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arXiv · 2507.12888

Chemical vapor deposition synthesis of (GeTe)n(Sb2Te3) gradient crystalline films as promising planar heterostructures

M. Zhezhu·A. Vasil'ev·M. Yapryntsev·E. Ghalumyan·D. A. Ghazaryan·H. Gharagulyan
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Abstract

Phase-change materials of the (GeTe)n (Sb2Te3) (GST) system are of high relevance in memory storage and energy conversion applications due to their fast-switching speed, high data retention, and tunable properties. Here, we report on a fast and efficient CVD-based method for the fabrication of crystalline GST films with variable Ge/Sb atomic content. In particular, the approach enables compositional control without changing the precursor, facilitating a gradient synthesis of Ge3Sb2Te6, Ge2Sb2Te5, and GeSb2Te4 phases in a single attempt. The analyses of their structural, optical, and electrical aspects highlight how compositional variation influences the film's properties. Our findings demonstrate a straightforward approach enabling the preparation of gradient crystalline GST films with tunable morphology and functionality. These gradient films can potentially provide in-plane multilevel and gradual switching thresholds for memory applications and altered refractive index and absorption for optical modulation and filtering applications.

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M. Zhezhu, A. Vasil'ev, M. Yapryntsev, E. Ghalumyan, D. A. Ghazaryan, H. Gharagulyan. 2025-07-17. Chemical vapor deposition synthesis of (GeTe)n(Sb2Te3) gradient crystalline films as promising planar heterostructures. https://doi.org/10.1016/j.mssp.2025.109863

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