Research Article
Temur Pagava, Levan Chkhartish
Abstract
Temperature dependencies of charge carrier Hall concentration and Hall mobility are systematically studied within the range 77 to 300 K for both n- and p-type silicon crystalline samples irradiated with high energy protons or electrons and annealed at temperatures up to 380°C and 600°C, respectively. In some cases, measured at a fixed temperature hall mobilities are found to be significantly lower or significantly higher than those in non-irradiated material. These results are interpreted on the basis of assumption that secondary radiation defects in silicon form clusters with conductivity significantly different from that of the surrounding matrix. A phenomenological theory, recently introduced by authors, explains apparent Hall mobility minima revealed on the temperature-dependence curves. Clusters themselves should possess high conductivity (be “metallic”), but in certain conditions they effectively act as (“dielectric”) clusters with low conductivity, because they can be screened by the shells consisting of defects capturing charge carriers.