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15LS-O-3
LASER SYSTEMS AND MATERIALS
^l^.ALT'22
Physical properties' temperature dynamics of GeTe, Ge2Sb2Te5, and
Ge2Sb2Se4Te1 materials
A.A. Burtsev, V.V. Ionin, A.V. Kiselev, N.N. Eliseev, V.A. Mikhalevsky, V.V. Grebenev,
D.N. Karimov and A.A. Lotin
ILIT RAS — Branch of FSRC "Crystallography and Photonics" RAS, 1, Svyatoozerskaya Str., 140700, Shatura,
Moscow Region, Russia Main author email address: [email protected]
Phase change materials (PCMs) are compounds with several stable phase states (amorphous and one or more crystalline) with very different properties. For applied application, the high contrast of the optical and electrical properties of PCMs between their amorphous and crystalline states is of great interest. This contrast is primarily due to a significant difference in the structural order, the concentration of charge carriers, and the mechanisms of chemical bonding [1, 2]. Among materials for optical data storage and electric non-volatile memory devices, chalcogenide alloys based on germanium telluride (GeTe, Ge2Sb2Te5) are the most mature and widely used in photonic and optoelectronic devices [2]. These alloys have very high amorphization and crystallization rates in the order of nanoseconds, which combined with large cyclability and a pronounced property contrast between the crystalline and amorphous phases [3, 4]. In [5] it was shown that doping of GST with selenium leads to a significant change in its refractive index, almost without changing the extinction coefficient, providing a high optical figure of merit. The presenting results include the results of comprehensive studies of the electrical resistivity and optical transmission coefficient temperature dynamics, phase transition heats, the phase composition, and Raman spectra of GeTe, Ge2Sb2Te5, and Ge2Sb2Se4Tet samples obtained by vacuum thermal deposition. It offers a more holistic view to understand crystallization process in different PCMs and select material for optoelectronic and memristive applications [6].
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[2] S. Raoux, M. Wutting (ed.). Phase Change Materials. Science and Applications (Springer), ch. 5 (2009).
[3] N. Yamada, E. Ohno, K. Nishiuchi, N. Akahira, M. Takao. Rapid-phase transitions of GeTe-Sb2Te3 pseudobinary amorphous thin films for an optical disk memory. Journal of Applied Physics, 69, pp. 2849-2856 (1991).
[4] K.-Y. Yang, S.-H. Hong, D. Kim, B. Cheong, H. Lee. Patterning of Ge2Sb2Te5 phase change material using UV nano-imprint lithography. Microelectronic engineering, 84, pp. 21-24 (2007).
[5] Y. Zhang, J.B. Chou, J. Li, H. Li, Q. Du, A. Yadav, S. Zhou, M.Y. Shalaginov, Zh. Fang, et al. Broadband transparent optical phase change materials for high-performance nonvolatile photonics. Nature communications, 10, pp. 1-9 (2019).
[6] T. Cao and M. Cen. Fundamentals and Applications of Chalcogenide Phase-Change Material Photonics. Advanced Theory and Simulations, 1900094 (2019)
