利用超音波噴塗法開發擴散製程應用於製備矽基太陽能電池N+型與P+型摻雜區之研究

Development of Diffusion Process for Fabrication of N+ and P+ Doped Region in Silicon-Based Solar Cell with Ultrasonic Spray Technique

廖建偉(Liao, JianWei)

指導教授 ： 陳福榮

國立清華大學/原子科學院/工程與系統科學系/碩士(2015年)

摘要

n+型摻雜區的製作，在工業製程上最常使用三氯氧磷(POCl3)在高溫爐管中進行擴散，但是POCl3本身便有劇毒與強烈臭味，在操作上不僅對人有危險，甚至對環境也有害。而p+型摻雜區的製作，主要是使用三溴化硼(BBr3)進行高溫摻雜，然而BBr3不但在使用過程中會產生有毒的Br2，且容易和水或是空氣中的水氣反應形成有毒且具腐蝕性的溴化氫(HBr)，故找到新的n+型摻雜區與p+型摻雜區的製備方法是勢在必行。
本研究是以超音波震盪噴塗法，預先在矽基板上噴塗磷酸與硼酸霧滴當作n+型與p+型摻雜源，並以最佳擴散溫度950℃與擴散時間30分鐘進行磷擴散摻雜，即可獲得最佳的磷原子n+型摻雜區。另外預先於矽基板上以噴塗600秒的硼酸霧滴，再以相同的擴散溫度、時間進行硼擴散摻雜，亦可獲得最佳的硼原子p+型摻雜區。此外，本研究以Boltzmann-Matano法分析得知磷原子與硼原子在矽基板中的擴散機制，得出磷擴散從高濃度到低濃度區分別由空位擴散、self-interstitial的矽原子以及interstitial的磷原子擴散主導；而硼擴散主要由高濃度的空位擴散與低濃度時self-interstitial的矽原子的擴散主導。
最後，本研究確認以超音波震盪噴塗磷酸與硼酸霧滴加上一次共擴散即可完成太陽能電池的n+型與p+型摻雜區的製備，並做出最高轉換效率15.57%的單面矽晶太陽能電池，與最高轉換效率7.86%的雙面太陽能電池。

關鍵字

太陽能電池

並列摘要

In industrial process, n+ doped region of solar cell often be fabricated by POCl3 diffusion. However, POCl3 is toxic and harmful to the environment. As for p+ doped region, it often be made with BBr3, but BBr3 is toxic and easy to form HBr when it was used.
In this research, n+ doped and p+ doped region was fabricated by spraying of dilute phosphoric acid and boric acid as doping source. After comparing the doping profile and sheet resistance, phosphorus diffused at 950℃/30min will get proper n+ doped region. Besides, spraying dilute boric acid 600s before diffusing at the same temperature and time will also have the proper doping result of p+ doped region.
Furthermore, by using the Boltzmann-Matano method to analyze the diffusion mechanism of phosphorus and boron. The results shows that phosphorus diffusion was dominated by vacancy、self-interstitial silicon atoms and interstitial phosphorus atoms at different concentration regions. As for boron diffusion mechanism, it was dominated by vacancy and self-interstitial silicon atoms when boron atoms diffused.
At last, by using spraying technique and co-diffusion to fabricate n+ and p+ doped region of solar cells. After measurement, monocrystalline solar cell can get the efficiency 15.57% and bifacial solar cell can get the efficiency 7.86% in respective.

並列關鍵字

Solar Cell

參考文獻

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