Simulazioni numeriche per lo sviluppo di tecniche innovative di casting per la produzione di SoGSi nel sistema iDSS.

The guidelines followed in the writing of this thesis are two different and clearly identifiable. One part aims to interest the readers in understanding the new possibilities in the field of fusion and solidification of Silicon introduced with the new type of melting furnace called induction - Directional Solidification System (i-DSS). In this first part the developments of new solution casting of the silicon are argued, with a possible new method to recycle the silicon for applications in the photovoltaic industry. The attention is focused on the improvement of the total efficiency of the i-DSS system and on the analyzation of the numerous possible configurations to integrate the electromagnetic stirring in the present building. The other part of the elaborate, in which it tries to give the more comprehensive answers, reports the functioning of i-DSS prototype furnace installed at LEP-Laboratory of Electroheat of Padua. The goal is to limit the difficulties that the followers maybe will encounter, difficulties that I met at the beginning of my training route

Effects of Superimpose Low and Medium Frequency Magnetic Fields in Induction Direction Solidification System

Nowadays, the PV market is still dominated by solar panels that are based on Silicon technology. The manufacturing process to obtain c-Si solar cells has numerous phases, among which, the casting process is one of the most energy consuming. In PV production the methods of silicon casting which have achieved a strengthened industrial maturity are Czochralski (Cz) technique and Directional Solidification method (DS). Previous works have demonstrated the effectiveness of the induction heating applied to DS processes, mostly in order to improve the control and reduce the process time. In addition, appreciable results have been achieved in producing high quality multi-crystal wafer, mc-wafer, in a prototype of iDSS (induction Directional Solidification System) furnace. In this paper, the application of a magnetic field at lower frequency respect to the actual frequency applied for heating in the furnace is studied in order to analyse the flow motion of the molten Silicon inside the crucible. The goal is to increase the mixing effect and consequently to delay the formation of SiC particles and focusing the impurity concentration in the last phase of solidification. The study has been conducted on numerical models of a G2 iDSS prototype installed at the Laboratory of Electroheat of Padua University

LEP-Laboratory for Electroheat of Padua University

The Laboratory for Electroheat of Padua University, LEP, is the only Italian academic group that researches about electroheating. LEP was founded about 40 years ago by prof. Di Pieri, it was leaded for many years by prof. Lupi and now it is directed by prof. Dughiero. Actually, about 10 people are working in the group. It is also the organizer of the conference ‘HES’, Heating by Electromagnetic Sources, whose 6th triannual edition will take place this year in May. In the paper, the latest research activities of LEP are presented, mostly with reference to the fields where LEP concentrates its research activity: innovative technologies for the through heating of non ferrous billets, contour induction hardening, silicon melting and crystallization, microwave heating and biomedical application of electromagnetic fields