Rutile GeO₂ and related materials are attracting interest due to their ultrawide band gaps and potential for ambipolar doping in high-power electronic applications. This study examines the growth of rutile Sn_1–xGe_xO₂ films through oxygen-plasma-assisted hybrid molecular beam epitaxy (hMBE). The film composition and thickness are evaluated across a range of growth conditions, with the outcomes rationalized by using density functional theory calculations. We find that up to 34% Ge can be successfully incorporated into Sn_1–xGe_xO₂/r-Al₂O₃ (x ≤ 0.34) at 600 °C. Our phase diagram calculations suggest that spinodal decomposition occurs at Ge concentrations exceeding 34%. However, the formation of a Ge-rich rutile phase is inhibited by amorphization of the Ge-rich film and volatility of GeO. We therefore speculate that maximizing the Ge content requires higher Ge flux and more oxidizing environments, providing insights into the growth mechanism of Sn_1–xGe_xO₂ and paving the way toward the synthesis of pure rutile GeO₂ films.

中文翻译：

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使用理论和实验揭示金红石 Sn1–xGexO2 的生长动力学


金红石型 GeO₂ 和相关材料因其超宽带隙和在高功率电子应用中可能进行双极掺杂而引起了人们的兴趣。本研究通过氧-等离子体辅助混合分子束外延 （hMBE） 检查了金红石型 Sn _1-xGe_xO₂ 膜的生长。在一系列生长条件下评估薄膜成分和厚度，并使用密度泛函理论计算使结果合理化。我们发现，在 600 °C 下，高达 34% 的 Ge 可以成功掺入 Sn_1–xGe_xO₂/r-Al₂O₃ （x ≤ 0.34） 中。 我们的相图计算表明，在 Ge 浓度超过 34% 时发生棘状分解。然而，富锗薄膜的不晶化和 GeO 的挥发性会抑制富锗金红石相的形成。因此，我们推测，最大化 Ge 含量需要更高的 Ge 通量和更多的氧化环境，从而深入了解 Sn _1-xGe_xO₂ 的生长机制，并为纯金红石 GeO₂ 薄膜的合成铺平道路。