201131788 142、 144、146、148:漸變附屬層 143、 145、147:碲摻雜中間層 149:第二緩衝層 五、本案若有化學式時， 請揭示最能__特_化學式： 六、發明說明：201131788 142, 144, 146, 148: Gradient auxiliary layer 143, 145, 147: 碲 doped intermediate layer 149: second buffer layer 5. If there is a chemical formula in this case, please reveal the most __ special _ chemical formula: Description:
【發明所屬之技術領域】 種具有漸變緩衝層 本發明係關於一光電元件，尤其關於一 的太陽能電池。 ' 【先前技術】 光電元件包含許多種類，例如發光二極體（Light emitting Diode ; LED)、太陽能電池(SGlar⑽)或光電二極體(ph〇t〇 Diode)等。 • 由於石化能源紐缺，且人們對環保重要性的認知提高，因 此人們近年來不斷地積極研發替代能源與再生能源的相關技 術，其中以太陽能電池最受矚目。主要是因為太陽能電池可直 接將太陽能轉換成電能，且發電過程中不會產生二氧化碳或氮 化物等有害物質，不會對環境造成污染。太陽能電池中又以 InGaP/GaAs/Ge的三接面太陽能電池最具發展潛力，然而 InGaP、GaAs和Ge的彼此的晶格常數不匹配，由Ge電池向 上依序成長GaAs電池與InGaP電池時，晶格之間會形成晶格 錯位，產生應力，破壞磊晶的品質，降低太陽能電池的能量轉 換效率。 m 2 201131788 反向變質多接面（Inverted Metamorphic Multijunction ; IMM)太陽能電池是在一成長基板上依序先成長晶格常數匹配 的GalnP電池及GaAs電池，接著再成長晶格常數與GalnP電 池及GaAs電池不匹配的inGaAs電池，將一支持基板與InGaAs 電池接合後移除成長基板，形成反向變質多接面(IMM)太陽能 電池。如此改善GalnP電池及GaAs電池的蟲晶品質，提高太 陽電池的能量轉換效率。但是在能隙較低的InGaAs電池仍會 產生晶格錯位’降低InGaAs電池的蠢晶品質。 上述如太陽能電池等之光電元件可包含基板及電極，可進 一步地經由焊塊或膠材將基板與一基座連接，而形成一發光裝 置或一吸光裝置。另外，基座更具有至少一電路，經由一導電 結構，例如金屬線，電連接光電元件之電極。 【發明内容】 第一實施例之一反向變質多接面（IMM)太陽能電池至少 包含一支持基板；一底電池位於支持基板之上；一漸變緩衝層 位於底電池之上；一中間電池位於漸變緩衝層之上；以及一頂 電池位於中間電池之上。 【實施方式】 本發明之實施例會被詳細地描述，並且繪製於圖式中，相 同或類似的部分會以相同的號碼在各圖式以及說明出現。 如第1圖所示，一反向變質多接面（IMM)太陽能電池1 包含一支持基板10 ; —底電池12位於支持基板10之上；一 漸變緩衝層14位於底電池12之上；一中間電池16位於漸變 緩衝層14之上；以及一頂電池18位於中間電池16之上。。 頂電池18之能隙大於中間電池16與底電池12之能隙，其材 201131788BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a photovoltaic element, and more particularly to a solar cell. [Prior Art] Photoelectric elements include many types, such as a light emitting diode (LED), a solar cell (SGlar (10)), or a photodiode (ph〇t〇 Diode). • Due to the shortage of petrochemical energy and the increasing awareness of the importance of environmental protection, people have been actively researching and developing technologies related to alternative energy and renewable energy in recent years, among which solar cells are attracting the most attention. The main reason is that solar cells can directly convert solar energy into electric energy, and no harmful substances such as carbon dioxide or nitrogen are generated during power generation, and the environment is not polluted. In the solar cell, the InGaP/GaAs/Ge three-junction solar cell has the greatest development potential. However, the lattice constants of InGaP, GaAs and Ge do not match each other. When the Ge cell is sequentially grown up to the GaAs cell and the InGaP cell, Lattice misalignment occurs between the crystal lattices, stress is generated, the quality of the epitaxial crystal is destroyed, and the energy conversion efficiency of the solar cell is lowered. m 2 201131788 Inverted Metamorphic Multijunction (IMM) solar cell is a GalnP cell and GaAs cell that grows lattice constants on a growing substrate, and then grows lattice constants with GalnP cells and GaAs. A battery mismatched inGaAs battery, a support substrate is bonded to an InGaAs battery, and the growth substrate is removed to form an inverse metamorphic multi-junction (IMM) solar cell. This improves the quality of the crystal of the GalnP battery and the GaAs battery, and improves the energy conversion efficiency of the solar battery. However, in the InGaAs cell with a lower energy gap, lattice misalignment is still produced, which reduces the stupid crystal quality of the InGaAs cell. The above-mentioned photovoltaic element such as a solar cell or the like may include a substrate and an electrode, and the substrate may be further connected to a susceptor via a solder bump or a glue to form a light-emitting device or a light absorbing device. In addition, the pedestal further has at least one circuit electrically connected to the electrodes of the photovoltaic element via a conductive structure, such as a metal line. SUMMARY OF THE INVENTION A first embodiment of an inverse metamorphic multi-junction (IMM) solar cell includes at least one support substrate; a bottom cell is disposed over the support substrate; a graded buffer layer is disposed over the bottom cell; and an intermediate cell is located Above the gradient buffer layer; and a top battery is located above the intermediate battery. [Embodiment] The embodiments of the present invention will be described in detail, and in the drawings, the same or the like As shown in FIG. 1, an inverse metamorphic multi-junction (IMM) solar cell 1 includes a support substrate 10; a bottom cell 12 is disposed on the support substrate 10; and a graded buffer layer 14 is disposed on the bottom cell 12; The intermediate battery 16 is located above the graded buffer layer 14; and a top cell 18 is located above the intermediate battery 16. . The energy gap of the top battery 18 is greater than the energy gap between the intermediate battery 16 and the bottom battery 12, and the material thereof 201131788
料包含 InGaP、InGaAs、AlGaAs 或 AlGalnP。中間電池 μ 之 能隙大於底電池12之能隙’其材料包含GaAs、GalnP、 InGaAs、GaAsSb 或 InGaAsN。底電池 12 之材料包含 Ge、GaAS 或InGaAs。頂電池18、中間電池16與底電池12可以吸收不 同頻譜之光線並產生電流。 如第2圖所示，漸變緩衝層14包含一第—緩衝層mi位 於底電池Π與中間電池16之間；複數個漸變附屬層142、144、 146與148位於第一緩衝層141與中間電池16之間；複數個碲 摻雜中間層143、145與147位於彼此相鄰之複數個漸變附屬 層142、144、146與148之間；以及一第二緩衝層149位於漸 變附屬層148與中間電池16之間。本實施例之漸變附屬層以 14 2、144、146與148四層為例’但不限於此，漸變附屬層之 數罝亦可為大於四或小於四。本實施例之碲摻雜中間層以 143、145與147三詹為例，但不限於此，碲摻雜中間層之數量 亦可為大於三或小於三。第一緩衝層141之材料包含InGaAs、The material contains InGaP, InGaAs, AlGaAs or AlGalnP. The intermediate cell μ has an energy gap larger than the energy gap of the bottom cell 12, and the material thereof includes GaAs, GalnP, InGaAs, GaAsSb or InGaAsN. The material of the bottom cell 12 comprises Ge, GaAS or InGaAs. The top cell 18, the intermediate cell 16 and the bottom cell 12 can absorb light of different spectrums and generate current. As shown in FIG. 2, the gradation buffer layer 14 includes a first buffer layer mi between the bottom cell and the intermediate cell 16; a plurality of gradual auxiliary layers 142, 144, 146 and 148 are located in the first buffer layer 141 and the intermediate battery. 16; a plurality of erbium doped intermediate layers 143, 145 and 147 are located between a plurality of gradual subsidiary layers 142, 144, 146 and 148 adjacent to each other; and a second buffer layer 149 is located between the gradual auxiliary layer 148 and the middle Between the batteries 16. The gradation auxiliary layer of this embodiment is exemplified by four layers of 1, 2, 144, 146 and 148, but is not limited thereto, and the number of gradation auxiliary layers may be greater than four or less than four. The erbium-doped intermediate layer of this embodiment is exemplified by 143, 145 and 147, but is not limited thereto, and the number of the erbium-doped intermediate layer may be more than three or less than three. The material of the first buffer layer 141 includes InGaAs,
GaAs、AlGaAs、InGaP 或 AlGalnP ;第二緩衝層 149 之材料包 含GaAs。複數個附屬漸變層142、144、146與148之材料包 含 InxGadwP、inxGa^-^s 或(AlyGa^XIiid^s，其中複數個 漸變附屬層之In含量X自靠近支持基板往遠離支持基板之方向 遞減’且0<x<:l，〇<y<卜複數個漸變附屬層142、144、146 與148僅被摻雜n型雜質，例如矽、硒或硫，濃度約為 3~E20cnf3，未被摻雜碲(Te)。複數個碲摻雜中間層143、 145與147被摻雜碲(Te)與η型雜質，厚度約為1A-500A，其 :η型雜質例如為矽、硒或硫，濃度約為E17em-3_E2〇Cm·3，碲 >辰度約為E17cnT3-E20cnf3。複數個碲摻雜中間層143、145 與 147 之材料包含1nxGa(1.x)P、InGaAs 或 AlInGaAs，〇<x<1。 201131788 以蹄摻雜中間層143為例，形成碲摻雜中間層⑷的方法包含 在成長氣室形成漸_屬層之後，持續通人形成漸變附屬 層144之氣體，同時通入具有n型雜質的叫成與具有蹄雜質 的DCTe以形成碲摻雜中間層143，上述同時通入具有雜質之 反應氣體之時間約為_秒，碌掺雜中間層⑷與w的形成 法與碎穆雜^間層143類似。由於反向變質多接面(麵^太 陽能電池1是在—絲基板(細示)上依序先成長晶格常數匹 配的頂電池18及中間電池16，接著再成長晶格常數與頂電池 • 18及中間電池16不匹配的底電池12，將-支持基板10與底 電池12接σ後移除成長基板，形成反向變質多接面(祕太陽 能電池1’所以底電池12與中間電池16之間會產生晶格錯位。 漸變緩衝層14可減少底電池12射間電池16之間晶格錯位 的產生，碲可改善漸變附屬層142、144、146與148的蟲晶品 $，有助漸變緩衝層14降低因底電池12與中間電池16晶格 常數不匹配所產生的應力，提升底電池12縣晶品質。 准上述實把例僅為例示性說明本發明之原理及其功效， » ❿非限制本發明。任何本發明所屬技術領域中具有通常知 識者均可在树背本發明之技術棘及精神的情況下，對上述 實施例進行修改及變化。因此本發明之權利保護範圍如後述之 申請專利範圍所列。 【圖式簡單說明】 圖式用以促進對本發明之理解，係本說明書之一部分。 圖式之實施例配合實施方式之說明以解釋本發明之原理。 第1圖係依據本發明之第一實施例之剖面圖。 201131788 第2圖係依據本發明之第一實施例之漸變緩衝層之剖面 圖。 【主要元件符號說明】 1:太陽能電池 10:支持基板 12:底電池 14:漸變緩衝層 141:第一缓衝層 142、 144、146、148:漸變附屬層 143、 145、147:碲摻雜中間層 149:第二緩衝層 16:中間電池 18:頂電池GaAs, AlGaAs, InGaP or AlGalnP; the material of the second buffer layer 149 contains GaAs. The material of the plurality of auxiliary gradient layers 142, 144, 146 and 148 comprises InxGadwP, inxGa^-^s or (AlyGa^XIiid^s, wherein the In content X of the plurality of graded auxiliary layers is from the support substrate to the support substrate Decrement 'and 0 < x <: l, 〇 < y < s complex gradient sub-layers 142, 144, 146 and 148 are only doped with n-type impurities, such as germanium, selenium or sulfur, at a concentration of about 3 to E20cnf3, It is not doped with yttrium (Te). The plurality of yttrium-doped intermediate layers 143, 145 and 147 are doped with yttrium (Te) and n-type impurities, and have a thickness of about 1 A to 500 A, and the η-type impurities are, for example, bismuth and selenium. Or sulfur, the concentration is about E17em-3_E2〇Cm·3, 碲> is about E17cnT3-E20cnf3. The material of the plurality of yttrium-doped intermediate layers 143, 145 and 147 comprises 1nxGa(1.x)P, InGaAs or AlInGaAs, 〇 <x<1. 201131788 Taking the hoof-doped intermediate layer 143 as an example, the method of forming the yttrium-doped intermediate layer (4) includes continuing to form a gradual subsidiary layer 144 after forming a gradual layer in the growth chamber. a gas, simultaneously introducing a DCTe having an n-type impurity and having a hoof impurity to form an erbium-doped intermediate layer 143, the above-mentioned simultaneous pass The time of the reaction gas of the impurity is about _ second, and the formation method of the doped intermediate layer (4) and w is similar to that of the ruthenium inter-layer 143. Since the reverse-deformed multi-junction (surface) solar cell 1 is a wire substrate The top cell 18 and the intermediate cell 16 which are sequentially matched with the lattice constant are sequentially grown, and then the bottom cell 12 whose lattice constant is not matched with the top cell 18 and the intermediate cell 16 is grown, and the support substrate 10 is After the bottom cell 12 is connected to the σ, the growth substrate is removed to form a reverse-deformed multi-junction (the secret solar cell 1', so a lattice misalignment occurs between the bottom cell 12 and the intermediate cell 16. The gradient buffer layer 14 can reduce the bottom cell 12 The generation of lattice misalignment between the cells 16 improves the crystallized product of the graded subsidiary layers 142, 144, 146 and 148, which helps the gradient buffer layer 14 to be lowered because the lattice constant of the bottom cell 12 and the intermediate cell 16 does not match. The generated stress enhances the quality of the bottom cell 12 crystal. The above examples are merely illustrative of the principles and effects of the present invention, and are not intended to limit the invention. Anyone having ordinary knowledge in the technical field to which the present invention pertains Can be used in the back of the tree The above embodiments are modified and changed in the context of the spirit of the present invention. Therefore, the scope of the present invention is as set forth in the appended claims. [Brief Description] The drawings are intended to facilitate an understanding of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate the principles of the invention. 201131788 Fig. 2 is a cross-sectional view showing a gradient buffer layer according to a first embodiment of the present invention. [Main component symbol description] 1: Solar cell 10: Support substrate 12: Bottom battery 14: Gradation buffer layer 141: First buffer layer 142, 144, 146, 148: Gradient subsidiary layer 143, 145, 147: erbium doping Intermediate layer 149: second buffer layer 16: intermediate battery 18: top battery