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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Eggleton, B. J., Luther-Davies, B. & Richardson, K. Chalcogenide photonics. Nat. Photonics 5 (3), 141–148 (2011).

Adam, J. L. & Zhang, X. Chalcogenide Glasses. Preparation, Properties and Applications (Woodhead Publishing, 2014).

Noe, P., Vallee, C., Hippert, F., Fillot, F. & Raty, J. Y. Phase-change materials for non-volatile memory devices: from technological challenges to materials science issues. Semicond. Sci. Technol.33 (1), 013002 (2018).

Blanc, W. et al. The past, present and future of photonic glasses: a review in homage to the United Nations International Year of glass 2022. Progress Mater. Sci.134, 101084 (2023).

Ovshinsky, S. R. Reversible electrical switching phenomena in disordered structures. Phys. Rev. Lett.21, 1450–1453 (1968).

Yamada, N., Ohno, E., Nishiuchi, K., Akahira, N. & Takao, M. Rapid-phase transitions of GeTe‐Sb2Te3 pseudobinary amorphous thin films for an optical disk memory. J. Appl. Phys.69 (5), 2849–2856 (1991).

Iwasaki, H., Ide, Y., Harigaya, M., Kageyama, Y. & Fujimura, I. Completely erasable phase change Optical Disk, Japan. J. Appl. Phys. Part. 1 - Regul. Papers Short. Notes Rev. Papers 31 (2B), 461–465 (1992).

Raoux, S., Welnic, W. & Ielmini, D. Phase change materials and their application to nonvolatile Memories. Chem. Rev.110 (1), 240–267 (2010). PubMed

Friedrich, I., Weidenhof, V., Njoroge, W., Franz, P. & Wuttig, M. Structural transformations of films studied by electrical resistance measurements. J. Appl. Phys.87 (9), 4130–4134 (2000).

Wuttig, M., Bhaskaran, H. & Taubner, T. Phase-change materials for non-volatile photonic applications. Nat. Photonics 11 (8), 465–476 (2017).

Zhang, W., Mazzarello, R., Wuttig, M. & Ma, E. Designing crystallization in phase-change materials for universal memory and neuro-inspired computing. Nat. Rev. Mater.4 (3), 150–168 (2019).

Gholipour, B. et al. Roadmap on Chalcogenide photonics. J. Phys. Photonics5, 012501 (2023).

Prabhathan, P. et al. Roadmap for phase change materials in photonics and beyond. iScience26, 107946 (2023). PubMed PMC

Müller, P. C., Elliott, S. R., Dronskowski, R. & Jones, R. O. Chemical bonding in phase-change chalcogenides. J. Phys. Condens. Matter. 36, 325706 (2024). PubMed

Wuttig, M. et al. Revisiting the nature of chemical bonding in chalcogenides to explain and design their properties. Adv. Mater.35, 2208485 (2023). PubMed

Bala, N. et al. Recent advances in doped Ge2Sb2Te5 thin film based phase change memories. Mater. Adv.4, 747–768 (2023).

Sandhu, S., Kumar, S. & Thangaraj, R. Study of aluminium-modified Ge2Sb2Te5 thin films for the applicability as phase-change storage device material. Phase Trans.90, 1013–1024 (2017).

Wang, G. et al. Improved thermal and electrical properties of Al-doped Ge2Sb2Te5 films for phase-change random access memory. J. Phys. D: Appl. Phys.45, 375302 (2012).

Wei, S. J. et al. Phase change behavior in titanium-doped Ge2Sb2Te5 films. Appl. Phys. Lett.98, 231910 (2011).

Park, J. & Bae, J. Effect of Ti diffusion on the microstructure of Ge2Sb2Te5 in phase-change memory cell. J. Electron. Microsc. 64, 381–386 (2015). PubMed

Zhu, Y. Q. et al. Ni-doped GST materials for high speed phase change memory applications. Mater. Res. Bull.64, 333–336 (2015).

Gao, Q. & Chen, L. Effect of Cu doping on microstructure and thermal stability of Ge2Sb2Te5 thin film. Appl. Phys. A 125, 564 (2019).

Ding, K. et al. Study on the Cu-doped Ge2Sb2Te5 for low-power phase change memory. Mater. Lett.125, 143–146 (2014).

Buller, S. et al. Influence of partial substitution of Te by Se and Ge by Sn on the properties of the blu-ray phase-change material Ge8Sb2Te11. Chem. Mater.24, 3582–3590 (2012).

Li, Z. G. et al. Changes in electrical and structural properties of phase-change Ge-Sb-Te films by Zr addition. J. Non-Cryst Solids 452, 9–13 (2016).

Park, T. J., Choi, S. Y. & Kang, M. J. Phase transition characteristics of Bi/Sn doped Ge2Sb2Te5 thin film for PRAM application. Thin Solid Films 515, 5049–5053 (2007).

Guo, P. et al. Sarangan, Tungsten-doped Ge2Sb2Te5 phase change material for highspeed optical switching devices. Appl. Phys. Lett.116, 131901 (2020).

Guo, S. et al. Temperature and concentration dependent crystallization behavior of Ge2Sb2Te5 phase change films: tungsten doping effects. RSC Adv.4, 57218–57222 (2014).

Wang, G. et al. Phase change behaviors of Zn-doped Ge2Sb2Te5 films. Appl. Phys. Lett.101, 051906 (2012).

Wang, Q. et al. Metal Doping of Phase Change materials: atomic arrangement of Cr-Doped Ge2Sb2Te5. J. Phys. Chem. C 123, 30640–30648 (2019).

Tan, Z. et al. Ruthenium doped Ge2Sb2Te5 nanomaterial as fast speed phase-change materials with good thermal stability. Solid State Electron.186, 108176 (2021).

Rao, F. et al. Reducing the stochasticity of crystal nucleation to enable subnanosecond memory writing. Science358 (6369), 1423–1427 (2017). PubMed

Chen, X. et al. Neuromorphic photonic memory devices using ultrafast, non-volatile phase-change materials. Adv. Mater.35, 2203909 (2023). PubMed

Ding, K. et al. Recipe for ultrafast and persistent phase-change memory materials. NPG Asia Mater.12, 63 (2020).

Chen, B. et al. Insights into the heterogeneous nuclei of an ultrafast-crystallizing glassy solid. Adv. Funct. Mater.34, 2314565 (2024).

Song, T. et al. Metal–insulator transition in ScxSb2Te3 phase-change memory alloys. Appl. Phys. Lett.124, 062106 (2024).

Schenk, F. M. et al. Phase-change memory from molecular tellurides. ACS Nano 18, 1063–1072 (2024). PubMed PMC

Hu, S., Liu, B., Li, Z., Zhou, J. & Sun, Z. Identifying optimal dopants for Sb2Te3 phase-change material by high-throughput ab initio calculations with experiments. Comput. Mater. Sci.165, 51–58 (2019).

Zhou, Y. et al. Bonding similarities and differences between Y–Sb–Te and Sc–Sb–Te phase-change memory materials. J. Mater. Chem. C 8, 3646–3654 (2020).

Chen, X. et al. Scandium doping brings speed improvement in Sb2Te alloy for phase change random access memory application. Sci. Rep.8, 6839 (2018). PubMed PMC

Wang, Y. et al. High thermal stability and fast speed phase change memory by optimizing GeSbTe with scandium doping. Scripta Mater.164, 25–29 (2019).

Wang, Y. et al. Scandium doped Ge2Sb2Te5 for high-speed and low-power-consumption phase change memory. Appl. Phys. Lett.112, 133104 (2018).

Cody, G. D. (ed) Jacques I. Pankove, in Semiconductors and Semimetals 1st edn 11–82 (Academic, 1984).

Baudet, E. et al. Selenide sputtered films development for MIR environmental sensor. Opt. Mater. Express 6, 2616 (2016).

Baudet, E. et al. Experimental design approach for deposition optimization of RF sputtered chalcogenide thin films devoted to environmental optical sensors. Sci. Rep.7, 3500 (2017). PubMed PMC

Tiwald, T. E., Thompson, D. W., Woollam, J. A., Paulson, W. & Hance, R. Application of IR variable angle spectroscopic ellipsometry to the determination of free carrier concentration depth profiles. Thin Solid Films 313, 661 (1998).

Bouska, M., Nazabal, V., Gutwirth, J., Halenkovic, T. & Nemec, P. Radio-frequency magnetron co-sputtered Ge-Sb-Te phase change thin films. J. Non-Cryst. Solids 569, 121003 (2021).

Zewdie, G. M., Debelab, T. T. & Asres, G. A. Effect of temperature on structural, dynamical, and electronic properties of Sc2Te3 from first-principles calculations. RSC Adv.12, 32796 (2022). PubMed PMC

Nemec, P., Prikryl, J., Nazabal, V. & Frumar, M. Optical characteristics of pulsed laser deposited Ge–Sb–Te thin films studied by spectroscopic ellipsometry. J. Appl. Phys.109, 073520 (2011).

Bruggeman, D. A. G. Berechnung Verschiedener Physikalischer Konstanten Von Heterogenen Substanzen. I. Dielektrizitätskonstanten und Leitfähigkeiten Der Mischkörper Aus Isotropen Substanzen. Ann. Phys.416, 636–664 (1935).

Yamada, N. Origin, secret, and application of the ideal phase-change material GeSbTe. Phys. Status Solidi B 249, 1837 (2012).