ABSTRACT
The elemental composition and trace element impurities are known to be two important factors which greatly influence the physical and electronic properties of semiconductor materials. In fact, deviations from stoichiometry of the constituent elements by as little as 0.1% and trace impurities levels of as low as ppb may lead to serious performance issues. Crystallographic investigations not only give valuable information on the quality of the growth method, but also are key to understanding transport properties, particularly for asymmetric materials. Based on such information it is possible to pre-screen new materials or gauge the performance of existing materials for detector applications. Rocking curves measure the amount of mosaicity in the crystal, an angular measure of the degree of long-range order of the unit cells. A basic powder diffractometer consists of a source of monochromatic radiation, a sample holder and an X-ray detector situated on the circumference of a graduated circle centered on the specimen.
