Multicrystalline

Cast lead-calcium-tin alloys, 14 775 Cast-link belt furnaces, 12 289 Cast-mature process, in bar soap manufacture, 22 749 Cast multicrystalline silicon material, 23 40... 

Figure 11.3 Process flow from silicon feedstock to wafers for the case of multicrystalline silicon.

After solidification, the ingots are shaped using diamond-coated band saws or wires in an abrasive medium in order to have square multicrystalline or pseudosquare rounded angle monocrystalline blocks. This process removes the outer parts of the ingots, generally out of specification for dimensions and with some contamination from the containers or the furnaces. 

Australia, and scaled up by BP Solar in Spain, the heterojunction with intrinsic thin layer (HIT) cells developed by Sanyo by replacing the diffused P-doped emitter with an amorphous silicon layer and the back contact cells developed by Stanford University for use in concentrator technology and now converted to a large area for flat plate use. All three use single-crystalline silicon, while the majority of screen-printed cells use multicrystalline silicon wafers. 

In catalysis, one does not expect the activity of a catalyst to be proportional to its surface area, since there is good evidence that in many instances catalytic action is limited to certain active regions which may constitute only a small fraction of the total surface area (129). As would be expected, the same reasoning holds true for gas-carbon reactions. Carbon is a multicrystalline material, which can present varying degrees of surface heterogeneity depending upon the size and orientation of the crystallites. In the broadest sense, two main orientations of crystallites in the carbon surface need be considered—(1) crystallites with their basal planes parallel to the surface and (2) crystallites with their basal planes perpendicular to the surface. 

Today, the energy payback period of PV collectors for thin-film PV systems is about 3-5 years and for multicrystalline silicon PV systems about 6-8 years. As manufacturing techniques improve and the use of preinstalled roof PV collectors spread, these payback periods are likely to drop. With a minimum life span of 25 years, the ratio of energy obtained to energy invested in manufacturing and assembling the PV collectors is about 10 1. This ratio compares favorably, for example, with the energy payback ratio of oil shale, which is only 4 1. 

Crystalline Si Cells Single crystal Multicrystalline Thin Film Technologies Cu(ln, Ga)Se2 O Cd Te... 

E. A. Meese et al. High Accuracy Predictive Furnace Model For Directional Growth Of Multicrystalline Silicon, in proceedings of the 22th european photvotaic solar energy conference, (Milano, 2007) p. 793... 

Abstract. This chapter introduces crystallization process of multicrystalline silicon by using a directional solidification method. Numerical analysis, which includes convective, conductive, and radiative heat transfers in the furnace is also introduced. Moreover, a model of impurity segregation is included in this chapter. A new model for three-dimensional (3D) global simulation of heat transfer in a unidirectional solidification furnace with square crucibles was also introduced. 

Multicrystalline silicon (mc-Si) has a large demand of photovoltaics to overcome difficulty of the present green problem [1]. The directional solidification method is a key method for large-scale production of mc-Si in highly efficient solar cells. The maximum efficiency of the solar cell based on mc-Si is 18%. However, the use of commercially available wafers typically results in solar cell efficiency of about 16% in industrial solar cell processes. 

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