201036175 六、發明說明： 【發明所屬之技術頜威】 本發明係有關於光吸收層，且特別是有關於一種 CIGS太陽能電池之光吸收層。 【先前技術】 近年來由於受到全球氣候變遷、環境污染問題以及資 源曰趨短缺的影響，在環保意識高漲與能源危機的警訊下 Ο 刺激了太陽光電產業的蓬勃發展。於各種太陽能電池中， 由於硒化銅銦鎵電池（Cu(In，Ga)Se2, CIGS)具備高轉換效 率、穩定性佳、低材料成本、可製成薄膜等優點，因此受 到極大的重視。 CIGS化合物屬於黃銅礦（chalcopyrite)結構，其主要由 IB-HA-VIA族化合物所組成，其為一種直接能隙（direct bandgap)半導體材料，可藉由調控材料組成而改變半導體 之能隙，是目前作為光吸收層之主要材料。 ❹ 目前製作CIGS吸收層的方法主要分為真空和非真空 製程’真空製程包括共蒸鍍(co-evaporation)、丨賤鍍(sputter) 荨製程’而非真空製程包括電沉積（electrodeposition)、無 電極電鍍（electr〇iess)、塗佈製程（coating process)或化學 喷霧熱裂解法(chemical spray pyrolysis)，其中真空製程較 早發展’技術也較成熟，但是由於製程成本與設備較為昂 貴’因此’許多公司分別朝向非真空技術的開發。 美國專利US 5871630提出一種電沉積製作CIGS光吸 收層之方法，其利用電化學方式得到含有銅、銦·、鎵和硒 0991A-A51511TW 3 201036175 之薄膜，接著利用物理氣相沉積法，使薄膜中的鎵/(銦+ 鎵）之比率為約0.39。 美國 ISET 公司（International Solar Electronic Technology Inc.)提出一種油墨製程（ink process)，其將 銅、銦、鎵之奈米金屬氧化物均勻塗佈於基材之上，再經 硒化步驟（selenization)得到CIGS薄膜。 美國UniSun公司提出一種喷霧熱裂解方式，其先經 超音波喷霧氧化得到金屬氧化物粉體，再將粉體進行研磨 與分散得到漿料，再將漿料以喷灑的方式塗佈於基材上’ ® 最後經由硒化步驟，得到CIGS薄膜。 上述提及的方法中，大多數需要先合成金屬薄膜’再 經由硒化步驟得到CIGS薄膜，其製程較為複雜。而電沉 積與無電極電鍍法雖不需硒化製程，但是其需要經由複雜 的氧化還原反應，因此鍍液不易調配且電極選擇受限。 綜上所述，若能提供一種簡易製作CIGS光吸收層之 方法’未來極有產業應用價值。 Q 【發明内容】 本發明提供一種光吸收層之製備方法’包括：混*合包 括I B族、ΠΙΑ族、VIA族之化合物於一溶劑中以得到〆 前驅物溶液（precursor);塗佈該前驅物溶液於一基板之 上；將該基板置於一氣氛(atm〇sphere)中進行熱處理，使 該基板之上形成光吸收層。 本發明另提供一種光吸收層，包括I Β-ΙΠΑ-VIA族化 合物，係由上述光吸收層之製備方法製備而得。 本發明亦提供一種前驅物溶液，包括IB族化合物、 II A族化合物、yj a族化合物與/溶劑。 0991A-A5151]TW 4 201036175 本發明另外提供一種太陽能電池，包括：一背電極， 形成於該基板之上；一光吸收層（light absorbing layer)， 形成於該背電極之上，其中該光吸收層包括I B-皿A-VIA 族化合物’係由申請專利範圍第1項所述之光吸收層之製 備方法製備而传，一緩衝層（buffer layer)，形成於該光吸 收層之上’ 一透明導電層（transparent conducting oxide， TCO);以及一前電極，形成於該透明導電層之上。 為讓本發明之上述和其他目的、特徵和優點能更明顯 易懂，下文特舉出較佳實施例，並配合所附圖式，作詳細 ®說明如下： 【實施方式】 本發明提供一種光吸收層之製造方法，包括：首先製 備一前驅物溶液(precursor)，藉由混合j B族、JHA族、 VIA族化合物之化合物於溶劑中而得，其中I b族包括銅 (Cu)、銀(Ag)、金(Au)或上述之組合，而I B族化合物包 括含有I B族之氧化物、氮化物、氫氧化物、鹵化物、石肖 ❹ 酸物、醋酸物、硫酸物、碳酸物、氯酸物、磷酸物、硒酸 物、草酸物、磷化物，例如氧化銅（CuO)、氮化銅（Cu(N3) 2 )、氫氧化銅（Cu(0H)2 )、氯化銅（CuC12)、硝酸銀 (AgN03)、硝酸銅(Cu(N03)2)、硫酸銅（CuS04)、醋酸銅 (Cu(CH3COO)2)、醋酸銀（CH3C00Ag)、碳酸銅 (Cu2C03)、草酸銅(CuC204)、氣酸銅(Cu(C104)2)、磷酸銅 (Cu3(P04)2)、硒酸銅（CuSe04)或磷化銅（Cu3P)。ΠΙΑ 族包 括紹（Α1)、銦（In)、鎵（Ga)或上述之組合，而瓜Α族化合物 包括含有HA族之氧化物、氮化物、氫氧化物、鹵化物、. 确酸物、酷酸物、硫酸物、碳酸物、氯酸物、鱗酸物、石西 0991A-A51511TW 5 201036175 酸物、草酸物或磷化物，例如氧化銦（Ιη203)、氧化鎵 (Ga203)、氮化銦（InN)、氮化鎵（GaN)、氫氧化銦（In(OH)3)、 氫氧化鎵（Ga(OH)3)、氣化鋁（A1C13)、氣化銦（InCl3)、氯 化鎵（GaCl3)、硝酸鋁（A1(N03)3)、硝酸銦（In(N03)3)、硝酸 鎵（Ga(N03)3)、醋酸銦（In(CH3COO)3)、醋酸鋁 (ai(ch3coo)3)、碳酸鋁(ai2(co3)3)、草酸鋁（ai2(c2o4)3)、 醋酸鎵（Ga(CH3COO)3)、硫酸銦（In2(S〇4)3)、硫酸鋁 (Al2(S〇4)3)、硫酸鎵(Ga2(S04)3)、氯酸銦(In(C104)3)、氯 酸鎵（Ga(C104)3)、磷酸銦（Inp〇4)、磷酸鎵（GaP〇4)、硒酸 銦（In2(Se04)3)、硒酸鎵（Ga2(Se04)3)、磷化銦（InP)或磷化 鎵（GaP)。VIA族包括硫（S)、硒（Se)、銻（Te)或上述之組合， 而VIA族化合物包括含有VIA族之氧化物、鹵化物、鹵 氧化物、硫化物、砸化物、胺化物、腺化物、砸酸物、疏 酸物或蹄酸物，例如氧化砸（Se02)、氧化蹄（Te〇2)、硫酸 (H2S04)、石西酸(H2Se04)、碲酸(H2Te04)、亞硫酸(H2S03)、 亞硒酸（H2Se03)、亞碲酸（H2Te03)、硫脲（thiourea, CS(NH2)2)、砸脲（selenourea，CSe(NH2)2)、二氯化碰 ❹ （SeCl2)、四氯化硒（SeCl4)、二氯化碲（TeCl2)、四氯化蹄 (TeCl4)、二溴化;5西（SeBr2)、四溴化硒（§eBr4)、二溴化碌 (TeBr2)、四溴化碲（TeBr4)、氯氧化硒（se〇Cl2)或硫化硒 (SeS2)。 上述前驅物溶液中，其中IB族、ΠΙΑ族、VIA族化 合物之莫耳數比為約（0.7〜1.3) : (0.7〜13) : (1.5〜20)，較 佳為約（0.8 〜1.2): (0.8 〜1.2): (1.7 〜16)，最佳為約（0.8 〜1.2): (0.8〜1.2) : (1.8〜15)。 而上述化合物之選擇，並不限於上述提及之化合物， 0991A-A51511TW 6 201036175 只要是能含I B族、DI A族、VIA族之化合物皆可。而溶 劑包括水、酸類、驗類、醇類、酮類、驗類、胺類或其它 有機溶劑，這些溶劑為無毒性之一般溶劑，其中酸類包括 硝酸、鹽酸、硫酸、醋酸或丙酮酸；鹼類包括氫氧化鈉溶 液或擰檬酸溶液、氨水；醇類包括曱醇、乙醇、丙醇、異 丙醇、正丁醇、異戊醇或乙二醇；酮類包括丙酮、丁酮、 甲基異丁酮；醚類包括曱醚'乙醚、曱乙醚、二苯醚、乙 二醇甲醚、乙二醇丁醚或乙二醇乙醚醋酸；胺類包括乙二 胺、二曱基曱醯胺、三乙醇胺或二乙醇胺。然而，溶劑之 ® 選擇並不限於上述提及之醇類、醚類或酮類溶劑，只要是 能將上述化合物溶解之單一或混合溶劑皆可。 此外，上述之前驅物溶液可再添加其它離子，以改善 太陽電池之特性。例如，可添加I A族化合物提高電池之 光電轉化效率，其中所選擇之I A族包括鋰(Li)，鈉(Na)、 鉀（K)或上述之組合，而ΙΑ族化合物包括ία族之鹵化 物、硝酸物、醋酸物、硫酸物、碳酸物或氯酸物，例如氯 化鋰(LiCl)、氯化鈉(NaCl)、氣化鉀（KC1)、硝酸鐘(LiN03)、 Q 硝酸鈉（NaN03)、硝酸鉀(KN〇3)、醋酸鋰(CH3COOLi)、醋 酸納（CH3COONa)、醋酸钾（CH3COOK)、硫酸鐘(Li2S04)、 硫酸鈉（Na2S04)、硫酸鉀（K2S04)、碳酸經(Li2C03)、碳酸 鈉（Na2C03)、碳酸鉀（K2C03)、氣酸鋰（LiC103)、氯酸鈉 (NaCl〇3)或氯酸鉀(KCIO3)。前驅物溶液與摻雜ία族之莫 耳數比為約（10〜2000) : 1，較佳為約（20〜1〇〇〇) : 1。 於一較佳實施例中’混合氯化銅（CuCl2)、氣化銦（inci3) 與硝酸鎵（Ga(N〇3)3)、亞硒酸(HJeO3)於乙醇溶液中，即 可製得本發明之前驅物溶液。201036175 VI. Description of the Invention: [Technology of the Invention] The present invention relates to a light absorbing layer, and more particularly to a light absorbing layer of a CIGS solar cell. [Prior Art] In recent years, due to global climate change, environmental pollution problems and the shortage of resources, under the warning of high environmental awareness and energy crisis, the solar photovoltaic industry has been booming. Among various solar cells, since Cu(In,Ga)Se2, CIGS has high conversion efficiency, good stability, low material cost, and can be made into a thin film, it has received great attention. The CIGS compound belongs to the chalcopyrite structure, which is mainly composed of IB-HA-VIA compound, which is a direct bandgap semiconductor material, which can change the energy gap of the semiconductor by regulating the composition of the material. It is currently the main material for the light absorbing layer. ❹ The current methods for fabricating the CIGS absorber layer are mainly divided into vacuum and non-vacuum processes. The vacuum process includes co-evaporation and sputtering. The process is not vacuum process including electrodeposition (electrodeposition). Electroplating (electr〇iess), coating process or chemical spray pyrolysis, in which the vacuum process develops earlier, the technology is also mature, but because the process cost and equipment are relatively expensive, 'Many companies are heading towards the development of non-vacuum technology. US Pat. No. 5,871,630 discloses a method of electrodepositing a CIGS light absorbing layer by electrochemically obtaining a film containing copper, indium, gallium and selenium 0991A-A51511TW 3 201036175, followed by physical vapor deposition to form a film. The ratio of gallium/(indium + gallium) is about 0.39. International Solar Electronic Technology Inc. has proposed an ink process that uniformly coats copper, indium, and gallium nano-oxides onto a substrate and then selenization. A CIGS film was obtained. UniSun Corporation of the United States has proposed a spray pyrolysis method, which first obtains metal oxide powder by ultrasonic spray oxidation, then grinds and disperses the powder to obtain a slurry, and then sprays the slurry on the spray. On the substrate ' ® finally through the selenization step, a CIGS film is obtained. Among the above-mentioned methods, most of them need to synthesize a metal film first, and then a selenization step to obtain a CIGS film, which is complicated in the process. While the electro-deposition and electroless plating processes do not require a selenization process, they require a complex redox reaction, so the plating solution is not easily formulated and the electrode selection is limited. In summary, if a method for easily fabricating a CIGS light absorbing layer can be provided, the future has extremely industrial application value. The present invention provides a method for preparing a light absorbing layer, which comprises: mixing a compound including a group IB, a lanthanum, and a group VIA in a solvent to obtain a ruthenium precursor solution; coating the precursor The solution is placed on a substrate; the substrate is placed in an atmosphere (atm〇sphere) for heat treatment to form a light absorbing layer on the substrate. The present invention further provides a light absorbing layer comprising an I Β-ΙΠΑ-VIA compound obtained by the method for producing the above light absorbing layer. The invention also provides a precursor solution comprising a Group IB compound, a Group II A compound, a yj a compound and/or a solvent. 0991A-A5151] TW 4 201036175 The present invention further provides a solar cell comprising: a back electrode formed on the substrate; a light absorbing layer formed on the back electrode, wherein the light absorption The layer comprising the I B-dish A-VIA compound ' is prepared by the preparation method of the light absorbing layer described in claim 1 , and a buffer layer is formed on the light absorbing layer' a transparent conducting oxide (TCO); and a front electrode formed on the transparent conductive layer. The above and other objects, features and advantages of the present invention will become more <RTIgt; The method for manufacturing an absorption layer comprises: first preparing a precursor solution obtained by mixing a compound of a group j B, JHA, and VIA compound in a solvent, wherein the group I b includes copper (Cu), silver. (Ag), gold (Au) or a combination thereof, and the Group IB compound includes an oxide, a nitride, a hydroxide, a halide, a sulphate, an acetate, a sulfate, a carbonate, and the like. Chloric acid, phosphoric acid, selenate, oxalic acid, phosphide, such as copper oxide (CuO), copper nitride (Cu(N3) 2 ), copper hydroxide (Cu(0H) 2 ), copper chloride ( CuC12), silver nitrate (AgN03), copper nitrate (Cu(N03)2), copper sulfate (CuS04), copper acetate (Cu(CH3COO)2), silver acetate (CH3C00Ag), copper carbonate (Cu2C03), copper oxalate (CuC204) ), copper oxylate (Cu(C104)2), copper phosphate (Cu3(P04)2), copper selenate (CuSe04) or copper phosphide (Cu3P). The lanthanum group includes lanthanum (In1), indium (In), gallium (Ga) or a combination thereof, and the lanthanide compound includes an oxide, a nitride, a hydroxide, a halide, an acid, Acids, sulphates, carbonates, chlorates, sulphates, slate 0991A-A51511TW 5 201036175 Acids, oxalic acids or phosphides, such as indium oxide (Ιη203), gallium oxide (Ga203), indium nitride (InN), gallium nitride (GaN), indium hydroxide (In(OH)3), gallium hydroxide (Ga(OH)3), vaporized aluminum (A1C13), indium sulfide (InCl3), gallium chloride (GaCl3), aluminum nitrate (A1(N03)3), indium nitrate (In(N03)3), gallium nitrate (Ga(N03)3), indium acetate (In(CH3COO)3), aluminum acetate (ai(ch3coo) 3), aluminum carbonate (ai2(co3)3), aluminum oxalate (ai2(c2o4)3), gallium acetate (Ga(CH3COO)3), indium sulfate (In2(S〇4)3), aluminum sulfate (Al2) (S〇4) 3), gallium sulfate (Ga2(S04)3), indium chlorate (In(C104)3), gallium chlorate (Ga(C104)3), indium phosphate (Inp〇4), gallium phosphate (GaP〇4), indium selenate (In2(Se04)3), gallium selenate (Ga2(Se04)3), indium phosphide (InP) or gallium phosphide (GaP). Group VIA includes sulfur (S), selenium (Se), tellurium (Te) or a combination thereof, and Group VIA compounds include oxides, halides, oxyhalides, sulfides, tellurides, aminations of Group VIA, An adduct, a citrate, an acid or a oleic acid, such as cerium oxide (Se02), oxidized hoof (Te〇2), sulfuric acid (H2S04), lithic acid (H2Se04), citric acid (H2Te04), sulfurous acid (H2S03), selenite (H2Se03), telluric acid (H2Te03), thiourea (CS(NH2)2), selenourea (CSe(NH2)2), dichlorinated tantalum (SeCl2) , SeCl4, SeCl4, TeCl4, Dibromination; 5 West (SeBr2), Selenium tetrabromide (§eBr4), Dibromide (TeBr2) ), TeBr4, SeOCl2 or SeS2. In the above precursor solution, the Mooran ratio of the Group IB, Group I, and Group VIA compounds is about (0.7 to 1.3): (0.7 to 13): (1.5 to 20), preferably about (0.8 to 1.2). : (0.8 to 1.2): (1.7 to 16), the best is about (0.8 to 1.2): (0.8 to 1.2): (1.8 to 15). The selection of the above compounds is not limited to the above-mentioned compounds, and 0991A-A51511TW 6 201036175 may be any compound which can contain Group I B, Group DI A, Group VIA. The solvent includes water, acid, test, alcohol, ketone, test, amine or other organic solvent, and these solvents are non-toxic general solvents, wherein the acid includes nitric acid, hydrochloric acid, sulfuric acid, acetic acid or pyruvic acid; The class includes sodium hydroxide solution or citric acid solution, ammonia water; alcohols include decyl alcohol, ethanol, propanol, isopropanol, n-butanol, isoamyl alcohol or ethylene glycol; ketones include acetone, methyl ethyl ketone, A Isobutyl ketone; ethers include oxime ether 'ether, oxime ether, diphenyl ether, ethylene glycol methyl ether, ethylene glycol butyl ether or ethylene glycol ethyl ether acetate; amines including ethylene diamine, dimercapto oxime Amine, triethanolamine or diethanolamine. However, the choice of the solvent ® is not limited to the above-mentioned alcohol, ether or ketone solvent, as long as it is a single or mixed solvent capable of dissolving the above compound. In addition, other ions may be added to the above precursor solution to improve the characteristics of the solar cell. For example, a group IA compound may be added to increase the photoelectric conversion efficiency of the battery, wherein the selected group IA includes lithium (Li), sodium (Na), potassium (K) or a combination thereof, and the steroid includes a halide of the ία group. , nitrate, acetate, sulfuric acid, carbonate or chloric acid, such as lithium chloride (LiCl), sodium chloride (NaCl), potassium carbonate (KC1), nitric acid (LiN03), Q sodium nitrate (NaN03 ), potassium nitrate (KN〇3), lithium acetate (CH3COOLi), sodium acetate (CH3COONa), potassium acetate (CH3COOK), sulfuric acid clock (Li2S04), sodium sulfate (Na2S04), potassium sulfate (K2S04), carbonic acid (Li2C03) ), sodium carbonate (Na2C03), potassium carbonate (K2C03), lithium silicate (LiC103), sodium chlorate (NaCl〇3) or potassium chlorate (KCIO3). The molar ratio of the precursor solution to the doped ία group is about (10 to 2000): 1, preferably about (20 to 1 Å): 1. In a preferred embodiment, 'mixed copper chloride (CuCl2), indium trioxide (inci3) and gallium nitrate (Ga(N〇3)3), selenous acid (HJeO3) in ethanol solution, can be obtained The precursor solution of the present invention.
0991A-A51511TW 7 201036175 此處須注意的是’上述前驅物溶液的製備過程，於一 般室溫與大氣環境下進行，不需額外控制製程之氣氛、溫 度、濕度與壓力。 另外’尚可添加一增稠劑（thickener)於前驅物溶液 中’以調整前驅物溶液之黏度及附著性，以利後續之塗佈 製程，而增稠劑例如為曱基纖維素、乙基纖維素、羧曱基 纖維素等纖維素衍生物、殿粉衍生物、乾酷素、聚丙稀酸 納、聚氧化乙烯、聚乙稀Π比ΪΤ各烧酮、聚乙稀醇、低分子聚 乙烯蠟、聚丙烯醯胺、檸檬酸/乙二醇或上述之組合。 ® 接著’將前驅物溶液塗佈於一基板之上，塗佈之厚度 為約0.1〜20 μπι’較佳厚度為0.25 μπι，最佳厚度為0.5 〜10 μιη，而所選擇之塗佈方法包括溶液塗佈法，例如旋轉 塗佈（spin coating)、棒狀塗佈（bar coating)、浸潰塗佈（dip coating)、滾筒塗佈（r〇U coating)、喷霧塗佈（spray coating)、凹版式塗佈（gravure coating)、喷墨印刷（ink jet printing)、狹縫塗佈（slot coating)或刮刀塗佈（blade coating) ° Q 上述提及之基板包括玻璃、高分子基板、金屬基板、 透明導電層（transparent conducting oxide, TCO)或上述之 組合，其中高分子基板例如為聚亞醯胺(polyimide, PI)、 聚對苯二曱酸乙二酯（poly(ethylene terephthalate)，PET)、 聚石炭酸酯（poly carbonate, PC)、聚曱基丙稀酸甲酯 (poly(methyl methacrylate), PMMA)或上述之組合，而該透 明導電層（TCO)例如為包括氧化鋅：鋁（ΖηΟ:Α1)、氧化銦: 錫（In203:Sn)、二氧化錫：氟（Sn02:F)或上述之組合。 此外，於玻璃、高分子基板或金屬基板之上尚包括一0991A-A51511TW 7 201036175 It should be noted here that the preparation process of the above precursor solution is carried out at room temperature and atmospheric environment without additional control of the atmosphere, temperature, humidity and pressure of the process. In addition, 'thickener can be added to the precursor solution' to adjust the viscosity and adhesion of the precursor solution to facilitate the subsequent coating process, and the thickener is, for example, mercapto cellulose or ethyl. Cellulose derivatives such as cellulose and carboxymethyl cellulose, powders of temple powder, dried curcumin, sodium polyacrylate, polyethylene oxide, polyethylene terpene, ketone, polyethylene glycol, low molecular weight Ethylene wax, polypropylene decylamine, citric acid/ethylene glycol or a combination thereof. ® then 'coating the precursor solution onto a substrate having a thickness of about 0.1 to 20 μm, preferably a thickness of 0.25 μm, and an optimum thickness of 0.5 to 10 μm, and the coating method selected includes Solution coating methods such as spin coating, bar coating, dip coating, roll coating, spray coating , gravure coating, ink jet printing, slot coating or blade coating ° Q The substrates mentioned above include glass, polymer substrates, and metals. a substrate, a transparent conducting oxide (TCO) or a combination thereof, wherein the polymer substrate is, for example, polyimide (PI), poly(ethylene terephthalate), PET. ), poly carbonate (PC), poly(methyl methacrylate) (PMMA) or a combination thereof, and the transparent conductive layer (TCO) includes, for example, zinc oxide: aluminum (ΖηΟ:Α1), indium oxide: tin (In2 03: Sn), tin dioxide: fluorine (Sn02: F) or a combination thereof. In addition, a glass, a polymer substrate or a metal substrate is included
0991A-A51511TW S 201036175 月電極，其中背電極包括翻（M〇)電極、鈦（Ti)電極、鶴（w) 電極、组（Ta)電極、鈮(Nb)電極或上述之組合。另外，於 透明導電層（transparent conducting layer)之上尚包括一緩 衝層（buffer layer)，其中緩衝層（buffer layer)包括硫化鎘 (cds)、氫氧化鋅（Zn(0H)2)、氧化鋅（Zn〇)、硫化鋅(ZnS)、 石西化銦（Inje3)、硫化銦（ir^sj或上述之組合。 另外，上述前驅物溶液可反覆塗佈於基板上，以增加 薄膜厚度，再經氣氛（atmosphere)之熱處理。或者是進行 熱處理後，重複塗佈與熱處理步驟，以控制薄膜厚度及特 性，另外重複塗佈步驟時，前驅物溶液成分可予調整。 此處須注意的是，上述所選擇之基板取決於製程步 驟，當太1%能電池先從背光侧（back contact)開始製作時， 例如會選擇玻璃作為基板，接著製作製作背電極，之後再 塗佈光吸收層。另外，當太陽能電池先從照光側（fr〇nt contact)開始製作時，例如會選擇氧化鋅：鋁（Zn〇:A1)作為 基板，接著製作緩衝層，之後再塗佈光吸收層。因此，基 板之選擇並不限於上述提及之基板，隨著太陽能電池製程 ❹技術的發展，基板之選擇也可隨著製程步驟而改變。 接著’將基板置於包括氣氛（atm〇sphere)中進行一熱 處理，使該基板之上形成光吸收層，其中光吸收層包括 IB-mA-VIA族化合物。氣氛包括真空或非真空，而該 非真空之氣體包括氧氣(〇2)、氮氣(N2)、氫氣士氬氣 或上述之組合。上述熱處理之溫度為約35〇〇C〜65〇〇C，較 佳為約400 C〜600。〇而熱處理之時間為約〇.丨小時〜8 小打，較佳為約0.3小時〜6小時，最佳為0.5小時〜4小時， 熱處理之後即可得到本發明之光吸收層，其能應用於0991A-A51511TW S 201036175 Month electrode, wherein the back electrode comprises a turn (M〇) electrode, a titanium (Ti) electrode, a crane (w) electrode, a group (Ta) electrode, a krypton (Nb) electrode, or a combination thereof. In addition, a buffer layer is further included on the transparent conducting layer, wherein the buffer layer comprises cadmium sulfide (cds), zinc hydroxide (Zn(0H)2), and zinc oxide. (Zn〇), zinc sulfide (ZnS), indium bismuth (Inje3), indium sulfide (ir^sj or a combination of the above. In addition, the precursor solution may be repeatedly applied to the substrate to increase the film thickness, and then The heat treatment of the atmosphere. Alternatively, after the heat treatment, the coating and heat treatment steps are repeated to control the thickness and characteristics of the film, and when the coating step is repeated, the composition of the precursor solution may be adjusted. The selected substrate depends on the process steps. When the 1% energy battery is first produced from the back contact, for example, glass is selected as the substrate, and then the back electrode is fabricated, and then the light absorbing layer is coated. When the solar cell is first fabricated from the light-emitting side, for example, zinc oxide: aluminum (Zn〇: A1) is selected as the substrate, and then a buffer layer is formed, followed by coating of the light-absorbing layer. Therefore, the selection of the substrate is not limited to the above-mentioned substrate. With the development of the solar cell process, the selection of the substrate can also be changed along with the process steps. Next, the substrate is placed in an atmosphere including atm〇. A heat treatment is performed in the sphere to form a light absorbing layer on the substrate, wherein the light absorbing layer comprises a IB-mA-VIA compound. The atmosphere includes vacuum or non-vacuum, and the non-vacuum gas includes oxygen (〇2), nitrogen. (N2), hydrogen gas argon gas or a combination thereof, the heat treatment temperature is about 35 ° C to 65 ° C, preferably about 400 C 600. The heat treatment time is about 〇. 8 small shots, preferably about 0.3 hours to 6 hours, preferably 0.5 hours to 4 hours, after heat treatment, the light absorbing layer of the present invention can be obtained, which can be applied to
0991A-A51511TW 9 201036175 CIGS太陽能電池。為促進反應進行，在上述非真空之氣 體尚包括VIA族之氣體，例如硒化氫（Hje)、硫化氫 (Hj)、砸（se)蒸氣、硫（s)蒸氣、碲（Te)蒸氣或上述之組合。 此外’為了得到較佳特性之光吸收層，進行熱處理步 驟之如’可進行一預處理（pre-treatment)步驟，其預處理 之溫度為約7〇。〇〜500¾ ,較佳為約15〇t：〜400°C，而預處 理之時間為約1分鐘〜4小時，較佳為約10分鐘~2小時， 以，除不欲殘留之有機物。該預處理之氣氛，可為空氣或 0含氧氣之氣體。經上述步驟後，最後可得到光吸收層之厚 度為約0.08 μιη〜18 ，較佳為01 μιη〜12 μπ1。 為了更加了解光吸收層之成份，本發明利用X光繞射 圖譜分析IB-DIA-VIA族化合物，實驗結果得知其具有 (112)、（211)、（204)/(220)與（312)/(116)四支主要繞射鋒， 其中（204)與(220)為同位置之繞射鋒，（312)與（116)亦為同 位置之繞射鋒，分析結果符合ICDD卡編號35-1102圖 譜’因此化合物為黃鋼礦（chalC〇pyrite)之晶體結構，其中 I B-IEA-VIA族化合物之化學式表示為 ❹ IBxDIAyVIA(x+3y)/2，其中 X ou，y =0·7〜13。此外， 該化合物中尚可摻雜其他元素。 於一實施例中，所得之化合物為CuIn0.3Ga0.7Se2。於 一較佳實施例中，所得之化合物為Culn〇7Ga〇.3Se2。 綜上所述，本發明光吸收層之製備方法，其特徵在於 在前驅物溶液之中直接加入族之化合物，而得到 I Β-ΠΙΑ-VIA族化合物中，而先前技術中，需要經過贝A 族氣體之熱處理（例如硒化步驟），或者是需要經由複雜的 氧化還原反應（例如電沉積與無電極電鍍法），才能得到0991A-A51511TW 9 201036175 CIGS solar cells. In order to promote the reaction, the above non-vacuum gas also includes a gas of Group VIA, such as hydrogen selenide (Hje), hydrogen sulfide (Hj), strontium (se) vapor, sulfur (s) vapor, strontium (Te) vapor or Combination of the above. Further, in order to obtain a light absorbing layer of a preferable characteristic, a heat treatment step may be carried out, and a pre-treatment step may be carried out at a pretreatment temperature of about 7 Å. 〇~5003⁄4, preferably about 15 〇t: ~400 ° C, and the pretreatment time is about 1 minute to 4 hours, preferably about 10 minutes to 2 hours, in addition to the organic matter which is not desired to remain. The pretreatment atmosphere may be air or a gas containing oxygen. After the above steps, the thickness of the light absorbing layer is finally obtained to be about 0.08 μm to 18, preferably 01 μm to 12 μπ1. In order to better understand the composition of the light absorbing layer, the present invention analyzes the IB-DIA-VIA compound by X-ray diffraction pattern, and the experimental results show that it has (112), (211), (204)/(220) and (312). ) / (116) four main diffraction fronts, where (204) and (220) are the same position of the diffraction front, (312) and (116) are also the same position of the diffraction front, the analysis results in accordance with the ICDD card number 35-1102 map 'so the compound is the crystal structure of chalC〇pyrite, wherein the chemical formula of the I B-IEA-VIA compound is expressed as IB IBxDIAyVIA(x+3y)/2, where X ou,y =0 · 7~13. In addition, other elements may be doped in the compound. In one embodiment, the resulting compound is CuIn0.3Ga0.7Se2. In a preferred embodiment, the resulting compound is Culn® 7Ga〇.3Se2. In summary, the method for preparing the light absorbing layer of the present invention is characterized in that a compound of the group is directly added to the precursor solution to obtain an I Β-ΠΙΑ-VIA compound, and in the prior art, it is required to pass through the shell A. Heat treatment of a family gas (such as a selenization step), or through a complex redox reaction (such as electrodeposition and electroless plating)
0991A-A51511TW 201036175 I B- IE A- VIA族化合物，因此，本發明之製作方法較為 簡易，能節省製作成本。0991A-A51511TW 201036175 I B- IE A-VIA compound, therefore, the production method of the present invention is simple and can save production costs.
另外，利用原子力顯微鏡（atomic force microscope, AFM)觀察本發明之光吸收層，實驗結果顯示光吸收層之 表面型態緻密且分佈均勻。再者，本發明之光吸收層之粗 糙度大小為約60〜75 nm，相較於習知真空硒化製程（粗糙 度大小為約80〜100 nm)，本發明光吸收層之表面粗链度 (roughness)較低，有利於後續其他各層材料之塗佈。再 者，有文獻（Solar Energy Materials & Solar Cells, 93 (2009) ® 114-118 ; Solar Energy，77,（2004) 685-695)指出，於 CIGS 太陽能電池中，需要光吸收層與缓衝層（buffer layer)之間 產生PN介面（PN junction)，使電子與電洞分離，若是光 吸收層表面粗糙度太高時，使緩衝層無法完全覆蓋於光吸 收層之上，將會導致光吸收層與電極直接接觸，造成不想 要的分流電流（unwanted shunt current)，進而使太陽能電 池的光電轉化效率（photoelectric conversion efficiency)降 低，因此，藉由本發明製備方法得到的光吸收層，其表面 ❹粗糙度較低，可避免發生分流電流，進而提高太陽能電池 的光電轉化效率。 本發明又提供一種光吸收層，包括I Β-ΠΑ-VIA族化 合物，係由上述之光吸收層之製備方法製備而得。 本發明亦提供一種前驅物溶液，包括有IB族化合 物、ΠΑ族化合物與VIA族化合物與一溶劑，其中IB族、 ΙΠΑ族、VIA族化合物之莫耳數比為約（〇·7〜1.3) ·· (0.7〜1.3) : (1.5〜20)，較佳為約（0.8〜1.2) : (0.8〜1.2): ’ （1.7〜16)，最佳為約（0.8 〜1.2) : (0.8 〜1.2) : (1.8 〜15)，而關 0991A-A51511TW 11 ^ 201036175 於I B族、ΠΙΑ族、VIA族化合物與溶劑之選擇同前所述， 在此不再贅述。此外，上述之前驅物溶液可再添加其它離 子，以改善太陽電池之特性。例如，可添加IA族化合物 提高電池之光電轉化效率，其中IA族化合物之選擇同前 所述，在此不再贅述。 本發明另外提供一種太陽能電池，請參見第1圖，其 包括一基板10 ’其中基板10包括玻璃、南分子基板、金 屬基板或上述之組合。一背電極20,形成於基板10之上， 其中背電極包括鉬（Mo)電極、鈦（Ti)電極、鎢（W)電極、 ❹ 鈕（Ta)電極、鈮(Nb)電極或上述之組合，背電極之厚度為 約 0.1 μιη ~ 2 μιη。一光吸收層（light absorbing layer)30 ’ 形成於背電極20之上’此光吸收層30包括I B-ΙΠA-VIA 族化合物，可藉由溶液塗佈法製得，其化合物成份、厚度 與其製備方式如同前述，在此不再贅述。一缓衝層（buffer layer)40，形成於光吸收層30之上，其中緩衝層40包括 硫化鎘（CdS)、氫氧化鋅（Zn(OH)2)、氧化鋅（ZnO)、硫化 鋅（ZnS)、石西化銦（Ir^Se〗）、硫化銦（I112S3)或上述之組合， Q 其作用在於與光吸收層30結合成為適當的異質接面，可 增加短波長光的吸收效率，其厚度為約〇.〇 1 μπι〜0.5 μπι。一透明導電層（transparent conducting oxide， TCO)50，形成於缓衝層40之上，其包括氧化鋅：鋁 (ΖηΟ··Α1)、氧化銦：錫（In203:Sn)、二氧化錫：氟（Sn02:F)或 上述之組合，其厚度為約0 · 1 μιη〜1 μπι。以及一前電極 60，形成於透明導電層50之上，其中前電極60包括鋁、 銅、鎳或上述之組合，其厚度為約〇. 1 μπι〜2 μπι。此外， 尚可於前電極60之上形成一抗反射層62,此抗反射層62 0991A-A51511TW 12 201036175 例如為氟化鎂（MgFz)或其他抗反射好 ==過程中造成損耗。此外除==少 層’其=r電流之損…：:;要= 之前媒物溶液製得，不需4過=:接含有w族化合物 原反應，能簡化製程心雜：:=== ❹ 度較小’有助於減少分流電繼1,2 知:升太陽《b電池之光電轉化效率。 【實施例】 實施例1 起始物 CuCl2、InC13、Ga⑽3)3 和 H2Se〇3 依 1:0.7:0.3:10之莫耳數比例溶於乙醇溶液中，其中過量添 加HJeO3。再添加乙基纖維素（ethyl 做為增稠劑 (thickener) ’也合均勻後，成為前驅物溶液，利用旋轉塗 〇 前驅物溶液塗佈於玻璃基材上，於高純度氮氫混合 氣％境下，以350°c加熱30分鐘，即可獲得所需之光吸 收層 CuIn〇.7Ga〇.3Se2。 第2圖顯示光吸收層之X-ray繞射圖譜，其結果顯示 光吸收層具有（112)、（211)、（204)/(220)、與（312)/(116) 四支主要繞射鋒，其中（204)與（220)為同位置之繞射鋒， (312)與（116)亦為同位置之繞射鋒，符合icdd卡編號 35-1102圖譜，此為黃銅礦晶體結構。 另外’以原子力顯微鏡（atomic force microscope, AFM)Further, the light absorbing layer of the present invention was observed by an atomic force microscope (AFM), and the experimental results showed that the surface of the light absorbing layer was dense and uniform in distribution. Furthermore, the roughness of the light absorbing layer of the present invention is about 60 to 75 nm, and the surface of the light absorbing layer of the present invention is thicker than the conventional vacuum selenization process (roughness is about 80 to 100 nm). The lower roughness is advantageous for subsequent coating of other layers of material. Furthermore, there are references (Solar Energy Materials & Solar Cells, 93 (2009) ® 114-118 ; Solar Energy, 77, (2004) 685-695) that in CIGS solar cells, light absorbing layers and buffers are required. A PN junction is formed between the buffer layers to separate the electrons from the holes. If the surface roughness of the light absorbing layer is too high, the buffer layer cannot completely cover the light absorbing layer, which will cause light. The absorbing layer is in direct contact with the electrode, causing an unwanted shunt current, thereby reducing the photoelectric conversion efficiency of the solar cell. Therefore, the surface of the light absorbing layer obtained by the preparation method of the present invention has a surface ❹ The roughness is low, and the shunt current can be avoided, thereby improving the photoelectric conversion efficiency of the solar cell. The present invention further provides a light absorbing layer comprising an I Β-ΠΑ-VIA compound obtained by the above-described method for preparing a light absorbing layer. The invention also provides a precursor solution comprising a group IB compound, a steroid compound and a group VIA compound and a solvent, wherein the molar ratio of the group IB, the lanthanum and the group VIA compound is about (〇·7~1.3) ·· (0.7~1.3) : (1.5~20), preferably about (0.8~1.2): (0.8~1.2): '(1.7~16), the best is about (0.8~1.2) : (0.8 ~ 1.2) : (1.8 ~ 15), and off 0991A-A51511TW 11 ^ 201036175 The choice of IB, steroid, VIA compound and solvent is the same as before, and will not be repeated here. In addition, other ions may be added to the above precursor solution to improve the characteristics of the solar cell. For example, a group IA compound may be added to increase the photoelectric conversion efficiency of the battery, and the selection of the group IA compound is the same as described above, and will not be described herein. The present invention further provides a solar cell, see Fig. 1, which includes a substrate 10' wherein the substrate 10 comprises glass, a south molecular substrate, a metal substrate, or a combination thereof. A back electrode 20 is formed on the substrate 10, wherein the back electrode comprises a molybdenum (Mo) electrode, a titanium (Ti) electrode, a tungsten (W) electrode, a (Ta) electrode, a niobium (Nb) electrode or a combination thereof The thickness of the back electrode is about 0.1 μm to 2 μmη. A light absorbing layer 30' is formed on the back electrode 20. The light absorbing layer 30 comprises an I B-ΙΠA-VIA compound which can be prepared by a solution coating method, and the composition, thickness and preparation thereof The method is the same as the foregoing, and will not be described again here. A buffer layer 40 is formed on the light absorbing layer 30, wherein the buffer layer 40 comprises cadmium sulfide (CdS), zinc hydroxide (Zn(OH)2), zinc oxide (ZnO), and zinc sulfide ( ZnS), indium sulphide (Ir^Se), indium sulfide (I112S3) or a combination thereof, and Q acts to form a suitable heterojunction with the light absorbing layer 30, thereby increasing the absorption efficiency of short-wavelength light. The thickness is about 〇.〇1 μπι~0.5 μπι. A transparent conducting oxide (TCO) 50 is formed on the buffer layer 40, and includes zinc oxide: aluminum (ΖηΟ··Α1), indium oxide: tin (In203:Sn), tin dioxide:fluorine (Sn02: F) or a combination thereof, having a thickness of about 0. 1 μm to 1 μm. And a front electrode 60 formed on the transparent conductive layer 50, wherein the front electrode 60 comprises aluminum, copper, nickel or a combination thereof, and has a thickness of about 1 μπι to 2 μπι. In addition, an anti-reflective layer 62 can be formed on the front electrode 60. The anti-reflective layer 62 0991A-A51511TW 12 201036175 is, for example, magnesium fluoride (MgFz) or other anti-reflection good == loss in the process. In addition to == less layer 'its = r current loss...::; to = before the preparation of the media solution, do not need 4 over =: the original reaction containing the w group compound, can simplify the process of the heart::=== The smaller the degree of 'helps to reduce the shunting power, 1, 2 know: the solar photoelectric conversion efficiency of the b battery. [Examples] Example 1 Starting materials CuCl2, InC13, Ga(10)3)3 and H2Se〇3 were dissolved in an ethanol solution in a molar ratio of 1:0.7:0.3:10, in which HJeO3 was excessively added. Ethyl cellulose (ethyl as a thickener) is added to form a precursor solution, which is applied to a glass substrate by a spin-coated precursor solution in a high-purity nitrogen-hydrogen mixture. The desired light absorbing layer CuIn〇.7Ga〇.3Se2 can be obtained by heating at 350 ° C for 30 minutes. Fig. 2 shows the X-ray diffraction pattern of the light absorbing layer, and the result shows that the light absorbing layer has (112), (211), (204)/(220), and (312)/(116) four main diffraction fronts, where (204) and (220) are the same position of the diffraction front, (312) And (116) is also the same position of the diffraction front, in line with the icdd card number 35-1102 map, this is the chalcopyrite crystal structure. In addition 'atomic force microscope (AFM)
0991A-A51511TW 13 201036175 分析光吸收層，如第3圖所示，其表面粗糙度為 69.7 nm 〇 比較例1 起始物 CuCl2、InCl3 和 Ga(N03)3 依照 1:0.7:0.3 之莫 耳數比例溶於乙醇溶液中。再添加乙基纖維素（ethyl cellulose)做為增稠劑，混合均勻後，成為前驅物溶液，利 用旋轉塗佈法將前驅物溶液塗佈於玻璃基材上，於高純度 氮氫混合氣環境下，以35〇DC加熱30分鐘’並通入硒蒸 氣，即可獲得所需之光吸收層CUIn〇.7Ga().3Se2。 此吸收層以X光繞射圖譜分析後可以發現具有 (112)、（211)、（204)/(220)、與（312)/(116)四支主要繞射鋒， 符合ICDD卡編號35-1102圖譜，此光吸收層為黃銅礦之 晶體結構。 另外’以原子力顯微鏡(atomic force microscope，AFM) 分析光吸收層，結果如第4圖，其表面粗糙度為80.7 nm。 由表1可得知，於溶液中添加硒可有效降低光吸收層之表 面粗韆度。 表面粗撻度 實施例1 69.7 nm 比較例1 80.7 nm 實施例2 起始物 CuCl2、InCl3、Ga(N03)3 和 H2Se03 依照 1:0.3:0.7:10之莫耳數比例溶於乙醇溶液中，其中過量添 加H2Se03。再添加乙基纖維素（ethyl cellulose)做為增稠 0991A-A51511TW 14 201036175 劑’混合均勻後’成為前驅物溶液，利用旋轉塗佈法將前 驅物溶液塗佈於玻璃基材上’於高純度氮氳混合氣環^ 下，以500°C加熱1小時，即可獲得所需之光吸收f CuIn〇.3Ga〇.7Se2。 此光吸收層經X-ray繞射圖譜分析，顯示其具有 (112)、（211)、（204)/(220)、與（312)/(116)四支主要繞射鋒， 符合ICDD卡編號35-1102圖5善’此光吸收層為黃銅礦晶 體結構。 、日日 ® 實施例3 起始物 CuCl2、InCl3、CS(NH2)2 和 H2Se03 依照 1:1:2.5:2.5之莫耳數比例溶於乙醇溶液中，其中過量添加 CS(NH2)2 及 H2Se03。再添加乙基纖維素（ethyl cellulose) 做為增稍劑，混合均勻後，成為前驅物溶液，利用旋轉塗 佈法將前驅物溶液塗佈於濺鍍Mo之玻璃基材上，於高純 度氮氣環境下，以450°C加熱30分鐘，即可獲得所需之 光吸收層CuInSeS。 ❹ 此光吸收層經X-ray繞射圖譜分析，顯示其具有 (112)、（211)、（204)/(220)、與（312)/(116)四支主要繞射鋒， 符合ICDD卡編號36-1311圖譜，此光吸收層為黃銅礦晶 體結構。 實施例4 起始物 CuCl2、InCl3、A1(N03)3 和 Se02 依照 1.2:0.1:0.7:1.5之莫耳數比例溶於水溶液中，其中Se02i^ 0991A-A51511TW 15 201036175 加量不足，之後藉由硒化反應補足不足量。 維素（ethyl cellulose)做為增稠劑及Ν 外、Π乙基纖 化加為如·8與⑽莫耳數比為質劑， 成為前驅物溶液，利用旋轉塗佈法將前驅物溶：^ 積CdS之透明導電玻璃基材上，於高純度 : 以航加熱30分鐘’並通入石西蒸氣進心下， 可獲得含Na之a^InuAV7^光吸收層薄膜故應’即 此光吸收層經X-ray繞射圖譜分析Y顯矛复 Ο (^、…^^/(，、與⑺^叫四支^要繞射鋒有 此光吸收層為黃銅礦晶體結構。 ’ 實施例5 起始物CuCl2、Ιηα3、Ga⑽3)3和Se〇2依照 0.8:0.5:0.5:1.8之莫耳數比例溶於丙酮溶液中。再添加乙 基纖維素(ethyl cellulose)做為增稠劑及NaC1為改質劑， CuoIno.sGao.sSe〗·8與NaCl莫耳數比為1〇:1，混合均勻後， 成為前驅物溶液，利用旋轉塗佈法將前驅物溶液塗佈於鈦 Ο 基材上，於高純度氮氣環境下，以400°c加熱30分鐘， 並通入硒蒸氣’即可獲得含Na之Cuo.Jno.sGao.sSeu光吸 收層薄膜。 此光吸收層經X-ray繞射圖譜分析，顯示其具有 (112)、（211)、（204)/(220)、與（312)/(116)四支主要繞射鋒， 此光吸收層為黃銅礦晶體結構。 實施例6 起始物 AgN03、InCl3、Ga(N03)3 和 Se02 依照 0991A-A51511TW 16 201036175 1:0.9:0.3:15之莫耳數比例溶於異丙醇溶液中，其中過量 添加Se〇2。再添加乙基纖維素（ethyl cellulose)做為增稠劑 及KC1為改質劑，AgIn〇.9Ga〇.3Se2.3與KC1莫耳數比為 10:1，混合均勻後，成為前驅物溶液，利用旋轉塗佈法將 前驅物溶液塗佈於不銹鋼基材上，於高純度氮氫混合氣環 境下，以400°C加熱2小時，即可獲得含K之 AgInQ.9Ga().3Se2.3 光吸收層薄膜。 此光吸收層經X-ray繞射圖譜分析，顯示其具有 (112)、（211)、（204)/(220)、與（312)/(116)四支主要繞射鋒， ^ 此光吸收層為黃銅礦晶體結構。 雖然本發明已以數個較佳實施例揭露如上，然其並非 用以限定本發明，任何所屬技術領域中具有通常知識者， 在不脫離本發明之精神和範圍内，當可作任意之更動與潤 飾，因此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。0991A-A51511TW 13 201036175 Analyze the light absorbing layer, as shown in Figure 3, the surface roughness is 69.7 nm 〇Comparative Example 1 The starting materials CuCl2, InCl3 and Ga(N03)3 are in accordance with the molar ratio of 1:0.7:0.3 The ratio is dissolved in the ethanol solution. Ethyl cellulose (ethyl cellulose) is added as a thickener, and after mixing, it becomes a precursor solution, and the precursor solution is applied to a glass substrate by a spin coating method in a high-purity nitrogen-hydrogen mixed gas environment. Next, heating at 35 〇 DC for 30 minutes' and introducing selenium vapor, the desired light absorbing layer CUIn〇.7Ga().3Se2 can be obtained. The absorption layer can be found by X-ray diffraction pattern with four main diffraction fronts of (112), (211), (204)/(220), and (312)/(116), in accordance with ICDD card number 35. -1102 map, the light absorbing layer is a crystal structure of chalcopyrite. Further, the light absorbing layer was analyzed by an atomic force microscope (AFM). As a result, as shown in Fig. 4, the surface roughness was 80.7 nm. As can be seen from Table 1, the addition of selenium to the solution can effectively reduce the surface roughness of the light absorbing layer by a thousand degrees. Surface roughness Example 1 69.7 nm Comparative Example 1 80.7 nm Example 2 The starting materials CuCl2, InCl3, Ga(N03)3 and H2Se03 were dissolved in an ethanol solution according to a molar ratio of 1:0.3:0.7:10. Excess H2Se03 was added thereto. Add ethyl cellulose as thickening 0991A-A51511TW 14 201036175 "after mixing" into a precursor solution, apply the precursor solution to the glass substrate by spin coating 'in high purity The desired absorption of light f CuIn〇.3Ga〇.7Se2 can be obtained by heating at 500 ° C for 1 hour under a nitrogen-nitrogen mixed gas ring. The light absorbing layer is analyzed by X-ray diffraction pattern and shows that it has four main diffraction fronts (112), (211), (204)/(220), and (312)/(116), which conforms to the ICDD card. No. 35-1102 Fig. 5 Good' This light absorbing layer is a chalcopyrite crystal structure. , 日日® Example 3 The starting materials CuCl2, InCl3, CS(NH2)2 and H2Se03 are dissolved in an ethanol solution according to the molar ratio of 1:1:2.5:2.5, in which CS(NH2)2 and H2Se03 are excessively added. . Further, ethyl cellulose was added as a thickening agent, and after mixing, it became a precursor solution, and the precursor solution was applied by spin coating to a glass substrate of sputtered Mo, and high-purity nitrogen gas was used. Under the environment, heating at 450 ° C for 30 minutes, the desired light absorbing layer CuInSeS can be obtained. ❹ This light absorbing layer is analyzed by X-ray diffraction pattern and shows that it has four main diffraction fronts (112), (211), (204)/(220), and (312)/(116), which is in line with ICDD. Card number 36-1311 map, this light absorbing layer is a chalcopyrite crystal structure. Example 4 The starting materials CuCl2, InCl3, A1(N03)3 and Se02 were dissolved in an aqueous solution according to a molar ratio of 1.2:0.1:0.7:1.5, wherein Se02i^0991A-A51511TW 15 201036175 was insufficiently added, after which The selenization reaction is insufficient to make up. The ethyl cellulose is used as a thickener and the bismuth and bismuth-ethyl fibrillation is added as a mass agent such as 8 and (10) molar ratio. As a precursor solution, the precursor is dissolved by spin coating: ^ On the transparent conductive glass substrate of CdS, in high purity: heated by air for 30 minutes' and passed into the core of Shixi vapor, the film of the light absorption layer containing a^InuAV7^ containing Na should be obtained. The absorption layer is analyzed by X-ray diffraction pattern. Y-ray spear retanning (^,...^^/(,, and (7)^called four-pieces to have a light-absorbing layer with a chalcopyrite crystal structure. Example 5 The starting materials CuCl2, Ιηα3, Ga(10)3)3 and Se〇2 were dissolved in an acetone solution according to a molar ratio of 0.8:0.5:0.5:1.8. Then ethyl cellulose was added as a thickener. And NaC1 is a modifier, CuoIno.sGao.sSe〗 8 and NaCl molar ratio is 1〇:1, after mixing uniformly, it becomes a precursor solution, and the precursor solution is applied to titanium bismuth by spin coating. On the substrate, a high-purity nitrogen atmosphere is heated at 400 ° C for 30 minutes, and a selenium vapor is passed to obtain a film of a light absorbing layer containing Na of Cuo. Jno.sGao.sSeu. The absorption layer is analyzed by X-ray diffraction pattern and shows that it has four main diffraction fronts of (112), (211), (204)/(220), and (312)/(116). The light absorption layer is Chalcopyrite crystal structure. Example 6 The starting materials AgN03, InCl3, Ga(N03)3 and Se02 are dissolved in an isopropanol solution according to the molar ratio of 0991A-A51511TW 16 201036175 1:0.9:0.3:15. Add Se〇2 in excess. Add ethyl cellulose as thickener and KC1 as modifier. AgIn〇.9Ga〇.3Se2.3 and KC1 molar ratio is 10:1, evenly mixed. Then, as a precursor solution, the precursor solution was applied to a stainless steel substrate by a spin coating method, and heated at 400 ° C for 2 hours in a high-purity nitrogen-hydrogen mixed gas atmosphere to obtain a K-containing AgInQ. 9Ga().3Se2.3 light absorbing layer film. This light absorbing layer is analyzed by X-ray diffraction pattern and shows that it has (112), (211), (204)/(220), and (312)/( 116) four main diffraction fronts, ^ the light absorbing layer is a chalcopyrite crystal structure. Although the invention has been disclosed above in several preferred embodiments, it is not intended to limit the invention, any Art having ordinary knowledge, without departing from the spirit and scope of the present invention, can be made herein with the modifier retouched, therefore the scope of the present invention when attached after the boundary of the range of claims which are set and their equivalents.
0991A-A51511TW 17 201036175 【圖式簡單說明】 第1圖為一剖面圖，用以說明本發明一實施例之太陽 能電池。 第2圖為一 X-ray繞射圖譜，用以說明本發明一實施 例之光吸收層之晶體結構。 第3圖為一原子力顯微鏡圖（AFM)，用以說明本發明一 實施例之光吸收層的表面型態。 第4圖為一原子力顯微鏡圖（AFM)，用以說明習知之光 吸收層的表面型態。 〇 【主要元件符號說明】 1 〇〜基板； 20〜背電極； 30〜光吸收層； 40〜缓衝層； 50〜透明導電層； 60〜前電極； ^ 62〜抗反射層； 0991A-A51511TW 180991A-A51511TW 17 201036175 [Simplified Schematic] FIG. 1 is a cross-sectional view for explaining a solar cell according to an embodiment of the present invention. Fig. 2 is an X-ray diffraction pattern for explaining the crystal structure of the light absorbing layer of an embodiment of the present invention. Fig. 3 is an atomic force micrograph (AFM) for explaining the surface morphology of the light absorbing layer of an embodiment of the present invention. Figure 4 is an atomic force microscope image (AFM) illustrating the surface morphology of a conventional light absorbing layer. 〇 [Main component symbol description] 1 〇 ~ substrate; 20 ~ back electrode; 30 ~ light absorbing layer; 40 ~ buffer layer; 50 ~ transparent conductive layer; 60 ~ front electrode; ^ 62 ~ anti-reflective layer; 0991A-A51511TW 18