201114688 六、發明說明： 【發明所屬之技術領域】 本發明係有關於太陽能塗層’特別係有關於一種太陽 能電池吸收層之前驅物及其形成方法。 【先前技術】 現今二代太陽能電池中，銅銦鎵硒（CIGS)系列的薄膜 光伏元件是擁有最高效率者，與非晶石夕薄膜太陽能電池 之光裂化的效應相比，CIGS薄膜光伏元件的穩定度盥抗 •㈣特性備受青睞。CIGS薄膜太陽能電池目前主要之作 法是以鈉玻璃作為基板，鍍上金屬鉬（M〇)為背電極然 後在Mo電極之上以共蒸鍍法或濺鍍法製作cigs吸收 層，其中CIGS(CuInGaSe2)屬於p型半導體，主要負責 元件中吸收光能的角色。 目前製作銅銦鎵硒吸收層的方法主要是採用真空製 程’其中包含蒸鍵法與_法。進—步而言，以^製 程來製作硒化銅銦鎵薄膜吸收層的技術已臻成熟， 得之元件亦具有相當高的轉換率，然而沉積薄膜的= 必須於真空的環境下進行，不僅設備的價格昂貴同時 製程中原料的使用並不經濟，製程放大時亦容易造成薄 膜產品的成分不均勻。為了克服前述問題，近來許多學 者積極地研究開發非真空製程，包括電鑛沉積法、喷霧 熱解法以及漿料塗佈法。其中，漿料塗佈法是直接使用 碼化物奈米粉末作為原料’透過夥體製程製備砸化銅銦 鎵薄膜，可大幅降低薄膜太陽能電池之生產成本，並避 201114688 免硒化反應過程中薄膜成份不均勻的問題。 然而，此製程目前最大的問題在於硒化熱處理過程無 法使晶粒有效地成長’達不到薄膜緻密化的效果。如第 1圖所示’由於以漿料塗佈法製作CIGS吸收層121，鑛 上金屬鉬（Mo)之鈉玻璃基板11〇，在硒化熱處理過程中 會對CIGS吸收層121產生束缚燒結之内應力，並於cIGS 吸收層120兩側產生張應力τ，導致CIGS吸收層121 無法有效地使晶粒成長，會在CIGS吸收層121内產生 孔隙121A或裂痕121B，故無法達到薄膜緻密化的效果 (如第2圖所示），以致於太陽能電池之轉換率低。 目前在本產業中，以漿料塗佈法開發硒化銅銦鎵薄膜 太陽能電池的主要廠商為Nanosolar，其使用技術是利用 捲對捲（roll-to-roll)的大量生產製程，將銅銦鎵硒直接塗 佈於鋁箔基板上，製成可撓式太陽能電池，其製程專利 的技術如以下分析： 廠商名稱:Nanosolar 美國專利申請案號 技術分析 20060062902 以I，III，VI之元素態粉末合成雙層殼層結構之粉體，或是 分別以Cu作為核，分別將ln，Ga批附其表面，均勻分散後 進行硒化熱處理。 20060207644 以各元素之奈米顆粒均勻混合，添加分散劑與黏結劑等 製成水系漿料，並調控In與Ga之間比例來調整能隙值， 在適當的溫度氣氛下反應成膜。 20070166453 先於基材塗佈一層Cu-In-Ga合金，再將VI元素覆蓋於合 金上，經過375°C熱處理形成〇.5~4.〇μιη之膜厚。 201114688 20071063639 首先合成缺硒之二元成分(Cu-Se，In-Se或Ga-Se)微米平 板，並利用添加VI元素方式填補其中空隙，再以富硒顆 粒彼附於上層’以擴散作用達到成分均勻與緻密性薄膜。 20070163644 20070092648 以工以^以^-㈤^族之化合物作為前趨粉“灸續添加 VI進行混合或包覆，熱處理370°C〜500。(：獲得緻密性薄 膜。另外’利用富栖之二元化合(CuSeInSeGaSe)進行摻 混後製膜，並於熔融溫度以上進行熱處理，獲得組成均 勻之I-III-VI之薄膜。 【發明内容】 為了解決上述問題’本發明之主要目的係在於提供一 種太陽能電池吸收層之别驅物及其形成方法，利用同時 混合兩種以上粒徑分佈之粉末於漿_料中來提升太陽能電 池吸收層之生胚密度’同時藉由富銅粉末相對於缺銅粉 末之較小粒徑分佈與較高銅含量而達到較低之溶點，在 猫化熱處理過程中能先行生成液相，藉由液相燒结來降 低束缚燒結之内應力’進而生成緻密且晶粒大之銅銦鎵 硒薄膜，以提升太陽能電池之轉換率。 本發明的目的及解決其技術問題是採用以下技術方 案來實現的。本發明揭示一種太陽能電池吸收層之前驅 物’主要包含一富銅粉末與一缺銅粉末。該富銅粉末之 粉末粒徑分佈在4至30奈米，其體積百分比為2〇 %至 50%。該缺銅粉末之粉末粒徑分佈在50至3〇〇奈米，其 體積百分比為50%至80 °/〇。其中，該富銅粉末與該缺銅 粉末的成份組合係相同於一太陽能電池吸收層，藉由該 昌銅粉末相對於該缺銅粉末之較小粒徑分佈盘較高銅含 201114688 達到較低之熔點，在硒化熱處 能先轩》t々★上 、、、竭·理過程中該富銅粉末 能先仃生成液相，用以降低束缚 另揭示該太陽能電池吸收層之形=内應力。本發明 本發明的目的及解決其技術問題還可採用以下技術 指狐進一步實現。 在則述之太除能電池吸收層 ^ ^ ^ 驅物中，該富銅粉末 之體積百分比係可為35%至4〇%。201114688 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a solar coating, particularly to a solar cell absorber layer precursor and a method of forming the same. [Prior Art] In today's second-generation solar cells, the thin-film photovoltaic components of the copper indium gallium selenide (CIGS) series are the ones with the highest efficiency, compared with the photo-cracking effect of amorphous Aussie thin-film solar cells. Stability, resistance, and (4) characteristics are favored. The main practice of CIGS thin-film solar cells is to use sodium glass as the substrate, metal molybdenum (M〇) as the back electrode and then co-evaporation or sputtering on the Mo electrode to make the cigs absorption layer, CIGS (CuInGaSe2). ) is a p-type semiconductor and is mainly responsible for the role of absorbing light energy in components. At present, the method for producing the copper indium gallium selenide absorbing layer is mainly a vacuum process, which includes a steaming method and a _ method. In terms of further steps, the technology for fabricating the absorbing layer of copper indium gallium selenide film by the process has matured, and the resulting component also has a relatively high conversion rate. However, the deposited film must be carried out in a vacuum environment, not only The cost of the equipment is expensive and the use of raw materials in the process is not economical, and the process composition is also prone to cause uneven composition of the film product. In order to overcome the aforementioned problems, many scholars have recently actively researched and developed non-vacuum processes, including electromineral deposition, spray pyrolysis, and slurry coating. Among them, the slurry coating method is to directly use the coded nano-powder as a raw material to prepare a copper-indium-phosphide film by using a bismuth system, which can greatly reduce the production cost of the thin film solar cell and avoid the film during the selenization reaction in 201114688. The problem of uneven composition. However, the biggest problem with this process at present is that the selenization heat treatment process cannot effectively grow the crystal grains, which does not achieve the effect of film densification. As shown in Fig. 1, 'Since the CIGS absorber layer 121 is formed by the slurry coating method, the sodium glass substrate 11 of the metal molybdenum (Mo) is mineralized, and the CIGS absorber layer 121 is bound and sintered during the selenization heat treatment. The internal stress and the tensile stress τ are generated on both sides of the cIGS absorption layer 120, so that the CIGS absorption layer 121 cannot effectively grow the crystal grains, and the pores 121A or the cracks 121B are generated in the CIGS absorption layer 121, so that the film densification cannot be achieved. The effect (as shown in Figure 2) is such that the conversion rate of the solar cell is low. At present, in this industry, the main manufacturer of copper selenide film solar cells with slurry coating method is Nanosolar, and its technology is to use a roll-to-roll mass production process to make copper indium. Gallium selenium is directly coated on an aluminum foil substrate to form a flexible solar cell. The patented process technology is as follows: Manufacturer Name: Nanosolar US Patent Application No. Technical Analysis 20060062902 Synthesis of elemental powders of I, III, VI The powder of the double-layered shell structure, or Cu as the core, respectively, is attached to the surface of ln, Ga, and uniformly dispersed, and then subjected to selenization heat treatment. 20060207644 The water particles are uniformly mixed with the nanoparticles of each element, and a dispersant and a binder are added to prepare an aqueous slurry, and the ratio between In and Ga is adjusted to adjust the energy gap value, and the film is reacted under an appropriate temperature atmosphere. 20070166453 A layer of Cu-In-Ga alloy is applied to the substrate, and the VI element is coated on the alloy, and the film thickness of 〇.5~4.〇μιη is formed by heat treatment at 375 °C. 201114688 20071063639 Firstly, the binary component (Cu-Se, In-Se or Ga-Se) micro-plates lacking selenium is synthesized, and the voids are filled by adding VI elements, and then the selenium-enriched particles are attached to the upper layer to achieve diffusion. Uniform and compact film. 20070163644 20070092648 The compound of ^^(五)^ is used as a pre-powder. "Moxibus will continue to add VI for mixing or coating, heat treatment 370 °C ~ 500. (: Get a dense film. In addition to the use of Fuqi II The film is formed by blending (CuSeInSeGaSe) and heat-treated at a temperature above the melting temperature to obtain a film of uniform composition of I-III-VI. [Invention] In order to solve the above problems, the main object of the present invention is to provide a film. A solar cell absorbing layer and a method for forming the same, which utilizes simultaneously mixing two or more particle size distribution powders in a slurry to increase the green density of the solar cell absorbing layer while simultaneously using copper-rich powder relative to copper deficiency The smaller particle size distribution of the powder and the higher copper content to reach a lower melting point, the liquid phase can be formed first during the catification heat treatment, and the internal stress of the bound sintering is reduced by liquid phase sintering to form a dense A copper indium gallium selenide film having a large grain size to improve the conversion rate of the solar cell. The object of the present invention and solving the technical problem thereof are achieved by the following technical solutions. The invention discloses a solar cell absorber layer precursor 'mainly comprising a copper-rich powder and a copper-deficient powder. The copper-rich powder has a particle size distribution of 4 to 30 nm and a volume percentage of 2% to 50%. The powder of the copper-deficient powder has a particle size distribution of 50 to 3 Å, and the volume percentage thereof is 50% to 80 °/〇. The composition of the copper-rich powder and the copper-deficient powder is the same as that of a solar cell. The layer, by the copper powder, the smaller particle size distribution plate relative to the copper-deficient powder has a higher copper content of 201114688 to reach a lower melting point, and in the heat of selenization can be first Xuan "t々 ★ up, and exhausted · During the process, the copper-rich powder can be firstly formed into a liquid phase for reducing the binding and revealing the shape of the absorption layer of the solar cell = internal stress. The object of the present invention and solving the technical problem thereof can also adopt the following technique: The volume percentage of the copper-rich powder may be 35% to 4% in the immersed battery absorption layer.
在前述之太陽能電池吸收層之前驅物中，該缺銅粉末 之體積百分比係可為60%至65%。 在前述之太陽能電池吸收層之前驅物中，可另包含一 有機溶劑’用以同時混合該富銅粉末與該缺銅粉末而形 成為漿料。 在前述之太陽能電池吸收層之前驅物中，該有機溶劑 係可選自於甲苯、氯仿（chl〇r〇f〇rm) '二甲基甲醯胺 (N，N-Dimethylf0rmamide)、二甲基亞砜 sulfoxide)與吡唆（pyridine)之其中之一。 在前述之太陽能電池吸收層之前驅物中，可另包含一 分散劑，用以均勻分散該富銅粉末與該缺銅粉末於該有 機溶劑中。 在前述之太陽能電池吸收層之前驅物中，該分散劑係 可選自於油胺（oleylamine)、烧基碼醇（alkyl senol)、烧基 硫（alkylthiol)、芳香族砸醇（aromatic selenol)與芳香族硫 (aromatic thiol)之其中之一。 在前述之太陽能電池吸收層之前驅物中，可另包含一 201114688 黏結劑，用以調整漿料之黏度與成膜性。 在前述之太陽能電池吸收層之前驅物中，該黏結劑係 可選自於乙基纖維素（dihydroterpineol)與聚乙稀醇缩丁 搭（polyvinyl butyral)之其中之一。 在前述之太陽能電池吸收層之前驅物中，該太陽能電 池吸收層係可為銅細鎵硝吸收層，·其化學式係為 CuInGaSe^。 在刖述之太陽能電池吸收層之前驅物中，該富銅粉末 之化學式係可為Cuy^InxGa^xKSeSh或Cu2-zSe，該缺銅 粉末之化學式係為Cuy2(InxGai-x)(SeS)2，其中 0.4$xS0.8、yl> 1、y2< 1 及 ο。。。 由以上技術方案可以看出，本發明之太陽能電池吸收 層之前驅物及其形成方法，有以下優點與功效： 一、可藉由富銅粉末與缺銅粉末之特定組合關係作為其 中一技術手段，利用同時混合兩種以上粒徑分佈之 粉末於漿料中來提升太陽能電池吸收層之生胚密 度，同時藉由富銅粉末相對於缺銅粉末之較小粒徑 分佈與較高銅含量而達到較低之熔點，在硒化熱處 理過程中能先行生成液相，藉由液相燒結來降低束 缚燒結之内應力，進而生成緻密且晶粒大之銅銦鎵 硒薄膜，以提升太陽能電池之轉換率。 【實施方式】 以下將配〇所附圖示詳細說明本發明之實施例，然應 注意的是’該些圖示均為簡化之示意圖，#以示意方本 201114688 來說明本發明之基本架構或實施方法，故僅顯示與本案 有關之元件與組合關係，圖中所顯示之元件並非以實際 實施之數目 '形狀、尺寸做等比例繪製，某些尺寸比例 與其他相關尺寸比例或已誇張或是簡化處理，以提供更 清楚的描述。實際實施之數目、形狀及尺寸比例為一種 選置性之設計’詳細之元件佈局可能更為複雜。 依據本發明之一具體實施例，一種太陽能電池吸收層 之前驅物舉例說明於第3A與3B圖之顯微結構圖。該太 陽能電池吸收層之前驅物係主要包含一富銅粉末與一缺 鋼粉末。請參閱第3A圖所示，該富銅粉末之粉末粒徑 分佈在4至30奈米（nm)，其體積百分比為20%至50%。 在一較佳實施例中，該富銅粉末之體積百分比係可更進 一步限定於35%至40%。再請參閱第3B圖所示，該缺銅 粉末之粉末粒徑分佈在50至300奈米（nm)，其體積百分 比為50°/。至80%。在一較佳實施例中，該缺銅粉末之體 積百分比係可更進一步限定於60%至65%。一般而言， 一太陽能電池吸收層係可為銅銦鎵磁吸收層，其化學式 儀為CuInGaSe2。在本實施例中，該富銅粉末之化學式 係為Cuyl(InxGa丨-x)(SeS)2或Cu2_zSe，該缺銅粉末之化學 式係為 CuyKInxGabxKSeSh，其中 〇.4$χ 各 〇·8、yi > 1、 y2<i及ogzsi。因此，該富銅粉末與該缺銅粉末的成 份組合係相同於該太陽能電池吸收層，藉由該富銅粉末 相對於該缺銅粉末之較小粒徑分佈與較高銅含量而達到 較低之熔點，在硒化熱處理過程中該富鋼粉末能先行生^ 201114688 成液相，用以降低束缚燒結之 心門應力。以下揭示本發明 之該富銅粉末與該缺銅粉末之製作方法 (1)富銅粉末（粒徑分佈在4 ? μ ★ Α 甘4至30奈米）之製作方法： 將 0.2 mmol 的 CUC12.2H20 加入 s , 至 5 ml 油胺（〇leyianiine) 中，待溶解形成溶液之後，將所 町听件之溶液加熱至8〇〇c， 並抽真空30分鐘，使其形成均 取9勺之透明藍色液體。接In the foregoing solar cell absorber layer precursor, the volume percentage of the copper-deficient powder may be from 60% to 65%. In the foregoing solar cell absorber layer precursor, an organic solvent may be further included to simultaneously mix the copper-rich powder and the copper-deficient powder to form a slurry. In the foregoing solar cell absorber layer precursor, the organic solvent may be selected from the group consisting of toluene, chloroform (chl〇r〇f〇rm), dimethylformamide (N,N-Dimethylf0rmamide), dimethyl One of sulfoxide and pyridine. In the foregoing solar cell absorber layer precursor, a dispersant may be further included for uniformly dispersing the copper-rich powder and the copper-deficient powder in the organic solvent. In the foregoing solar cell absorber layer precursor, the dispersant may be selected from oleylamine, alkyl senol, alkylthiol, aromatic selenol. One of the aromatic thiols. In the foregoing solar cell absorber layer precursor, a 201114688 binder may be further included to adjust the viscosity and film forming property of the slurry. In the foregoing solar cell absorber layer precursor, the binder may be selected from one of dihydroterpineol and polyvinyl butyral. In the foregoing solar cell absorber layer precursor, the solar cell absorber layer may be a copper gallium nitride absorber layer, and the chemical formula thereof is CuInGaSe. The chemical formula of the copper-rich powder may be Cuy^InxGa^xKSeSh or Cu2-zSe, and the chemical formula of the copper-deficient powder is Cuy2(InxGai-x)(SeS)2. , where 0.4$xS0.8, yl> 1, y2 < 1 and ο. . . It can be seen from the above technical solutions that the solar cell absorber layer precursor and the method for forming the same have the following advantages and effects: 1. A specific combination relationship between the copper-rich powder and the copper-deficient powder can be used as one of the technical means. The use of simultaneously mixing two or more particle size distribution powders in the slurry to increase the green density of the solar cell absorber layer, while at the same time by the smaller particle size distribution and higher copper content of the copper-rich powder relative to the copper-deficient powder Achieving a lower melting point, the liquid phase can be formed first during the selenization heat treatment, and the internal stress of the bound sintering is reduced by liquid phase sintering, thereby forming a dense and grainy copper indium gallium selenide film to enhance the solar cell. Conversion rate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in detail below with reference to the accompanying drawings in which: FIG. The method is implemented, so only the components and combinations related to the case are shown. The components shown in the figure are not drawn in the actual number of shapes and sizes. Some sizes are proportional to other related sizes or exaggerated. Simplify the process to provide a clearer description. The actual number, shape and size ratio of the implementation is an optional design. Detailed component layout may be more complicated. In accordance with an embodiment of the present invention, a solar cell absorber layer precursor is illustrated in the microstructures of Figures 3A and 3B. The solar cell absorber layer precursor system mainly comprises a copper-rich powder and a steel-deficient powder. Referring to Fig. 3A, the copper-rich powder has a particle size distribution of 4 to 30 nanometers (nm) and a volume percentage of 20% to 50%. In a preferred embodiment, the volume percentage of the copper-rich powder may be further limited to 35% to 40%. Referring again to Fig. 3B, the copper-deficient powder has a particle size distribution of 50 to 300 nanometers (nm) and a volume percentage of 50 °/. Up to 80%. In a preferred embodiment, the volume percentage of the copper-deficient powder may be further limited to 60% to 65%. In general, a solar cell absorbing layer can be a copper indium gallium magnetic absorbing layer, and its chemical formula is CuInGaSe2. In this embodiment, the chemical formula of the copper-rich powder is Cuyl(InxGa丨-x)(SeS)2 or Cu2_zSe, and the chemical formula of the copper-deficient powder is CuyKInxGabxKSeSh, wherein 〇.4$χ 〇·8, yi > 1, y2 <i and ogzsi. Therefore, the composition of the copper-rich powder and the copper-deficient powder is the same as that of the solar cell absorbing layer, and the copper-rich powder is lower by the smaller particle size distribution and the higher copper content of the copper-deficient powder. The melting point of the steel-rich powder can be first formed into a liquid phase during the selenization heat treatment process to reduce the stress of the bound gate. Hereinafter, the copper-rich powder of the present invention and the method for producing the copper-deficient powder are disclosed. (1) A method for producing a copper-rich powder (particle size distribution of 4 μ μ 4 Α 4 to 30 nm): 0.2 mmol of CUC12. 2H20 is added to s, to 5 ml of oleylenimine. After the solution is dissolved, the solution of the listener is heated to 8 〇〇c, and vacuum is applied for 30 minutes to form a transparent solution of 9 scoops. Blue liquid. Connect
著，將上述溶液在通氮氣之情況下迅速加熱至ΜΙ得 到一 A溶液。將〇」mm〇1硒粉溶入至8 μ油胺 ⑷eyUmine)中’加熱至120t，並同時通入氮氣，持溫 〇.5小時後，再將其升溫至25吖，並持溫1〇分鐘。此 時會侍到一棕紅色溶液，顯示硒粉已溶解於油胺 (oleylamine)令，此溶液稱做B溶液。這時迅速將$刎 之A溶液快速注入B溶液中並攪拌，此時人與b的混合 溶液會立即轉為黑色，將上述混合溶液在25(rc下反應ι 小時。之後，再加入冷的正己烷中止反應，並將不溶物 質透過離心去除。最後，加入足量的無水乙醇，以使該 田鋼粉末從溶液中析出，並透過離心分離出該富銅粉 末’所得之該富銅粉末可均勻分散於非極性有機溶劑 中。如第3A圖所示之顯微結構圖，顯示該富銅粉末之 粒徑係約為20奈米（nm) » (2)缺銅粉末（粒徑分佈在50至300奈米）之製作方 法.首先’依照銅（Cu):鎵（Ga):銦（In):磁（Se)之莫耳 劑量比 0.1 : 0.3 : 0.7 : 2，將銅（Cu)、鎵（Ga)、銦（In)、 确（Se) —同放入至震動磨機中，以震動磨機混合24小時 201114688 至’ 一固相混合物。再將該固相混合物轉置於真空 ㈤相媸中’並加熱至1〇〇〇t持溫30 /分鐘，使該混合物由 為液相。接著’靜置該混合物使其緩慢冷卻至室 溫’而形成為—CIGS錠1該cigs錠先以機械方式磨 成細粉’再以高能磨機細磨3G小時，即可得到該缺銅粉 _第3B圖所示之顯微結構圖，顯示該缺銅粉末之 粒徑係約為100_30〇奈米（nm)。The solution was rapidly heated to obtain an A solution under nitrogen. Dissolve 〇"mm〇1 selenium powder into 8 μ oleylamine (4) eyUmine) and heat to 120t, and simultaneously pass nitrogen gas. Hold the temperature for 5 hours, then heat it to 25 吖 and hold the temperature for 1 〇. minute. At this time, a brown-red solution is served, indicating that the selenium powder has been dissolved in oleylamine, and this solution is referred to as a B solution. At this time, the A solution of A sputum is quickly injected into the B solution and stirred. At this time, the mixed solution of human and b is immediately turned black, and the mixed solution is reacted at 25 (rc for 1 hour). Then, the cold positive is added. The alkane terminates the reaction, and the insoluble matter is removed by centrifugation. Finally, a sufficient amount of absolute ethanol is added to precipitate the field steel powder from the solution, and the copper-rich powder obtained by centrifuging the copper-rich powder is uniformly obtained. Dispersed in a non-polar organic solvent. The microstructure shown in Figure 3A shows that the copper-rich powder has a particle size of about 20 nm (nm) » (2) copper-deficient powder (particle size distribution at 50) Production method to 300 nm). First, according to copper (Cu): gallium (Ga): indium (In): magnetic (Se) molar dose ratio of 0.1:0.3:0.7:2, copper (Cu), Gallium (Ga), Indium (In), and indeed (Se) are placed in a vibrating mill and mixed in a vibrating mill for 24 hours 201114688 to a solid phase mixture. The solid phase mixture is then transferred to a vacuum (5). In the middle of the 'heating to 1 〇〇〇t holding temperature 30 / min, the mixture is made into the liquid phase. Then 'static The mixture is allowed to cool slowly to room temperature' to form - CIGS ingot 1 the cigs ingot is first mechanically ground into a fine powder' and then finely ground in a high-energy mill for 3G hours to obtain the copper-deficient powder_3B The micrograph shown in the figure shows that the copper-deficient powder has a particle size of about 100 Å to 30 nanometers (nm).
更進一步地，該前驅物係可另包含一有機溶劑，用以 同時混〇該§銅粉末與該缺銅粉末而形成為漿料。在本 實施例中’該有機溶劑係可選自於甲苯、氯仿 (Chl〇r〇f〇rm)、二甲基甲醯胺（N，N-Dimethylformamide)、 二甲基亞砜（Dimethyl sulf0xide)與吡啶（pyridine)之其中 之一。並且，可另包含一分散劑，用以均勻分散該富銅 粉末與該缺銅粉末於該有機溶劑中。在本實施例中該 为散劑係可選自於油胺（oleylamine)、烧基栖醇 (alkylsenol)、烷基硫（alkylthi〇1)、芳香族砸醇（心则心 selenol)與芳香族硫（ar〇inatic thiol)之其中之一。此外， 可另包含一黏結劑，用以調整漿料之黏度與成膜性。在 本實施例中，該黏結劑係可選自於乙基纖維素 (dihydroterpineol)與聚乙烯醇缩丁醛（p〇lyvinyl butyral) 之其中之一。詳細而言，將最終組成為CuCInxGa^KSeSh (〇·4$χ$〇.8)之該富銅粉末與該缺銅粉末一同加入至該 有機溶劑中’並添加該分散劑加以混合，再加入該黏結 劑，以三軸滾輪混練3至7次，即可製得本發明之太陽^ 10 201114688 此電池吸收層之前驅物，即為一種銅銦鎵硒（CIGS)漿料。 在本發明中’藉由富銅粉末與缺銅粉末之特定組合關 係作為其中一技術手段’利用同時混合兩種以上粒徑分 佈之私末於浆料中’以提升太陽能電池吸收層之生胚密 度，同時藉由該富銅粉末相對於該缺銅粉末之較小粒徑 分佈與較南銅含量而達到較低之熔點，在硒化熱處理過 程中能先行生成液相’藉由液相燒結來降低束缚燒結之 φ 内應力’進而生成緻密且晶粒大之銅銦鎵硒（CIGS)薄 膜’以提升太陽能電池之轉換率。進一步而言’本發明 之前驅物係可藉由網版印刷機印刷至一玻璃基板上。在 本實施例中，該玻璃基板係已溅鍍1微米（μηι)厚度之鉬 (Μο)層。接著，先將該漿料經70°C乾燥之後，以得到厚 度約3至8微米（pm)之太陽能電池吸收層。再將該太陽 能電池吸收層經250°C熱處理去除該黏結劑。最後，轉置 於猫化爐中以550。(：持溫30分鐘，即可得到緻密且晶粒 • 大之CIGS薄膜。 請參閱第4圖所示，其繪示習知與本發明之CIGS漿 料經70°C乾燥後之生胚密度之比較示意圖，顯示出本發 明同時混合兩種以上粒徑分佈之粉末（即該富銅粉末與 該缺銅粉末）於CIGS漿料中，可有效提升太陽能電池吸 收層之生胚密度。請再參閱第5A與5B圖所示，分別繪 示習知與本發明之CIGS漿料經550°C持溫30分鐘後所 形成的太陽能電池吸收層之顯微結構，顯示出本發明利 用同時混合兩種以上粒徑分佈之粉末於CIGS漿料中％ 201114688 形成之太陽能電池吸收層’可有效降低束缚燒結之内應 力，並藉由液相燒結之溶解及再析出可生成緻密且晶粒 大之CIGS薄膜。請參閱第6圖所示之X光繞射圖譜， 其中顯示本發明之CIGS漿料經550°C燒結30分鐘之 後，所形成之太陽能電池吸收層可得單一的黃銅礦相 (chalcopyrite)，即為緻密且晶粒大之銅銦鎵硒薄膜。 本發明還揭示該太陽能電池吸收層之形成方法舉例 鲁 說明於第7A至7C圖之元件截面示意圖，詳細說明如下 所示。首先，如第7A圖所示，提供一太陽能電池基板 2 1 0。在本實施例中’該太陽能電池基板2丨〇係可為一玻 璃基板’並形成有一金屬層211，該金屬層211之材質 係為翻。具體而言’該金屬層211係以溅鍍形成，其厚 度約為1微米（μπι)。 接著，如第7Β圖所示，形成一太陽能電池吸收層之 前驅物220於該太陽能電池基板21〇上，該前驅物22〇 籲 係包含一富銅粉末與一缺銅粉末，該富銅粉末之粉末粒 徑分佈在4至30奈米且其體積百分比為2〇%至5〇%，該 缺鋼粉末之粉末粒徑分佈在5〇至3〇〇奈米且其體積百分 比為50/。至80%。在第7Β圖中粒徑較小者即為該富銅 粉末粒徑較大者為該缺銅粉末。其中，該富銅粉末與 §缺銅粉末的成份組合係相同於一太陽能電池吸收層， 藉由該田鋼粉末相對於該缺銅粉末之較小粒徑分佈與較 高銅含量而達到較低之熔點。在-較佳實施例中，該富 銅粉末之體積百分比係可更進-步限定於35%至40〇/。， 12 201114688 並且該缺銅粉末之體積百分比係可更進一步限定於6〇0/〇 至65 %。具體而言’該太陽能電池吸收層係為銅銦鎵硒 吸收層’其化學式係為CuInGaSe2 ^另外，該富銅粉末 之化學式係為Cuyl(lnxGai x)(SeS)2或Cu2-zSe，該缺銅粉 末之化學式係為CUydlnxGauKSeSh ，其中 0.4Sx$0.8、yl> 1、y2< i 及 。 詳細而言’該前驅物220可另包含有一有機溶劑，用 φ 以同時混合該富銅粉末與該缺銅粉末而形成為漿料，並 且該前驅物220係為印刷形成。在本實施例中，該有機 溶劑係可選自於甲苯、氯仿（chl〇r〇f〇rin)、二甲基甲醯胺 (Ν,Ν-Dimethylformamide) > 二曱基亞砜（Dimethyl sulfoxide)與ο比咬（pyridine)之其中之一。在形成該前驅物 220於該太陽能電池基板21〇上之後，乾燥該前驅物 220 ’以去除該有機溶劑，其中該前驅物22〇之乾燥溫度 係約為70°C。更進一步地，該前驅物22〇可另包含一分 # 散劑’用以均勻分散該富銅粉末與該缺銅粉末於該有機 溶劑中。在本實施例中’該分散劑係可選自於油胺 (oleylamine)、烷基硒醇（alkylsen〇1)、烷基硫 (alkylthiol)、芳香族砸醇（aroniatic selenol)與芳香族硫 (aromatic thiol)之其中之一。此外，該前驅物22〇可另 包含一黏結劑，用以調整漿料之黏度與成膜性。在本實 施例中，該黏結劑係可選自於乙基纖維素 (dihydroterpineol)與聚乙烯醇缩丁醛（p〇lyvinyl butyral) 之其中之一。在形成該前驅物220於該太陽能電池基# 13 201114688 210上之後熱處理該前驅物220，以去除該黏結劑，並 且此步驟之熱處理溫度係約為25(rc。在一變化實施例 中，該前驅物220係可以靜電吸附方式所形成，直接將 該富銅粉末與該缺銅粉末固著於該太陽能電池基板21〇 上0 最後如第7C圖所示，進行一磁化熱處理，以使該 刖驅物220形成為一太陽能電池吸收層221，在過程中 該富銅粉末能先行生成液相，用以降低束缚燒結之内應 力。詳細而δ，此步驟係將形成有該前驅物22〇之該太 陽能電池基板210放置於硒化爐中，並以55〇它持溫3〇 分鐘，以形成該太陽能電池吸收層221，即是一種緻密 且晶粒大之銅銦鎵硒（CIGS)薄膜。因此，本發明在該硒 化熱處理過程中，能降低該玻璃基板對該太陽能電池吸 收層221所產生之束縛燒結之内應力，在張應力之作用 下，能避免該太陽能電池吸收層22丨於内部產生孔隙或 裂痕，進而達到緻密化的效果，以提升太陽能電池之轉 換率。 以上所述，僅是本發明的較佳實施例而已，並非對本 發明作任何形式上的限制，雖然本發明已以較佳實施例 揭露如上，然而並非用以限定本發明，任何熟悉本項技 術者，在不脫離本發明之技術範圍内，所作的任何簡單 乜改、等效性變化與修飾，均仍屬於本發明的技術範圍 内。 【圖式簡單說明】 14 201114688 第1圖：為習知的一種銅銦鎵硒槳料所形成之吸收層之 截面示意圖。 .第2圖：為習知的一種銅銦鎵硒漿料之顯微結構圖。 第3A至3B圖：依據本發明之一具體實施例的一種太陽 能電池吸收層之前驅物之富銅粉末與缺銅粉末 之顯微結構圖。 第4圖：依據本發明之一具體實施例的太陽能電池吸收 層之前驅物繪示其與習知經70 °C乾燥後之生胚 •冑度之比較示意圖。 第5 A與5B圖：依據本發明之一具體實施例的太陽能電 池吸收層之前驅物繪示其與習知經550°C燒結 30分鐘後所形成之吸收層之顯微結構圖。 第6圖：依據本發明之一具體實施例的太陽能電池吸收 層之前驅物經550 °C燒結30分鐘後所形成之吸 收層可得單一之黃銅礦相之X光繞射圖譜。 φ 第7A至7C圖：依據本發明之一具體實施例的太陽能電 池吸收層之形成方法之元件截面示意圖。 【主要元件符號說明】 T 張應力 11 0玻璃基板 121 CIGS吸收層121A孔隙 121B裂痕 210玻璃基板 211金屬層 220太陽能電池吸收層之前驅物 221太陽能電池吸收層 15Further, the precursor may further comprise an organic solvent for simultaneously mixing the § copper powder and the copper-deficient powder to form a slurry. In the present embodiment, the organic solvent may be selected from the group consisting of toluene, chloroform (Chl〇r〇f〇rm), dimethylformamide (N, N-Dimethylformamide), and dimethyl sulfoxide (Dimethyl sulf0xide). And one of pyridine. Further, a dispersing agent may be further included for uniformly dispersing the copper-rich powder and the copper-deficient powder in the organic solvent. In the present embodiment, the powder may be selected from the group consisting of oleylamine, alkylsenol, alkylthi〇1, aromatic sterol (selenol) and aromatic sulfur. One of (ar〇inatic thiol). In addition, a binder may be further included to adjust the viscosity and film formation of the slurry. In this embodiment, the binder may be selected from one of dihydroterpineol and p〇lyvinyl butyral. Specifically, the copper-rich powder having a final composition of CuCInxGa^KSeSh (〇·4$χ$〇.8) is added to the organic solvent together with the copper-deficient powder, and the dispersant is added and mixed, and then added. The bonding agent is kneaded by a three-axis roller for 3 to 7 times to obtain the solar absorber of the present invention, which is a copper indium gallium selenide (CIGS) slurry. In the present invention, 'the specific combination relationship between the copper-rich powder and the copper-deficient powder is used as one of the technical means to utilize the simultaneous mixing of two or more particle size distributions in the slurry to enhance the growth of the solar cell absorption layer. Density, at the same time, by the smaller particle size distribution of the copper-rich powder relative to the copper-deficient powder and the lower copper content, the lower melting point can be obtained, and the liquid phase can be formed first during the selenization heat treatment. To reduce the internal stress of the φ bond sintering, and then to form a dense and grainy copper indium gallium selenide (CIGS) film to improve the conversion rate of the solar cell. Further, the precursor of the present invention can be printed onto a glass substrate by a screen printing machine. In this embodiment, the glass substrate is sputtered with a layer of molybdenum (Μο) having a thickness of 1 μm. Next, the slurry was dried at 70 ° C to obtain a solar cell absorber layer having a thickness of about 3 to 8 μm. The solar cell absorber layer is further heat treated at 250 ° C to remove the binder. Finally, it was transferred to a cat furnace at 550. (: Holding a temperature of 30 minutes, a dense and grainy CIGS film can be obtained. Please refer to Fig. 4, which shows the density of the raw embryos of the conventional CIGS slurry after drying at 70 ° C. A comparative diagram showing that the powder of the two or more particle size distributions (i.e., the copper-rich powder and the copper-deficient powder) is simultaneously mixed in the CIGS slurry, which can effectively increase the green density of the absorption layer of the solar cell. Referring to Figures 5A and 5B, respectively, the microstructure of the solar cell absorption layer formed by the conventional CIGS slurry of the present invention after being held at 550 ° C for 30 minutes, respectively, shows that the present invention utilizes simultaneous mixing of two The above-mentioned particle size distribution powder in the CIGS slurry% 201114688 formed solar cell absorption layer' can effectively reduce the internal stress of the bound sintering, and can form dense and grainy CIGS by dissolution and re-precipitation by liquid phase sintering. Film. Please refer to the X-ray diffraction pattern shown in Fig. 6, which shows that the CIGS slurry of the present invention is sintered at 550 ° C for 30 minutes, and the formed solar cell absorption layer can obtain a single chalcopyrite phase (chalcopyrite). ), that is The invention discloses a copper-indium gallium selenide thin film which is dense and has a large crystal grain. The present invention also discloses an example of a method for forming an absorption layer of the solar cell, which is illustrated in the cross-sectional view of the elements in FIGS. 7A to 7C, and the detailed description is as follows. First, as shown in FIG. 7A As shown, a solar cell substrate 210 is provided. In this embodiment, the solar cell substrate 2 can be a glass substrate and a metal layer 211 is formed, and the material of the metal layer 211 is turned over. The metal layer 211 is formed by sputtering and has a thickness of about 1 micrometer (μm). Next, as shown in Fig. 7, a solar cell absorber layer precursor 220 is formed on the solar cell substrate 21 The precursor 22 comprises a copper-rich powder and a copper-deficient powder having a particle size distribution of 4 to 30 nm and a volume percentage of 2% to 5% by weight. The powder has a particle size distribution of 5 to 3 nanometers and a volume percentage of 50% to 80%. In the seventh diagram, the smaller particle size is the larger particle size of the copper-rich powder. Copper-deficient powder, wherein the copper-rich powder and § copper-deficient powder The composition of the composition is the same as that of a solar cell absorber layer, and the lower melting point is achieved by the smaller particle size distribution of the field steel powder relative to the copper deficiency powder and the higher copper content. In a preferred embodiment, The volume percentage of the copper-rich powder may be further limited to 35% to 40 Å/, 12 201114688 and the volume percentage of the copper-deficient powder may be further limited to 6 〇 0 / 〇 to 65%. 'The solar cell absorption layer is a copper indium gallium selenide absorption layer' whose chemical formula is CuInGaSe2 ^ In addition, the chemical formula of the copper-rich powder is Cuyl (lnxGai x) (SeS) 2 or Cu2-zSe, the copper-deficient powder The chemical formula is CUydlnxGauKSeSh, where 0.4Sx$0.8, yl> 1, y2 < i and . In detail, the precursor 220 may further comprise an organic solvent, which is formed by simultaneously mixing the copper-rich powder and the copper-deficient powder with φ, and the precursor 220 is formed by printing. In this embodiment, the organic solvent may be selected from the group consisting of toluene, chloroform (chl〇r〇f〇rin), dimethylformamide ( &-Dimethylformamide) > Dimethyl sulfoxide (Dimethyl sulfoxide) ) one of the pyridines. After the precursor 220 is formed on the solar cell substrate 21, the precursor 220' is dried to remove the organic solvent, wherein the precursor 22 is dried at a temperature of about 70 °C. Further, the precursor 22 may further comprise a portion of a powder to uniformly disperse the copper-rich powder and the copper-deficient powder in the organic solvent. In this embodiment, the dispersant may be selected from the group consisting of oleylamine, alkyl selenium, alkylthiol, aromatic sultanol and aromatic sulphur ( One of the aromatic thiol). In addition, the precursor 22 may further comprise a binder for adjusting the viscosity and film forming properties of the slurry. In this embodiment, the binder may be selected from one of dihydroterpineol and p〇lyvinyl butyral. The precursor 220 is heat treated after the precursor 220 is formed on the solar cell substrate #13 201114688 210 to remove the binder, and the heat treatment temperature of this step is about 25 (rc. In a variant embodiment, The precursor 220 is formed by electrostatic adsorption, and the copper-rich powder and the copper-deficient powder are directly fixed on the solar cell substrate 21, and finally, as shown in FIG. 7C, a magnetization heat treatment is performed to make the crucible. The insulator 220 is formed as a solar cell absorbing layer 221, and the copper-rich powder can first form a liquid phase in the process to reduce the internal stress of the bound sintering. In detail, δ, this step will form the precursor 22 The solar cell substrate 210 is placed in a selenization furnace and held at a temperature of 55 Torr for 3 minutes to form the solar cell absorption layer 221, which is a dense and grain-shaped copper indium gallium selenide (CIGS) film. Therefore, in the selenization heat treatment process of the present invention, the internal stress of the bound sintering generated by the glass substrate to the solar cell absorption layer 221 can be reduced, and the sun can be avoided under the action of the tensile stress. The battery absorbing layer 22 generates voids or cracks inside to further achieve a densification effect to improve the conversion rate of the solar cell. The above is only a preferred embodiment of the present invention, and does not form any form on the present invention. The present invention has been disclosed in the above preferred embodiments, but is not intended to limit the invention, and any simple modifications and equivalent changes made by those skilled in the art without departing from the scope of the invention. And the modification are still within the technical scope of the present invention. [Simple description of the drawing] 14 201114688 Fig. 1 is a schematic cross-sectional view of an absorption layer formed by a conventional copper indium gallium selenide paddle. Fig. 2: A micro-structural diagram of a conventional copper indium gallium selenide slurry. Figures 3A to 3B are diagrams showing a copper-rich powder of a solar cell absorber layer precursor and a copper-deficient powder according to an embodiment of the present invention. Microstructure diagram. Fig. 4: The precursor of the solar cell absorber layer according to an embodiment of the present invention shows the comparison with the conventional green embryos after drying at 70 °C. 5A and 5B: The solar cell absorber layer precursor according to an embodiment of the present invention shows the microstructure of the absorber layer formed after sintering at 550 ° C for 30 minutes. Fig. 6 is a view showing an X-ray diffraction pattern of a single chalcopyrite phase obtained by absorbing an absorber layer of a solar cell absorber layer at 550 ° C for 30 minutes in accordance with an embodiment of the present invention. 7A to 7C are cross-sectional views showing the components of the method for forming an absorption layer of a solar cell according to an embodiment of the present invention. [Description of main components] T-tension 110 G glass substrate 121 CIGS absorption layer 121A Pore 121B Crack 210 Glass substrate 211 metal layer 220 solar cell absorption layer precursor 221 solar cell absorption layer 15