Crystallographic Parameters of Special Grain Boundaries in Multicrystalline Silicon

Crystallography Reports - The orientation of grains and the special boundaries formed by them in multicrystalline silicon has been studied by electron backscattered diffraction. It is found that...     

Study of solar silicon multicrystals by SEM and EPMA methods

Multisilicon crystals grown from refined metallurgical silicon are studied by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The varieties of intergranular boundaries are revealed. Impurities are found to be contained in inclusions in multisilicon. The intergranular boundaries contain no impurities, and they do not concentrate the elements present in multisilicon. It is proved experimentally that, in the homogeneous areas of the crystal the lifetime of minor charge carriers is maximum, whereas its minimum value corresponds to the areas with numerous intergranular boundaries.     

Determination of the orientation parameters of grains from the contrast of an image of a multisilicon polished surface using backscattered electrons

The grain structure of multisilicon crystals are investigated by scanning electron microscopy and electron backscatter diffraction. It is found that the contrast of an image obtained by scanning polished multisilicon surfaces in the mode of backscattered electrons by electron-probe microanalysis is caused by the fact that the contrasting grains on the test site of the surface belong to different crystallographic orientations. It is revealed that high-angle grain boundaries are areas where the contrast varies, whereas small-angle boundaries are not observed on the polished surfaces. Consequently, the degree of contrast of the image obtained in this scan mode can be used to qualitatively assess the degree of misorientation of neighboring grains.