Evaporated metal aluminium and calcium removal from directionally solidified silicon for solar cell by electron beam candle melting

摘要

During the refinement of metallurgical-grade silicon (MG-Si), Al and Ca cannot be reduced to a target level by conducting directional solidification only once. Electron beam candle melting (EBCM) is a new method that can be used to further reduce Al and Ca by directly melting Si ingots after directional solidification. A certain stable molten pool with a maximum surface area and a minimum depth exists and is proven to effectively remove Al and Ca. The energy utilization ratio during EBCM is also compared with that of electron beam melting (EBM).