2009-12-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/686459摘要：太陽光電產業這幾年隨著環保意識的抬頭與石化原料的短缺，全球以每年約40%的複合成長率成長相當快速。台灣從2002年開始更以每年倍速的成長，在去年已超過一千一百億的產值，成為世界第四大的太陽能電池生產國。政府在今年啟動的國家型能源計畫與綠能產業旭昇方案，更以太陽光電為最重要的支持項目，期待在2015 年可以創造四千五百億的產值。然而，國內的產業問題多半仰賴國外的turnkey技術，長期而言，缺乏國際競爭力。特別是最大宗的多晶矽太陽能電池產業，從長晶到太陽能電池與模組製程，都需要先進的技術來擴大差異化。而此計畫主要重點放在多晶矽吸收層的長晶先進技術的開發，將最先進的成核與長晶概念透過長晶爐的熱場設計，植入現有的大型長晶爐內，以期大幅降低晶體缺陷提升多晶矽吸收層的品質，進而提升太陽能電池的光電轉化效率。 的確，相較於單晶矽，在多晶矽的結構中存在著各類型的缺陷，特別是晶界與雜質，對太陽能電池的光電轉化效率上產生很大的影響，而如何控制成核與晶粒競爭生長，得到高比例的電鈍性晶界，是長晶最為關鍵的技術。在本計畫中，我們將開發新型的長晶技術，可以有效控制溫梯與過冷度等成核與長晶條件，來得到超高品質的多晶矽，具有比例的電鈍性晶界與超低的缺陷密度，並用於太陽電池的吸收層，獲得高的電池光電轉化效率。此技術將逐步引入工業界量產，提升國內在太陽能產業的國際競爭力。值得一在強調的是，在台灣雖然有超過600MW的多晶矽產能，但基礎與應用研究，特別是評價技術，十分缺乏，有賴政府與產業的持續投入，強化產學合作，才能提升技術，培育人才，創造更大的價值。此計畫預期將使產業生產的多晶晶片，在現有產業網印製程中超過提升效率0.5~1%，達到17%以上的光電轉化效率。 <br> Abstract: With the awareness of global warming and the shortage of fossil energy, the global solar photovoltaic (PV) market has been growing very rapidly with the growth rate more than 40%. Particularly in Taiwan, dtaring from 2002, the revenue of the PV industry has been doubled every year. In 2008, the revenue had been over 110 billions NT dollars. This put Taiwan the No. 4 in the global cell production. In view of this growth momentum, the government has launched the National Energy Project and the Green Energy Sun Rising Act to booster the industry, and the target is to reach the revenue of 540 billions NT dollars by year 2015. However, there is a big issue in the PV industry, especially in multicrystalline silion (mc-Si) PV, that almost all the technology, from ingot to cell and module production, is imported turnykey solutions, which do not gurantee the long-term competitiveness. Therefore, there is an urgent need to enlarge the technology diffenerentiation from the turnkey solution, and this is the main theme of this proposal. It is to focus on the crystal growth technology of the mc-Si absorber, by using advanced control methods for the nucleation and gain competition during directional solidification. It is well known that a few different kinds of defects exist in mc-Si. The defects include random grain boundaries, metal impurities, inclusions, and oxides. They are usually electrically active, as electron-hole recombination centers, and thus affect the solar cell conversion efficiency. On the other hand, it has been shown that twin boundaries like Σ3 and Σ9 are electrically inactive, and with extremely low defects inside the grains. Terefore, to enhance the crystal quality, the most efficieny way is to grow the crystal with high percentage of the twin boundaries. In this project, we will collaborate with SAS to develop the technology for better nucleation and grain control, so the grain orientations and boundaries can be better controlled. The advanced concept will be verified in the lab-scale experiment, and then further implemented in the production-scale fuenace. We aniticipate that the solar cell efficiency will increase about 0.5 to 1% by using the mc-Si wafers grown by our technlogy, and this should give an average mc-Si solar cell efficient over 17% by using the present screen-printing cell technology.單向凝固晶粒生長半導體材料矽晶半導體太陽能電池Directional solidificationGrain GrowthSemiconducting MaterialsSemiconducting siliconSolar cells