CC BY
7*
ALT'23 The 30th International Conference on Advanced Laser Technologies
LM-I-26
Promising phase-changing materials for neuromorphic devices and
memory elements
A.V. Kiselev, A.A. Burtsev, V.V. Ionin, N.N. Eliseev, A.A. Nevzorov, V.A. Mikhalevsky,
A.A. Lotin
ILITRAS — Branch of FSRC "Crystallography and Photonics " RAS, 1, Svyatoozerskaya Str., 140700, Shatura, Moscow Region, Russia
Main author email address: [email protected]
Non-volatile photonic memory and neuro-inspired computing are promising technologies that can enhance data storage and processing capabilities [1]. Photonic memory devices offer high operational speed and non-volatility, while neuro-inspired computing integrates processing and storage into a single cell [2]. Phase-change photonics is the conjunction between phase-change materials (PCMs) and nanophononics, which enables integrated photonic circuits (PICs) with novel functionalities [3]. Chalcogenide alloys based on germanium telluride (GeTe, Ge2Sb2Te5) are the most mature and widely used materials for optical data storage and electric non-volatile memory devices. These alloys have rapid amorphization and crystallization rates, along with a distinct property contrast between their crystalline and amorphous phases [4].
The research presented in this study demonstrates stable multilevel reversible phase transitions in thin films of chalcogenide alloys, as well as an optical synapse prototype based on a planar waveguide with a chalcogenide cell [5]. The optical transmission and reflection coefficients of Ge2Sb2Te5 (GST) thin films, which change dynamics during nano- and femtosecond laser radiation-induced phase transitions, are studied. The authors propose a predictive model based on the thermokinetic approach, which allows the qualitative and quantitative determination of the of the crystalline phase and the depth of its occurrence in the GST film [6]. Experimental methods including Raman spectra, XRD and TEM were used to validate the model. The modelling and experimental results can be used to optimize the duration, shape and spatial distribution of laser pulses to control the state of PCM-based devices.
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[5] V. V. Ionin, A. V. Kiselev, N. N. Eliseev, V. A. Mikhalevsky, M. A. Pankov, A. A. Lotin, Multi-level reversible laser-induced phase transitions in GeTe thin films. Applied Physics Letters, 117, 011901 (2020).
[6] A.A. Nevzorov, V.A. Mikhalevsky, A.V. Kiselev, A.A. Burtsev, N.N. Eliseev, V.V. Ionin, & A.A. Lotin. Controlling optical properties of GST thin films by ultrashort laser pulses series impact. Optical Materials, 141, 113925 (2023)
