2016-01-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/699166摘要：太陽光電產業快速發展，仍以矽晶電池為主流。近年來，一項新技術稱為高效多晶(HPmcSi)的概念逐漸成熟。此法是利用許多小晶粒在坩堝底部或是坩堝表面的特殊結構，而長晶時成核出來的晶粒是小的且均勻，其中產生的晶界可以釋放長晶過程中產生的熱應力，進而降低差排的產生而增加效率。因此，晶界的種類對於雜質的偏析與不純物的捕捉具有關鍵性的影響，長晶時控制晶粒大小對於晶錠的性質及純度是很重要的。目前在長晶過程中，界面、晶界、差排、缺陷等對於效率影響的基礎研究仍是缺乏的。 在此兩年的計畫裡，我們和法國團隊(IM2NP)合作。法國團隊會利用發展多時的X光射線與散射的實驗，在長晶實驗中動態的觀察固液界面的變化，以了解固液界面的動態過程、生長動力學、成核、晶向與應力的發展。此法可以讓我們更加了解固化的機制，並探討晶粒競爭、攣生成核與缺陷之間的關係，而我們則會利用雷射光源加強的電區融裝置，分析實驗後的晶向與晶界發展，歸納出晶粒由多變少時的晶界選擇，此外，利用實驗室發展多年的相場模擬，導入多相相場與孿生晶界的生長動力學，用以理解矽晶生長的行為。 <br> Abstract: With the rapid development of photovoltaic industry, silicon solar cell is still the main stream. Recently, a new technology called “High-Performance multi-crystalline Silicon (HPmcSi)” has become matured. To produce HPmcSi, the nucleation phase at the beginning of the solidification is controlled either by using seed material or by use of specially designed crucible surfaces in order to get a high initial density of small grains. As a consequence, the internal stress during crystal growth is diminished, leading to lower dislocation density and increase the efficiency of wafers. Therefore, grain boundaries play an important role on the segregation and trapping. It is necessary to optimize the grain size in mc-Si to optimize its properties as a function of the purity of the feed source. As a consequence, research addresses several issues such as surfaces, grain boundaries, dislocations, precipitates, micro-cracks and other defects inherited from the solidification and cooling stages that can severely affect the solar-cell efficiency. In this project, we collaborate with the French team “IM2NP (Institut Mat&#233;riaux Micro&#233;lectronique et Nanosciences de Provence)”. IM2NP team will study the relation between the grain competition, twinning nucleation, and the defect, including the solidification microstructure and solidification phenomena dynamics by in situ and in real time characterisation (optical means, X-rays) during the experiments. They can also analyse the dominated orientation, nucleation orientation, residual stress and wafer quality after experiments. For our team, we use the developed in-situ observation based on the laser-enhanced electrical zone-melting available to analyze the evolution of grain orientations and grain boundaries and summarize the selection of grain boundaries during grain coarsen. Moreover, the vast work remaining for the simulation of the grain structure in mc silicon has also been pointed out by using phase field modeling. We will input the multi-phase model and growth kinetic of twinning boundaries to explain the behavior of silicon crystal growth.孿生成核晶粒競爭缺陷相場模擬twinning nucleationgrain competitiondefectphase field modelling