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畢業(yè)設(shè)計(jì)-噴涂工藝對(duì)氮化硅涂層品質(zhì)的影響(已修改)

2024-12-19 15:02 本頁(yè)面
 

【正文】 河南科技大學(xué)畢業(yè)設(shè)計(jì)(論文) I 噴涂工藝對(duì)氮化硅涂層品質(zhì)的影響 摘 要 鑄造多晶硅生產(chǎn)流程中的第一道工序就是坩堝涂層的噴涂。 工業(yè)中通常使用的坩堝是石英或石墨坩堝,熔融硅與坩堝接觸時(shí)不可避免的產(chǎn)生反應(yīng)粘連,同時(shí)坩堝中的雜質(zhì)也會(huì)進(jìn)入硅熔體中。高濃度的雜質(zhì),如 C、 O、 Fe、Ca 等將使少子壽命顯著降低,影響電池性能。通常在坩堝上涂敷涂層使熔體與坩堝壁隔離,來減少反應(yīng)粘連使 晶 錠順利脫模,并阻止坩堝中的雜質(zhì)在 長(zhǎng)晶 過程中進(jìn)入 熔 硅中 。高純的 Si3N4 自擴(kuò)散系數(shù)低,且耐高溫性能和化學(xué)穩(wěn)定性良好,抗雜質(zhì)擴(kuò)散能力強(qiáng),與熔硅不發(fā)生反應(yīng),通常被用來作為多晶硅鑄 造的涂層材料。 坩堝涂層的制備方法很多,現(xiàn)在通常采用成本低廉的氮化硅涂層制備技術(shù),它是 在石英坩堝內(nèi)壁上 直接 噴涂氮化硅涂層的 ,并 將涂有氮化硅涂層的石英坩堝在 1050℃ 下進(jìn)行燒結(jié),形成結(jié)構(gòu)更加致密的氮化硅層。 但是由于這種技術(shù)缺乏檢驗(yàn)技術(shù)支持,工藝可追溯性差,實(shí)際生產(chǎn)中晶錠常會(huì)出現(xiàn)粘堝現(xiàn)象,進(jìn)而在晶錠內(nèi)引起雜質(zhì),裂紋,影響硅片的質(zhì)量。所以我們希望通過改變氮化硅與純凈水的配比,坩堝的預(yù)熱溫度及溶液攪拌混合方式進(jìn)行產(chǎn)品優(yōu)化。 研究結(jié)果表明:氮化硅與水的配比為 1: 4 時(shí)效果最好,氮化硅涂層無(wú)裂紋,顆粒結(jié)合緊密。坩堝預(yù)熱 溫度為 50℃時(shí)最佳,氣孔少。超聲波與機(jī)械共同攪拌比單純的機(jī)械攪拌的效果要好,涂層的顆粒分布更均勻,表面無(wú)孔洞。坩堝在 1050℃燒結(jié)時(shí),氮化硅涂層與坩堝之間相互擴(kuò)散。 關(guān)鍵詞: 多晶硅,氮化硅涂層, SEM,宏觀組織 河南科技大學(xué)畢業(yè)設(shè)計(jì)(論文) II Quality Of Si3N4 Coating Influenced By Spraying Technology ABSTRACT In the process of mcSi purification by Physical Metallurgical Method, spraying Si3N4 coating is the first working procedure, crucibles, typically graphite or quartz crucibles have been used as support of melting silicon. However, in the casting process, there are reaction adhesions on the interface of melting silicon and crucible. Moreover,high density of impurity,such as C,O,Fe,Ca,which plays a crucial role on the degradation of mcSi solar cells performance,are usually incorporated through the contact of the melt with the crucible walls. Usually coating has been spayed on the crucible wall as release agent to avoid melting Silicon contacting with the crucible wall directly, eventually decrease the impurity diffusion from crucible. High purity Si 3N4 has been used as typical coating materials in the mcSi casting process for its low selfdiffusion coefficient, good high temperature resistance and chemical stability. There are kinds of methods to fabricate coating。 now we adopt low cost method for Si3N4 coating. In this study, we adopt the technique that spraying Si3N4 on the wall of crucible directly. We sinter the crucible with Si 3N4 coating at the temperature of 1050℃ . But this technique lacks test technology。 the traceability of craftwork is very bad. There are adhesions on the interface of melting Silicon and crucib le. More over, it can bring in impurity and crackle。 affect the products’ quality. So we hope to change the proportion of pure water and Si 3N4, warmup temperature and the way of mixing liquor to optimize our products. Investigation results show that: when the ratios of Si3N4 powder and pure water is 1:4, the effect is the best, There is not any crack in the Si 3N4 coating, the grains bined tight. When the warmup temperature is 50℃ , the effect is the best, there is little air hole in the Si 3N4 coating. The effect of ultrasonic and mechanism whisking the liquor together is better than that of only using 河南科技大學(xué)畢業(yè)設(shè)計(jì)(論文) III mechanism, the grains distribute uniformly, there is not any hole on the surface. When the crucible is sintered at 1050℃ ,there is expanding between Si 3N4 coating and crucible. KEY WORDS: multicrystalline silicon, Si3N4 coating, SEM, macrostructure 河南科技大學(xué)畢業(yè)設(shè)計(jì)(論文) IV 目 錄 第一章 前 言 ............................................ 1 167。 多晶硅生產(chǎn)工藝 ................................. 1 167。 氮化硅概述 ..................................... 2 167。 防止坩堝對(duì)多晶硅硅錠污染的方法 ................. 3 167。 坩堝涂層表面技術(shù) ......................... 4 167。 鑄造多晶硅涂層用氮化硅微粉制造方法 ...... 6 167。 本文研究的主要目的和內(nèi)容 ....................... 7 第二章 實(shí)驗(yàn)方法及過 程 ................................... 9 167。 涂層制備 ....................................... 9 167。 氮化硅溶液的配置 ......................... 9 167。 坩堝的準(zhǔn)備 ............................... 9 167。 氮化硅涂層的 噴涂 ........................ 10 167。 氮化硅涂層的燒結(jié) ........................ 12 167。 涂層表觀分析及性能測(cè)試 ....................... 13 167。 涂層宏觀組織的分析 ...................... 13 167。 結(jié)合性能的測(cè)試 .......................... 13 167。 掃描電子顯微鏡( SEM)觀察 ............... 14 第三章 實(shí)驗(yàn)結(jié)果與分析 .................................. 15 167。 結(jié)果與分析 .................................... 15 167。 不同預(yù)熱溫度下涂層的宏觀組織 ............ 15 167。 不同的攪拌方法下涂層的宏觀組織 ......... 16 167。 不同配比漿液噴涂涂層的宏觀組織 ......... 16 167。 涂層結(jié)合性能的測(cè)試結(jié)果 .................. 17 167。 SEM 分析 ................................. 18 167。 實(shí)驗(yàn)結(jié)果綜合分析 .............................. 18 結(jié) 論 ................................................... 21 參考文獻(xiàn) .......................
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