201025633 六、發明說明： 【明 屬 3 技術領域 本發明係有關於矽太陽能電池及製造該太陽能電池的 5 方法，且詳而言之，係有關於高效率多晶矽太陽能電池及 製造該太陽能電池的方法。 C先前技術3 背景技術 太陽能電池在將太陽光直接轉換成電力之光電池技術 10 中是重要的元件，且被廣泛地使用在由科學領域至家庭的 各種應用中。 一太陽能電池基本上是一具有一p-n接面之二極體，且 其操作原理如下。當具有一大於一半導體之帶隙能量之能 量的太陽光照射在一太陽能電池之ρ-η接面上時，產生多數 15 電洞對。藉一在該ρ-η接面處產生之電場，電子被移送至11 層，而該等電洞則被移送至ρ層，藉此在該等ρ與η層之間產 生光電力。當該太陽能電池之兩端連接至一負載或一系統 時，於電流流動時產生電力。 依據用以形成一本質層（即，光吸收層）之材料，太陽能 20 電池被分類成多數種類。通常，具有由矽製成之本質層的 矽太陽能電池是最普遍者。目前有兩種矽太陽能電池：基 板型（單晶矽或多晶矽）太陽能電池及薄膜型（非晶質或多晶 矽）太陽能電池。除了這兩種太陽能電池以外，亦有CdTe 或CIS(CuInSe2)化合物薄膜太陽能電池、以III-V族材料為基 201025633 礎之太陽此電池、色素增感太陽能電池、有機太陽能電池 等。 相較於其他種類之太陽能電池，單晶石夕基板型太陽能 電池具有相當局的轉換效率，但卻具有由於利用單晶石夕晶 5圓而使製造成本非常高的致命弱點。又，多晶石夕基板型太 陽能電池可以相當低之製造成本製造，但是它們與單晶石夕 基板型太陽能電池並沒有太多不同，因為這兩種太陽能電 池均是由整塊原料製成。因此，它們的原料價格是昂貴的 且它的製造程序是複雜的，使得製造成本難以下降。 1〇 ㈣解決這些基板型太陽能電池之缺點的-種方法， 薄膜裂太陽能電池已受到許多注意，因為藉將一石夕薄膜沈 積在-如玻璃等基板上作為_本質層，它們的製造成本相 當低。事實上’該等薄膜型石夕太陽能電池可以製成為比該 基板蜇矽太陽能電池薄大約100倍。 15 薄膜域能電池先在㈣财切能電池中 發展出來，且開始被用在家庭中。由於非晶質石夕可以藉化 學蒸氣沈積(CVD)來形成，它大大地有助於非晶詩太陽能 電池之大量生產與低製造成本。但是，有一個問題是相^ 於該基板型碎太陽能電池之轉換效率，非晶質石夕薄膜太陽 20能電池之轉換效率太低。非晶質矽太陽能電池之低效率的 一可能之原因是a為在非晶f糾之大部㈣原子係以非 鍵結狀態存在，即，非晶質料有許多具有_之㈣子。 為了滅少這些懸鍵’非晶質石夕可以氫加以處理以形成具有 氫原子連接於具懸鍵之矽原子的氫化非晶質矽(a Si抝， 201025633 使得該局限狀態密度減少以增加效率。但是，該氫化非晶 質矽(a-Si : H)對光極為敏感，因此由這些材料製成之太陽 能電池老化且其效率亦下降（即，Staebler-Wronski效應）， 藉此在大量電力產生方面出現限制。 5 同時，多晶矽薄膜太陽能電池已發展成可補足前述非 晶質石夕薄膜太陽能電池之不足。利用多晶石夕作為一本質 層，多晶矽薄膜太陽能電池具有比使用非晶質矽作為一本 質層之非晶質矽薄膜太陽能電池更佳之效能。 【發明内容：！ 10 内容 技術問題 但是，這種多晶矽薄膜太陽能電池之一問題是不容易 製備多晶矽。詳而言之，多晶矽通常是透過一非晶質矽之 固相結晶製程獲得。該非晶質矽之固相結晶製程涉及一 10 15 小時期間之高溫(例如，等於或大於600°c)退火，而這並不 適合大量生產太陽能電池。特別地，其中必須使用一昂貴 的石英基板而不是一般的玻璃基板，以在該固相結晶製程 中承受這種等於或大於600°C之高溫，但這會增加太陽能電 池之製造成本。此外’該固相結晶製程會因為多晶矽晶粒 20 將朝一不規則方向成長且尺寸非常不規則而使一太陽能電 池之性質與效能變差亦是已知的。 技術解決方案 因此，本發明之一目的是提供一具有一高轉換效率之 多晶矽薄膜太陽能電池、及一製造該太陽能電池的方法。 5 201025633 本發明之另一目的是提供一可大量生產之多晶矽薄膜 太陽能電池及一製造該太陽能電池的方法。 有利效果 利用一多晶矽層，本發明之太陽能電池可以改善轉換 5 效率。 此外，當該多晶石夕層形成在一般玻璃基板上時，本發 明之太陽能電池可以較低之製造成本製造。 又，本發明之太陽能電池製造方法可以輕易地應用於 大量生產大型太陽能電池。 10 圖式說明 本發明之前述與其他目的與特徵可以由以下配合附圖 提出之較佳實施例說明而了解，其中： 第1圖顯示本發明一實施例之一太陽能電池的構形。201025633 VI. Description of the invention: [Mings 3] The present invention relates to a solar cell and a method for manufacturing the same, and more particularly to a high efficiency polycrystalline solar cell and a method of manufacturing the same . C. Prior Art 3 BACKGROUND OF THE INVENTION Solar cells are important components in photovoltaic cell technology 10 that convert sunlight directly into electricity, and are widely used in various applications from the scientific field to the home. A solar cell is basically a diode having a p-n junction, and its operation principle is as follows. When a solar light having an energy greater than the band gap energy of a semiconductor is irradiated onto a ρ-η junction of a solar cell, a majority of 15 hole pairs are produced. By the electric field generated at the ρ-η junction, electrons are transferred to the 11 layers, and the holes are transferred to the p layer, thereby generating photo power between the ρ and η layers. When both ends of the solar cell are connected to a load or a system, electric power is generated when current flows. Solar 20 cells are classified into a plurality of types depending on the material used to form an intrinsic layer (i.e., a light absorbing layer). Generally, tantalum solar cells having an intrinsic layer made of tantalum are the most common. There are currently two types of tantalum solar cells: substrate type (single crystal germanium or polycrystalline germanium) solar cells and thin film type (amorphous or polycrystalline germanium) solar cells. In addition to these two kinds of solar cells, there are also CdTe or CIS (CuInSe2) compound thin film solar cells, based on the III-V material, the solar cell of 201025633, the dye-sensitized solar cell, the organic solar cell, and the like. Compared with other types of solar cells, single crystal slab-type solar cells have the conversion efficiency of the phase authority, but have an achilles heel that is very expensive to manufacture due to the use of single crystal slabs. Further, polycrystalline solar substrate type solar cells can be manufactured at a relatively low manufacturing cost, but they are not much different from single crystal substrate type solar cells because both solar cells are made of a single piece of raw material. Therefore, their raw material prices are expensive and its manufacturing process is complicated, making manufacturing costs difficult to reduce. 1 〇 (4) A method for solving the shortcomings of these substrate type solar cells, the thin film splitting solar cell has received a lot of attention, because the deposition cost of a thin film is deposited on a substrate such as glass as an _essential layer, and their manufacturing cost is relatively low. . In fact, these thin film type solar cells can be made approximately 100 times thinner than the substrate 蜇矽 solar cells. 15 The thin film domain energy battery was first developed in the (four) financial energy battery and began to be used in the home. Since amorphous azure can be formed by chemical vapor deposition (CVD), it greatly contributes to mass production and low manufacturing cost of amorphous poetry solar cells. However, there is a problem that the conversion efficiency of the amorphous silicon solar cell is too low. One possible reason for the inefficiency of amorphous tantalum solar cells is that a is in the non-bonded state of the atomic system of the amorphous (f) atomic system, that is, many of the amorphous materials have the (four)th. In order to eliminate these dangling bonds, 'amorphous stone can be treated with hydrogen to form a hydrogenated amorphous ruthenium having a hydrogen atom bonded to a helium atom having a dangling bond (a Si拗, 201025633, which reduces the density of the confinement state to increase efficiency) However, the hydrogenated amorphous germanium (a-Si:H) is extremely sensitive to light, so solar cells made of these materials age and their efficiency is also lowered (ie, the Staebler-Wronski effect), thereby using a large amount of electricity At the same time, polycrystalline tantalum thin-film solar cells have been developed to complement the above-mentioned amorphous Shishi thin-film solar cells. Using polycrystalline as an intrinsic layer, polycrystalline tantalum thin-film solar cells have a higher ratio than amorphous germanium. As an intrinsic layer of amorphous tantalum thin film solar cell, better performance. [Inventive content:! 10] Technical problems However, one of the problems of such a polycrystalline tantalum thin film solar cell is that it is not easy to prepare polycrystalline germanium. In detail, polycrystalline germanium is usually Obtained through a solid phase crystallization process of amorphous germanium. The solid phase crystallization process of the amorphous germanium involves a 10 15 hour process. Annealing at a high temperature (for example, equal to or greater than 600 ° C), which is not suitable for mass production of solar cells. In particular, an expensive quartz substrate must be used instead of a general glass substrate in the solid phase crystallization process. Withstanding this high temperature equal to or greater than 600 ° C, but this will increase the manufacturing cost of the solar cell. In addition, the solid phase crystallization process will cause a solar cell because the polycrystalline germanium grains 20 will grow toward an irregular direction and the size is very irregular. A deterioration of the nature and performance is also known. Technical Solution Accordingly, it is an object of the present invention to provide a polycrystalline silicon thin film solar cell having a high conversion efficiency, and a method of manufacturing the same. 5 201025633 Another object is to provide a polycrystalline germanium thin film solar cell which can be mass-produced and a method of manufacturing the solar cell. Advantageous Effects The solar cell of the present invention can improve the conversion efficiency by using a polysilicon layer. Further, when the polycrystalline layer is When formed on a general glass substrate, the solar cell of the present invention can be compared Moreover, the solar cell manufacturing method of the present invention can be easily applied to mass production of large-scale solar cells. 10 The foregoing and other objects and features of the present invention can be derived from the following preferred embodiments. It is to be understood that: FIG. 1 shows a configuration of a solar cell according to an embodiment of the present invention.
K：實施方式]I 15 發明之最佳態樣 依據本發明之一方面，提供一種太陽能電池，其包含 多數石夕層’其中前述多數石夕層之至少一㈣含有一金屬組 份。 依據本發明之另一方面，提供一種太陽能電池，其包 2〇含一基板，—第一導電型矽層1，係形成在該基板上；一第 一導電型矽層11，係形成在該矽層I上；及一第二導電型矽 層III，係形成在該石夕層Π上’其中該等石夕層卜峨⑴之至 少一矽層含有一金屬組份。 依據本發明之又-方面，提供一種太陽能電池，其包 201025633 含：一基板；一第一導電型矽層i，係形成在該基板上；一 第一導電型矽層II，係形成在該矽層I上；及一第二導電型 矽層III，係形成在該矽層II上，其中該等矽層I、II與III之 至少一石夕層含有一金屬組份。 5 該基板可包含玻璃、塑膠、矽與金屬。 . 如果該第一導電型是一 η型，則該第二導電型是一p 型；且如果該第一導電型是一ρ型，則該第二導電型是一η 型。 • 該等抗反射矽層I、II與III之至少一矽層可以是一結晶 10 ί夕層。 該金屬組份可包括Ni、Al、Ti、Ag、Au、Co、Sb、Pd、K: Embodiment] I 15 BEST MODE FOR CARRYING OUT THE INVENTION According to one aspect of the invention, there is provided a solar cell comprising a plurality of layers, wherein at least one (four) of the plurality of layers of the foregoing layer contains a metal component. According to another aspect of the present invention, a solar cell is provided, which comprises a substrate, a first conductive type germanium layer 1 is formed on the substrate, and a first conductive type germanium layer 11 is formed thereon. And a second conductive type of germanium layer III formed on the layer of the earthworm layer, wherein at least one layer of the layer of the stone layer (1) contains a metal component. According to still another aspect of the present invention, a solar cell is provided, the package 201025633 comprising: a substrate; a first conductive type germanium layer i formed on the substrate; and a first conductive type germanium layer II formed thereon And a second conductive type germanium layer III formed on the germanium layer II, wherein at least one layer of the germanium layers I, II and III contains a metal component. 5 The substrate may comprise glass, plastic, tantalum and metal. If the first conductivity type is an n-type, the second conductivity type is a p-type; and if the first conductivity type is a p-type, the second conductivity type is an n-type. • At least one of the anti-reflective germanium layers I, II and III may be a crystalline 10 layer. The metal component may include Ni, Al, Ti, Ag, Au, Co, Sb, Pd,
Cu或其組合。 該太陽能電池更包含一在該基板與該矽層I之間的抗 反射層。 15 依據本發明之再一方面，提供一種製造一包含多數石夕 層之太陽能電池的方法，其中前述多數矽層之至少一矽層 @ 係、在-金屬組份存在下結晶。 依據本發明之另一方面，提供一種製造一太陽能電池 的方法，其包含以下步驟：製備一基板；在該基板上形成 20 一第一導電型矽層I;在該矽層I上形成一第二導電型矽層 II ;及在該矽層II上形成一第二導電型矽層III，其中一金屬 層形成在該等矽層I、II與III之至少一矽層上，且該方法更 包含將該等矽層I、II與m退火之步驟。 依據本發明之又一方面，提供一種製造一太陽能電池 7 201025633 的方法，其包含以下步驟：製備一基板；在該基板上形成 一第一導電型矽層I;在該矽層I上形成一第一導電型矽層 II ;及在該矽層II上形成一第二導電型矽層III，其中一金屬 層形成在該等矽層I、II與III之至少一矽層上，且該方法更 5 包含將該等矽層I、II與III退火之步驟。 該基板可包含玻璃、塑膠、矽與金屬。 如果該第一導電型是一η型，則該第二導電型是一p 型；且如果該第一導電型是一ρ型，則該第二導電型是一η 型〇 10 該等矽層I、II與III之至少一矽層可藉一退火製程來結 晶。 該金屬組份可包括Ni、Al、Ti、Ag、Au、Co、Sb、Pd、 Cu或其組合。 該太陽能電池更包含在該基板與該矽層I間形成一抗 15 反射層之步驟。 該等矽層I、II與III可藉一選自於低壓化學蒸氣沈積 (LPCVD)、電聚加強化學蒸氣沈積（PECVD)、及熱線化學 蒸氣沈積(HWCVD)之方法形成。 該金屬層可藉一選自於LPCVD、PECVD、原子層沈積 20 (ALD)、及濺鍍之方法形成。 該金屬層之厚度可被調整，以控制在該等矽層I、II與 III之至少一石夕層内的殘餘金屬量。 發明之態樣 以下，本發明之一示範性實施例將參照附圖詳細地說 201025633 明。 本發明之-多晶碎薄膜太陽能電池的特徵在於使用一 金屬觸媒以—降低結晶溫度之方式形成一多晶石夕層。長期 以來使用-金屬觸媒之方法(所謂__mic(金屬誘發結晶) -.5紐）已被用於多晶石夕TFT(薄膜電晶體），且該多晶石夕TFT係 . 作為如LCI)等平板顯示器之驅動元件。換言之，在製造一 多曰曰_TFT時最重要的製程是與在一低溫下結晶非晶質矽 有關，其中，特別地，使結晶溫度下降是必要的。雖然已 藝 #多種製程可供在一射豆時間内以一低溫形成多晶碎，但 10是在已知可藉使結晶溫度下降而應用於大量生產後，該 MIC方法引起許多注意。雖然使用一金屬觸媒之結晶製程 可以在一低溫下實施，但是由於在一TFT之作用區中存在相 當大的金屬量，漏電流會明顯增加。因此，事實上無法將 該MIC方法直接應用於製造多晶矽TFT。 15 有鑒於前述說明，本發明之發明人注意到如果用以使 用一金屬觸媒製備多晶矽之MIC方法被應用於製造一太陽 _ 能電池之一多晶矽層，則由金屬污染所造成之漏電流在該 太陽能電池中將不會如在該TFT中般嚴重。即，在一太陽能 電池中之多晶矽層事實上不需要與將該多晶矽層應用於一 20 TFT之作用區同樣地以高精度控制電性質。因此，即使有金 屬污染，亦不會造成一明顯的問題。 第1圖顯示本發明一實施例之一太陽能電池100的構 形。如第1圖所示，該太陽能電池100包括以一多層方式依 序積層在一基板10上之一抗反射層20、一透明導電層30、 9 201025633 一p+型矽層40、一η-型矽層50、一n+型矽層6〇、及一電極 70。 對這實施例之太陽能電池1〇〇而言，該基板10最好是由 一如玻璃或塑膠等透明材料製成，以吸收太陽光。該抗反 5射層20係用以藉確使通過該基板10射入之太陽光立即反射 至外側而不會被一矽層吸收’防止該太陽能電池之效率變 差。用於該抗反射層20之材料的例子可包括，但不限於， 矽氧化合物與矽氮化合物。該透明導電層30可讓太陽光穿 透且用以將該p+型碎層40電麴合至該電極7〇，為達此目 10 的，該透明導電層30可包括，例如，ιτο(銦錫氧化物）。 在該透明導電層30上的是一由該p+型碎層4〇、該n_型 碎層50與該n+型石夕層60構成之三層石夕結構，且這三層依序 積層以形成一薄膜矽太陽能電池之基本p-i-n結構。該p-i_n 結構係藉以一低密度在一高摻雜p+型矽層40及一高摻雜n+ I5 型碎層60之間掺雜一雜質來形成，藉此得到一相較於p+型 石夕層40與該n+型碎層60更具絕緣性之n_型碎層5〇。一典型 太陽能電池係設計成讓入射太陽光由該p側進入。 如前所述，雖然本發明之太陽能電池採用該p-i-n結構 作為其基本結構，但是本發明不限於此且可採用如一n_i-p 20 結構（即，一由n+矽層/p-矽層/p+矽層構成之積層結構）等其 他結構。若為該n-i-ρ結構，則由於太陽光由該p側，即，該 基板之相反側射入，所以該基板不一定要由如玻璃等透明 材料製成’且該基板可由例如妙或金屬製成。 此外，依據本發明先前所述之太陽能電池的構形，该1 201025633 側矽層之導電型與接觸該基板之矽層的導電型相反但是 本發明不限於此。即，一太陽能電池可以藉將該丨側矽層設 定為具有與接觸該基板之矽層之導電型相同的導電型。 總之，本發明之太陽能電池可採用由該基板向上看時 5之以下結構的任一者：P+矽層/n-矽層/n+矽層、n+矽層/p_ 石夕層/p+碎層、P+矽層/p_矽層/n+矽層、及n+矽層/n_矽層/p+ 矽層。以下’針對第丨圖所示之構形說明，即，p+型矽層4〇/n_ 型矽層50/n+型矽層60。 同時，該太陽能電池100之另一特徵是由p+型矽層4〇/n_ 10型石夕層50/Π+型石夕層60製成之至少一層係—多晶碎層且最 好所有的P+型石夕層40/n_型石夕層5〇/11+型石夕層6〇均是由多晶 石夕製成。簡言之，該多晶石夕薄膜太陽能電池是有利的，因 為它可以-相當低之價格透過利用其保留量與一原料一樣 多之秒的薄膜太陽能電池製造程序來大量生產且同時它 15具有-較佳之效率，因為多晶石夕本身具有比非晶詩更高 之電子移動性。 以下是有關於本發明-實施例之太陽能電池⑽的製 造方法。 20 =在第纟驟中’製備一基板10。如前所述，該基板 10最好是麵等翻材㈣成。此外，該基板1〇可 進行-表面紋卿成(te咖^ng)製程，以改善該太陽能電池 之效率。紐理形成製程完祕可防止-域能電池之 土板表面由於入射光之反射造成之光損失而破壞其性質。 因此’該紋理形成製程主要包括使在-太陽能祕中所使 11 201025633 用之目標基板的一表面粗糙，即，在一基板之表面上形成 一不規則圓案。一旦該基板之表面藉形成紋理而變粗糙， · 則反射一次之光將再次反射且降低入射光之反射能力，使 得較多量之光被捕捉，以減少光損失。 5 在下一步驟中，在該基板10上形成一抗反射層20。如 - 前所述，該抗反射層20可包括一矽氧化物或矽氮化物，且 可藉低壓化學蒸氣沈積(LPCVD)、電漿加強化學蒸氣沈積 (PECVD)等形成。 在下一步驟中，在該抗反射層2〇上形成一透明導電層 參 10 30。如前所述，該透明導電層3〇可包括IT〇(銦錫氧化物）， 且可藉濺鍍等形成。 在下—步驟中，在該透明導電層3〇上形成ρ+型矽層 40/η-型矽層5〇/η+型矽層6〇。這三層矽積層係藉LpcVD、 PECVD、熱線化學蒸氣沈積(HWCVD)等以一非晶質矽狀 15態形成或成長，且該二層石夕積層最好在形成該非晶質石夕層 時藉現場摻雜被n型掺雜或P型摻雜。通常，鱗(P)被用來作 為η型摻雜之雜質，且硼(Β)或砷(As)被用來作為ρ型摻雜之 參 '、 ^層石夕積層之厚度與摻雜濃度最好依循被摻雜在 多曰曰石夕薄膜太陽能電池甲之典型P-i-n結構的厚度與摻雜 20濃度。 ’ 在下—步驟中，在非晶質狀態中之P+型矽層40/Π-型石夕 層50/n+型矽層6〇結晶形成一多晶p+型矽層撕打型石夕層 50/Π+型矽層6〇。 本發明利用該MIC方法將該非晶質碎結晶成多晶石夕。 12 201025633 為達此目的，先將一金屬層沈積在一非晶質矽層上且進行 結晶-退火製程。該金屬層形成在由p+型矽層4〇/n_型矽層 50/n+型矽層60結構之至少一層上，且該金屬層所使用之材 料可選自於Ni、Al、Ti、Ag、Au、Co、Sb、Pd、及 Cu，而 5這些材料可以單獨或組合兩或兩種以上來使用。該金屬層 係藉LPCVD、PECVD、原子層沈積(ALD)、濺鍍等形成。 該結晶-退火製程係在—典型退火爐中進行，且最好是在 400-700°C之條件下進行u1〇小時。 在此同時，於使用該MIC之結晶-退火製程後，在該多 1〇晶矽層内殘留之金屬量可以藉調整欲沈積在該非晶質矽層 上之金屬量來控制。調整該金屬量之一種方法是調整被沈 積在該非晶質矽層上之金屬層厚度，但本發明不限於此。 在某些例子中，該金屬層必須做成比 一原子層更薄，以保 持在該多晶矽層内之殘留金屬的量為最少。在此，將該構 15件做成比一原子層更薄表示假如該非晶質矽層之整個面積 未被該沈積金屬層完全覆蓋，則該金屬層被稀疏地沈積在 该非晶質矽層上（覆蓋率<1}而不是被連續地沈積。換言之， 如果該金屬層以例如小於丨之覆蓋率被沈積，則可在已沈積 在非晶質矽層上之金屬原子之間沈積更多的金屬原子。 2Q / 最後，分別在該透明導電層30及該n+型矽層60上形成 電極70 ’以藉此獲得—完成形態之多晶矽薄膜太陽能電 池1〇〇。該電極70係由一如鋁之導電材料製成，且可以藉熱 蒸發、濺鍍等形成。 雖然先前已說明一單一接面太陽能電池作為本發明之 13 201025633 一實施例，但是本發明不限於此且亦可包括一雙接面（稱為 所謂串聯結構）太陽能電池、一三接面太陽能電池等作為另 一實施例。換言之，雙與三接面太陽能電池或任何其他太 陽能電池及其製造方法均應被視為屬於本發明之範圍，只 5 要構成一太陽能電池之多晶矽層之至少一層含有一金屬組 份即可。 如前所述，本發明之多晶矽薄膜太陽能電池100及其製 造方法之優點在於非晶質矽在一低溫下利用該ΜIC方法被 結晶成多晶石夕，藉此可使用一般玻璃作為一基板。因此， 10 該太陽能電池之轉換效率因多晶矽而改善，且其製造成本 亦可減少。 雖然本發明已對該等較佳實施例顯示與說明過了，但 是發明所屬技術領域中具有通常知識者應了解的是，在不 偏離在以下申請專利範圍所界定之本發明之精神與範疇的 15 情形下，可以進行各種變化與修改。 t圖式簡單說明3 第1圖顯示本發明一實施例之一太陽能電池的構形。 【主要元件符號說明】 10...基板 50...η-型石夕層 20...抗反射層 60.·.η+型矽層 30...透明導電層 70...電極 40...p+型矽層 100...太陽能電池Cu or a combination thereof. The solar cell further includes an anti-reflective layer between the substrate and the germanium layer 1. According to still another aspect of the present invention, there is provided a method of fabricating a solar cell comprising a majority of the enamel layer, wherein at least one of the plurality of ruthenium layers is crystallized in the presence of a metal component. According to another aspect of the present invention, there is provided a method of fabricating a solar cell comprising the steps of: preparing a substrate; forming a first conductive type germanium layer I on the substrate; forming a first layer on the germanium layer I a second conductive type germanium layer II; and a second conductive type germanium layer III formed on the germanium layer II, wherein a metal layer is formed on at least one of the germanium layers I, II and III, and the method is further A step of annealing the ruthenium layers I, II and m is included. According to still another aspect of the present invention, a method for manufacturing a solar cell 7 201025633 is provided, comprising the steps of: preparing a substrate; forming a first conductive type germanium layer I on the substrate; forming a layer on the germanium layer I a first conductive type germanium layer II; and a second conductive type germanium layer III formed on the germanium layer II, wherein a metal layer is formed on at least one of the germanium layers I, II and III, and the method Further, 5 includes the step of annealing the ruthenium layers I, II and III. The substrate may comprise glass, plastic, tantalum and metal. If the first conductivity type is an n-type, the second conductivity type is a p-type; and if the first conductivity type is a p-type, the second conductivity type is an n-type 〇10 At least one layer of I, II and III may be crystallized by an annealing process. The metal component can include Ni, Al, Ti, Ag, Au, Co, Sb, Pd, Cu, or a combination thereof. The solar cell further comprises the step of forming an anti-15 reflective layer between the substrate and the germanium layer 1. The ruthenium layers I, II and III can be formed by a method selected from the group consisting of low pressure chemical vapor deposition (LPCVD), electropolymerization enhanced chemical vapor deposition (PECVD), and hot line chemical vapor deposition (HWCVD). The metal layer can be formed by a method selected from the group consisting of LPCVD, PECVD, atomic layer deposition 20 (ALD), and sputtering. The thickness of the metal layer can be adjusted to control the amount of residual metal in at least one of the layers of the layers I, II and III. MODE FOR CARRYING OUT THE INVENTION Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. The polycrystalline thin film solar cell of the present invention is characterized in that a metal catalyst is used to form a polycrystalline layer in a manner to lower the crystallization temperature. The method of using a metal catalyst for a long time (so-called __mic (metal induced crystallization) -.5 NZ) has been used for polycrystalline lithographic TFT (thin film transistor), and the polycrystalline slab TFT system. As LCI ) The driving components of flat panel displays. In other words, the most important process in the fabrication of a multi-turn _TFT is related to the crystallization of amorphous yttrium at a low temperature, wherein, in particular, it is necessary to lower the crystallization temperature. Although the technocratic process can be used to form polycrystalline granules at a low temperature during a shot time, the MIC method has attracted much attention after it has been known to be applied to mass production by a drop in crystallization temperature. Although the crystallization process using a metal catalyst can be carried out at a low temperature, the leakage current is significantly increased due to the presence of a relatively large amount of metal in the active region of a TFT. Therefore, the MIC method cannot be directly applied to the fabrication of a polycrystalline germanium TFT. In view of the foregoing description, the inventors of the present invention have noted that if the MIC method for preparing polycrystalline germanium using a metal catalyst is applied to the fabrication of a polycrystalline germanium layer of a solar cell, the leakage current caused by metal contamination is The solar cell will not be as severe as in the TFT. Namely, the polysilicon layer in a solar cell does not need to control the electrical properties with high precision as much as the application of the polysilicon layer to the active region of a 20 TFT. Therefore, even if there is metal pollution, it will not cause an obvious problem. Fig. 1 shows the configuration of a solar cell 100 according to an embodiment of the present invention. As shown in FIG. 1 , the solar cell 100 includes an anti-reflection layer 20, a transparent conductive layer 30, and a high-conductivity layer 30, 9 201025633, a p+ type germanium layer 40, and a η- layer on a substrate 10 in a multi-layer manner. The ruthenium layer 50, an n+ type ruthenium layer 6 〇, and an electrode 70. For the solar cell 1 of this embodiment, the substrate 10 is preferably made of a transparent material such as glass or plastic to absorb sunlight. The anti-reflection layer 20 is used to ensure that the sunlight incident through the substrate 10 is immediately reflected to the outside without being absorbed by a layer of ’ to prevent the efficiency of the solar cell from being deteriorated. Examples of materials for the anti-reflective layer 20 may include, but are not limited to, a ruthenium compound and a ruthenium nitride compound. The transparent conductive layer 30 can penetrate the sunlight and electrically couple the p+ type layer 40 to the electrode 7. For the purpose of the object 10, the transparent conductive layer 30 can include, for example, ιτο (indium). Tin oxide). On the transparent conductive layer 30 is a three-layered stone structure composed of the p+ type fracture layer 4, the n_ type fracture layer 50 and the n+ type stone layer 60, and the three layers are sequentially laminated. Forming a basic pin structure of a thin film tantalum solar cell. The p-i_n structure is formed by doping an impurity between a highly doped p+ type germanium layer 40 and a highly doped n+ I5 type ground layer 60 at a low density, thereby obtaining a phase compared to the p+ type stone. The layer 40 is more insulating with the n+ type layer 60. A typical solar cell system is designed to allow incident sunlight to enter from the p-side. As described above, although the solar cell of the present invention employs the pin structure as its basic structure, the present invention is not limited thereto and may employ an n_i-p 20 structure (i.e., an n+矽 layer/p-矽 layer/p+ Other structures such as a laminate structure composed of a ruthenium layer). In the case of the ni-ρ structure, since the sunlight is incident from the p side, that is, the opposite side of the substrate, the substrate does not have to be made of a transparent material such as glass, and the substrate can be made of, for example, a metal or a metal. production. Further, according to the configuration of the solar cell previously described in the present invention, the conductivity type of the side layer of the 1 201025633 is opposite to the conductivity type of the layer of the layer contacting the substrate, but the invention is not limited thereto. That is, a solar cell can be configured to have the same conductivity type as the conductivity type of the germanium layer contacting the substrate. In summary, the solar cell of the present invention may adopt any of the following structures of 5 or less when viewed from the substrate: P+矽 layer/n-矽 layer/n+矽 layer, n+矽 layer/p_石夕 layer/p+碎 layer, P+矽 layer/p_矽 layer/n+矽 layer, and n+矽 layer/n_矽 layer/p+矽 layer. The following description is for the configuration shown in the figure, that is, the p+ type germanium layer 4〇/n_ type germanium layer 50/n+ type germanium layer 60. Meanwhile, another feature of the solar cell 100 is at least one layer-polycrystalline layer and preferably all of the p+ type 矽 layer 4〇/n_10 type shi layer 50/Π+ type shi layer 60. The P+ type Shixia layer 40/n_ type Shixi layer 5〇/11+ type Shixi layer 6〇 is made of polycrystalline stone eve. In short, the polycrystalline silicon solar cell is advantageous because it can be mass-produced at a relatively low price by using a thin film solar cell manufacturing process that retains as much as one second of a raw material and at the same time it has - Better efficiency, since polycrystalline stone itself has a higher electron mobility than amorphous poetry. The following is a method of producing a solar cell (10) according to the present invention. 20 = In the second step, a substrate 10 was prepared. As described above, the substrate 10 is preferably formed by turning the surface (4). In addition, the substrate 1 can be subjected to a surface etching process to improve the efficiency of the solar cell. The formation of the New Zealand process prevents the surface of the earthen battery from damaging its properties due to the loss of light caused by the reflection of incident light. Therefore, the texture forming process mainly includes roughening a surface of the target substrate used in the solar cell, i.e., forming an irregular circle on the surface of a substrate. Once the surface of the substrate is roughened by texture, the light that reflects once will again reflect and reduce the ability of the incident light to reflect, allowing a greater amount of light to be captured to reduce light loss. 5 In the next step, an anti-reflection layer 20 is formed on the substrate 10. As previously described, the anti-reflective layer 20 may comprise a tantalum oxide or tantalum nitride and may be formed by low pressure chemical vapor deposition (LPCVD), plasma enhanced chemical vapor deposition (PECVD), and the like. In the next step, a transparent conductive layer 510 is formed on the anti-reflective layer 2''. As described above, the transparent conductive layer 3A may include IT〇 (indium tin oxide), and may be formed by sputtering or the like. In the next step, a p + type germanium layer 40 / n - type germanium layer 5 / n + type germanium layer 6 is formed on the transparent conductive layer 3 . The three-layer stratified layer is formed or grown in an amorphous 矽-like 15 state by LpcVD, PECVD, hot-line chemical vapor deposition (HWCVD), etc., and the two-layer diagenetic layer is preferably formed in the amorphous slab layer. The doping by the field is doped with n-type or P-type. Generally, the scale (P) is used as an impurity of the n-type doping, and boron (germanium) or arsenic (As) is used as the p-type doping, the thickness and doping concentration of the layered layer. It is preferable to follow the thickness and doping 20 concentration of a typical Pin structure doped in a polysilicon solar cell. In the next step, the P+ type 矽 layer 40/Π-type 石 layer 50/n+ type 矽 layer 6 〇 crystal in the amorphous state forms a polycrystalline p+ type 矽 layer tearing type shi layer 50/ Π + type 矽 layer 6 〇. The present invention utilizes the MIC method to pulverize the amorphous material into polycrystalline spine. 12 201025633 To achieve this, a metal layer is first deposited on an amorphous germanium layer and subjected to a crystallization-annealing process. The metal layer is formed on at least one layer of the p+ type germanium layer 4〇/n_type germanium layer 50/n+ type germanium layer 60, and the material used for the metal layer may be selected from Ni, Al, Ti, Ag. , Au, Co, Sb, Pd, and Cu, and 5 of these materials may be used alone or in combination of two or more. The metal layer is formed by LPCVD, PECVD, atomic layer deposition (ALD), sputtering, or the like. The crystallization-annealing process is carried out in a typical annealing furnace, and preferably at a temperature of 400 to 700 ° C for u1 Torr. At the same time, after the crystallization-annealing process using the MIC, the amount of metal remaining in the polysilicon layer can be controlled by adjusting the amount of metal to be deposited on the amorphous layer. One method of adjusting the amount of the metal is to adjust the thickness of the metal layer deposited on the amorphous germanium layer, but the invention is not limited thereto. In some instances, the metal layer must be made thinner than an atomic layer to maintain a minimum amount of residual metal in the polysilicon layer. Here, the 15 members are made thinner than the one atomic layer to indicate that if the entire area of the amorphous germanium layer is not completely covered by the deposited metal layer, the metal layer is sparsely deposited on the amorphous germanium layer. (coverage <1} instead of being deposited continuously. In other words, if the metal layer is deposited at a coverage of, for example, less than erbium, more deposition may be deposited between metal atoms that have been deposited on the amorphous germanium layer. 2Q / Finally, an electrode 70' is formed on the transparent conductive layer 30 and the n+ type germanium layer 60, respectively, thereby obtaining a polycrystalline germanium thin film solar cell of the completed form. The electrode 70 is composed of It is made of a conductive material of aluminum and can be formed by thermal evaporation, sputtering, etc. Although a single junction solar cell has been previously described as an embodiment of the present invention 13 201025633, the present invention is not limited thereto and may include a pair a junction (referred to as a so-called series structure) solar cell, a three-junction solar cell, etc. as another embodiment. In other words, dual and triple junction solar cells or any other solar cell and its manufacture The method should be considered as belonging to the scope of the present invention, and only at least one layer of the polycrystalline germanium layer constituting a solar cell contains a metal component. As described above, the polycrystalline germanium thin film solar cell 100 of the present invention and the method of manufacturing the same The advantage is that the amorphous germanium is crystallized into polycrystalline silicon by the ΜIC method at a low temperature, whereby ordinary glass can be used as a substrate. Therefore, the conversion efficiency of the solar cell is improved by polysilicon, and its fabrication is improved. The present invention has been shown and described with respect to the preferred embodiments thereof, and it should be understood by those of ordinary skill in the art that the present invention is defined without departing from the scope of the following claims. Various changes and modifications can be made in the case of the spirit and the category of the present invention. Fig. 1 is a view showing the configuration of a solar cell according to an embodiment of the present invention. [Description of main components] 10... 50...η-type stone layer 20...anti-reflection layer 60.·.n+-type layer 30...transparent conductive layer 70...electrode 40...p+type layer 100... Solar battery