Floating zone growth of Si bicrystals using seed crystals with artificially designed grain boundary configuration

We attempted to grow Si bicrystals with a controlled grain boundary configuration using a pair of single-crystal seeds, which was purposely designed to have a specified character. The floating zone technique under an ultrahigh-vacuum environment was exploited to grow bicrystals and the growth rate was found to be important to control the grain boundary configuration. The grown bicrystals are useful for the fundamental study of the role of grain boundaries, which might control the overall properties of multicrystals. As one of the examples, a series of Si bicrystals, which were grown using seed crystals with a specified misorientation from Σ3, was processed in solar cells, and the short-circuit current density was found to be strongly affected by the misorientation given to the seed.