Bulk Crystal Growth and Wafering for PV

Silicon Crystallization Technologies

“…In the case of Cz growth, the heat is released by radiation mainly, but in case of VGF, it has to be extracted by heat conduction through the bottom of (Rodriguez et al, 2011) Thermal expansion coefficient 2.6 Â 10 À6 /K Electrical conductivity Liquid 1.33 Â 10 6 Ω À-1 m À1 (Brandes and Brook, 1992) the crucible, where the crucible made of sintered quartz ceramic acts as an insulation barrier. Discussing the crystallization of silicon for PV application, it is helpful to have a look at the actual size and geometry of the ingots (Table 3).…”

“…We will therefore focus in the following on the predominant and most promising PV silicon bulk crystallization technologies. A detailed discussion of the different ribbon and foil techniques is provided by Rodriguez et al (2011).…”

Crystalline Silicon Solar Cells

“…Considerable attention, however, has been directed towards reducing the cost of the silicon wafer, initially grown by the Czochralski technique, since this accounts for a large fraction of the cost of a standard silicon module. The most successful approach has been the simplification of the ingot growth processes by using cruder directional solidification approaches to produce multicrystalline ingots (Ferrazza, 1995;Rodriguez et al, 2011).…”

“…Several companies have developed commercial processes for producing the precursor multicrystalline silicon ingots (Ferrazza, 1995;Rodriguez et al, 2011). Advantages over the Czochralski process are lower capital costs, higher throughput and a higher tolerance to poor feedstock quality.…”

“…A good summary can be found elsewhere (Ferrazza, 1995). The size of nominally rectilinear ingots can be very large, presently up to 100 cm × 100 cm × 30 cm, with each ingot weighing over half a tonne (Rodriguez et al, 2011). This weight is expected to double over the coming decade (SEMI, 2011).…”