The carbon distribution in multicrystalline silicon ingots grown using the directional solidification process

• Published in: Journal of crystal growth Vol. 312; no. 8; pp. 1282 - 1290
• Main Authors: Teng, Ying-Yang, Chen, Jyh-Chen, Lu, Chung-Wei, Chen, Chi-Yung
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2010; Elsevier
• Subjects: A1. Computer simulation; A1. Heat transfer; A1. Impurities; A1. Mass transfer; B3. Solar cells; Carbon; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystal structure; Directional solidification; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Furnaces; Growth from melts; zone melting and refining; Ingots; Materials science; Mathematical models; Melts; Methods of crystal growth; physics of crystal growth; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Silicon; Simulation; Solidification; Solubility, segregation, and mixing; phase separation; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; A1. Heat transfer; A1. Mass transfer; A1. Computer simulation; A1. Impurities; B3. Solar cells; Solar cells; Directional solidification; Digital simulation; Growth interface; Polycrystals; Flow pattern; Computerized simulation; Carbon; Mass transfer; Operating conditions; Growth mechanism; Silicon; Heat transfer; Crystal growth from melts; Concentration distribution
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2009.11.020

In this study, we performed a numerical simulation of the growth of multicrystalline silicon ingots using the DSS method and compared the results with the experiments. The thermal flow field and the carbon concentration distribution during the growth process were analyzed under the same operating conditions. The carbon concentration distribution in the grown ingots was measured and the results compared with that of the simulation predictions. The simulation results are in good agreement with the experimental ones. The simulation shows that in a directional solidification furnace carbon impurities accumulate easily in the melt near the central region of the melt/crystal interface due to convection. This is the main reason for the non-uniformity of the carbon concentration in ingots grown in the DSS furnace. In order to improve the uniformity of carbon distribution in the melt, a higher convexity of crystalline front interface in the central region needs to be maintained during the growth process to reduce the strength of melt convection around the crystalline front interface.