Finite element analysis of the interface shape in the growth of RAD silicon ribbons

Computational simulations of Ribbon-Growth on substrate for photovoltaic silicon wafer

“…Actual silicon with melting temperature of 1685 K was used, with a carbon ribbon pulled at a speed of 7-10 cm/min. Experimental data for only the resulting layer thickness and the relative concentrations of some impurities are reported, although additional data from finite analyses are also included in Hamidi and Belouet [7]. The similarity between vertical and horizontal pulling is that a thin film is formed from a melt liquid, with heat dissipation from the sides.…”

“…There is, however, a limited data set on the layer thickness during crystallization of silicon films on both front and back surfaces of a carbon ribbon which is pulled vertically upward through silicon melt [7]. Actual silicon with melting temperature of 1685 K was used, with a carbon ribbon pulled at a speed of 7-10 cm/min.…”

“…Of these, we use the data from Wetzel et al [11], mainly due to convenience in setting up a corresponding geometry, boundary conditions and in comparing the resultant melt flow and temperature data. For validation of the solidification component of our model, we go back to the work by Hamidi et al [7] on somewhat limited data on the solidified layer thickness during vertical ribbon growth of silicon. This work reported on one set of data consisting of two data points for thickness of the silicon layer grown on a carbon substrate, which was pulled vertically upward from a silicon melt chamber [7].…”

“…For validation of the solidification component of our model, we go back to the work by Hamidi et al [7] on somewhat limited data on the solidified layer thickness during vertical ribbon growth of silicon. This work reported on one set of data consisting of two data points for thickness of the silicon layer grown on a carbon substrate, which was pulled vertically upward from a silicon melt chamber [7]. This vertical ribbon growth geometry was set up using our simulation capabilities along with the test conditions to compare with the reported solidified layer thickness data.…”

“…Combined with semiconductor use of polycrystalline silicon, the demand for photovoltaic silicon is expected to outpace the supply in the next several years, placing high emphasis on optimizing the use of available material [2]. In this regard, two production methods of the silicon wafer for solar cell, such as horizontal ribbon growth and vertical ribbon growth, have been investigated and reviewed by many researchers [3][4][5][6][7][8][9][10], just to include a few among many. In particular, ribbon growth on substrate (RGS) methods has been studied since its inception in the late 1990s [3], and are very promising due to its high speed of production at low manufacturing costs.…”