Adjacent to the enlarged structure of the second electrode 132, the aluminum ions of the metal layer 14 internally diffuse the p-type semiconductor layer 112 to form a p+ type semiconductor layer ι41, wherein the P+ type semiconductor layer 141 is bonded to the p type semiconductor layer 112. The electric field built in 10 is called a back surface field (BSF), and the electrons moving toward the second electrode 132 are moved toward the n-type semiconductor layer 111 by the formation of the BSF, thereby increasing the photoelectric flow rate; For the hole moving toward the second electrode 132, the p + -type semiconductor layer 141 provides a low resistance ohmic contact, thereby effectively contributing to an improvement in photoelectric conversion efficiency. Xi Zhiming (Α1) metal layer 14 and metal electrode pair 13 must be formed by the process of excessive high temperature sintering, due to the shrinkage of the sintering process, and due to the difference in thermal expansion coefficient between the 10 metal material and the tantalum material, so during the sintering process The phenomenon of warping of the solar cell 1 is caused, and this phenomenon is more remarkable under the trend of the thinned stone substrate of the present day, and even causes the energy of the fragmentation in the subsequent process. ° With this in mind, how to provide a photoelectric conversion device and its photoelectric conversion element that avoids distortion and improves the photoelectric conversion efficiency is one of the important topics of today. SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a photoelectric conversion device and a photoelectric conversion device thereof that avoid warpage and improve photoelectric conversion efficiency. In order to achieve the above object, a photoelectric conversion element according to the present invention is electrically connected to a first electrode and a second electrode, and the photoelectric conversion element comprises a first semiconductor layer, a second semiconductor layer and a Metal layer. The second semiconductor layer is connected to the first semiconductor layer, the metal layer is disposed on one side of the second semiconductor layer, and the metal layer has at least one first trench and at least one second trench, first The trenches divide the metal layer into a plurality of blocks, and the second electrode is disposed in the second trench. In order to achieve the above object, a photoelectric conversion device according to the present invention comprises a photoelectric conversion element, a first electrode and a second electrode. Wherein the 'photoelectric conversion element has a first semiconductor layer, a second semiconductor layer and a metal layer, the second semiconductor layer is connected to the first semiconductor layer, and the metal layer is disposed on one side of the second semiconductor layer, the metal The layer has at least one first trench and at least one second trench, the first trench is formed by dividing the metal layer into a plurality of blocks; the first electrode is connected to the first semiconductor layer; and the second electrode is disposed In the second trench, and connected to the second semiconductor. According to the above, a photoelectric conversion device and an optical* electrical conversion device thereof according to the present invention utilize a trench (ie, a first trench) to divide a metal layer into a plurality of blocks, that is, the metal layer can be, for example, a mesh. a structure in which the stress generated by the metal layer in the high-temperature sintering process is dispersed, thereby effectively reducing the warpage of the metal layer due to high temperature, and therefore, the photoelectric conversion device including the metal layer structure of the present invention, In addition to the effect of increasing the photocurrent and lowering the impedance of 200810134, the fabrication yield of the photoelectric conversion device is further improved. [Embodiment] Hereinafter, a photoelectric conversion device and a photoelectric conversion element thereof according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings, wherein the same elements will be described with the same reference numerals. Referring to FIG. 3, a photoelectric conversion device 2 according to a preferred embodiment of the present invention includes a photoelectric conversion element 21, a first electrode 22 and a second electrode 23. In this embodiment, the photoelectric conversion device 2 is a solar cell. The photoelectric conversion element 21 has a first semiconductor layer 211, a second semiconductor layer 212, and a metal layer 213. The first semiconductor layer 211 and the second semiconductor layer 212 are interconnected to form a junction 'as a separation region for the generation of electron/hole pairs of light energy. As shown in Fig. 3, in the present embodiment, the first semiconductor layer 211 is a doped semiconductor, and the second semiconductor layer 212 is a p-type semiconductor and serves as a substrate for a solar cell. Of course, the first semiconductor layer 211 may also be a p-type semiconductor, and the second semiconductor layer 212 is an n-type semiconductor. Wherein, the p-type semiconductor is doped with a dopant such as boron or gallium, and is doped in a slate substrate to form 'the n-type semiconductor is doped with, for example, phosphorus and arsenic. It is formed by being doped into a p-type semiconductor, and the doping may be, for example, a diffusion method or an ion implantation method. The metal layer 213 is formed on one side of the second semiconductor layer 212 by printing or vapor deposition. In the present embodiment, the material of the metal layer 213 is made of aluminum, as shown in FIG. 4, which is shown in FIG. In a bottom view of the photoelectric conversion device 2 of the embodiment, the metal layer 213 has at least one first trench 214 and at least one second trench 215. The first trench 214 divides the metal layer 213 into a plurality of blocks 2131. The blocks 2131 are electrically connected to each other, and the metal layer 213 is formed into a plurality of blocks 2131 by patterning of the plurality of first trenches 214, and the first trench 214 or the second trench 21.5 is permeable or The metal layer 213 is not disposed, that is, the blocks 2131 are separated from each other or the blocks 2131 are connected by the bottom of the first trench 214, wherein the blocks 2131 are separated from each other. The blocks 2131 can be electrically connected by interconnecting a conductive member 216. The conductive member 216 of the present embodiment can be formed by one side of the block 2131. In this embodiment, the width of the first trench 214 ranges from about 0.1 mm to 10 mm. Preferably, the width of the first trench 214 is about 3 mm, and the area of the block 2131 is 20 mm. < 22.5 mm As shown in FIG. 4, in the present embodiment, the shape of the blocks 2131 is not limited, and the block 2131 may be circular, elliptical or polygonal, and the metal layer 213 may have a mesh structure or a The honeycomb structure absorbs the stress of the metal layer 213 during the high-temperature sintering process to avoid warping. As shown in FIG. 3, the first electrode 22 is a surface electrode 'that is disposed on the light incident surface of the photoelectric conversion device 2, and the first electrode 22 is coupled to the first semiconductor layer 211 to increase incident incidence of incident light. The first electrode 22 is in the form of a strip, a finger or a mesh; the second electrode 23 is a back electrode disposed in the second trench 215 and connected to the second semiconductor layer 212 by the 200810134 junction. An electrode 22 and a second electrode 23 are used to output a current generated by the active region. Among them, the first electrode 22 or the second electrode 23 is formed by a conductive paste containing silver, aluminum, titanium or platinum by, for example, screen printing. In addition, as shown in FIG. 3, the photoelectric conversion device 2 of the present embodiment may further include an anti-reflection layer 24 disposed on one side of the first semiconductor layer 211, that is, one side of the light incident surface. In this embodiment, anti-reflection The material of layer 24 is included
氮化矽、氧化鈦、氧化钽或氧化鈦；另外，如圖5所示， 本實施例之光電轉換裝置2亦可更包含一抗反射結構25 設置於第一半導體層211之一侧，抗反射結構25係具有 祓數凸塊，且该專凸塊的其中之一係呈金字塔型、倒金字 塔型或可降低反射之不規則型凸塊，藉由抗反射層24及/ 或抗反射結構25設置於入光面，降低入射光反射之機會， 進而提咼光電轉換裝置2之光電轉換效率。 因依據本發明之一種光電轉換裝置及其光電轉換元 件係利用溝槽（即第—溝槽）將金屬層區分為複數個區 塊’即金屬層可例如為-網狀結構，於此藉由溝槽分散金 屬層於高溫燒結過程中缝生的應力，而有效降低金屬層 因南溫所發生_曲現象，因此，包含本發明之 構的光電轉換裝置，除了具有辦 萄 咬果下，w， 切m降低阻抗的 效果下更獒鬲了光電轉換裝置之製作良率。 以上所述僅為舉例性，㈣為限制性去。 本發明之精神與料，㈣其騎 ％。任何未脫離 應包含於後附之申請專職射。仏改或變更’均 200810134 【圖式簡單說明】 圖1為顯示習知之一種太陽電池的示意圖，· 圖2為顯示習知之一種太陽電池的局部放大示意圖，· 圖3為一顯示依據本發明較佳實施例之一種光電轉換 裝置的示意圖； 圖4為一顯不依據本發明較佳實施例之一種光電轉換 裝置的仰视圖；以及 圖5為一顯不依據本發明另一較佳 一 • 轉換裝置的示意圖。 元件符號說明： 1 10 11 111 112 12 13 131 132 14 141 2 太陽電池 基板 p-η接合半導體 η型半導體層 ρ型半導體層 抗反射層 金屬電極對 第一電極 第二電極 金屬層 Ρ+型半導體層 光電轉換裝置 光電轉換元件 12 21 200810134 211 第一半導體層 212 第二半導體層 213 金屬層 2131 區塊 214 第一溝槽 215 第二溝槽 216 導電元件 22 第一電極 23 第二電極 24 抗反射層 25 抗反射結構In addition, as shown in FIG. 5, the photoelectric conversion device 2 of the present embodiment may further include an anti-reflection structure 25 disposed on one side of the first semiconductor layer 211. The reflective structure 25 has a number of bumps, and one of the special bumps is a pyramid type, an inverted pyramid type or an irregular type bump which can reduce reflection, by the anti-reflection layer 24 and/or the anti-reflection structure. 25 is disposed on the light incident surface to reduce the chance of reflection of the incident light, thereby improving the photoelectric conversion efficiency of the photoelectric conversion device 2. A photoelectric conversion device and a photoelectric conversion device thereof according to the present invention utilize a trench (ie, a first trench) to divide a metal layer into a plurality of blocks, that is, a metal layer may be, for example, a mesh structure. The groove-dispersed metal layer is sewed during the high-temperature sintering process, and effectively reduces the occurrence of the metal layer due to the south temperature. Therefore, the photoelectric conversion device including the structure of the present invention has the effect of the bite, w, The effect of cutting m to lower the impedance further spurs the production yield of the photoelectric conversion device. The above description is only exemplary, and (4) is restrictive. The spirit and material of the present invention, (4) its ride %. Any application that is not included in the attached application is a full-time shot. Tampering or changing 'both 200810134'. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a conventional solar cell, FIG. 2 is a partially enlarged schematic view showing a conventional solar cell, and FIG. 3 is a view showing a comparison according to the present invention. 4 is a schematic view of a photoelectric conversion device according to a preferred embodiment of the present invention; and FIG. 5 is a view showing another preferred conversion according to the present invention. Schematic diagram of the device. Description of the component symbols: 1 10 11 111 112 12 13 131 132 14 141 2 Solar cell substrate p-η bonded semiconductor n-type semiconductor layer p-type semiconductor layer anti-reflection layer metal electrode pair first electrode second electrode metal layer Ρ + type semiconductor Layer photoelectric conversion device photoelectric conversion element 12 21 200810134 211 first semiconductor layer 212 second semiconductor layer 213 metal layer 2131 block 214 first trench 215 second trench 216 conductive element 22 first electrode 23 second electrode 24 anti-reflection Layer 25 anti-reflection structure