Effect of Reentrant Twin Corners on Directional Solidification of Polycrystalline Silicon

The solidification microstructure and crystal orientation have been investigated for solar cell grade high purity polycrystalline silicon through a unidirectional solidification technique. In the solidification velocity range of 1.25-2.5times10 -6 m/s, the grain size enlarges as solidification progr...

Full description

Saved in:
Bibliographic Details
Published in2006 IEEE 4th World Conference on Photovoltaic Energy Conference Vol. 1; pp. 1219 - 1222
Main Authors Miyahara, H., Nara, S., Ogi, K.
Format Conference Proceeding
LanguageEnglish
Published IEEE 01.05.2006
Subjects
Crystal microstructure
Furnaces
Grain boundaries
Grain size
Morphology
Optical scattering
Photovoltaic cells
Photovoltaic systems
Silicon
Temperature
Online AccessGet full text

Cover

More Information
Summary:The solidification microstructure and crystal orientation have been investigated for solar cell grade high purity polycrystalline silicon through a unidirectional solidification technique. In the solidification velocity range of 1.25-2.5times10 -6 m/s, the grain size enlarges as solidification progresses. Furthermore, large columnar grains contain many twin boundaries. However, in above the critical velocity around 40times10 -6 m/s, equiaxed structure appears. A model of two-dimensional nucleation on the reentrant corner was established, and the critical nucleus could be estimated to be 70 % to 80 % of the radius of the general two-dimensional nucleus. The reduction of the critical radius and undercooling on the reentrant corner could influence on the priority growth direction and the enlargement of the grain size
ISBN:1424400163
9781424400164
ISSN:0160-8371
DOI:10.1109/WCPEC.2006.279401