Radio frequency magnetron co-sputtering method employing GeTe and Sc targets was exploited for the deposition of Sc doped GeTe thin films. Different characterization techniques (scanning electron microscopy with energy-dispersive X-ray analysis, X-ray diffraction, atomic force microscopy, sheet resistance temperature-dependent measurements, variable angle spectroscopic ellipsometry, and laser ablation time-of-flight mass spectrometry) were used to evaluate the properties of as-deposited (amorphous) and annealed (crystalline) Ge-Te-Sc thin films. Prepared amorphous thin films have Ge48Te52, Ge46Te50Sc4, Ge44Te48Sc8, Ge43Te47Sc10 and Ge41Te45Sc14 chemical composition. The crystallization temperatures were found in the region of ~ 153-272 °C and they increase with scandium content. Upon amorphous-crystalline material phase change, large changes in sheet resistance were measured, with electrical contrast in terms of sheet resistance ratio Rannealed/Ras-deposited in the range of 1.37.10-4 - 9.1.10-7. Simultaneously, huge variations of optical functions were found as demonstrated by absolute values of optical contrast values (at 405 nm) in the range of |Δn|+|Δk| = 1.88-3.75 reaching maximum for layer containing 8 at% of Sc.

Center of Materials and Nanotechnologies Faculty of Chemical Technology University of Pardubice nám Čs legií 565 Pardubice 530 02 Czech Republic

Department of Chemistry Faculty of Science Masaryk University Kotlářská 2 Brno 611 37 Czech Republic

Department of General and Inorganic Chemistry Faculty of Chemical Technology University of Pardubice Studentská 573 Pardubice 532 10 Czech Republic

Department of Graphic Arts and Photophysics Faculty of Chemical Technology University of Pardubice Studentská 573 Pardubice 532 10 Czech Republic

Institute of Applied Physics and Mathematics Faculty of Chemical Technology University of Pardubice Studentská 95 Pardubice 532 10 Czech Republic

ISCR UMR 6226 CNRS Univ Rennes Rennes F 35000 France

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