Presentation of the Electrical Molten Zone (EMZ) Technique

Abstract

This article presents a new zone melting crystallization technique for photovoltaic silicon ribbon production. It starts by showing some background research on related methods concerning, in particular, to ways of achieving and moving electrical molten zones (EMZ). It presents the fundamental mechanism responsible for the electric current concentration, which allows zone formation. Demonstrates the possibility of zone melting recrystallization (ZMR) through this technique and shows growth rates and energy consumptions that can be expected of it. It exposes ideas and results of the first attempts to obtain silicon ribbons using commercial (granular) feedstock. The electrical characteristics and control methods of the system are shown as well as the related temperature distributions in the ribbons. It reveals the existence of interfacial instability phenomena, which is thought to be of magnetohydrodynamic (MHD) origin, thus (tentative) explanations for those are illustrated by analogy with typical occurrences observed (in other contexts) in tubes of electrically conducting fluids.