Electronic properties of crystalline Ge_1-xSb_xTe_y thin films

Ge_1-xSb_xTe_y thin films, grown by metalorganic and hot-wire liquid injection chemical vapor deposition in different crystalline phases, are investigated to determine resistivity, carrier density, and carrier mobility in the 4.2–300 K temperature range. It is found that all these chalcogenides exhibit p-type conduction, high carrier density (>2 · 10²⁰ cm⁻³), and no carrier freeze-out, regardless of composition. Low-temperature mobility data show that both chemical composition and growth technique affect the defect density and, in turn, the carrier scattering mechanisms. In this regard, charge carrier mobility is analyzed according to semi-empirical scattering models and an interpretation is provided.