Spherical Si Crystal Fabricated by Drop Tube Method

4 Spherical Si Crystal Fabricated by Drop Tube Method 

Finally, another advantage of the semisolid process is described, based on simple heat transfer calculation during free fall. In the case of the sample superheated above Tm, the falling distance is more than 10 m, since the sample is undercooled due to suppression of nucleation. However, for the semisolid process, where each droplet includes a tiny solid particle before ejection, the falling distance required for complete crystallization is considerably reduced to 3 mm for /s 0.1 because of the lack of undercooling. This information is useful in terms of capital investment. 

The authors thank Prof. M. Tajima, ISAS/JAXA for PL measurements. This work was financially supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan. 

Prince, 14th Annual Proceedings of Power Sources Conference, 26 (1960) 

IEEE Trans. Components Hybrids Manuf. Technol. 5, 336 (1982) 

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