摘要 |
<p>An original wafer, typically silicon, has the form of a desired end PV wafer. The original may be made by rapid solidification or CVD. It has small grains. It is encapsulated in a clean thin film, which contains and protects the silicon when recrystallized to create a larger grain structure. The capsule can be made by heating a wafer in the presence of oxygen, or steam, resulting in silicon dioxide on the outer surface, typically 1-2 microns. At least one support element supports the wafer at the time the capsule is provided and blocks only minimal surface area from contact with the film forming atmosphere. There may be a plurality of support elements, or a surface may provide such support. The capsule contains the molten material during recrystallization, and protects against impurities. Recrystallization may be in air. After recrystallization, the capsule is removed.</p> |
申请人 |
MASSACHUSETTS INSTITUTE OF TECHNOLOGY |
发明人 |
SACHS, EMANUEL, M.;SERDY, JAMES, G.;HANTSOO, EERIK, T. |